MINNESOTA PAPERBACKS

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Traditions of

WATERFOWL

H. ALBERT HOCHBA

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WATERFOWL

by H. Albert Hochbaum

THE UNIVERSITY OF MINNESOTA PRESS, Minneapolis

g) Copyright 1955 by the University of Minnesota. AU rights reserved

PRINTED AT THE NORTH CENTRAL PUBLISHING COMPANY, ST. PAUL

Second printing 1S56

Library of Congress Catalog Card Number: 55-11707

Published as Minnesota Paperback No. 8 in 1967

PUBLISHED IN GREAT BRITAIN, INDIA, AND PAKISTAN BY THE OXFORD UNIVERSITY

PRESS, LONDON, BOMBAY, AND KARACHI, AND IN CANADA BY THE

COPP CLARK PUBLISHING CO. LIMITED, TORONTO

To James Ford Bell, of Minneapolis
who founded the Delta Waterfowl Research Station in 1931

to Arthur Sullivan, of Winnipeg
who established the international breadth of its program

and to the everlasting fellowship of

scientist and sportsman upon which hinges

the wildfowling of generations to come

/

Foreword

Ihe migration of birds has doubtless fascinated the mind of man
throughout history. Certain iy the artists of the Altemira Caves must already
have been interested, since their drawings include migratory species. Prac-
tically all over the world some favorite winter absentee is welcomed back
as the harbinger of spring upon its annual return. To Albert Hochbaum,
author of this book, living on his Manitoba marsh, it is the Canada Goose
and the Whistling Swan that constitute the first tangible guarantee that
spring is on its way back, no matter what the frozen lake may be doing at
the time or how belated the weather prospects. Seemingly the birds are as
sure of themselves — taking their performance year in and year out — as the
devisers of our own calendar. And therein lies a patent mystery, since birds
are not equipped with sextants and compasses, mathematical tables or the
gift of speech. How do they come to be so wise?

The various aspects of this problem have been a matter of observation
for centuries and of scientific research for decades. In more recent years
some of the refinements of the experimental method have been applied to
certain of its phases, such as the physiological timing mechanisms and
reproductive rhythms of migrants or the navigational equipment of homing
pigeons. Experiments, however, have to be based on previously acquired
knowledge derived from observations, and the days of observation are not
yet by any means over. Field records remain as important as they have
ever been.

When Albert Hochbaum published his first book, The Canvasback on a
Prairie Marsh, in 1944, he won for himself an enviable reputation as ob-
server, recorder, and artist from which it is safe to predict that his present
volume will detract nothing. It has been a more difficult book to write,
since it includes a review of much of the literature and questions some of
the theories currently held. With his views one may, of course, agree or
disagree as one thinks fit, but much of what he has to say is new and deals

TRAVELS AND TRADITIONS OF WATERFOWL

with an aspect of migration seldom enough touched upon — the matter of
tradition. In this respect he has made as definite a contribution to the litera-
ture as he did with his Canvasback, and is doubtless destined to modify
present modes of thinking on numerous aspects of bird migration.

Mr. Hochbaum has had opportunities that come to few people to collect
the material he now presents to his readers. For sixteen years he has resided
at Delta, Manitoba, on the south shore of Lake Manitoba, on one of the
most celebrated wildfowl marshes of the province. Here he has canoed,
photographed, hunted, and ruminated, in an environment which, although
static in its main features, is perpetually undergoing change. He has seen
his marsh almost dried out, as in the forties, and virtually flooded out, as
in 1954. He has watched the resident populations rise and fall, flourish and
fail. As Director of the Research Station, he has organized and conducted
pertinent investigations into the field to which he has devoted his life. This
station, sponsored by the North American Wildlife Foundation and the
Wildlife Management Institute, and operating in an atmosphere of com-
plete academic freedom, untrammeled by Government restrictions and
red tape, moreover has won for itself a reputation that has attracted many
ornithological celebrities, each of whom has left some constructive contribu-
tion behind him. We shall again be grateful that fate has placed so able
an observer in such a favorable setting, the fruits of which we can now
ourselves enjoy.

To close without a reference to the excellent illustrations which accom-
pany the text would be to do Mr. Hochbaum an injustice. It has been my
privilege to be associated with the Delta station for many years. During
intermittent visits I have seen the marsh in its varying moods. I can only
say that our author-artist has caught the spirit of the birds and their en-
vironment as successfully in his drawings as in his writing.

William Rowan
Department of Zoology
University of Alberta

Author's Preface

1ms is a story of the travels of waterfowl. Many discussions
of bird passage begin with migration, but I choose to speak first of the
flights of ducks and geese on their home range. The wider journeys are
not to be understood, I believe, without an examination first of the patterns
of local behavior. Part I of this book is therefore an analysis of the movements
of waterfowl on their home range on the Delta Marsh in southern Mani-
toba.

Migration is discussed in Part II as I have studied it directly in the field,
mostly in Manitoba, and as I have followed it in the literature for othei
regions. During the preparation of the manuscript, some helpful friends
inquired, in effect: "What you say about waterfowl is understood, but how
does one explain the migrations of Arctic Tern and Golden Plover?" I can
but reply that this book concerns the birds I have watched. I hope others
will make more extensive studies of tern and plover, but I have tried to
heed Farner's warning against "the rather frequent tendency to transfer
conclusions concerning one species into explanations concerning another."
Moreover, this is merely a discussion; I have not aimed at over-all conclu-
sions. I feel, with Herbert Spencer, that "the truth generally lies in the
co-ordination of antagonistic opinions," and I simply report observations and
ideas that will, I hope, stimulate further study.

A pigeon fancier I know acknowledges no mystery in the homing be-
havior of his flock. "How do they find their way? By instinct, of course 1"
So, too, some have explained migration; many unknowns have been cata-
logued under the convenient tab of instinct. Such an approach does not
always take into account our present understanding of bird behavior. How-
ever dominant the inborn heritage of action, each bird lives freely in an
elastic environment where its responses to its companions and surroundings
are constantly being modified through experience. I believe that the migrant
may be instinctively related to the patterns of its ecological environment

TRAVELS AND TRADITIONS OF WATERFOWL

and selects those most closely fitting its innate breeding req* irements, but
that it must learn its geographical place in its world. The ai r " migration
may be inherent, but the world in which this takes place is learned. If this
is so, then for some species the route of migration is handed down through
tradition — and this is the theme of Part III.

Throughout the book waterfowl refers to North American ducks, geese,
and swans of the Family Anatidae.

H. A. H.

Delta Waterfowl Research Station
Delta, Manitoba
November 1955

Table of Contents

FOREWORD by William Rowan vii

Part I. Travels of Waterfowl

1 PATTERNS OF LOCAL MOVEMENT 3

2 LEARNED RESPONSE TO THE ENVIRONMENT 14

3 THE VISUAL WORLD 29

4 THE FUNCTION OF MEMORY 46

5 THE AERIAL ENVIRONMENT 55

6 AWARENESS OF TIME AND SPACE 73

Part II. Migrations of Waterfowl

7 THE CYCLE OF MIGRATION 89

8 FLIGHT TRAILS SOUTH 95

9 HOMEWARD MIGRATION 114

10 THE CLASSIFICATION OF WATERFOWL TRAVEL 135

11 THE DIMENSIONS OF TRAVEL 149

12 THE INFLUENCE OF BAD WEATHER 163

13 OVERSEAS MIGRATION 177

14 MAGNETIC AND RADIO FIELDS 186

15 AWARENESS OF DIRECTION 192

Part HI. Traditions of Waterfowl

16 BIOLOGICAL TRADITIONS 217

17 BUILDING NEW TRADITIONS 227

18 TRADITION AND RACIAL ISOLATION 237

19 BROKEN TRADITIONS 243
BIBLIOGRAPHY 259
NOMENCLATURE OF BIRDS 284
ACKNOWLEDGMENTS 289
INDEX OF AUTHORITIES 293
SUBJECT INDEX 295

PART I

Travels of Waterfowl

'When a bird hath flown through the air, there is no token of
her way to be found, but the light air being beaten with the
stroke of her wings, and parted with the violent noise and motion
of them, is passed through, and therein afterwards no sign where
she went is to be found."

Wisdom of Solomon

'For, lo ! the winter is past." Song of Solomon

Patterns of Local Movement

Listen! . . . No, it's only the wind.

"But listen ! Quiet, Tim, you fool hound-dog." No, it is only the children
at their game.

"Listenl . . . No, it is nothing at all." A heavy black cloud hangs in the
west ; through a rift the sun bathes the marsh in gold. The evening flight has
begun; small parties of ducks lift from the bay, flying into the northwest.
The tall poplar by the channel is dark with a thousand blackbirds creaking
and tinkling.

"Listen, listen] . . . Yes, it is the swan! The Whistling Swans are back\"

Our eyes scan the purple east. There they are: fourteen great white birds
halfway across the bay, coming straight toward us, their high-pitched voices
yodeling loud and clear. They swerve, moving north to the lake. They turn
again, swinging wide; now they are coming back, the south wind on their
breasts. Now they are overhead. What a sight to behold! They are dropping,
dropping. A dozen yards above the water their necks arch, they set their
wings, spreading feet wide like Canvasback. Then softly they alight near
Archie's Point. Another leg of their northward journey is completed.

A band of Whistling Swan seen in the evening light of the first day of
spring stirs the heart and soul of a man so that, for a moment, his communion
with the wilderness is complete. Yet tonight I feel more than the beauty of
the scene itself. Here, mind you, in the fading day when you or I might lose
ourselves in the maze of marshland, this band of swan has come from far
beyond the horizon to a place they have not visited since last spring. There
was no faltering; they came unerringly to this small corner of marsh that
has been the April rendezvous of Whistling Swans for at least forty years.
Tomorrow there will be more, and more again on following days, until the
chorus of their multitudes will not let us sleep. Then, sometime in mid-May,
they will be on with their journey and Archie's Point will be swanless until
next April. . . .

3

TRAVELS OF WATERFOWL

Saturday night 1 For those who live in the country, this is the big event
of the week: early supper, hurry with the dishes, change to best clothes,
and off to town for three hours of shopping and small talk. Last evening
Joan and I crossed the marsh at sunset on our way to Portage la Prairie.
We had just slipped past Slack's Bluff when Joan touched my arm and I
brought the car to a stop. "There, over toward Portage Creek. What are
they, ducks or geese ?" Far to the southeast there hung a thin line above the
horizon, a frail wisp of thread, barely visible. We watched in silence as it
grew until finally we could make out its components. "Geesel" Then, of a
sudden, their voices drifted to us on the south wind. "Waviesl" We stepped
from the car to stand in the gathering dusk as the birds passed. Most were
Blue Geese, but their lines were punctuated here and there by Lesser Snow
Geese. They flew in a wide line from which sprouted small branches, the
whole forming a great blunt "V." As the mass moved it rose and fell as if
riding a rolling swell, the individuals within the flock ever shifting position
so that the pattern changed constantly. The geese were in full and constant
voice, a guttural gabbling accented by high, nasal shouts, by no means as
rousing as the whoop of swans or the bark of Canada Geese, but sweet
music, nevertheless, over the April prairie.

The flock held steady course ; then at a point near Slack's Bluff it turned
sharply toward the annual lakeshore stopping place at the mouth of the
Whitemud River. As their voices faded, there came a louder clangor from
the southeast. As far as we could see came the geese, one broad "V" after
another. It was a great moment in my life, and I removed my hat in uncon-
scious response to some inner urge of respect as they passed.

Each flock followed the same route as the first, and as the second group
approached Slack's Bluff it turned sharply to the west. Every successive band
held a steady course until it reached the turning place where the bend west
was made. Not only were these birds moving toward a destination, but their
trailway was marked by some special pattern which they followed. Maybe
it was Slack's Bluff. Maybe it was the arrangement of the fields or the plan
of the marsh and lake beyond or some other features of the landscape near
or far. Whatever it was, these geese moving in the boundless prairie skies
followed some cue that held them to their route.

The sun has dropped into the lake. It is an April evening, not of one
day or of one year, but of at least three hundred April days of sixteen years. I
am standing at the bayside. Before me is the vast expanse of marshland still

PATTERNS OF LOCAL MOVEMENT

frozen except at the edges, where a black moat of water separates ice from
tules. Behind, to the north, is the narrow ridge of woodland that marks the
south shore of Lake Manitoba. Beyond that, far past the northern horizon, are
the marshes of Winnipegosis, of the Saskatchewan, of the MacKenzie.

The setting sun is the signal for Mallards and Pintails to leave these dark
waters and move to other marshlands. Paired drakes and hens in company
with their kind rise from the bays and go directly into the northwest. I am
impressed by their precision, for, although their numbers are scattered far
and wide over the marsh, the departure is not along a solidly broad front.
Instead, as the bands leave the bays, the flight resolves into well-defined
lanes of travel. The movement over the lakeshore is not in a wide sweep. The
crossings are at passes. From where I stand I can see a flight over the village

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TRAVELS OF WATERFOWL

of Delta; there is another over Dr. Cadham's garden, and still another not
far to the east. It has been so for countless springs — the trails to the north-
west cross the lake ridge at the same places year after year. Are these
passes cues to orientation, each a step in the long journey from the winter-
ing grounds to the breeding marshes far beyond?

The annual return of the Whistling Swan ° to their April rendezvous, the
turning of the wavies at Slack's Bluff, the lakeshore crossings of the Mallard
and Pintail are examples of the avian reaction to the pattern of landscape.
These movements are not indiscriminate, nor are they directed primarily
toward the final destination somewhere beyond. Here is an awareness of
special plots of terrain along the way, responses to mere pinpoints on the
map of total migratory movements. Here are the resting places and local
crossings that are just as incidental, yet just as important, to the over-all jour-
ney as a Chicago transfer is to a transcontinental railway passenger. Clearly
the Delta Marsh is a key point in the northward travels of a great number of
waterfowl. Yet in Manitoba this is but one of many such stopping places.
The Libau and Netley marshes at the south end of Lake Winnipeg are hosts
to wildfowl each spring. Whitewater Lake, the marshes of Lake Dauphin
and Lake Winnipegosis, and the delta of the Saskatchewan are all focal
points where ducks, geese, and swans cross or stop for a while on their
travels to the breeding grounds. These lakes and marshes are steps along
the highway of migration.

There is a temptation to think of the journeys of waterfowl in terms
of such steps. For instance, the Canvasback from Chesapeake Bay has a
route marked by important stopping places at Lake Erie, Lake Winnebago
in Wisconsin, Lake Christina in Minnesota, and Delta in Manitoba, to name
but a few. The pattern is so broad, however, that any discussion would soon
become lost in complexities should it begin with this wide aspect of migra-
tion. The following chapters of Part I, therefore, consider only the local
movements of waterfowl on their home range on the Delta Marsh.

The Delta Marsh lies at the south end of Lake Manitoba, separated from
the lake by a low, narrow, heavily-wooded sand ridge that skirts the shore-
line. Behind the ridge, and protected by it from the lake, the marsh spreads
south to reach the rich agricultural land of the Portage Plains. East and west
the marshland stretches more than twenty miles, and at its deepest point
there are five miles between the agricultural prairie and the lake ridge. From

° See Appendix I for scientific names.

PATTERNS OF LOCAL MOVEMENT

the air it is seen as a complex pattern of shallow bays, connecting channels,
sloughs, and small potholes, all fringed with bulrush or cattail and set in a
matrix of Phragmites, the tall "yellow cane."

Throughout the season, from spring break-up in April until freeze-up
in November, the Delta Marsh has its own population of waterfowl. Early,
this is made up mostly of breeding pairs, but soon bands of drakes that have
abandoned their nesting hens come to the big marsh for their molting pe-
riod. Here they don the drab eclipse plumage and become flightless, for
ducks, like geese and swans, lose the flight feathers of the wing all at once
and are unable to fly until new pinions are grown. Birds-of-the-year add to
local numbers; and before summer is old, many youngsters raised else-
where come to Delta. From early August until heavy frost there are constant
arrivals and departures, comings and goings, some birds staying only a few
days, others remaining weeks or months.

Not one of these wildfowl finds that a given part of the marsh serves all
its needs. There may be a mile or more between the hen's nest and her terri-
tory. Most birds find their feeding, loafing, and graveling places at sepa-
rate locations, often far apart; and each may have more than one locality
for these activities. Some Mallards in late summer and autumn regularly
travel ten to fifteen miles from their loafing bars to the stubble fields, such
trips being made twice daily. Except during the flightless period, each
duck takes daily and often lengthy journeys within the realm of the marsh-
land.

In the travel from marsh to lake, the local ducks cross the wooded ridge
at the same passes the transients used when they departed northward in mi-
gration. When a flock is flushed from the marsh, the birds seldom fly directly

TRAVELS OF WATERFOWL
to the lake by the shortest route. Instead they bend their flight east or west
toward one of the passes where they cross over the trees to the lake. In
August and through autumn Mallards and Pintails that loaf on the lakeshore
move over these same passes in their journeys to the stubble fields. Many
times I have watched a flock of Lesser Scaup, Redhead, or Canvasback cruise
along the lakeshore for a mile or more, then suddenly swing south to cross
over a pass to the marsh. One July a band of pre-eclipse Redhead drakes fed
daily in a bay east of the village. A quarter-mile flight due north would have
given them a direct route; but instead of taking the short cut, they usually
moved west a mile to cross at a favored pass.

In general, the width of the lakeshore passes at Delta is 100 to 400 yards,
although the core of a pass, through which goes the major flight line, often
is narrower than this. The main passage of birds through the pass may vary
from day to day, the travel within the boundaries apparently being dictated
by the wind's direction. It is not true that all trading is confined to passes ;
now and then a flock makes a crossing well to one side or the other. On
days of heavy traffic, however, hundreds of ducks fly over the pass for every
dozen going elsewhere. So closely does the great majority hold to the cross-
ings that these lanes of travel are well-known to guides and hunters.

I have watched the flights over the lakeshore through sixteen years. The
pathways have been the same as long as the oldest guides can remember.
Dr. Fred Cadham, who has hunted the Delta Marsh since boyhood, tells
me that the pass over his cottage has been the same since 1898. For at least
fifty-six years — many generations in the life of waterfowl — ducks have
moved between marsh and lake on this same path. I suspect the history of
Cadham's Pass is much older than this.

The gunner's eye detects little reason for this regularity as he watches
from marsh level. But a bird's-eye view from an aircraft reveals a sharp rela-
tion between the flight lines and the pattern of the terrain (Figure 1). Most
passes are at narrows where marsh water comes close to the lake ridge. Others
are at channels flowing near the ridge or cutting through to enter the lake.
Some are at old creek beds, long dry and overgrown, yet clearly defined
from the air. In short, the pass is where there is the shortest distance be-
tween marsh and lake.

Such trailways are not confined to the lakeshore. These are doorways to
the north, but the marsh itself is a pattern of aerial lanes as well marked by
the flights of waterfowl as the roads on a highway map. In the marsh the
travel follows the path of least resistance; that is to say, the trails take the

Figure 1. The pattern of the Delta Marsh

easiest low-altitude routes over land, usually following the shortest path be-
tween two water areas. Where two water areas are connected by gap, chan-
nel, or creek, this is the passageway for waterfowl. In the absence of a water-
way, the pass is at the narrowest neck of land separating two areas ; or a flight
may follow a dry channel bed that once linked two bodies of water. Where
a creek meanders aimlessly, the more direct overland route may be favored.
The lakeshore passes are used regardless of wind and weather, but many
marsh crossings serve only in certain winds. A given pass may be used regu-
larly when the wind blows from the northwest or southeast, but may seldom
or never be followed when the wind is from another direction, at which
time travel is made by some more favorable course. Thus, in moving over
the marsh, the duck has several trailways, from which one is selected ac-
cording to the wind. Many a gunner has been disappointed when a shifting
wind robbed him of a flight of ducks he had located the previous day. One
afternoon Peter Ward and I stood at a narrow neck of land between two

TRAVELS OF WATERFOWL

large bays. About 3 p.m. there began a flight of Canvasback that moved
over us in an apparently endless stream until we departed at dusk. The wind
was just south of west, and the birds came out of the northeast, alighting in
the bay west of us to feed on the abundant beds of sago pondweed. It hap-
pened that we had but half a dozen shells apiece ; hence it was with keen
anticipation that Ward returned to the spot the following afternoon, well
equipped for a fine shoot. But the wind had changed and, although he re-
mained until dusk, no birds crossed the narrows. As he paddled home, Pete
found the west bay again littered with Canvasback which apparently had
arrived by some other route.

Some passes are very narrow. The crossing of ducks just mentioned was
confined to a span hardly more than 30 yards wide. At one narrow gap the
lane of flight is not more than 25 yards across, the width of the waterway.
I know of several other passes that are similarly restricted. On the other
hand, where a long thin strip of land separates two large lakes, the passes
may be very wide.

Many of the passes are used by all species of ducks. Some, however, are
followed frequently by one species and seldom used by others. I believe this
is simply because different kinds move to different places to loaf and feed.
Canvasbacks that rest daily on the open water of Cadham Bay fly east to
their feeding waters over a route that is seldom followed by Mallards. Mal-
lards crossing the marsh to stubble fields take flight lines rarely used by
Canvasbacks. Several passes at Delta are used heavily only in late autumn,
when Lesser Scaup crowd the marsh.

Since the marsh is a maze of scattered potholes, channels, bays, and
sloughs, a flight of any distance must take a duck over a number of passes.
The pass itself is merely a step in the flight trail. In general, traffic from one
pass to another follows well-defined routes. Where ducks cross large bodies

PATTERNS OF LOCAL MOVEMENT

of open water, the travel usually is straight and direct. But where the land-
scape has outstanding landmarks, the flight may be influenced by these.
Where, for example, an open body of water is broken by an island, flight
lines generally cut close to the isle. Where a bay has an undulating shore-
line or clumps of islands, the trails digress according to these land patterns.
Travel frequently follows the shoreline, usually swinging around rather than
across points of land jutting into the bay. Where the shoreline is much
broken, the trail moves from point to point. The main course of travel sel-
dom swings over islands, more frequently following the waterways between
them.

The height at which the bird moves greatly influences the course of
travel. When flying low, a duck tends to obey land patterns in almost every
detail; a shoreline or a creek is followed through all its meanderings. When
moving high, the flight is more direct. The general course of a creek is
followed, for instance, but the line of flight "cuts corners" and does not wind
as the creek does.

On several recent occasions the establishment of new trails has come in
response to changes in the pattern of the marsh. In the late autumn of 1945
a pond was dug at Station headquarters, located in a dry field where ducks
seldom crossed. Next spring, waterfowl began using it, and in their approach
arrived along regular flight paths never used before. In a south wind the
line most frequently taken by Blue-winged Teal cuts over my yard, and
we now see ducks flying past the kitchen window, where they seldom came
before.

The tight adherence to trailways is well known to the hunter who sets
out his rig of decoys where the ducks will cross. Gunners often refer to the
pathways as "leads," and the most successful native guides are those who
are familiar with these in any wind. Some locations are "handed down" from
father to son among the guides. Old Dan Ducharme once took me to a lead
where the Duke of York had shot when he visited the marsh in 1901. This
place is still a choice location for gunning Canvasback in a south wind.

No doubt every marsh and lake across the land has its leads and passes,
its "Narrows" or its "Hole-in-the-wall" where generations of gunners have
shot. Wildfowlers, as a matter of fact, distinguish "pass shooting" from other
types of gunning, and some of the most famous duck-hunting places are at
passes. When a gunner travels to a new ground, he spends the first day of
his visit studying the pattern of the flights to detect the flight lines. One
old-time gunner visiting Delta for the first time spent a few minutes with a

11

TRAVELS OF WATERFOWL

map of the marsh and then went directly to a narrows connecting two bays,
where he found himself located on one of the best passes in the region.

At Buckeye Lake, Ohio, Trautman (1940:88) observed that in the diving
ducks "the outstanding feature of arriving flocks was their pronounced
tendency to approach the lake at or within a fourth of a mile of Sellers Point.
During twelve years of observations at least 65 per cent of all arriving flocks
came to the lake within a fourth of a mile of that point." In southern Oregon,
Robert H. Smith (letter) noted that in local feeding flights out of Klamath
Valley "both ducks and geese follow passes across the ridges to other parts of
the basin and these passes are favorite shooting spots, particularly if it is
windy. It is an odd sensation to hide among the sagebrush and junipers on a
mountain pass and watch the birds beat their way up to you."

Geese and swans, like ducks, cross the lakeshore at the same places year
after year. Some of these passes are the same as those used by ducks ; others
are at independent crossings which ducks seldom follow. Given the same
wind, geese fly day after day along a line of flight from lake to stubble
fields, often maintaining this regularity despite a daily barrage of gunfire
met along the way. The geese seem more sensitive than ducks to changes
in wind direction, however, and the slightest shift in the breeze will often
prompt them to select a different flight-line. In a location I have watched for
many years, the geese, I am confident, will come over in a southwest wind.
In all other winds they cross elsewhere and, after many fruitless dawn ex-
periences, I have learned that one may as well stay home as to go there
when the wind is wrong.

Waterfowl are not the only birds that use regular lanes of travel. Rey-
naud ( 1899 ) noticed that other kinds follow "air roads invisible to our eyes,
but which can be revealed by observation. The bird, like the quadruped,
contracts the habit of always returning to the same point by the same route."
In autumn the Black-bellied Plovers loaf on the lakeshore sandbars and, like
Mallards (but not with them), they make twice-daily trips across the marsh
to the prairie, where they feed on fallow fields rather than on stubble. In
these feeding travels, plover move along the same flight lines day after day.
When the Franklin's Gulls trade back and forth between lake and prairie,
their travel shows a regularity similar to that of waterfowl. In the Herring
Gull, Tinbergen (1952:5) found that the route of local travel in dune coun-
try "changes with changing wind." Black-crowned Night Herons follow
established routes to the feeding shallows. A pair of crows I watched one
year used the same route daily when traveling between lake ridge and the

12

meadowland a mile south of the marsh. A robin almost always flies to the
same fencepost in my yard before dropping to the lawn. When children
frighten the Yellow Warbler from her nest by the hatchery door, she departs
the same way every time. The Yellow-headed Blackbirds that steal grain
from the duck pen generally use a routine approach. Day after day the
Marsh Hawk that nests near the channel may be seen on its regular course
down the north side of Cadham Bay.

Here is an orderly pattern of movement. The waterfowl of the Delta
Marsh respond to the physical design of their environment in much the
same way as elk or mice follow their earth-worn trails. But unlike the mam-
mals, whose feet mark the paths for all to see, the bird leaves no record of
its passing. These waterfowl must obey the natural shape of the land and
water when moving from one area to another, responding to visual cues as
these are presented by points and bays, channels and islands, reeds and
willows.

Here is a rule of order, a design of habit. Free as the winds to fly when,
where, and how they might choose, wildfowl hold almost as closely to lanes
of passage as do earthbound mammals. Such habit, such conservation of
energy, is probably a universal trait of animals. The game trails of larger
mammals are well known to hunters ; and who is there who has not seen the
Meadow Mouse path in an old field? Our own lives we know to be influ-
enced by habit. This permits us to accomplish complicated acts with the
least expenditure of energy; it simplifies our world. Daily we take the same
route to school or office, although many variations of the trail might be fol-
lowed. We walk along the same streets, over regular short cuts to shop at
the usual stores, and pick up the morning paper at the same corner because
it is easier to follow an established pattern than to pioneer a new trail every
day.

13

"There are few aspects of animal behavior that have
been more neglected by present-day zoologists than
learning, which we may provisionally define as that
internal process which manifests itself as adaptive
change in individual behavior as a result of experi-
ence." W. H. Thorpe (1950:387)

Learned Response to the Environment

The system of aerial trails about a duck marsh
is evidence that waterfowl react positively to their environment. What is
behind this response to their surroundings? Is this rigid, set, innate be-
havior? A downy Canvasback less than a day old benefits from neither past
experience nor parental guidance when it first takes to water ; it swims with-
out an intervening period of learning. Thenceforward throughout its life as
a duckling and as an adult, its activities are directed primarily toward its
aquatic world. In flight the duck's movements are physically unbounded; it
is free to go where its wings might take it. Yet its aerial journeys are re-
stricted largely by the pattern of water on the earth below. Hence, in its
selection of trailways about a marsh, a duck may be following, in large
measure, an inborn attachment to water.

We must believe, however, that adherence to regular flight trails and
passes is far above the level of purely inborn behavior. This we know to be
true because the trail has its beginning and end; a duck departs from a
special place and arrives at a particular destination. The starting point, the
trail, and the destination vary with individuals and with groups; different
birds or flocks select different starting points, trails, and destinations, and
these are always small parts of a complex landscape. Such travel cannot
rely on innate behavior alone. The loafing spots, the feeding places, and the
trails must be found, either by exploratory movements or by following the
actions of experienced companions. In other words, the feeding and loafing
places are learned, and the trails between these are learned routes. A duck,
then, is innately attracted to its special environment, but it learns its posi-
tion within that sphere.

14

Let us now consider a duckling, a downy Canvasback that has just
emerged from its shell. Shortly after its down is dry it ventures forth into the
world equipped with a remarkable set of actions with which it successfully
meets its environment. It can walk. The moment it touches water it swims. It
can dive under water. The complicated process of picking up an object with
its bill is readily accomplished. The initial actions are not learned movements ;
these are the duckling's endowment, its inborn heritage. The fact that a
bird hatched alone in an incubator accomplishes these same acts before it
ever sees another of its kind, or before it has lived to experience its environ-
ment is evidence that they are not learned. This we know as inborn, innate,
or instinctive behavior.*

As the duck grows older there is a maturation of further instinctive acts
These begin to function as the time for their use arrives, just as the feathers
of the specific color pattern develop on a growth schedule. The act of flight,
for instance, is not learned. This is merely the development of an instinct
that will gain maturity when the primary feathers of the wing are fully
grown and the bird is physically ready to fly. Ducks raised in small pens
where flight was impossible were able to fly when first cast into the air. The
act of flight is as much a heritage as walking, but does not mature until the

•Thorpe (1951a:3) explains that before about 1935 the term instinct "had tended to fall
out of use among biologists, while the psychological schools of behavior study tended to use it
for behavior which is: 1. Relatively complex; 2. Markedly constant and therefore presumed to
be inherited; and 3. Related to a situation rather than to locally-defined stimulus. In the last
15 years, however, comparative ethologists have been using the term in a much more precise
sense and have been finding it almost essential for their discussions. The attempt has been
made to formulate this more recent usage in the following definition: Instinct: An inherited
and adapted system of co-ordination within the nervous system as a whole, which when ac-
tivated finds expression in behavior culminating in a fixed action pattern. It is organized on a
hierarchical basis, both on the afferent and efferent sides. When charged, it shows evidence of
action-specific-potential and a readiness for release by an environmental releaser." Tinbergen, in
his book The Study of Instinct (1951:112), says that "it may seem a little early to attempt a
definition of 'an instinct'; yet in my opinion, such an attempt could be of value for future re-
search. I will tentatively define an instinct as a hierarchically organized nervous mechanism
which is susceptible to certain priming, releasing and directing impulses of internal as well as
of external origin, and which responds to these impulses by coordinated movements that con-
tribute to the maintenance of the individual and the species."

15

Mating displays of Canvasback

wings have reached the necessary stage of development. Until the duck has
completed its life cycle, which in most species covers a period of about
fifteen months (from birth to rearing of young and post-breeding molt),
new innate actions become ready for use as the need for their function
arises. The hen does not build her nest until she is nearly a year old; but
when nesting time arrives, the structure is completed without any previous
experience and is essentially the same as nests of her ancestors. Mating be-
havior, the displays and voicings characteristic of pair formation and nuptial
life, while they may see rudimentary expression during the natal or juvenile
period, are not fully developed until the bird enters its reproductive cycle.
We see, now, that the basic actions by which a duck meets its world
are inborn rather than learned. Notwithstanding the strength of this inborn
guidance, each bird's behavior is modified by learning; each individual
must learn to meet its environment. Lorenz ( 1935 ) clearly shows how the
object toward which an innate activity is directed may be learned. Examine,
for instance, the feeding actions. Eating movements are innate, but the ob-
ject toward which those actions are directed — food — is learned. A duck
learns what to eat and what not to eat. Furthermore it learns what foods it
prefers and those that are of secondary palatability. The development of
feeding behavior in captive-reared Canvasback ducklings at Delta is as
follows: First the feeding actions are indiscriminately directed toward al-
most any object the duckling encounters. This behavior begins in the incu-
bator when the birds, but a few hours old, explore the wire with their bills.
Then, when the ducklings are placed in brooder pens, the exploratory bill-
ings continue, nibbling at the wires, at the cloth screen, at straw and sticks.
Objects which are not food may be eaten. When, on their second day,
chopped egg is placed before them, it is billed only casually at first in this
random sampling. But the egg, of all objects in the pen, is edible; soon the

16

LEARNED RESPONSE TO THE ENVIRONMENT

feeding actions are directed almost entirely toward the food trays. Hard-
boiled egg, let us note, is a new food to Canvasback, unknown to its species
in the wild.

In a few days the diet of the downy Canvasback is changed, egg being
replaced by a mash of mixed cereals, dried greens, and powdered animal
products — again, a new food in the natural history of Canvasback. This is
accepted readily. Here, with mash, the youngsters soon demonstrate learned
discrimination. They show a dislike of ground corn, expertly separating this
from other ingredients of their meal. I suspect that this same approach to
food takes place in the wild; through the experience of trial and error the
duckling finds the food most useful to it. True, the youngling follows its
mother, being led by her to choice feeding localities. Some foods may be
learned by the example of her feeding behavior, but it is clear that much
of the nourishment is found independently. Many times I have seen the
mother diving, while the young fed at the surface, no doubt on some other
food.

It is the same with flight. The bird flies instinctively, but it must learn
to relate this act to its environment. For instance, a duck must learn the
fine art of alighting. Young on their first flights are often hesitant and ap-
parently bewildered when approaching a landing, often coming down with
a hard splash. They must learn to direct the course of their aerial travels.
The movements of the tail-rudder are often so awkward in new-flying ju-
veniles that these actions clearly distinguish them from adults. In the
making of a turn, for example, the tail may be tipped too far to one side;
then the bird over-compensates with "reverse rudder" and the tail tips too
far in the opposite direction. The use and dangers of the wind must be
learned. Down-wind landings are such frequent mishaps in young water-
fowl that one must believe that it is only through experience that they learn
to alight facing the wind. They learn to relate their speed of flight to ter-
restial objects so that they do not overshoot their mark. During these early
days of flight there develops the unity of instinct and learning by which the
bird masters its aerial environment.

It is much the same with other basic movements. A duck swims instinc-
tively, but it must learn where to swim. On land, when it travels there ( as
when a hen walks through the grass to her nest), it walks instinctively, but
it learns where to walk. Its courtship and reproductive activities are in-
stinctive, but it learns the companions toward which these activities are
directed. Thus, while a duck's behavior is ruled by instinct, its place in the

17

TRAVELS OF WATERFOWL

environment and in its society is learned. "A very large part of learning in
birds is to be considered as the process of adjusting fixed automatisms or
patterns of behavior to the changes and chances of the world" (Thorpe,
1951b:8).

The duck does not learn what it wants to learn ; there is no evidence of
any conscious direction of experiences and activities toward learning. It
learns those companions and parts of its environment toward which it is
directed by its instincts. Since the pattern of inborn behavior shows no
measurable variation from one generation to the next, the species behavior
shows little change. The wild Canvasback of today learns the same things its
ancestors learned: the foods that are edible, the feeding places, the routes
to and from food, the mate, the nest site, the nest and the young. When
confronted with new situations related to basic rules of life, however, the
Canvasback and other ducks are remarkably plastic in their ability to learn
their relation to new (for the species) objects and places. I have already
noted the young Canvasback's ability to learn foods not naturally available.
Captive ducks at Delta learn to recognize the human "companions" who
supply their needs, and they recognize objects related to food, such as the
grain pail. They learn the functional parts of their highly artificial environ-
ment: metal swimming tank, food trays, brooders. In the wild, too, ducks
have learned to adjust themselves to changes. None of the cultivated cereal
grains are natural foods, for example, but Mallard and Pintail now seek
these for food.

Some species accommodate themselves to changes more readily than
others. In our banding traps we find all kinds, young and old alike, feeding
readily on wheat or barley. Indeed, these grains soon become preferred
foods, young ducks returning again and again to the traps for meals. But
only two species, Mallard and Pintail, regularly forage in the stubble fields
for these exotics. In some regions, these two species now feed almost ex-
clusively on cultivated grains in late summer and autumn, despite an abun-
dance of natural food. Arthur S. Hawkins tells me that in Illinois there is
evidence that the Wood Duck is learning to feed on upland corn fields.
Often we see individual variations in the pattern of learning — that is to say,
in a large flock of captives, certain birds learn places and objects not learned
by others. A captive female European Widgeon, for example, has learned
to jump to the top of a wire frame in the winter pen at Delta, and for three
years she has spent much of her time perched there, although no other
ducks have followed her action.

18

LEARNED RESPONSE TO THE ENVIRONMENT

Several farmers on the Portage Plains have told me of their experience
in moving duck nests during spring cultivation. When the hen is flushed in
front of the tractor, the farmer lifts the nest carefully and moves it to a new
location, where straw is often thrown over it for cover. Many times, accord-
ing to these accounts, the hen returns to accept the nest in its new location
and continue her incubation. Sowls (1951:56) gives an account of one
Pintail hen which tolerated the moving of her nest four times. It was moved
about seven feet (the width of the cultivator) each of the first three times
and twenty feet on the fourth shift, so that when the farmer, Murray Wer-
biski, showed Sowls the incubating hen, her nest was at least forty-one
feet from its original location.

Ducklings reared by foster mothers learn to adapt themselves to parents
of entirely different species (Lorenz, 1935, 1937). A brood of Gadwall
hatched and reared at Delta by a White Leghorn hen accepted her as their
mother and learned some of her gallinaceous calls, to which they responded.
It is easier to cite examples of the duck's ability to learn than it is to
establish the point beyond which learning ceases to function. For example,
the female is aware of the location of her nest in the intricate grassy pattern
of the meadow, but she does not learn the identity of her eggs. Some nesting
females have been known to sit for long periods on stones. A brood mother
learns the identity of her youngsters, but she cannot count them. When a
brood is disturbed, the hen may return to retrieve only a part of her family.
If others are beyond sight and sound, one or two young will satisfy her
maternal instincts and she does not seek out the remainder of her family.
A duck or goose with one wing permanently pinioned by amputation does
not learn that it is unable to fly; when pursued it makes futile attempts to
take wing.

It is not the purpose here to make a thorough analysis of learned be-
havior.* I simply wish to show how the bird learns its position in its en-
vironment and among its companions and that such behavior is directed
by the ruling instinct. We must observe, however, that a duck learns not
only by its own experiences, but also from the experienced actions of social
companions. A captive duck living in isolation learns the objects to be eaten
and those to be avoided quite independently. It learns its position within
its environment so that it moves to its feeding tray, water tank, or brooder
when hungry, thirsty, or cold. It may reach adulthood, learning which ob-

• For a discussion of learning in birds and a recent bibliography on the subject, the reader
is urged to read Thorpe, 1951b.

19

TRAVELS OF WATERFOWL

jects enable it to satisfy its innate requirements, thus demonstrating the
ability of the single bird to learn through its own experiences. An isolated
duck, however, is found only in the laboratory, for in the wild, waterfowl
are gregarious and highly social. From the beginning, in the society of the
brood, the duck lives in the companionship of other members of its kind, and
the actions of the individual are ever influenced by the behavior of the society.
Hence we must discuss learned behavior as it relates to the individual in
its social group.

In their society the waterfowl do many things together. They feed to-
gether; and this is a more efficient way of life than isolated search by each
individual for its own separate food supply. They loaf together; and alert-
ness to danger is more efficient in a resting group than with the lone bird.
The society is functional. Companion-hunger is not merely the desire for
associates ; it is the urge to do things in companionship. We note, too, that
every waterfowl society is made up of lesser social groups, each bound
together by common behavior characteristics. On the May marsh, for in-
stance, we find the following social units : pairs in migration, resident pairs
on territory, prenuptial courting parties, hens with broods, stag parties of
molting males. Each bird, then, desires not only companionship; it seeks
special kinds of companions (Lorenz, 1935, 1937). Some of the social groups
so formed are exclusive societies, membership depending upon the individ-
ual's position in the reproductive cycle. Members of these different as-
semblages are most discriminating in their choice of companions. In May
a molting drake never joins a cluster of courting birds, nor do the sexually
active males team up with the molters. Nor do pairs join courting birds.
Each belongs to the clan of its own kind, not simply because it is the same
species, but because it behaves as its chosen companions behave. On a
sunny April afternoon one may distinguish at least three of these societies
and witness their complete isolation, although circumstances bring them
close together. Among the Canvasback on the bay there is an isolated pair,
no doubt local breeders. Feeding busily nearby are five pairs. Each hen
holds close to her drake, but it is obvious that all together make up a unit
band, probably pairs that are migrating together. Finally there are five
drakes and a hen together, the males alternately displaying and pursuing
the female, a prenuptial courting party. No group intrudes on the others,
nor is there intermingling of the societies.

There must be some means of communication by which the social bond
is established and maintained. So with waterfowl there is a rudimentary

20

"language." In part, this language is expressed vocally; a duck is aware of
its companions through auditory as well as visual perception. The peeping
of ducklings holds the brood together in dense vegetation, and their voicings
identify their position to their mother. In turn, the ducklings follow the low
voice of the parent when she moves ahead of them in dense growth. When
Mallards and Pintails fly northward on April evenings, I hear their soft
chuckles, which undoubtedly are a factor in holding bands together when
overtaken by darkness. On evenings when Coots move in spring passage I
can mark the pattern of their unseen numbers by voices drifting down.
April nights are alive with the cheeps of migrant songbirds. Such simple
notes are termed "contact-calls." The contact-call has no seasonal perio-
dicity. Often it is as clear a mark of identification as the feathers themselves.
It identifies the individual of the species and its position. Such notes are
generally short, simple, and, for many species, easily imitated by man. While
I was writing this page, a Black-crowned Night Heron passed over the
marsh close by, and from my door I uttered a loud "quock." The bird turned
immediately to bend its flight my way. Contact-calls function to hold a
group of birds together, and probably tell very little of what the individual
is doing.

21

TRAVELS OF WATERFOWL

Ducks and geese have a rather broad vocabulary above the level of the
contact-call, special voicings that identify the situation as well as position.
In situations related primarily to survival there is a vocabulary which, like
the identification call, is not seasonal. It functions to identify the situation
at any time of the year : the presence of food, the contentment of safe loaf-
ing, alarm. The Mallard hen gives a rapid "tuckata-tuckata-tuckata" series
of notes in the presence of feed. A series of loud, descending quacks, which
Lorenz ( 1953 ) terms the "decrescendo call" and which hunters refer to as
the "hail call," is given only in undisturbed groups of Mallard. A low, single
"whank" is uttered in alarm. The feeding and hail calls are imitated the
world over by hunters to lure Mallards to the gun. The Canada Goose has
a distinct note for alarm and the presence of food. One of the most beauti-
ful utterances of waterfowl is the departure "song" of the Whistling Swan,
a melodious, soft, muted series of notes which in my experience always
precedes the take-off run when the birds are about to fly. This pre-flight
melody is probably the "swan song" of legend, for when a swan is shot and
falls crippled to the water, it utters this call as it tries in vain to join its
fellows in the sky.

For each social group of the reproductive season there are notes that
identify the condition of the bird as well as the situation. These are pre-
sented only during the times of the year coinciding with the periods of the
reproductive cycle to which they are hinged. Such voicings are uttered by
and draw responses from only those individuals which, by reason of their
physiological condition, fit the special group of sexually active birds. In
prenuptial courtship, all drakes have notes that advertise their sexual status,
such as the catlike "mee-owh" of the Redhead drake or the sharp whistle
of the male Pintail. Only sexually active birds respond to this breeding-
season vocabulary. By following a group from prenuptial courtship to the
mated pair, we find some notes of the drake to be directed only toward
males, these no doubt constituting sexual challenge. Other calls and displays
are aimed primarily at the female. In the family group, both young and
mother have voicings delivered only in certain situations — that is, when
traveling, when escaping danger, when captured by enemy.

All the notes of a duck are innate. The response of a fellow duck to those
notes may be inborn, as probably applies in courtship; or the voice of a
companion may be learned, as the young learn the call-note of the mother
(Fabricius, 1951). There is some interspecific response to calls identifying
situation. I have seen Pintails turn sharply toward the feeding call of a

22

LEARNED RESPONSE TO THE ENVIRONMENT

female Mallard. Such individuals no doubt have lived with Mallards, thus
having learned to associate this series of notes with a favorable situation.

It is essential that we understand the limits of this "language." This is
not communication as we know it in our highly articulate human inter-
course. The call of a bird is an innate vocal response to certain stimuli. These
may be inner stimuli, such as are induced by hormonal changes in the
sexually active bird. Or the responses may be to outer stimuli, such as the
presence of food or enemy. The voice is merely the inborn response to a
condition or situation. The reaction on the part of the companion, whether
innate or learned, is an answer to an outer stimulus, the note heard. Full
response, however, depends upon inner forces. A passing Mallard may not
come to the feed call unless the stimulus of an empty gizzard directs it to
respond. The Canvasback hen does not respond to the courting note of a
Canvasback drake unless her position in the sexual cycle so directs her.

An insight into the operation of the avian vocabulary may be had, I be-
lieve, by drawing an analogy from human behavior. Baby tumbles down
the steps and immediately begins to cry. The crying of the infant is not
consciously directed toward the parent; the situation demands that the
baby cry and it cannot avoid the act. The child's mother responds by run-
ning to the scene of the accident, directed there by the child's voice and
her parental drive. The voice in ducks is similar to the cry of the injured
human infant in that it identifies the individual and it may also identify the
situation and the condition; but the voice does not consciously convey a
message.

Certain sounds, not vocal, which are related to functional movements,
may serve as signals. I have lured Mallard, Gadwall, and Blue-winged Teal
into a dense stand of bulrush by swishing my hand in the water to simulate
feeding sounds. Martin Bovey told me that on the Currituck Sound he saw
a guide bring Lesser Scaup to his stool on a calm day by sloshing his feet
in the water. There are reactions to certain sounds that are not to be ex-
plained. This morning three White-winged Scoters slipped by me at a dis-
tance of five hundred feet, heading pell-mell for the open lake. I gave a loud
yell and immediately the band turned to fly back over me. Forbush (1925:
276) tells how hunters along the New England coast bring these Scoters
within gunshot by firing a charge or by shouting from a dory. I have seen
Lesser Scaup and Green-winged Teal swing back over my blind when I beat
the paddle sharply on the side of the canoe. A quick wave of the hat or a
kick of the boot sometimes serves to turn a flock into the decoys. This might

23

TRAVELS OF WATERFOWL

be explained on the basis of curiosity. I suspect, however, that a band of
ducks seeking congenial company might turn at almost any noise strange or
poorly heard, making the full response when the source was identified. The
hunter's rule when calling ducks or geese is to keep quiet after the birds
have turned, lest the ruse be detected.

Before leaving the subject of voice, note must be made of the duck's abil-
ity to localize sound. Waterfowl readily locate a noise even though they may
be moving rapidly through the air and the source of the sound is hidden
from their sight. Once a band of passing Redhead drakes wheeled to fly
directly over my hiding place when I imitated a Redhead female. In autumn
twilight Peter Ward and I have called Mallards directly to our voices, al-
though we were hidden and without decoys.

Movement is another means of communication. All or most functional
actions serve as signals. For instance, in ducks the quickly lifted head is a
signal of alarm. A hunter attempts to sneak up on a flock of loafing Mallards,
but one bird sees him, lifts its head, and in a flash every head in the flock
is raised, all alert, although only one bird saw the hunter's movement. The
lifted head of the first bird was simply an adjustment ; he raised his eye-level
to see better. His movement released similar actions in his companions
which, either innately or through conditioning, associate the sudden lifting
of the head with the presence of danger. When the hunter makes another
false move, the entire flock is away in a flash, although only several may
have seen his second blunder. The action of an individual is repeated by the
flock. Obviously this rapid reaction is of great survival value ; escape move-
ments would be far less efficient if each duck examined the cause of an
alarm before departing.

The native guide's explanation of the first Mallard's behavior would be
that this bird told the others of the hunter's presence. Wre know that his ac-
tion, as a signal, is merely a response to a situation. The drake does not in-
tentionally communicate with his fellows, and his behavior is the same when
he is alone. Let us note that the lifted head is not a stereotyped response
to danger, but depends entirely on the Mallard's condition. During the
summer wing-molt, when the male is flightless, he quickly lowers his head
when aware of danger, and the lowered head is the signal for other flightless
males to lower theirs. The flightless drake does not wish to see better but
to avoid being seen, and with lowered head he is much less conspicuous.
The same behavior is to be noted in a wounded duck.

When the mother Blue-winged Teal feigns injury in the presence of a

24

In Canada Geese there is a nervous shaking and uptilting of
the head when a bird is disturbed.

man, she does not communicate a message of danger to her young. When
they hear her distress notes, they seek to escape perils of which they are
not aware; the response is to the mother's voice, not to the danger. Thus
one summer day a village-bred family of Blue-winged Teal walked into my
yard, the babies still wearing the egg-tooth, evidence that they were less
than forty-eight hours out of the shell. The mother was very tame, not at
all bothered by us as we followed close behind, nor were the babies dis-
turbed. We herded the family into the corner of the fence, and there I
gently lifted the hen from the ground. The moment I touched her she ut-
tered an alarm note, and the ducklings quickly hid in the grass.

In Canada Geese, as in several other geese, there is a nervous uptilting
and shaking of the head when a bird is disturbed. As one individual begins
this action, its companions become alert, and the movement is repeated by
all members of the flock. When shaking reaches a certain degree of intensity,
the birds invariably take to the air. "Such formalized preparatory move-
ments often have communicative function, each individual of the species
being brought into the flying mood by its companions' movements" (Tin-
bergen, 1942:90).

Again, if we consider the social releasers as a part of the bird's vocabu-
lary, we may draw an analogy from human behavior. We, too, have a vo-
cabulary of signals. A neighbor drops in to sit for a chat. Half an hour later he
places his hands on the sides of the chair. He has not yet said, "Well, I must
be running along." But the signal of his hands cannot be mistaken, and the

25

TRAVELS OF WATERFOWL

moment he makes the next move — pressing down on his hands — I am
rising too, ready to bid him goodbye. Children quickly learn to interpret the
actions of parents or teacher, anticipating pending behavior on the basis of
signals.

As with voice signals, there may be interspecific responses to action sig-
nals. When I approach a flock of mixed species of ducks loafing on a sand
bar, they all raise their heads, regardless of the species of the individual that
first responded to my presence. Many species of ducks react to the alarm
signal of Canada Goose, and these geese to the actions of ducks. Feeding
actions draw interspecific responses ; ducks of many kinds react to the feed-
ing movements of Whistling Swans. When the swan dips its head to dig for
sago tubers, ducks swim over to rob the gleanings. Canvasbacks and Red-
heads often join feeding Lesser Scaup ; Pintails join Mallards.

The reply to a signal, whether vocal or active, is often immediate — as
sharp, almost, as the response of the electric light to the turn of a switch.
This is especially true of situations related to reproduction or to survival,
where instant reaction is the key to life. All social communication, however,
is not limited to the sharp response. Every action of an individual or group
identifies its behavior to other members of the society. Since it is easier for
members of a social group to do things at the same time, every action is a
cue or signal, and the behavior of the individual is repeated by the crowd.
If a duck had a creed it would be: Do as others do; go where others go.
When one bird happens on a choice bed of food, it is easier for the group
to feed there than for each member to seek out its own special plot. When
one of a band of Lesser Scaups begins to dive busily over a sago bed it has
just located, its lead is the signal for companions to come hither and feed
in the same place. When one small party finds a safe loafing bar, the locality
soon is the resting place of many. In any social gathering of waterfowl the
members do the same things at the same places at the same times. In old
birds this may be merely a matter of convenience; in ducklings, the very
survival of the individual hinges on co-ordinating its behavior with that of
its companions. A bird thus learns by following the actions of others more
experienced.

A striking example of group behavior is seen when a gathering is con-
fronted by an entirely new situation. In late April, when Lesser Scaups
litter the bay in their many hundreds, they depart quickly from the edge in
escape movements when I walk boldly to the shore. But when I sneak
through the tules unseen, then remove my plaid shirt to wave it above my

26

head, the nearest birds stop their feeding to watch, first in alarm, then to
swim closer to gain a better view of this strange thing. Soon most of the
ducks within a radius of a hundred yards have stopped feeding and are
swimming toward the shirt. Many of these, because of the undulating shore-
line, cannot see the shirt; they are following others that do see it. Such
"tolling," often accomplished with a dog, was once a common ruse of hunt-
ers to bring birds to the gun. By the same methods, antelope and sometimes
deer may be brought within gun range. How like our own human behaviorl
Surely each of us at some time has interrupted the business of the moment
to follow with quickened step a gathering crowd of people without know-
ing what draws them together.

The same sympathetic behavior is to be seen in the selection of flight
routes. When I flush a band of Mallards on the lakeshore in August, they do
not depart individually to all points of the compass. After the initial surprise,
there is a regrouping, and most of the birds go away together in one direc-
tion to some other part of the lake or marsh. Since these August aggrega-
tions often take on new members daily, it may be assumed that some of
these are newcomers which are merely following the actions of experienced
birds. One duck goes where its companions go and in doing so it learns the
way. The same holds for young birds, such as the color-banded individuals
which first meet the world from the Station ponds. At first their outward
journeys take them no farther than the nearby slough or bay edge, and in
such flights they are in their own small company. It is not long, however,
before they return with unbanded, wild birds and then depart to distant
regions of the marsh with these, no doubt sharing experiences as well as
learning new places together.

27

TRAVELS OF WATERFOWL

So it must be in its travels about the marsh, the duck learns its place in
the environment, learns the location of the various areas it uses for life's
requirements, and learns the routes, the leads, and passes that link one place
with the other. Some of these places and routes may be learned independ-
ently, but often the bird is first directed to these by the actions of experi-
enced companions. In companionship with others, each bird gradually
expands the range of its activities as it learns to accommodate itself to an
ever enlarging world.

28

"In all sciences depending on observation, we must
reckon with errors due to imperfections of our
senses." Henri Poincare, Science and Method

The Visual World

Ihese ducks of the Delta Marsh use their en-
vironment in an orderly fashion; there is a pattern to their travels. They
learn to follow the arrangements of land and water, reeds and willows, that
make every corner of this marshland different from any other part of the
world. The duck accommodates itself to the environment that meets the
eye; it learns the places in its world by seeing them; its local orientation
depends upon eyesight. A clue to the importance of sight is to be found in
the size of the avian eye. One is misled by outward appearances, for the
cornea is enclosed in a relatively small lid-opening. When the skin is re-
moved, the eye structure is found to occupy a very large part of the head,
and the two eyes of a Mallard weigh nearly as much as its brain ( Figure 2 ) .

In examining the world of waterfowl, it must not be assumed that earth,
sky, and all things between appear the same to man and bird. Indeed, the
true nature of the world has been the study of philosophers since the be-
ginning of civilization; earlier than the year 400 B.C., Protagoras exclaimed
that "what seems to me is to me, what seems to you is to you" (Jeans,
1943 : 32 ) . Leibnitz believed that he was "able to prove that not only light,
color, heat and the like, but motion, shape, and extension too were mere
apparent qualities," and Berkeley claimed that "all the choir of heaven and
furniture of earth, in a word all those bodies which compose the mighty
frame of the world, have not any substance without the mind" (Barnett,
1948:306). We become aware of the poorly defined boundaries between
science and philosophy when speaking to a color-blind friend about the
things we perceive. There is no science to aid in the hopeless attempt to
define the color red to such a companion. He simply does not perceive red as
we do, nor do we see it as he does. Thus the visible world for him is not

29

Figure 2. Eye of Mallard drake. The combined weight of the two eyes
was 3.2 grams. The brain weighed 5.3 grams.

entirely the same as ours, and science shows no pathway leading to a com-
mon understanding.

The naturalist often assumes that bird and man look upon a landscape
that appears alike to both. Yet the world of man and bird cannot be the
same ; the bird's eye is structurally different, and its actions, experiences, and
visual perspectives are different. The eyes of the duck, goose, and swan
are placed on the sides of the head, and by such an arrangement the water-
fowl enjoys the advantage of horizon-wide vision. In a glance a duck may
see nearly twice as much of the landscape as a man can take in. Among
gregarious birds this wide visual field permits each individual to see its
companions on all sides, which is of special importance in flock movements.
An enemy does not easily approach unseen from behind. The broad view
of the landscape is an aid to orientation during travel; in an instant a duck
sees where it was a moment earlier, where it is now, and where it is going.
Man understands the value of such wide vision when he ventures into
strange country; it is characteristic of human beings to turn the head many
times in unfamiliar surroundings to examine the region just traversed.

Though having this advantage of wide vision, the duck lacks the ability
possessed by man and the owl to perceive the landscape with stereoscopic
solidity; there cannot be the same awareness of depth and distance that is
inherent in our own binocular vision. To be sure, the eyes of the waterfowl
are set slightly forward so that there is some overlapping of the visual field,
hence a narrow binocular span ( Figure 3 ) . In feeding, a duck faces its food

THE VISUAL WORLD

directly and selects grain precisely with its bill. Often, when food floats on the
water, it reaches out with its bill neatly to take a morsel from the surface.
In sexual fights and in the frequent bodily encounters of courting birds, it
thrusts its bill straightforward in a well-aimed blow. Such direct actions sug-
gest depth perception for a narrow zone directly facing the duck.

But it is obvious, both from the structure and the behavior of the duck,
that there is monocular fixation for all parts of the landscape beyond reach
of the bill. While writing this paragraph, I visited the winter pens where
there are more than a hundred ducks and geese of a dozen species. As I
entered the room, each turned its bill to one side or the other to view me
with one eye. Not a single bird had its forehead in my direction. So, at othei
times, the object of interest is examined with one eye. This is especiall)
noticeable when a hawk or an aircraft crosses over the pen and the birds
tilt their heads to watch. Often I have seen waterfowl tip their heads when
in flight, as when a band of Whistling Swans comes directly over my hiding
place, suddenly taking notice of my presence. A most interesting observation
of the monocular response of a pet parakeet to its visual world was related
to me by Robert L. Lillestrand. The bird, a pet of Roy P. Van Devener,
was released in a bedroom which had rose-colored wallpaper patterned in
a floral design with thin vines. The little parakeet, then only six weeks old
and with no experience of the outdoor world, attempted to alight on the
painted vines. The same thing occurred on later releases in the room, and it
was not till the bird was nine months old that it learned the impossibility
of using the painted stems as its perch.

For a man there is little stereoscopic effect in the landscape beyond fifty
or sixty yards from the eyes. As an aerial traveler, the bird has lost little and

Figure 3. Drake Ruddy Duck

showing the eye position

typical of waterfowl

gained much in the lateral position of the eyes. At high altitudes depth
perception is little needed. Close to the earth, however, and particularly
when alighting, there must be some awareness of the three-dimensional
character of the environment. Pumphrey (1948:182) has pointed out that
such depth perception hinges on time and motion, that "the appreciation
of distance has to be built up by a succession of glances from different
points toward the same point of the field." He refers, of course, to parallax.
The moment the bird is in flight, the position of the eye in relation to objects
in the landscape is ever changing. The most rapid changes are in the nearest
objects, hence the relativity of motion is the clue to the depth of the land-
scape. "Near objects seem to move extensively in the opposite direction as
compared with far objects, while the latter seem to move slightly, in the
same sense as the head movements, in relation to the nearer objects. It is
chiefly this cue which enables a one-eyed man to move about in an un-
familiar roomful of furniture without bumping into things any more often
than a two-eyed person" (Walls, 1942:314).

We human beings employ parallax daily in measuring our environment,
and it must be the most important clue the bird has in the perception of the
landscape's three-dimensional character. For birds the motion of travel
establishes the parallax; the more rapid the flight, the more keen is the

32

THE VISUAL WORLD

awareness of depth. In some species there are instinctive body actions which
apparently function to increase the effect of parallax. Walls (1942:342) re-
minds us that some "birds when walking (fowls, pigeons, doves) and
others when swimming ( coots and gallinules ) make perpetual f orward-and-
backward oscillatory movements of the head. It has been claimed that the
eyes never actually move backward through space — the forward move-
ment of the body just cancels the backward movements of the head. Thus,
although the body moves forward steadily, the head moves forward through
space by jerks and pauses. In effect, the eyes obtain a rapid succession of
previews of the surroundings from constantly new angles. The forward
movements of the head being so quick, each new parallactic observation
of the field is made almost simultaneously with the preceding one, and the
exaggeration of the apparent relative motions of objects at different dis-
tances furnishes a basis for the estimation of distance and relief."

While ducks and geese do not jerk the head as does the Coot, still their
heads are often in motion when traveling through dense cover. The head of
a swan is seldom idle as it swims. In low-flying ducks there often is an up
and down swinging of the head, and on several occasions I have seen a
Green-winged Teal skimming along just above the reeds with its head in
constant motion. J. C. Lynch, pilot-biologist for the U.S. Fish and Wildlife
Service, and a specialist in low flying, told me that it is most helpful to the
pilot of an aircraft at low elevations to look at the ground from first one
side of the plane, then from the other. This is termed "scanning" and is
especially useful in judging distance when bringing a light plane in for a
landing.

Other clues to distance possibly are learned. The size of the retinal
image depends on the distance of the object from the eye, but as a guide
to distance the bird must have a familiarity with the object seen. Perspec-
tive is another clue which depends to some extent on a familiarity with the
components of the landscape. Aerial perspective, the variation in color due
to atmospheric influences, probably is used by birds in the perception of
distance. All these clues no doubt serve in establishing the awareness of
altitude when in flight.

The structure of the eye has a profound influence on perception (Figure
4). Pumphrey (1948:174, 182) points out that the retina of the bird "is
shaped so as to lie almost wholly in the image plane, so that all distant ob-
jects within the visual angle are sharply focused on the photo-sensitive
cells, whereas in the human eye this is only true of objects lying close to

33

RE.TIN*

Figure 4. Eye of Mallard (twice natural
size), cut away to show position of
retina, lens, and pecten

CORNLA

the optic axis. . . . For man, the distance element enters into every glance,
but the appreciation of detail of the field has to be built up by a succession
of glances from the same point and directed to different parts of the field.
For the bird, detail enters immediately into every glance." Let us measure
the focal angle of our own human eye by looking up from this page to the
landscape beyond the window. To read the entire scene we must shift our
eyes back and forth. When the eyes are at rest, only the narrow field directly
in the line of vision is in focus. On either side of this narrow focal angle we
are aware of form, color, and movement, but these are out of focus and
may not be understood completely until the eye is moved. From its eye
structure, we must believe that the duck or goose viewing this same land-
scape perceives much more of it in sharp focus. In a single glance, then, the
duck obtains a sharply defined image of much of the landscape meeting
the eye. It perceives clearly in an instant what a man can understand only
after a series of shifting glances. Of course, we must remember that the
scanning movements of the human eye are very rapid, the speed compen-
sating in part for the narrow field of sharp vision.

Man has long acknowledged avian superiority in visual acuity (sharp-
ness of vision), and the example of the falconer's experience is traditional.
"It was the habit of the medieval falconer to carry a caged shrike on his
saddle, to keep track of the falcon. As long as the shrike acted fearful and
excited, the hawker knew that his proud tercel was in sight — though not to
him!" (Walls, 1942:169).

All who have lived close to waterfowl have witnessed their awareness
of objects we human beings could not perceive. One afternoon I sat watch-
ing a band of Mallards loafing on a lakeshore sand bar. In the distant sky
there appeared a hawk which, as it approached more closely, I identified
as a Pigeon Hawk. From the time this bird was first seen until, after pass-
ing within a hundred yards of the ducks, it disappeared in the east, I ob-
served no reaction on the part of the waterfowl. The hawk seemed nothing

34

THE VISUAL WORLD

more nor less in their lives than the drifting leaves of a nearby poplar.
Shortly afterward the ducks suddenly stood up on the sand bar, some of
them swimming away. Looking westward I saw a bird of rapid wing-beat
approaching at low elevation. It was several seconds before I was sure
that this was a hawk and some moments more before I could be certain it
was a Duck Hawk and not another Pigeon Hawk. When the predator was
within two hundred yards, all the ducks were in the water. None flew and,
as the falcon passed over, most of them dived, some frantically in water too
shallow to cover them. After the hawk had gone on, a few of the Mallards
flew away, but most returned to their island to pick up the lazy thread of
their afternoon siesta. At this point I will not raise the argument whether
the enemy-fear was instinctive or learned. The matter of importance is that
these birds recognized their enemy long before I did.

The photoreceptive cells of the eye lie within the outer layer of cells of
the retina and are of two types, the rods and the cones, so named because
of their shapes. The rod cells are more sensitive to light intensity, respond-
ing to much lower degrees of illumination than the cones. Within their re-
stricted range, however, "the cones are responsive to much smaller changes
in intensity; and it is the cones which are responsible for color vision. The
cone system is consequently suited for the registration of detail in a brightly
illuminated visual field. The rod system, because of its extensive summation,
is comparatively incapable of resolving detail but can register an achroma-
tic picture of the gross features of the field at illuminations so low that the
cone system is quite blind. We might expect, therefore, to find, as in fact
we do, that cones are predominant in the retinae of eyes which are exclu-
sively diurnal, and rods in eyes used only at night. Acuity (the power of
resolving detail) and sensitivity are inverse requirements which cannot be
fully satisfied in the same eye" (Pumphrey, 1948:177). By and large, the
waterfowl come as close as any bird toward meeting the mixed require-
ments of day and night vision. Their acuity is sharp and they are active
by day; and yet in many respects they are crepuscular birds, moving swiftly
and surely in the dusk of morning and evening. Ducks are active under a
full moon through the night, especially during the breeding season. But
on dark and moonless nights, with the added curtain of cloud, their travel
about the marsh comes to a halt.

In birds, especially those swift of wing that feed in the open, it is most
important that there be a clear image of near and far objects at every in-
stant. In man the adjustment of focus is accomplished by an involuntary

35

TRAVELS OF WATERFOWL

muscular adjustment of the lens. In birds both the lens and the cornea are
altered in accommodation ; hence two parts of the eye function to maintain
instant sharpness of both near and far parts of the visual field, and objects
rapidly approaching the eye are held in focus.

The best experimental work, Pumphrey says ( 1948 : 185 ) , seems to estab-
lish that "there is very little difference between the color vision of birds and
man," but he goes on to explain why he believes that even though "the
limits of color vision seem to be the same for man and birds, it is likely,
nevertheless, that color sense plays a more emphatic part in the visual
sensations of diurnal birds than of man." Kalmbach (1943), who studied
the feeding responses of wild Mallards to colored grains, found that "water-
fowl have shown a degree of aversion to unnaturally colored grain, though
the discrimination by ducks is less emphatic than with passerine and galli-
naceous birds. This, it is felt, is due largely to the 'puddling' method of
feeding which operates probably as much by the sense of touch as by sight."

Vanderplank (1934) and Wojtusiak (1949), among others, have pre-
sented what they believe to be evidence of avian awareness of infrared.
Griffin (1952a: 369) has made a careful review of the many studies of
visual sensitivity to infrared radiation, concluding that there is "strong evi-
dence that the visible spectrum of birds is approximately the same as that
of the human eye" and that "theories of bird navigation based upon sensi-
tivity to thermal radiation from bodies of low temperature scarcely deserve
serious consideration." Pumphrey (1948) concurs in this view. Supporters
of the view that birds are sensitive to infrared claim that such perception
accounts for the bird's ability to fly in heavy darkness or through fog; but I
have observed that waterfowl refuse to travel in dense fog or complete
darkness.

The pecten, a fanlike structure in the posterior chamber of the eyeball,
is universally present in birds (Figure 4). Its function is still speculative,
and many theories have been advanced in regard to its role in vision. An
important lead was presented by Menner (1938), who observed not only
that the foliations of the pecten cast shadows on a functional part of the
retina but that these foliations, hence the shadows, varied with different
kinds of birds. The pecten proved to be the most highly developed in diur-
nal birds with good visual acuity, such as hawks, and the least in nocturnal
species. Walls (1942) remarked that before Menner, some thirty theories
had been advanced regarding the function of the pecten, and Griffin
(1953:227) offers a conjecture that might be given, he says, "the serial

36

THE VISUAL WORLD
number '32'." He points out that if, as Kramer's studies (1952) suggest, the
sun is useful to a bird in navigation, then the pecten's function might be
to this end, just as a sextant serves man in his navigation.

"What would be more useful to a bird than a built-in yardstick laid out
upon its retina, a series of fixed points against which the bird might learn to
estimate the angular distance of the sun above the horizon? Furthermore,
to guide itself by means of the sun a bird obviously must spend some time
looking at its intensely bright disk, a process which is uncomfortable, to
say the least, for the human eye. Hence perhaps the evolution of the pecten
with its plicated outline of densely pigmented tissue and with the rich
blood supply which would serve to carry away excess heat from the sun's
image if this image should fall on any part of the pecten. Considering the
extent to which the avian eye is fixed in its socket, in contrast to the great
freedom of rotation of the human eyeball, it is a plausible supposition that
the definite outline of the two pectens, plus the fixed points provided by
the foveas, might provide the bird with a visual frame of reference against
which the position and movements of the sun could be gauged."

In the lives of all waterfowl the perception of movement is a very im-
portant function of the eye. Every hunter knows of the Mallard's immediate*
reaction to the slightest motion. He may tip his face or move his hand ever
so slightly; but even though the approaching bird may still be well beyond
gunshot, it alters its course or "flares" upward to avoid danger. Indeed,
one of the most important things in wildfowling is the art of remaining
motionless. The downy Canvasback shows a keen awareness of movement;
only a few days after being hatched it is able to strike swiftly to snap a fly
from the air. Waterfowl live in a world that is important to them in terms
of movement. At rest they must be ever aware of the motion of enemies,
companions, and living food. On the water, subject to the pressure of wind
and waves, they must perceive movement to maintain their local orienta-
tion. In the air it is the apparent flow of the world beneath that gives them
their awareness of movement through space.

The eye of the bird is specially adapted to the perception of movement.
The panoramic vision of these waterfowl serves to introduce movement
to the eye over a wide span of the landscape. Their high visual acuity and
the breadth of the sharp retinal image likewise serve to give them a keen
awareness of motion. Movement is perceived in the changing illumination
of the visual field. If the background is moving ( cattails in a breeze ) , if the
color of the shifting object is quite the same as the background ( a brown-

37

TRAVELS OF WATERFOWL
coated hunter crawling in front of autumn cattails), and if the object moves
slowly, awareness of motion is difficult But where the background is sta-
tionary, the color contrast sharp between background and object, and the
movement rapid, awareness is keen. We must judge that ducks are more
successful than men in detecting motion under adverse conditions of speed
and background. Their field of movement perception is probably greater
than that of men not only because of the position and structure of the eye,
but because of their different response to the environment. Men are highly
sensitive to movement on a horizontal plane, since they meet their world
largely between their feet and the horizon. Ducks, on the other hand, meet
the world from above when flying ; and they must be ever aware of their aerial
environment when on the ground.

The visual world of the waterfowl, then, while probably having the same
colors as that of man, is much wider. It is viewed monocularly, and more
of its detail is perceived sharply at a glance. Perception of movement is
keener than in man, the power to resolve detail is greater, and the avian eye
accommodates itself to changes in the position of objects more quickly. It
is impossible, with our binocular vision and narrow visual field, to imagine
how the world appears to a duck, but it is easy to understand how percep-
tion is highly efficient for spatial orientation.

At this point we must acknowledge that visual perception concerns more
than the eye, both in birds and men. The eye is simply the window of the
brain. The eyes of a man (and of a bird) receive stimuli, such as rays of
light, from the outer world, "and these produce electric changes which are
propagated over his nerves to his brain. Here they produce further changes,
as the result of which — after a series of processes we do not in the least
understand -his mind acquires perceptions, to use Hume's terminology, of
the outer world" (Jeans, 1943:6). Bird and man respond not directly to
their environment, but only to the image that reaches the brain. Seeing is
merely the physical reception of an image; the delicate organ of sight, in
effect, is the camera. Perception follows only when the brain has "examined"
the image. Thus the visual world depends not only on the nature of the
eye, but on that of the brain as well, and each animal lives in its own per-
ceptual world which in some way is distinct from that of any other in-
dividual.

We who live outside the worlds of birds study avian perception through
their response to their environment. We know they are aware of something
only when they show behavior. As we watch the flight of Mallards out to

38

THE VISUAL WORLD

stubble every evening along the same creek bed, we judge that they are
aware of the terrain, just as they are of the narrows between two lakes
which they cross regularly. When the drake holds close to his mate through
all the days of migration, we conclude that he perceives in her some char-
acter that distinguishes this particular hen from all others. When the Can-
vasback hen finds the way through the tules to her nest, she must be aware
of environmental patterns.

"The important thing to realize," says Russell (1934:181), "is that the
animal's perceptual world is essentially a practical or functional one. The
animal attends to, perceives, and shows behavior in respect of, only those
events, objects and characters of objects that are at the moment functional-
ly important to it, those about which it is impelled to do something; only
these have valence for it." Such valence * hinges on the condition of the
bird: on its age, its sexual status, the time of the day and the time of the
year. The mother is valent for the ducklings only during the period of
growth, the nesting cover has valence for only the nesting hen, and she has
valence for her drake only a part of the year.

Some components of the environment must have valence because of
the innate make-up of the bird. In our captive ponds are Canvasbacks and
Pintails that have been hatched together and raised as companions in the
same pens. Until nearly a year old they share this captive environment.
When May arrives, however, the Canvasback hens select emergent vegeta-
tion for nesting cover, while the Pintails walk up on the dry ground to seek
out nesting places in grass some distance from water. Such selection follows
the visual inspection of the entire landscape, of which a part is perceived
as the place for nesting, the choice between emergent and upland cover
being inborn. When young hand-reared Mallards are released to the wild,
they soon seek out the part of the landscape that is their never-before-seen
birthright. Set free in the grassy thickets behind the lakeshore, they soon
move to the emergent beds of bulrush at the shoreline shallows.

This seems a simple shift, and yet it does represent a choice between
favorable and unfavorable environment that is not based on experience.
Our Pintails and Mallards seek out the rushy borders when given freedom,
but the young Redheads and Canvasbacks go to the open water that is the
natural haunt of their wild brethren. In his studies of ducklings ( 1951 : 167)
Fabricius found that "the newly hatched birds showed some apparently

"Russell (1934:179) considers as "valent, or possessing valence, those objects, or char-
acters of objects, and those events, in the perceptual world of an animal, in respect of which
it shows behavior."

TRAVELS OF WATERFOWL

innate reactions to the features of the country. The young birds went into
the water spontaneously and swam out even if they were not conducted
into the water. Young tufted ducks and shovellers which are left to them-
selves were — even when newly hatched — strongly attracted to reeds, where-
as young eiders avoided reeds and instead were especially fond of swim-
ming along open rocky shores." Mayr remarks (1942:246) that "naturalists
have always marvelled at the unfailing accuracy with which animals can
find the right ecological niche to which their species is adapted." And
Thorpe suggests (1949:86) that "one can safely assume that, quite apart
from the recognition of a particular locality, birds can recognize the right
type of environment for themselves. If this were not so, every year would
find birds trying unsuccessfully to breed in all sorts of unsuitable places.
This recognition of an environmental type may be very largely the result
of experience, but it is in line with the modern concepts of instinctive be-
havior to assume that there may be an innate hereditary, primarily visual
recognition of the right type of environment."

The valence of certain components of the bird's visual world hinges on
time and condition. Thus the Mallard drake on his breeding territory dis-
tinguishes between migrant Mallard pairs passing overhead and resident
pairs that threaten to alight on his domain. The former draw no response
from him, but the intruders are driven away. He is aware of behavior
differences by which sexual intruders are distinguished from passing mi-
grants of the same species. Perception of these differences depends upon
the drake's position in the sexual cycle. A few days earlier he was a gregari-
ous being and perceived all Mallards as companions; a few weeks later this
will be true of him again.

As we watch a gathering of spring transients at the edge of the ice on
Cadham Bay, we notice two Canvasback drakes that go about their busi-
ness without paying the slightest attention to the females of close-by pairs
of Canvasback. But suddenly a hen of their kind, followed by three drakes,
alights. Immediately the unattached males join this courting group. Here is
selection and rejection hinging on physiological condition. The unmated
drakes ignore the paired hens but pursue the single female. The mated
drakes disregard the single hen to remain at the sides of their own mates.
Every sexually active duck accepts or rejects those of its companions which
its sexual status directs it to acknowledge or ignore. This calls for sharp
awareness of behavior. The lone drake must perceive the difference in be-
havior between a mated and an unmated hen. The Mallard must distinguish

40

I^v- %v..

*^ ^

*iStf.*

V^ ^y S ^ V5*~^"'^^S

"^H

^'s

^«^a

Mallard drake rising to defend his pond

behavior differences between the sexual intruder and the uninterested mi-
grant. Surely such physiological influence governs our own human aware-
ness of companions. The youth of twenty years perceives certain charac-
teristics in a girl of his own age of which the lad of ten is not aware.

Against this sharp awareness in the spring, let us compare the behavior
of autumn. When hunting far afield I seldom carry bulky decoys. I use the
first birds bagged, arranging them in the shallows or on the stubble with
their necks held up with willow wands. Even at a distance of one hundred
yards or more a man can detect the counterfeit. I wait with confidence,
however, and if it is a day for gunning, it is not long before some duck has

41

TRAVELS OF WATERFOWL

come to this stool. I (and many other hunters) have resorted to methods
even cruder than this. On the lakeshore I have formed duck-sized mounds
of sand in the shallow water. The sand is too soft to be arranged in true
duck form: these are merely small oval mounds placed in loose formation
with most of them pointing into the wind. This fools no duck in daylight;
but in the same evening light in which the spring drake distinguishes an
intruder from a migrant, I have seen autumn Mallards swing in close to my
sand decoys and even alight amongst them. Where the Lesser Snow and Blue
Geese fly in autumn, hunters often bring them into gun range with news-
papers or white rags tied to little sticks arranged in flock formation.

Lorenz (1937:247) found that his tame but free-living Jackdaws would
attack him furiously when he carried a black bathing suit in his hand and
that "anything glistening black and dangling, carried by any living creature
would release the very same reaction in the Jackdaws. ... In a bird that
readily recognizes and discriminates fellow-members of the flock, it is
rather surprising that the process of releasing the social defending reaction
so closely resembles that which elicits the responses of lower organisms.
... An instinctive reaction of survival value, when directed exclusively to
a particular object, may be released as if through a surprisingly small choice
among the large number of stimuli normally emanating from the object."
The white of small rags arranged in flock formation is sufficient to release
the gathering behavior in traveling Blue and Lesser Snow Geese, bringing
them within range of hunters' guns. The white of the rags is a "key-stimu-
lus"; and all such colors or plumage patterns, structures or actions, that
draw responses from social companions, Lorenz ( 1937 ) has termed releasers
(Ausloser). (See also Baerends, 1950 ; Tinbergen, 1951.)

It is very interesting that the female Pintail, which distinguishes her
drake from all other males, does not perceive differences between her own
eggs and stones or wooden eggs placed in her nest (Farley , 1939:57; Sowls,
1955:103). Even though the stones are seen several times a day, the hen con-
tinues to incubate, satisfied with the "feel" of the small rocks under her breast.
Perception of the visual world may be conditioned by learning and ex-
perience. The Mallard drake has an innate awareness of certain sexual ac-
tions of the Mallard female, but he must learn the identity of his own sexual
partner. The duckling must learn its parent. The female may be innately
attracted to a certain type of nesting cover but she learns to find the place
of her nest. I believe that each duck learns to perceive characteristics in the
landscape as guides to orientation. The large meadow meets the innate nest-

42

THE VISUAL WORLD

ing requirements of many Pintail hens, yet each must perceive variations in
the monotonous pattern that direct her to her own nest site. Laven ( 1949 )
carried out an interesting experiment in nest-perception in the Ringed
Plover. This little shore bird nests on open beaches. When one encounters
a pair, it may be an hour or more before the nest can be located, even
though it is "in plain sight" close by. If we let our eyes stray from the nest
after it is found, it may be several minutes before the eggs are relocated,
so closely do they resemble their background. Laven removed eggs from
a nest, then obliterated the cavity and tracks nearby. Even so, the birds
found the site without difficulty. But when he changed the nature of the
environment to a distance of three meters around the nest by leveling it
off, the plovers were disoriented. They must have followed visual cues pre-
sented by the whole of the local landscape. I presume this applies to nesting
ducks, for even when the nesting cover has been removed by fire or mow-
ing, I have seen hens return to their nests, guided there, probably, by cues
presented by the landscape patterns beyond the immediate vicinity of the
nest.

Canada Geese are interesting subjects to study because they are so re-
sponsive in voice as well as in action. The flock of Canada Geese at Delta
is, so to speak, a part of the little community. The birds live but a few yards
from our homes and offices ; we watch them, as they watch us, many hours
a day. Our normal human activities are accepted without "comment" by the
geese. When I walk past the pen they do not seem to notice me; but when
I pick up a large box from the truck and carry it on my shoulders to the
hatchery, the geese lift their heads high, and give voice as evidence of their
awareness of something new. One brisk September afternoon I noticed the
birds suddenly alert, all looking toward my house, many of them uttering
the gutteral notes of disturbance. In the first autumn chill my son Albert
had donned his new red, white, and blue hockey sweater which he had
never worn before. Here, suddenly, was a bright, strange thing against the
landscape. The geese noticed it immediately. They watched for several
minutes, then resumed their feeding, never again to react to the sweater.

Where, as with geese lifting their heads to a man carrying a box, there
is a sharp response to the object seen, the valence of the object is established
by the birds' behavior. Indeed, it is only by the birds' action that we can
measure and study their awareness of the components of their environment
But action surely is not the only criterion of awareness. For example, I step
from the hatchery to the pond side where the geese are resting and not

43

TRAVELS OF WATERFOWL
one moves. A moment later a stranger steps out and the geese lift then-
heads to acknowledge his entry. If I walk toward them they hold their
ground; if the stranger approaches, they retreat. They respond directly to
the stranger, but they are aware of me and their very lack of action is evi-
dence of this. On the pasture I have often stood among the cattle during
the evening stubble flight. The ducks come low over the grazing beasts, but
flare upward when they pass over me. In their action they acknowledge me
as an enemy even though I have not moved; but their lack of response to
the cattle surely cannot be evidence that they do not perceive these animals
as harmless components of the scene.

Watching the daily travels of waterfowl, we see them moving in a famil-
iar environment. It is clear that each bird recognizes the various aspects of
its range — the nesting meadow, the slough, the Station pond, the edge of
Cadham Bay. We see them approach these from different directions, travel-
ing by different routes as the wind varies. They must perceive the parts of
their range as familiar from many visual aspects. Yet the home range of a
duck, I suspect, is not made up of so many discrete objects or landmarks;
the bird probably reacts to the whole of its familiar visual world.

Various portions of the range may have valence according to time and
condition, the nesting meadow, the sand bar, the slough each being per-
ceived according to the individual's physical requirements for these places.
In local travel only proximate patterns have valency. In the flight to stubble
much more of the landscape may be important to orientation. In long travels
and in migration, the sun or sky-brightness, cloud formations, or (at night)
the moon and other heavenly bodies may be perceived, not as discrete
guides, but as parts of the whole. When a duck has become lost, however,
as in a storm or in a flight over unfamiliar terrain, one isolated part of the
visual world may then have valence. Thus a duck flying over strange, dry
prairie responds abruptly to the shimmer of sun on water; a goose flying
over unbroken forest reacts directly to the silver streak of a river interrupt-
ing the solid green of spruce. Then, perhaps, the relation between the bird
and one single part of the environment is of much the same order as the
mechanism of the social releaser. And just as the response to the social re-
leaser may lead to error (as Snow Geese joining white rags), the bird often
errs in its response to single parts of the environment. Each year many water
birds alight on wet roads. Ducks and geese are able to take wing after dis-
covery of their mistake, but annually large numbers of loons and grebes
are stranded where they have alighted on highways far from water.

44

THE VISUAL WORLD

In our study of avian perception we are in much the same position as
the blind men examining the elephant. The whole of the truth cannot be
understood by study, however careful and complete, of the parts. To the
laboratory student studying the releaser mechanisms, the breadth of per-
ception of birds seems very limited indeed, whereas to the field observer
the birds' familiar response to the whole of the wide visual field may be
overwhelmingly impressive. What we must do is to continue the controlled
studies of isolated parts of the visual world. Controlled studies of social re-
lations have developed rather widely during the past twenty years; but it
has not been until recently, as in the pioneering studies of Kramer ( 1951,
1952) and Matthews (1951a, b; 1952), that responses to individual compo-
nents of the physical environment have been examined. And then, along
with these controlled experiments, we must surely carry on with more field
studies, like those of Griffin ( 1952a, b ) , who watched the behavior of free-
flying experimental birds from an aircraft, and with more field work like
that of L. Tinbergen (1941), Deelder (1949), the Lacks (1949), Svardson
(1953), and others who study the behavior of wild birds in the very act of
traveling cross-country from one place to another.

45

"Memory is the vehicle of duration." Will Durant,
The Story of Philosophy

The Function of Memory

The ducks of the Delta Marsh move familiarly
within an environment they have learned. Some have been hatched there,
learning their place in ever increasing spans. Others have been reared else-
where, arriving at Delta in summer or fall. When flying from one place to
another for feed, rest, or grit, these residents travel over country that is
familiar through the experience of use; but no matter how broad or narrow
the local experience, there must always come a time for departure from the
northland. Some juveniles disperse from their natal range soon after taking
wing. After the midsummer molt, many males leave for other places. By
late August the southward migration is in full swing, with the Blue-winged
Teal leading the parade. Successive flights bring a constant turnover of ar-
rivals and departures until finally, when November ice covers the bays, all
waterfowl migrate southward. They are gone from Delta for five months.
Some, such as the Blue-winged Teal, are away even longer. Most bluewings
have left by the first week of October and they do not return until late
April, an absence of nearly seven months.

When spring brings these wildfowl back from the wintering grounds,
we know that many return to their old haunts. Sowls's study (1949) of
marked females leaves little doubt of the close tie between the breeding hen
and her nesting locality. Not only does she come back to her marsh, but fre-
quently to the same meadow where she had nested previously. Sowls (1955)
also showed how young females return home after their first migration.
Regional fidelity is further suggested in banding records such as those of
Sullivan (1953), who captured a Canvasback hen and brood at his lodge on
the Libau Marsh. Four years later a hunter shot the mother less than a mile
from the place of original capture. While many drakes do not make a direct
spring return to their native marsh, banding studies suggest that, after the
breeding period is ended, they often revisit familiar places.

46

THE FUNCTION OF MEMORY
Here is a continuity in learned behavior from one season to the next.
These waterfowl "pick up" the routine of their lives in a familiar environ-
ment despite an absence long in both time and space. Such continuity is
explained in terms of memory. Rowan (1931:81) remarks that "of the many
interesting facts brought out by bird banding, none is more striking than
the return of given individuals to the same nesting box year after year, in
some cases with thousands of miles of travel to their credit during the in-
tervening nine or ten months. That topographical memory is involved in a
feat of this nature seems more than likely." Lincoln (1950a: 29) speaks of
"retentive memories" in migrants; and many others working with bird
movements have explained the recognition of old haunts in terms of mem-
ory. Seldom, however, is the word defined ; each reader is free to make his
own individual judgment of a function he does not thoroughly understand
in himself, much less in birds. Gerard (1953:118) points out that "even to
identify memory, let alone explain it, is no simple matter. ... Is a film
a memory of light in chemicals and a tape recording a memory of sound in
magnetism? Is a library a memory of thought in books and a brain a memory
of thoughts in protoplasm?"

In developing this discussion, I feel obliged to digress briefly to consider
the function of memory in our own lives. To most of us the word implies
conscious recollection, the mental process whereby past experiences are
recalled to present awareness. When searching the past to give memory a
play, we readily call to mind many segments of personal history, such as
the plan of our first schoolroom, the old barn, the corner store. It is pos-
sible to recollect hundreds of places, incidents, and companions, retrieving
these from the near or distant past. In our doing so, the memory function is
accompanied by imagery; our mind's eye "sees" the shape of experiences
we recall. In careful examination of our past, however, we realize that the
recollective memory has its limitations. The total of our experience is not
remembered ; we know that much of the past cannot be brought to present
awareness at will.

This part of the personal life story not to be remembered at command
is, nevertheless, brought to awareness by certain related cues. When clean-
ing the attic I come across toys of childhood and suddenly remember some-
thing that could never have been recalled without my first discovering the
playthings. Seven years ago I ate a meal in a neighboring city where I was
in a restaurant not longer than thirty minutes. Afterward the place had no
importance in my life, never so much as entering my mind until I returned

47

TRAVELS OF WATERFOWL
to the city and went there for another meal. As I approached the building
I could but vaguely recall its gross details; then, as I stepped within the
door, I was suddenly in a familiar place. This was not a new or strange
room ; I had been there before. As my eyes wandered, many details I could
not have remembered a moment before were now familiar. The position of
the kitchen door, the rack of glasses, the mirror behind the pies were hardly
different in arrangement and pattern from those in many other restaurants
I have visited or in thousands I had never seen. Yet this room I experienced
briefly seven years ago was a familiar place.

As a lad of eight I spent a day at Estes Park where I caught my first trout.
My next trip there was thirty-two years later; and, while I could recall only
a few details of the place, I was able to find at once the very bend in the
stream where I had taken my first fish. On the road to Amaranth, Manitoba,
there is a whitewashed log cabin which is important to me only once a year.
On the first day of Prairie Chicken hunting, it is suddenly remembered be-
cause when it comes to view the next turn is to the favorite hunting grounds.
How vastly important is this continuity of personal history! Although mem-
ory cannot serve to bring all our life story to awareness, there is a retentive-
ness by which continuity is maintained, with the present always built on the
past, each new instant modified by earlier experiences.

Many trips might be taken over the same route until it is known "by
heart," the impressions deepened till more and more of the landscape is sub-
ject to conscious recollection. The point is, however, that one trip over a
trail is sufficient to render it familiar, even though memory does not func-
tion to recall the details to mind after the trip is completed. Nor, despite
the depth of impression resulting from many trips, will memory of the whole
route ever be at the call of the will. Few can remember all the details of
the route between the dining room table and the refrigerator in their own

THE FUNCTION OF MEMORY

homes, much less the wayside configurations in a trip of a hundred miles.
Yet we see the former daily, and the latter may be accomplished a second
time without the aic] of a map. "Mental states of every kind — sensations,
feelings, ideas — which were at one time present in consciousness and then
have disappeared from it, have not with their disappearance absolutely
ceased to exist. Although the inwardly-turned look may no longer be able
to find them, nevertheless they have not been utterly destroyed and an
nulled, but in a certain manner they continue to exist, stored up, so to speak,
in the memory" (Ebbinghaus, 1913).

I believe that these analogies with human experiences make for a better
understanding of memory in waterfowl. We speak here not of the recollec-
tive memory, but of the subconscious retentiveness which "is the basal fact
of life. All growth and development in an organism depends upon con-
tinuity. . . . The events of a life story would form no story, could have no
continuity, one with another, unless at every moment the past lived into the
present. But such continuity does not necessarily involve knowledge of
the past. ... In retentivenes, the past is continued into the present and
loses itself in making the present what it is" (Gulliksen, 1950). By some
process we do not understand, visual experiences become part of an or-
ganism, so that the sum total of its being is not only flesh and blood, bone
and nerve, but includes the memory traces of parts of the world that have
been seen and experienced and that always exist within.

The duckling has memory of its mother and distinguishes her from all
other females. You and I standing beside the pond cannot distinguish each
female of a kind with constant surety, yet the duckling still wearing the
egg-tooth directs its activities toward the one hen that is its parent. This
holds even when the mother returns after separation from her family. Hein-
roth (1911) showed that this recognition of the mother was not inborn;
the young are not innately attracted to their genetic parent. Young geese,
Heinroth observed, may become attached to the human caretaker who first
handled them, accepting this man as their parent. Ducklings hatched under
a domestic chicken recognize her as their mother. Thenceforward this
chicken to which they directed their first actions remains their mother,
even though they may be brought into association with females of their
own species; and they recognize their gallinaceous parent from all other
chickens. Lorenz (1935, 1937) called this mother-recognition "imprinting,"
pointing out that the young do not recognize their mother instinctively,
but must be conditioned to her. "Parents and young thus appear to inherit

49

TRAVELS OF WATERFOWL

a generalized ability to form a family association, the specific features of
which are not inherited" (Cushing and Ramsay, 1949:82).

Fabricius (1951), who studied imprinting in wild ducks, concluded
that "it is not possible to draw a sharp line between imprinting and ordinary
conditioning." Thorpe (1944:80) has proposed extending "the original
definition of imprinting to cover the possibility of attachment not to a living
object but to the immediate locality first perceived by the newly emerged
organism." I agree in principle with this suggestion, but the term itself, "im-
printing," is, I think, now so widely applied to the parent-child relationship
that the word can hardly be given a wider connotation without misunder-
standing.

Visual images of the surroundings as well as of the parent must be im-
pressed upon the young bird from the very beginning of its life story. In
the captive pens, ducklings become familiar with the arrangement of the
brooder enclosures within a few hours. Ducklings only a day or two old
move in an oriented manner about the complex pattern of the Station pond.
In the wild, ducklings may range widely with their parents ( Evans, 1951 ;
Dzubin, 1954), but there is evidence of an oriented use of the ponds and
sloughs in which they live. I have found parentless ducklings ranging on
the same part of the marsh throughout their growing period.

A remarkable evidence of retentiveness was shown in the behavior of
several captive-reared Pintails at Delta. In the days before the establish-
ment of captive ponds at Delta, juvenile hand-reared ducks were removed
eight or ten miles away, where they were given their freedom at the edge
of the lake or marsh. On three different occasions a young Pintail flew
home, where, on our return, we found it walking around the pen, trying
to enter the place where it had been reared. On one of these occasions there
were no birds in the pen ; hence the youngster could not have been guided
there by the voice of companions. Chance, I believe, directed these juve-
niles to fly west along the lakeshore, and they recognized their familiar home
as they passed by.

Manitoba's premier, the Honorable D. L. Campbell, told me of the ex-
perience of a friend, Wes Owens, who raised a brood of young Mallards
in the family farmyard. After taking wing, they gradually expanded their
range away from the farm, going out of sight to the wild country beyond.
But each night at dusk they returned to the domestic confines of their first
home. Peter Ward raised a Mallard female at Delta, giving it full-winged
freedom in midsummer. It soon disappeared from the local scene, but one

50

The decoy pipe at Delta. Recaptures of ducks banded here show how some individuals

return each year to the decoy pond, a familiar stopping place on their

path of migration, a place that must be held in memory

from one season to the next.

bitter day in late autumn it returned to the dooryard of its early days. For
these birds, the artificial environments of their first homes had been im-
pressed on their beings; their memories kept the traces of their natal ranges.
Despite the call of wilder places, they were faithful to the special locality
of earliest experience.

Many pages could be given to a recitation of the tie between the baby
bird and its natal environment. The home, whether in the wild marsh or
within the domestic realm of a farmyard or research station, is learned dur-
ing the early hours of life. This tie to the home must be nearly as strong as
the bond to the parent. I suspect that the imprinting which Lorenz saw so
clearly in the relationship between the baby bird and its parent must be a
process similar to that of the retention we have been discussing. Visual
experiences with parent and environment are impressed upon the being of
the young bird; thus begins a retentiveness upon which the continuity of
life depends. Since responses between companions ( as between mother and

51

TRAVELS OF WATERFOWL

child) are much more sharply defined than responses to the environment, it
is quite reasonable that Lorenz should first have described this process in
the parent-child tie. But surely, as Thorpe declares, this process of rapid
learning relates the infant to its environment in the same manner that it
conditions it to its mother.

I suggest further that this recording of visual perceptions is not limited
to early life but is a constant and life-lasting process relating the bird to its
world. The retention of visual experiences is the key to life's continuity, by
which the past is ever related to the present. Each hour and day of life the
visual experiences of the present create the past upon which the future de-
pends. Through the traces it has left on the memory, a landscape seen only
briefly is familiar after an absence, whether it be the natal slough or a stop-
ping place on the wayside of migration. The function of memory might be
likened to a reel of movie film. The memory, like the film, records images in
individual segments to make up the continuous whole. New records are
made as the bird pioneers into new regions. Then, as a duck flies over a
countryside it has visited before, the pattern of the landscape, as seen each
instant, is familiar. Once out of sight, the scene is stored away to be recalled
only by the next trip over the same place. As in the movie, the landscape
meeting the eye at the present instant has meaning only in the context of
the familiar scenes that have just been viewed. The present becomes the
past the moment it is seen.

Here in my hand is a Baldpate hen, trapped on our Decoy where she was
banded last fall. She is a spring migrant lingering briefly at a familiar stop-
ping place on the way to her home. And what of her mate? She distinguishes
him from all males of the kind, and the two join on the pond after she is
free from my hand. This process of retention must go on through all the
days of life, ending only when life itself comes to a close. We measure its
strength when we watch the response of the duckling to its mother or when
we record the return of a bird to the nesting place ; but it must hold that in
all periods of the life history, each individual lives efficiently in the present
because of its link with the past.

So far I have spoken of the visual world, but we must not forget physical
experiences that are perceived not only by the eye, but by other senses as
well. For example, the catching of a duck is felt as well as seen. The two
objects related to catching are man and hand-net. When I walk about the
pen, my simple presence evokes no response from the ducks and geese. Nor
do they react to the net which hangs on the wall. Even when I stand close

52

THE FUNCTION OF MEMORY

to the net, there is no response. But when I grasp the net in my hands, the
birds scurry away and shortly are safe in the center of the pond. Nearby is a
bucket I have forgotten while I work at the Decoy. Neither I nor the bucket
draws any response from the ducks ; but the instant I step over to pick it up,
the birds walk toward me or to the corner of the pond where they usually
are fed. Here are sharp associations. Man plus net equals catching experi-
ence; man plus bucket equals food. The two objects must be acting together
to draw responses, being neutral features of the landscape when isolated
from each other.

I have considered only the relation between the past and the present
in the continuity of a waterfowl's life. There is evidence of deliberate ac-
tions which, although hinged to the past, are aimed at the future. An ex-
ample is the behavior of our Whistling Swans, old "pensioners" that live at
Delta because shot wounds will not permit them to take wing. Their hearts
are wild, and when spring or autumn winds blow, they become restless.
Again and again, sometimes for more than an hour, they race across the
pond in frantic, futile attempts to reach the freedom that calls. In this ac-
tion, a swan walks deliberately to the downwind end of the pond, faces into
the wind, utters the pre-flight call of all Whistling Swans, then starts his
race across the water. The destination is the far shore. This attained, he
flaps his wings, preens for a moment, then walks back to the south end of
the pond. It seems to me that when he goes toward the downwind edge of
the pond, all his past experiences press him to the place where he will start
his flight run. Moreover, he not only selects the downwind position, but
many times I have watched these great birds choose the exact point on the
shore that will give them the longest run across the water, just as the pilot
of an aircraft measures Cadham Bay for his take-off. A difference of a few
feet at the start means several more yards for the run, and the birds invari-
ably stand where they face the widest stretch of water. Thus, so it seems,
past take-off experiences direct the swan to the point opposite the longest
span of water where the flight run will take place.

To carry this point further, let us examine the behavior of a nesting
duck. She sits on her loafing spot, from which one of several inner stimuli
may bend her to move to a special destination. She may fly to her source
of grit on the lakeshore, to a choice feeding place in a neighboring slough,
or to her nest in the meadow. The impending movement will be in response
to the stimuli from a gritless gizzard, an empty crop, or a full-formed egg
in the oviduct. She has no control over these stimuli; she can only respond

53

TRAVELS OF WATERFOWL

to their respective urges. She must direct this response to the proper destina-
tion: lakeshore, slough, or meadow. Since (as holds for some hens on their
loafing places ) she cannot see any of these destinations, it must be assumed
that when she directs her movement toward the proper goal, she does so
on the basis of past experience. Her destination is not in sight, but her flight
goes in the proper way. Past experience guides present action to carry her
to the unseen future. Without such preselection she could not move pre-
cisely, as we see she does, to the goal the inner stimuli direct her to attain.
All three destinations are familiar places, but none can exist to her in the
present because each place is beyond eyesight. Thus there must be a flow
of continuity not only from the past to the present but projected into the
immediate future.

The same continuity of action from the past into the future may be seen
in Mallards flighting to stubble. When they depart from the lakeshore at
dawn, the path of their travel from the very beginning leads them to a par-
ticular destination which must have been selected when the journey began.
The field is a prospective factor for these birds ; physically it can exist only
in their future because it is several miles beyond their eyesight, hence the
field cannot be a part of their present. Yet somehow the place lives in these
Mallards' present at the time of departure, or how else could they make the
direct and orderly journey? Retentiveness gives duration to life, "the con-
tinuous progress of the past which gnaws into the future" (Bergson, 1911a).

Once more we come to that indefinite boundary between science and
philosophy. Lashley (1950) points out that in the three hundred years
since Descartes's attempt to explain memory in terms of the action of the
brain "much has been learned concerning the nature of the impulses trans-
mitted by nerves. Innumerable studies have defined conditions under which
learning is facilitated or retarded, but, in spite of such progress, we seem
little nearer to an understanding of the memory trace than was Descartes."
Somehow, quite beyond our understanding, there are within and as a part of
each bird all the phases of its life story : the places and the companions near
and distant both in time and in space, its mother, its first home, its mate,
its nest, its home range and territory, its molting place, its wintering area.
However alike two ducks may be in their physical structure, however simi-
lar may be the innate behavior of one duck to that of its specific compan-
ions, each individual bird is different from all others of its kind by virtue
of its unique experiences.

54

"In the marsh, long windy waves surge across the
grassy sloughs, beat against the far willows. A tree
tries to argue, bare limbs waving, but there is no
detaining the wind." Aldo Leopold, A Sand County
Almanac.

The Aerial Environment

1he aerial environment is the medium of trans-
portation to ranges far and near, a haven in the face of enemies, the source
of companions. The sky is the realm of weather, the place of sun and moon,
a shroud of darkness, the home of the wind.

On land or water the duck is ever aware of air as a force. It obeys the
pressure of the moving air mass by facing the wind. Ducks napping on the
Station pond are sensitive to the wind's strength and must paddle with the
feet, even as they repose, to keep from being blown ashore. Geese sleeping
on the beach all have their breasts aimed at the wind. They are "weather-
cocking," to borrow an airman's term; the natural streamlining of then-
bodies offers the least resistance when they face into the wind like weather-
vanes. All wildfowlers know the relation between ducks and the lee on
windy days. Here the decoy hunter sets his rig, the jump shooter plies his
canoe; this is where one finds waterfowl in a storm. No wildfowler com-
mits himself to a plan by the evening fireside; he awaits the dawn, when
his first act is to test the wind, his guide to location for hide and rig. The
finest of all shooting places in a south blow is worthless for gunning when
the wind comes from the west.

The duck is always sensitive to the wind when taking off and alighting;
it must face the air stream at start and finish of flight. Several times in nar-
row channels I have forced ducks to take off downwind; each time the bird
stalled, its initial thrust being insufficient to make it airborne. Edgar M.
Queeny's superb photographs (1947) of waterfowl in flight tell us much of
the bird's relation to its aerial environment, his high-speed camera revealing
secrets never detected by the unaided eye. His photographs of a Mallard

55

drake crash-landing with back to wind give eloquent testimony to the im-
portance of obeying the fundamental rules of aerial maneuver.

Once airborne, all physical contact with the earth is lost and the bird
no longer has any bodily sensation of the speed or direction of the wind. An
awareness of the air flow depends on a visual reference to the earth. In
short, the bird, like the human pilot, must appraise the speed and direction
of the air mass in which it travels by perceiving the relation between its
own movement and the earth below. The duck turning upwind to a gun-
ner's rig sets its course, not by feeling the wind, but by obeying visual cues
it perceives in the marsh below.

This problem of wind-perception by flying birds has been a matter of
considerable confusion for many groundling ornithologists who believe that
the bird is sensitive to the wind pressure as this may be felt or the feathers
ruffled on the windward side of the body. Lewis (1939b: 22) explains that
once the bird is on the wing it is "supported by the stream of air surrounding
it and has no solid attachment to anything. It cannot then apprehend the
direction of the wind by any pressure of the latter against its body, for, aside
from the possible effect of turbulence, the air pressure against its body
would be the same on all sides if the bird allowed itself to be swept along
as an inert object in the air current. By^its own efforts in flying ahead
through the surrounding air, the bird causes increased pressure against its
forward side, but this result is obtained indifferently and to the same extent
whether the bird directs its flight with, or against, or across a uniform
stream of air. Except under unusual circumstances, the flying bird therefore
presumably has no awareness of the direction or the velocity of the wind or
of the direction or velocity of its own movement in relation to the surface
of the earth or in relation to the direction or velocity of the wind unless it
can perceive some fixed points on the earth or, for knowledge of direction but

56

THE AERIAL ENVIRONMENT

not of velocity, some recognizable heavenly body or bodies. It may also be
presumed that it usually has such awareness as a result of seeing the surface
of the earth." Acworth (1946:28) says that to a bird in flight "there is no
such thing as 'wind/ the bird being, in fact, in a dead calm so far as pressure
is concerned."

This is the stand of airmen, based not on theory, but on the personal
experience of flight. "The space in which the pilot flies is not the abstract
space of theories, nor the lines and figures of the stereoscope, nor the space
of the usual laboratory apparatus for studying depth perception. It does
not consist of objects at varying empty distances. It consists chiefly of one
basic object, a continuous surface of fundamental importance — the ground.
A pilot who cannot see the ground or sea is apt to lose touch with reality in
his flying" (Gibson, 1950:59). Without the aid of instruments and without
visual reference to the earth, a pilot is unable to judge the direction or the
force of the wind and quickly loses geographical orientation. A complaint
might be placed against this analogy on the ground that the airman is en-
closed within his craft, protected from the air. The objection, however, does
not hold on a physical basis; the inability of the pilot to judge the wind
aloft may be tested in an open cockpit or by having him thrust his arm into
the air stream. With a constant air speed, variations in the direction or the
velocity of the wind cannot be perceived, regardless of the craft's relation
to the wind.

The speed of the bird's movement over the ground, the ground speed,
depends upon the force and direction of the wind relative to the velocity
and direction of flight. When a Mallard (or an aircraft) flies 45 miles per
hour in still air, its ground speed and its air speed are exactly the same. Its
ground speed is reduced when it moves against the wind, so that with a
45 m.p.h. air speed, the ground speed is 30 m.p.h. when the bird flies di-
rectly into a 15 m.p.h. wind. Against a 30 m.p.h. wind its ground speed is
reduced to 15 m.p.h. With a 15 m.p.h. wind directly on its tail, this Mallard's
ground speed is increased to 60 m.p.h. Air speeds of 65 to 70 m.p.h. have
been recorded for ducks (Cooke, 1937) ; and with tail winds of 30 to 40
m.p.h., which sometimes occur during periods of late-autumn migration,
waterfowl are able to progress over the ground at speeds better than 100
m.p.h. as indeed we have observed them at Delta in October and November
passages.

Very often the goal of travel is not precisely with or against the wind,
the duck meeting a quartering or beam flow of air. The bird must then com-

57

Figure 5. The "calculated course." The bird travels along the shore line, but to hold

this course it must face away from the line of flight into the wind. The slower

its air speed, the more nearly the bird must face into the wind.

pensate for the angular force of the wind to obtain its objective. When
ducks fly westward along the lakeshore, for example, and the wind is blow-
ing from the northwest, the birds do not point like arrows in the direction
of their movement over the ground; their bodies aim into the northwest,
away from the shore and into the wind. Airmen call this "crabbing," a com-
mon and essential technique in human flight. The course of the bird is set
by its eyes, thus demanding the bodily adjustment to the force of the wind.
The degree to which the bird must face into the wind depends on the air
speed of the bird and the velocity of the wind according to the "triangle
of velocities" (Allen, 1939; Smith, 1945; Jack, 1953) (Figure 5). This pat-
tern of flight is seen most frequently where waterfowl follow a shoreline or
a river or stream, but I have seen high-flying stubble Mallards "crabbing"
on an overland route to the fields.

Another technique for adjusting to the wind is the "duffer's" course
(Smith, 1945:155), where the bird aims its body continually at its destina-
tion without regard to the overland path required to reach its objective
(Figure 6). This technique is most frequently observed where birds are
moving short distances and where the terrain is very broken. Smith (1945)
speaks of starlings flying in a series of duffer's curves from one landmark

58

Figure 6. The "duffer's course."
Here the bird aims its body always
toward the objective. Flight path
"A" shows the duffer's course when
a bird with a 40 m.p.h. air speed
flies against a quartering wind of
28 m.p.h. In flight path "B" the
bird crosses a 28 m.p.h. wind, while
in flight path "C" the bird is fa-
vored by a 28 m.p.h. wind quar-
tering from behind. The birds shown
on each of the flight paths have
flown an equal time interval, the
bird of flight path "C" having nearly
reached its objective, the bird of
flight path "A" having gone only
a third of the way. With no wind
at all, the flight path would be a
straight line from start to finish.

to the next in cross-country travel. At Delta I have seen this not only in
blackbirds, but in Blue-winged Teal flying along the edge of Cadham Bay
in a series of curves from one point of reeds to the next. One sees ducks
following the duffer's course when they come in to the decoys, and this
technique is often used in making landings either on water or ashore. When
a bird has been flying with the wind from behind, it frequently adopts the
duffer's course as it turns to make its landing into the wind.

When the speed of the wind is greater than a bird's air speed, forward
motion over the ground is impossible. More than once I have seen Mallards
hanging for several seconds in mid-air when meeting the strong lake breeze
pouring into the mouth of the Delta channel. I have watched Canada Geese

59

TRAVELS OF WATERFOWL

moving to stubble against heavy wind at a ground speed of only 4 m.p.h.
In the face of winds that approach their air speed, ducks and geese may re-
main grounded in sheltered situations, and several times in periods of strong
south winds I have known Mallards to forego their afternoon feeding flight.
Often, however, these stubble birds ride the north wind for a quick trip to
the fields, then are required to "inch" their way back to the marsh after
their meal. It is common knowledge amongst gunners that waterfowl mov-
ing against a strong wind fly much closer to the ground than usual. I once
met Mallards flying against a 40 m.p.h. wind only ten or fifteen feet above
the ground, some birds dropping almost to the field. It is known that ground
friction reduces the speed of the wind near the earth's surface, and it is
reasonable to assume that the low-flying birds seek the slower currents of
low altitude.

The flow of the air over the earth is not without variation; hence there
are frequent changes in the relation of the bird to the air mass in which it
travels. Because of hills and valleys, buildings, trees and other obstacles, and
also because of differential warming of the land, as between lake and shore
or plowed field and cropland, the constant flow of the wind is often inter-
rupted by eddies and gusts. "Such gusts of wind are often sudden and vio-
lent and it is sometimes true that birds near the earth's surface do, for a
fraction of a second, get struck by a gust with a consequent lifting of feath-
ers. But the inertia of a bird is so low that it almost instantly assumes the
velocity of the gust and is once more in a dead calm" (Smith, 1945:154).
This feather-lifting, of course, may occur on the top of the wing and the
back when a bird slows its flight close to the point of stalling. Then "the air
flow no longer follows the contour of the wing's upper surface, and a con-
dition known as 'flow separation' has taken place. When this occurs, a
partial vacuum on the upper wing surface results and the coverts are
pushed out of place by a reversed air flow rushing over the area" ( Queeny,
1947:108). We may have visual evidence of gusts, as where ducks cross the
lake ridge to rise abruptly in the face of the updraft over the shore. Wood-
cock (1940) tells how gulls at sea search for convection eddies and when
found "one sees them change abruptly from a wing-flapping horizontal
flight to a steep climb." Human beings experience this effect of turbulence
when traveling in an aircraft. The passenger perceives the plane's entrance
into a rising column of air as a "bump," but this awareness of the new air
mass is fleeting, lasting only for that instant when the shift is made from one
air mass to the other.

60

A descending Canvasback

Waterfowl sometimes encounter difficult navigational problems when
flying with a strong tail wind. I have seen Lesser Scaup arrive with a north
wind on Cadham Bay, then swing around to join a flock of birds on the
water. In making the swing they were carried so far south of the flock that
they alighted many yards short of their objective. Several times our young
Canada Geese have crashed into trees on the lakeshore when coming off the
lake in a strong northwest wind. They apparently were unable to judge their
speed accurately enough to maneuver over the trees in time to prevent an
accident. Sometimes in late autumn when the last open hole is closed to the
reeds and the wind blows strongly shoreward, ducks are obliged to land
with the wind to their backs, and after circling the pond several times, they
come down to crash with heavy splashes or to slide across the ice on then-
tails.

When a duck makes a landing under unstable air conditions, the body
may be shifted rapidly into many positions and the feet thrown wide for
balance as the bird maneuvers downward; but the head holds its position
steady with the horizon, as if the neck were the pivot upon which the body
swung. This steadiness of the head must be of tremendous importance to
a bird's safe arrival from flight, especially in landings made under turbulent
conditions or in wooded places. While this stability of the head, regardless
of body posture, no doubt serves the visual process during flight, it does not
result from the function of the eyes — that is to say, visual orientation alone
is not responsible for this balance. Thus, when a duck or goose, or any other
bird, is blindfolded with a hood or mask, the body may be turned left or
right, up or down, but the head remains constantly oriented to gravity, hold-

61

Figure 7. The Carrick blindfold. Made of
light, opaque paper. The size and shape
vary according to the species.

ing steady posture. In short, the duck does not need to see its surroundings
in order to keep the balanced position of its head.

Not only is the blindfolded bird able to balance its head when held in
the hand, but when it is cast into the air, body and head quickly assume the
posture of flight. Like a cat falling with its feet to the ground, the blind-
folded bird quickly adjusts to its belly-down flight attitude when cast aloft.
A blindfolded Blue-winged Teal, or any other duck, when thrown into the
air with tail or belly upward, twists in a flash to flight posture and flies away.
In experiments designed by William H. Carrick (1949) we flew 249 blind-
folded birds of eighteen species at Delta between 1946 and 1952 (Figure
7).° Regardless of how these blindfolded birds were cast into the air, suc-
cessful flight was the rule rather than the exception and only 5 per cent
refused to fly.

The ability of birds to right themselves and fly when they cannot see
their surroundings or the sun depends heavily upon the balancing function
of the vestibule of the ear with its semicircular canals and otolith organs
(Lowenstein, 1950; Wendt, 1951). Wendt points out, however, that muscle
receptors also play an important role in establishing body posture and "it is
not always easy to separate vestibular effects from other factors." Paton
(1928), who studied the equilibrium of the domestic Mallard, concluded
that "some visceral change is produced as a result of the disturbance of

• The species flown with blindfold were : Mallard, Pintail, Green-winged Teal, Blue-
winged Teal, Redhead, Marsh Hawk, Cooper's Hawk, Wilson's Snipe, Great Horned Owl,
Barn Swallow, Catbird, English Sparrow, Bronzed Grackle, Yellow-headed Blackbird, Red-
winged Blackbird, Cowbird, Song Sparrow, Crow.

62

THE AERIAL ENVIRONMENT

balance, and that this initiates the various compensatory movements." The
whole evolution of the bird, of course, has been toward aerial activity. In
this he has certain important advantages over the human pilot, whose her-
itage is that of man as a terrestrial being.

Once the eyes of the human pilot lose sight of the earth, the horizon, and
the sun, he can no longer hold his aircraft on a straight and level course.
In a cloud the pilot without instruments quickly becomes disoriented with
respect to the earth. Believing he is holding a level course, it is typical of
him unwittingly to let his craft move into a spiral turn.

Flight actions are inherent in the bird; man must learn to fly. More-
over, tie bird is the flight structure. A man airborne operates by remote
control the complex machine in which he sits but of which he is not a part.
In bird and aircraft, pressures produce the same forces and stresses upon
the flight structure. In the bird, however, every feather springs from a nerve
ending, and each flight feather is subjected to varying pressures. Hence the
most minute changes in balance create stresses that the bird must per-
ceive much more intimately than the human pilot who is in touch with his
plane only through the stick in his hands, the rudder pedals at his feet and
the "seat of his pants."

The human pilot is committed to operate his airplane as it was con-
ceived by its designer, while a bird may alter its flight structure in a flash
as occasion demands. For instance, in both plane and bird stability is closely
related to the dihedral angle* of the wing; as this angle is raised, stability is
increased. The dihedral is an unalterable feature of the aircraft's design
over which the pilot has no control; but the Mallard descending to a
wooded pond, or a blindfolded sparrow, may alter wing angle at will. More-
over, modern aircraft, although they may be stable in the vertical, longi-
tudinal, and lateral axes, are normally designed to be spirally unstable. Such
spiral instability is planned for the comfort of pilot and passenger ;f but
left to itself, such a plane will eventually fly in an ever tightening spiral
with a resultant loss in altitude. Thus a human pilot, when confronted with
the problem of flying without reference to the horizon ( and lacking instru-
ments), must overcome severe handicaps that do not obtain with birds, and
it is not entirely fair to make direct comparisons between a blindfolded bird

• The angle at which each side of a wing inclines upward or downward from the hori-
zontal.

t The reason that airplanes are not designed to be spirally stable is that such aircraft are
very uncomfortable for the passenger, developing lateral oscillations in rough air which the
human stomach is incapable of tolerating (G. S. Trimble, Jr.; letter).

63

TRAVELS OF WATERFOWL

and a blind-flying pilot in a standard aircraft. Aerodynamically it is possible
to design an airplane spirally stable with high wing dihedral which, like the
blindfolded bird, will stay right side up relative to the earth for an indef-
inite period of flight. By such design, free-flying model aircraft carry suc-
cessful flight, quite obviously without sensory control.

Just as birds, unlike aircraft, can alter their structural design to increase
stability, so, too, their flight structure may instantly achieve a reduction in
stability — an advantage, J. M. Smith says (1953:69), "provided there is a
parallel increase in the efficiency of control. This can be seen by analogy
with aeroplanes. Transport aeroplanes are normally designed with a fairly
high degree of stability since safety in steady flight is of greater importance
than manoeuvrability. In fighter aircraft, however, manoeuvrability is of
first importance, and the stability margin is usually reduced to a minimum."
Such control, Smith points out, is greatest in the higher orders of birds
where sensory awareness of balance may be more important than structural
stability. This variation in inherent structural stability and sensory control
may be seen when we compare a loon or a grebe with a Mallard or a Duck
Hawk. The loon and grebe, like an arrow sped from its bow, are stable only
at a certain velocity; but the Mallard and Duck Hawk are able to shift in
a flash from transport-like stability to fighter-plane maneuverability. That
a bird is able to compensate for changes in flight structure was shown by a
blindfolded Yellow-headed Blackbird which flew 400 yards, then made a
successfully gende landing even though it had lost all its tail feathers.

The "thumb," or winglet, of the bird and the leading edge wing slot in
some aircraft are structures that increase stability at low speeds, and thus
inhibit stalling, "A bird's winglets he closely against the leading edges of
its wings in cruising flight when the wings have a low angle of attack. In
fact, they form a part of this neatly rounded edge. But they are usually
raised when turning, pitching, and landing, and they are often raised when
climbing. To describe this action of the winglet, one might almost use
Ludington's words describing the action of an airplane's wing slot — 'it
opens automatically as the angle of attack passes a certain point' " ( Queeny,
1947:106).

In the observations made at Delta, hooded birds were given their free-
dom by being tossed upward into the air. If there was a wind, the bird
usually faced into the air stream the moment it began flight, and this initial
adjustment was accomplished regardless of the bird's position relative to
the wind when it was cast aloft. This orientation was but momentary, how-

64

ever; the bird faced into the air flow for only an instant, then turned to fly
in another direction, usually downwind. It appeared that the impetus of
the upthrust into the air was a reference by which the bird made its orien-
tation into the wind, for it was only at this starting instant that the hooded
birds seemed truly sensible of a steady flow of air.

It was typical of the hooded bird to carry its flight downwind from the
starting place, and exceptions were few (Table 1).* In slow-flying birds,
like English Sparrows and Yellow-headed Blackbirds, this downwind drift
was usually in patterns of circles. After facing the wind for a moment, the
bird turned to swing around in a circle, and each complete turn was a leg
in the downwind shift, as indicated in Figure 8, A, C. The direction of this
circling was not constant ; on any given day some flew clockwise, others coun-
terclockwise. Several times when we flew the same bird twice, it circled to the
right on the first flight and to the left on the second.

In a breeze of less than 5 m.p.h. the circles were well formed and the
downwind progress was slow. With an increased wind velocity the flight
pattern showed a series of loops (Figure 8, D, E, F) rather than full circles,
and the downwind progress was more rapid. In flying these loops, the hooded
sparrow or blackbird seemed to hang in the air a moment on the upwind turn,
its ground speed reduced or, if the speed of the wind was the same as the
air speed of the bird, stopped completely. After a moment of hovering into
the wind, the bird continued with its circle. When the wind velocity was
greater than the air speed of the bird, it traveled backward over the ground
during the moment it faced the wind. In heavy winds the pattern of the

* Tables 1 and 2 include only the hooded flights which were made in 1950, '51, and '52.
From this point the discussion is based entirely on the results of these flights, for which com-
plete data were recorded. Although notes on behavior were made in all 249 flights, imperfect
recording techniques made it impossible to include the earlier experiments in Tables 1 and 2.

65

TRAVELS OF WATERFOWL

circle was reduced to a series of loops, the bird turning at intervals into the
air stream, then swinging around to fly swiftly downwind.

To the casual observer, this hesitation when the bird flew into the air
current appeared to be an awareness of the wind ; but when the pattern of
a hooded flight was timed and plotted on paper, it became apparent that the
into-wind reduction of ground speed was merely the variation in relative
motion due to the bird's position in the moving air mass. Its air speed was
constant around the flight circle, as was obvious in a calm. In each into-wind

Figure 8. Flight patterns of blindfolded birds

Ot/T OF ilCMT

100 ft. j «u.t — "■

A. Juvenile Yellow-headed Blackbird; wind 2 m.p.h.; flight lasted 55 seconds; bird
climbed to 100 feet.

B. Adult male Redhead; wind 5 m.p.h.; bird flew out of sight at elevation of about
300 feet.

C. Juvenile Yellow-headed Blackbird; wind 2 m.p.h.; flight lasted 50 seconds; bird
climbed to 100 feet.

fXcio Winj
Foa Am 1»wtant

D. Juvenile Yellow-headed Blackbird; wind 4-5 m.p.h.; bird climbed to about 200
feet and flew out of sight.

E. Juvenile English Sparrow; wind 20-25 m.p.h.; bird climbed to about 40 feet.

F. Juvenile male Green-winged Teal; wind 30-35 m.p.h.; elevation 50 feet; bird flew
out of sight.

Figure 8 continued

G. Juvenile Yellow-headed Blackbird; wind nil on ground behind trees, 15-20 m.p.h.
above tree level; bird climbed to about 150 feet and flew out of sight.
H. Adult male Pintail; wind 25 m.p.h.; bird flew at about 100 feet.
I. Juvenile Yellow-headed Blackbird; wind 15 m.p.h.; bird climbed to 150 feet.

leg of a circle, however, the ground speed was reduced by the force of the
wind, just as forward motion over the ground was increased by the air flow
in every downwind turn. The circles remained constant to the air mass, but
were distorted relative to the ground and to the observer, this distortion
being proportionate to the strength of the wind. This was shown in the
hooded flight of a juvenile Yellow-headed Blackbird set free behind the
shelter of trees where there was no wind at ground level. When released,
it flew in well-defined circles until it climbed above the trees, where it met
a 15 m.p.h. wind. Thenceforward its circling continued at the same rate, but
the flight pattern described a series of widely separated loops (Figure 8, G).
The circle was not invariably the pattern in all hooded tests. Some birds
adopted flights that varied widely from the true circle (Figure 8, H, I);
but these variations, though individually distinct, always followed a pattern
of curves that carried the bird downwind from the starting place. In the
swift-flying birds, like the ducks, the flight did not fit into the circling pat-
tern as frequently as in the smaller species. This may have been because
they so often and so quickly flew out of sight that the true shape of the
flight could not be judged. One Redhead made a clean circle a mile in
diameter before flying out of sight (Figure 8, B), and three hooded Green-

67

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winged Teal set free in a 25-30 m.p.h. wind made distinct into-wind loops
such as those characteristic of the sparrows ( Figure 8, F ) .

This downwind drift of the blindfolded birds finds an interesting analogy
in the behavior of the fry of Chum Salmon, Oncorhynchus keta, as described
by Hoar (1953). "Chum Salmon fry emerging from gravel of the lower
reaches of coastal streams swim vigorously into currents and maintain their
position during the day — even in quite rapid water. They are lively little
fish and do not behave in any way like floating plankton. ... As the light
intensity falls, rheotactic responses, which are to a large degree dependent
on vision, fail, and these fish pass downstream in shoals. The fact that such
mass movements occur during a rather precise period of the night is prob-
ably due to the dark adaptation of the eye and a period of night blindness.
It is not necessary to assume that fish transported in this way will move at
the same rate as floating objects. They are active fish and as they dart to
and fro will move most easily and farthest with the current, and will, at
night, go downstream rapidly until they can again see to maintain position
with respect to fixed objects." For the salmon fry in darkness or the bird
flying blindly, the total of any movement, regardless of whether the pattern
is circling or otherwise, must add up to a down-current drift when the
eyes cannot see some stable part of the environment.

Wing-stroke and other flight actions of the hooded birds varied accord-
ing to the species. In those, such as ducks, with a heavy wing load the beat
was rapid, strong, and deliberate. * Once a hooded duck was in flight, there
often was no characteristic of action distinguishing it from another flying
naturally with full sight. Such rapid travel was a necessity for these birds
if they were to remain aloft, just as the jet aircraft with its heavy wing load
must fly faster than the broad-winged "cub" type. In sparrows and others
with light wing loadings, there was a wide variation in flight action. Some
hooded blackbirds and sparrows flew in a natural manner; but many, es-
pecially among the English Sparrows, adopted a hovering flight like that
used by free-flying birds when alighting.

Most of the birds in these tests were young-of-the-year taken in banding
traps and flown shortly after their capture. Many of the English Sparrows
and Yellow-headed Blackbirds still showed the yellow gape as evidence of
their recent departure from the nest. I was able to detect no difference be-

* "Wing load" is the ratio between wing area and body weight. Poole (1938) has com-
puted wing loadings of many wild birds, showing, for example, that the English Sparrow has
a wing load of 3.78 centimeters per gram of body weight while the Blue-winged Teal has a
wing load of 1.10.

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THE AERIAL ENVIRONMENT

tween juveniles and adults in the hooded flights. Of twenty juvenile English
Sparrows flown in 1951 and 1952, none crashed and three remained on the
wing until they had circled out of sight (Table 2).

The hooded birds generally spiraled upward to a certain elevation, then
leveled off to continue the downwind movement at that height. The opti-
mum flying level was approximately the same for all birds of a species on
a given day, but there were specific differences ; for example, Yellow-headed
Blackbirds always flew higher than English Sparrows. The flight level was
lowest for the English Sparrow, which mounted from twenty to fifty feet,
depending on the strength of the wind. In stiff winds there seldom was a
stable flight level; the subjects often spiraled upward until lost to sight.
William Carrick has suggested that this flight level depends on ground
turbulence, the depth of such disturbance being shallower in light winds.

While these hooded birds were not able to orient their flight to the wind
when it blew without variation, they did show awareness of sudden, sharp
shifts in the air flow, as on a gusty day when they were met by a quick
change of wind from a new direction. The bird showed its awareness by
facing the gust. But, as after its initial thrust into the air, this moment of
orientation was fleeting and the circling flight was quickly resumed.

Although unable to orient to the wind, hooded birds, especially the
passerines, often responded skillfully to auditory cues. When hooded English
Sparrows were released near a clump of willows in which wild companions
chirped, they flew directly toward these voices without circling. A Red-
winged Blackbird released near trees where wind whistled in the branches
flew directly toward this grove, crashing therein. If we talked loudly during
a hooded flight or whistled or made other noises, the hooded birds often
faced abruptly in our direction.

Of birds which accomplished successful
flight, only 20 per cent of those we saw
come to earth descended with a hard crash.
Most of the birds either spiraled down
gently at a shallow angle, or "parachuted"
with hovering wings. If parachuting, the
bird showed its awareness of descent by
thrusting its legs forward in landing atti-

Figure 9. Direction of landings relative to the
wind as observed in 51 hooded flights, 1950

TRAVELS OF WATERFOWL

tude. When these hooded birds came to earth they gave further evidence
of their inability to perceive the wind's direction, for there was no into-wind
pattern of alighting. Their landings aimed at all points of the compass, re-
gardless of wind direction (Figure 9).

Here, then, is the successful accomplishment of blind flight. The water-
fowl and these other birds are inherently attuned to movement within their
medium. They are innately balanced in their aerial environment as fish are
in water. The wild bird, even as a juvenile, is able to remain aloft in flight
even though it cannot see the ground. But if the bird does not have visual
contact with the earth, it must lose its orientation with the wind when
traveling in a moving air mass and thus be displaced geographically without
awareness of this displacement.

72

"Time and space exist, only as far as things or events
fill them." Charles P. Steinmetz

6
Awareness of Time and Space

As waterfowl come and go from one part of
the marsh to another, there is a regularity in their daily travels. We men
have formed the habit of dividing the day into hours of the clock, but birds
have no such artificial regulator. The break of dawn is the beginning of the
waterfowl day. How well the hunter knows this! Dawn is the wildfowler's
joy. No matter how quiet the night or how calm the day that follows, morn-
ing twilight brings a flurry of activity to the marsh. Most precise are the
Mallards, which leave their shorelines for the stubble fields at the first hint
of day; throughout the autumn one may rise to greet this flight, to hear
overhead the wings that cannot be seen because the dome of sky is still in
darkness. This dawn flight comes out in one full sweep, and most of the
birds pass over within a few minutes after one hears the first whicker of
wings, each flock following the next so rapidly that they are seldom out of
one's earshot. As day unfolds, the movement dwindles. Now flocks are sev-
eral minutes apart; and finally there are none at all except the odd duck or
small band moving aimlessly, birds that were disturbed when they met guns
or tractors at the field of their choice. This lull lasts only twenty or thirty
minutes. Then, before the sun tops the horizon, some are returning to lake
or marsh, the silhouettes of their swollen necks giving evidence that they
have fed well. These returning wedges usually fly at a greater elevation
than on the outflight, and hunters who leave home at daybreak often believe
them to be of birds that have spent the night on the fields.

When skies are clear, stubble flights begin at nearly the same time every
dawn, about fifty minutes before sunrise in early October. Bossenmaier
(1953a) found that when the sky is overcast, the journey is not so early as
on bright mornings, the blanket of cloud delaying the threshold light which
is the cue sending the birds off to the fields. As the arrival of dawn is slightly

73

The Mallards finish their breakfast on the fields and return to the
marsh before the sun tops the horizon.

delayed each morning, so in the course of an autumn the morning flight is
deferred accordingly, and in October the passage to the fields starts more
than an hour later than in August.

Mallards must respond to the light of the sun. This is not remarkable,
but it is an important point in our understanding of waterfowl. Clearly they
are aware of the sun and act upon that awareness in a positive manner.
When Mallards shot in the dawn flight are examined, we find their gizzards
empty. These stubble birds are ready for food well ahead of dawn, but they
hold to their sand bars until the stain in the east is their signal to make away
to the fields.

After returning from stubble, Mallards loaf, preen, and find their grit,
then take their morning nap on lakeshore or mud bar. In the afternoon they
fly once more across the marsh to their second meal of the day. The be-
ginning of this afternoon passage is never so precise as that of dawn and is
more frequently modified by other influences. For example, I have never

74

AWARENESS OF TIME AND SPACE

known the wind to start the morning birds before the break of light, but
a noon wind usually sends the fowl to the fields earlier than they choose to
go on calm days. The afternoon flight continues longer, always lasting more
than an hour and frequently consuming several hours. After the first ducks
appear, there is a steady passage, so that on a heavily used flight line the
supply of birds sometimes seems inexhaustible from early afternoon until
sunset.

I suspect that the timing of the afternoon flight is related to metabolism.
Assuming that a Mallard takes its meal at the same time each morning, it
is reasonable to believe that hunger must be felt at about the same time
each afternoon. The ducks do not return to the fields while breakfast is still
heavy in their gizzards; but once digestion has progressed to the point of
hunger, this stimulus urges them to the prairies for a second meal. The wide
spread of the afternoon movement is further evidence, I believe, of the role
of hunger. In the dawn flight, all are pressed at about the same time by this
common urge. Once on their way, however, they are not equally successful
in taking their meal. Some find a close, safe, and abundant food supply,
then return quickly to the lake. Others are disturbed by hunters or by farm-
ing activity, and they must fly to a second or a third farm. All do not travel
the same distance to feed. It is plain that each band does not breakfast at
the same time ; hence, although the first are returning to their loafing bars
before sunup, others, not so fortunate, drift back to the lake all through the
forenoon. So it seems that these morning variations must cause the differ-
ences in the timing of the afternoon flights. Birds that come back from the
fields early are probably the first to go out in the afternoon.

The second passage moves in the full light of day. When the shooting
season arrives, however, ducks feeding in areas heavily hunted sometimes
delay their meal until dusk. South of the village of Delta, where there is
much gunning, I have found ducks waiting until sunset before venturing
to stubble. Several miles farther west, where the hunting pressure is less
severe, the birds feed earlier and return to the lake before sundown. The
Delta Mallards apparently shift from "gizzard" time to sun time.

I have spoken only of the Mallard, but of course the Pintail and a small
number of Black Ducks, mixed with the Mallards, make regular flights to
the stubble, following a schedule like that described for the "greenheads."

It seems clear that the timing of stubble flights follows two types of
cues : the metabolic cue and the solar cue. The former is measured by the
interval between the filling of the bird's crop and the first hunger. If food

75

TRAVELS OF WATERFOWL

is taken at the same time each morning and the post-feeding period daily
spent in the regular manner, the duck must receive stimuli from the diges-
tive tract directing it to its second meal at about the same hour each after-
noon. The metabolic cue is modified by the solar cue. In the timing of the
dawn flight, hunger is secondary to light. Crop and gizzard may be empty
some time before dawn, but the hungry bird awaits the light of day before
going to breakfast.

Among our captives there is a sharp awareness of time that seems to
obey the metabolic cue. They are fed at a given hour each day, but if for
some reason the feeding is delayed, they gather around the edge of the
pond awaiting their handout. Some of the geese walk to the granary at the
appointed hour.

Unlike the Mallards, Canada Geese often start out for the fields after sunup.

AWARENESS OF TIME AND SPACE

Canada Geese, like Mallards, go to stubble each morning, but unlike
these ducks they do not respond to the sharp division between night and
dawn. The big honkers usually remain on their night roost until the sky is
bright and the details of the landscape are well lighted. Some keep a routine
that does not take them to the fields until after sunup. Nevertheless, they
are regular in their delayed breakfast travel; if the weather remains con-
stant they are seen on the way to the fields at about the same time each
morning. For a week in early October I watched a group of Canada Geese
leave the lake every day between 6:45 and 7:00 a.m. Another flock crossed
Slack's field daily within a few minutes of 8:00 a.m. Geese must be hungry
at dawn, and several morning birds I have shot on the out-flight had empty
gizzards. It is neither dawn-light nor hunger by which the time of their
departure is regulated. Somehow they must be aware of intervals of time.
That such awareness of time must exist seems evident in the pioneering
studies of Gustav Kramer (1951, 1952). His work suggests that birds do,
indeed, appreciate intervals of daytime on the basis of the sun's position
and the angle-speed of its movement — a perception of periods of time be-
tween sunrise and sunset. Canada Geese measure the interval between
dawn and that point of the morning when they fly out to feed. A similar per-
ception of interval was noted for bees by von Frisch ( 1950:78), who tells us
that "bees have a good memory for time. If one feeds them at a certain spot
for a few days between ten and twelve o'clock, they visit this spot for the
next few days from ten to twelve even though the food dish is empty."

Many other birds go out to feed on regular schedules. The autumn marsh
is the roosting place for Redwings and other blackbirds that launch forth
to the farmland at the same time each morning. The blackbirds, however,
hold to their roosts while the Mallards are outbound, and it is three-quarters
of an hour after the first duck flights that they leave for breakfast. Next
come the Herring Gulls, forewarning the goose hunter to keep his eye on
the horizon for the first sight of Canada Geese. Seibert (1951), who studied
the feeding flights of herons, observed that the "time of sunset and sunrise
was found to be the most important factor controlling the arrival and de-
parture of all species." Nice (1935) watched the regular morning move-
ments of Starlings and Bronzed Grackles and found that the "first Starlings
left the roost at lower light values than did the Grackles . . ." At Delta the
small Richardson's Geese regularly depart for the fields earlier than the
Canada Geese; they are often shot during the dawn flight of Mallards,
while Canadas are seldom killed on farmland so early as dawn.

77

TRAVELS OF WATERFOWL

Geese, like Mallards, take their second meal in the afternoon, following
regular schedules. At Skunk Creek I watched a flock of Canada Geese go
over the trees at about four o'clock every afternoon for five days. As with
ducks, there is individual variation in the time of the afternoon feeding
trip, so that all geese do not leave the lake at the same time. At the mouth
of the Whitemud River there is a traditional spring and autumn rendezvous
where geese loaf and preen not far from shore. I have watched the after-
noon departures as one flock after another breaks away from the main body
and starts toward the prairie. Sometimes more than two hours are consumed
before the last band goes out to feed. I suspect that this spread, as in ducks,
may be due to differences among them in the place and success of the
morning meal, those breakfasting first probably getting away earliest in
the afternoon.

Fatigue is another cue to the passage of time. Each day there is a period
of rest in the rhythm of activity of all waterfowl. On our pond such loafing
is a part of the pen routine among both wild and captive birds. They doze
at the pond's edge or float with the head turned over the back, the bill
tucked under the scapular feathers, the eyes nearly shut in complete re-
pose. All are occupied with their nap at the same time. Minor disturbances
do not cause them to interrupt their rest, and even though the wind blows
hard, they continue to sleep. Then suddenly, without apparent outer in-
fluence, first one, then the next, lifts its head. Shortly a bird will flex its
wings, and the entire flock is awake.

The morning bath of waterfowl is a sight to behold, particularly when
large geese and swans are so occupied. There is a wild splashing of wings
as they douse themselves. Then follows a dipping of the head and neck,
with still more wing-splashing. Finally one bird after another rolls over
on its back, flapping its wings while upside down in the water. Sometimes
a mad excitement overtakes the crowd. One bird races across the surface as
if the devil himself were on its tail. Then in full stride it dives. The instant
it comes up it goes down again; up it comes, down it goes. All the birds in
the flock may be consumed in this devil-chase, helter-skelter, this way and
that, over the water and down under. After a few minutes the divings end.
The flock regains composure and settles quietly to the job of preening.

I give these details because such antics attracted the attention of Dr.
Roper Cadham one Sunday on his way to the store. He stopped his car for
a moment to watch the geese in their wild splashings and divings on the
Station pond, then drove on to the village. There, on the channel, another

78

AWARENESS OF TIME AND SPACE

band of Canada Geese was occupied in the same way. Here were two
groups of birds doing the same thing at the same time. They were in the
flightless period of the summer molt so that there could have been no inter-
change from one group to the other. The flocks were a quarter of a mile
apart, with trees and buildings intervening ; hence one band could not have
seen the other's actions, nor did sound of their activity carry so far. I suspect
that the channel geese and those at the pond fed at about the same time in
the morning, and thus they began their post-breakfast bath and frolic at
about the same moment.

I have never seen adult waterfowl driven to the point of exhaustion in
their local movements, but when new arrivals reach the marsh on migration,
their behavior is that of tired birds. Trautman observed (1940:90) that
"the newly arrived birds seemed very tired, for upon alighting most of them
tucked their bills under the feathers of their back or wings and apparently
went to sleep." Of migrant Mallards arriving in Arkansas, Queeny says
(1947:37), "They are exhausted. Some have lost as much as half a pound
during their flight. If they become aware of an interloper, they do not fly
away . . ."

In downy young I have watched what amounts to a relation between
fatigue and the passage of time. Once I followed a brood of Redheads along
a road at the marsh edge. They traveled ahead of me undisturbed as I ob-
served at a distance with field glasses. From their location I judged that
they had walked about two miles when I first encountered them. They
toddled along behind their mother, then squatted down for a rest of three
or four minutes while she waited patiently. Soon they went on again, only
to stop once more to rest. Their stops were made every forty or fifty yards
and apparently were timed according to their requirement for rest.

Regularity of activity has been noted in other birds. Pettingill (1936)
has discussed the relation between the sun and the beginning of the morn-
ing and evening "peenting" in the Woodcock. This begins at about the same
moment each twilight, but as the sun sets later each day, there is a similar
delay in the beginning of the evening "song." Nice (1943:108), working
with songbirds, observed that "each species has its own 'Waking-Light' "
and that in some kinds the first song, like the feeding flight of the Canada
Goose, does not begin until long after the first glow of dawn. Palmgren
(1949), who has given an excellent review of the experimental work on
the diurnal rhythm in birds, points out that in the European Robin 'light
is not the only factor. If the natural light is shut off and the cages lighted

79

TRAVELS OF WATERFOWL

with constant light intensity day and night, the sleeping time nevertheless
remains on the whole unchanged for some time." He concludes that sleep
"behaves as an autonomous periodical function, although largely controlled
by the light conditions." Armstrong (1954) and Cullen (1954), presenting
careful reviews of the literature and reports of their own original observations
of birds living under continuous daylight, conclude that little is known re-
garding the "factors which may modify the length of a bird's working day"
(Armstrong), and that "there is still a virtually untouched field of investiga-
tion of diurnal rhythm in the Arctic" ( Cullen ) .

There is a similar regularity in the activities of mammals. A doe White-
tailed Deer and her fawn passed down a trail within sight of my office each
afternoon for a week, the two reaching this spot within a few moments of
four o'clock. Those who live on the western prairies know the sunset song
of the coyote. Along the edge of the Delta Marsh skunks begin to wander
along the road at the same hour of twilight each evening. At Cornell Uni-
versity my Pointer dog Nelly had a routine of classes which she attended
more precisely than some students. She always entered a classroom quietly,
walked to her usual corner, and flopped down to endure the lecture hour.
The Library bell was the usual announcement ending class, but Nelly in-
variably became restless a moment or two before the bell rang. In one room,
where she had a conspicuous position up front, her pre-bell rise and yawn
was the students' mark for the end of the hour. I presume that some cue
which I could not perceive was her signal of the end of the period. Similar
behavior on the part of animals in a zoo is well known; lions and bears
follow the actions of their keepers that identify feeding or pen-cleaning
time. We know that cattle wend homeward at evening, beckoned by their
distended udders as well as by twilight.

We recognize both sun time and metabolic time in our own lives, awak-
ening earlier with the vernal increase in the length of the day. Through the
course of the day, many of us find ourselves checking the sun's position. It
is a rule with some gunners to walk outward until the sun attains a point
halfway between the horizon and its position at the start; then the turn is
made toward home, which is reached at sundown. The office worker and
the farm hand both recognize the metabolic cues that signal lunch hour.
The time of the daily bowel movement obeys metabolic rhythm. Perhaps
the most precise response to metabolic time is found in the human infant
which is fed on schedule ; if this is not met, the baby cries. Woodrow ( 1951 )
suggests that "time is always judged indirectly by means of some process

80

AWARENESS OF TIME AND SPACE

that serves as a cue. By a temporal cue is meant any process that changes
progressively with the lapse of time. . . . Time is not a thing that, like an
apple, may be perceived. Stimuli and patterns of stimuli occupy physical
time; and we react to such stimuli by perceptions, judgements, comparisons,
estimates, etc."

The discussion so far has considered the natural cause and effect of
timed activity. The relation between dawn-light and the rhythm of daily
behavior may be measured under artificial conditions. In the brooder house
young ducks are quiet all night, and activity does not begin until daybreak.
But if we create artificial dawn with electric lights turned on an hour ear-
lier, the birds respond at once. Likewise, the influence of the hunger stimuli
may be observed in the pens. The Mallard that has fed well at his morning
meal loafs quietly; but the bird that has been held from his breakfast until
noon runs to the trays to feed eagerly.

Regarding what he calls a "sense of time," Pumphrey (1948:196) says
that it is possible "to adopt either of two radically different theoretical ap-
proaches. The sense of time has been regarded as a sense of interval, for
which the reference standard is the solar day. And alternatively, the refer-
ence standard has been thought to be inherent and associated in some way
with the rate of living of the animal organism." I do not think these to be
alternative or opposing theories. The rate of living is hinged to the rhythm
of the solar day and to the metabolic processes of lif e ; the relation between
these constitutes biological time. This relation is not entirely an inborn
heritage of the organism, since the timing of its activities may be altered
by changing the rhythm of light and dark.

All who have watched the vernal return of waterfowl are aware that
activities not only follow a daily schedule, but show a regular response to
the time of year. The same species arrive at the same locality at about the
same time each spring (see Table 4 in Chapter 9). Nesting has a certain
regularity in its beginnings ; the first gatherings of molting drakes are seen
in about the same week each May; the start of the flightless season has a
remarkable regularity; and the first southward movements annually begin
at the same time. Just as the daily rhythm of the sun governs the timing of
local activity, so the annual solar cycle, with its effects on weather and on
the bird itself, influences the schedule of spring arrival (Rowan, 1931). An
amazing coincidence of seasonal activity is recorded by Sowls (1955:167),
who observed the mass fall migration of November 2, 1946, arriving to pass
over the Delta Marsh at 4:15 p.m. His cooperator, Mr. T. H. Schindler, of the

81

TRAVELS OF WATERFOWL

Manitoba Game and Fisheries Branch, that same afternoon watched the first
members of the mass migration arrive over the Netley Marsh (68 miles east
of Delta ) at exactly the same minute.

We can hardly speak of time without considering the bird's orientation
in space. Waterfowl are visually oriented to their environment, having
learned their place in the world by sight. The channels, passes, leads, and
chains of sloughs are followed as they are seen; passes are used again and
again because they are learned. No duck, of course, lives on the same home
range or even on the same marsh through all of one season. The breeding
territory is distinct from the rearing place; there is the molting marsh and
there are still other zones of late summer activity. The first move of a bird
to a new place is a pioneering venture, albeit this trip may be made with
experienced companions. Once settled on a fresh range, the bird learns the
new area and is ever linked (so the evidence of banding tells us) to this
region of experience. The thread of continuity from range to range strength-
ens as experiences are repeated ; this explains the tendency of waterfowl to
revisit the same areas year after year.

The importance of eyesight in spatial orientation is evidenced by the
relative heights of travel. Where the distance is short, as when Mallards fly
from the Station pond to the bay edge, travel is low. Where the distance is
greater, as when they fly to the far shore of the bay, the altitude of flight is
increased, and stubble birds on the way to the prairie go still higher.
Travelers to nearby fields fly at the edge of gunshot range, around two
hundred feet, but Mallards going ten or fifteen miles travel more than twice
as high as that. Rowan writes me that he and his hunting partner have
"always taken altitude as a direct indication of distance and have regulated
our gunning accordingly. The correlation is very marked." In his studies
of the Canada Goose in Missouri, Lewis G. Helm (letter) saw a direct rela-
tion between length and height of travel, the birds rising higher as the
distance of daily feeding flights increased.

The bird on its home range is aware of its position not only through
what it immediately sees, however, but through the retention of previous
experiences there. In short, the duck is oriented not only to the space of
the present, but to this as related to places of past experience. The orienta-
tion of the moment is not only to the surroundings seen, but to places over
the horizon beyond the edge of visibility. Dr. A. A. Alford and I observed
Mallards and Pintails making daily feeding flights to flooded fields south of

82

AWARENESS OF TIME AND SPACE

Fannestelle, Manitoba, fifty to sixty miles from their night roost on Lake Man-
itoba. These were as precise and direct to the unseen destination as a flight
across a small bay. The birds moved just as surely to a field sixty miles away as
to the bay edge plainly seen. It is possible to conduct a simple experiment
to demonstrate this relation between the past and the present. In four
feet of water in Cadham Bay I dumped a bucket of wheat. Within twenty-
four hours some ducks had located this grain. Once found, they fed there
regularly. They swam directly to this place — a hidden pinpoint in the vast
expanse of water — finding it precisely again and again. The grain could not
be seen, and so every trip there depended upon an awareness of something
beyond sight.

The bird cannot travel guided by experience alone, of course, and when
the landscape is not visible, as in dense fog, local movement comes to a halt.
A flock of Canada Geese roosting on Cadham Bay went to their stubble
fields when visibility was at about a hundred yards in a light fog ; but when
this thickened so that we could see no farther than fifty yards, they did
not make their trip and loafed all day on the bay. Peter Scott writes me
that his flock of free-winged Greater Snow Geese at the Severn Wildfowl
Trust "got up in a fog and couldn't get down." Local aerial activity about
the marsh is intense on bright, moonlit nights, but there are few or no
waterfowl in the air on nights that are overcast and moonless.

Let us remember that the size and complexity of a range are relative
to the size and age of the bird. Some ducklings spend their first eight or ten
weeks on small sloughs and potholes, their total range of activity covering
only a few acres at most. Others may spread their early days over many
acres, but the span of activity is restricted by the young bird's requirement
to swim or walk wherever it goes. However small in extent, the reedy edges
and deep beds of emergent vegetation of the first home are complex grounds
for the duckling to learn. To such a downy young, Fannestelle, sixty miles
away, is far beyond the edge of eternity. Two months later, however, the
home pond is only a small corner of this bird's world as it now flies in an
oriented manner about the large marsh and adjacent countryside. For the
little duckling the patch of reeds is as large and as complex, relatively speak-
ing, as the whole wide marsh for the same bird after it has grown its wings
and taken flight.

When ducks take short, low flights, we infer that the topographic
features which their travel obeys — the creeks, channels, and other features
of the landscape - are their guides to orientation. In going greater distances

83

TRAVELS OF WATERFOWL

overland, as to Fannestelle, they may follow cues presented by blocks of
woodland, by stream and river valleys, and, at their destination, by the
varying pattern of the fields. Perhaps such man-made features as main
roads, grain elevators, and city lights serve in orientation. In 1953 I found
a heavy flight of stubble Mallards regularly coursing down a quarter-mile
stretch of railway track on flights from grain fields to Longburn Creek,
which they then followed to the marsh.

No doubt the sun, as the studies of Kramer ( 1951, 1952 ) and Matthews
(1951a, b; 1952) suggest, is of importance in the bird's orientation in space,
not only when it is directly east or west at dawn and dusk, but through
the day. We most readily think of cues to orientation as "landmarks," but
certain details of the sky may be important. For example, regularly in fall
and spring, and often during summer, thermal currents build a layer of fair-
weather cumulus clouds over the Portage Plains, but these are not produced
over the colder lake. The result is a sharp line between cloud and blue sky
that precisely marks the edge of Lake Manitoba. This effect may last all
day, sometimes a regular local feature for many days. I have seen this edge
of clouds from the Riding Mountains, seventy miles away; and regularly
we see the same cloudline over Lake Winnipeg, sixty miles east of Delta.
In summer, thunderheads build up on the west shore of Lake Manitoba
and in the interlake country to the east. These often hold their position
through much of the afternoon and evening; and their tops may be seen
for a hundred miles, lighted clearly long after the countryside is in dusk.
Mirage frequently lifts details of the landscape above the true horizon, and
I have seen the ice on Lake Manitoba from a distance of eighteen miles.

Edge of cloud bank over south shore of Lake Manitoba. This line of clouds marks
the position of the lake for the traveler still many miles away.

AWARENESS OF TIME AND SPACE

To the human wayfarer such sky configurations are always interesting and
sometimes helpful as travel guides. It is possible that they may be useful
to birds in local orientation. Surely, at least, as we study the bird in its en-
vironment, we must acknowledge that there are a great many features of the
landscape, not all to be defined simply as "landmarks," that serve as cues
to avian orientation.

Because the bird is so free on the wing we often think of its range as
boundless. All children, of course, know of the Robin's faithfulness to the
city neighborhood, and the work of Howard (1920) and his followers has
stressed the confining influence of territorial behavior and the home range
in birds. This restriction of activity does not hold for the breeding season
alone. The drake may move many miles from the nesting grounds to his
molting place, but once there, he settles down to a routine that covers a
rather restricted area. The stubble Mallard in August may range as far as
Fannestelle to feed, but bandings show that each night it returns with its
companions to the same sand bar on the Lake Manitoba shoreline. Juvenile
waterfowl may roam far and wide in their late-summer wanderings, but
when they stop for a while, banding records show that they usually use
the same restricted part of the marsh for feeding and loafing. During migra-
tion a banding trap will have many "repeats" of birds that come again and
again to the same feeding place during the course of their temporary
residence. Seton said (1910) that each animal "has a home-region, even if
it is not an actual home. ... In the idea of a home-region is the germ of
territorial rights. At every step it presents close and interesting parallels
with the growth of territorial law in man."

Ornithologists have tended to view time and space as a series of dis-
crete, objectively determined units. Time is most often considered as though
broken into moments in the flow of life (like the time of morning song) or
into periods of life (like the length of incubation). Space is thought of as
though segmented into ranges (such as nest and territory) or into lineal
distances (such as between nesting place and wintering grounds). Such
time and space we measure precisely in hours or miles or in units thereof.
By so confining our thought to isolated or limited divisions of time and
space, we greatly restrict our understanding of the avian world. Each bird
lives in time that is not an instant of the present or a series of present in-
stants ; time is the flow of past, present, and future. "Time is as fundamental
as space ; and it is time, no doubt, that holds the essence of life, and perhaps

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TRAVELS OF WATERFOWL

of all reality. What we have to understand is that time is an accumulation,
a growth, a duration" (Durant, 1952:451). Time is relative to motion and
to space; hence time is also relative to structure. Time for the flightless
duckling, with its short wings and rapid metabolism, is not the same as
for the mother with her rapid flight and slower rhythm of body processes.
By the clock, to be sure, and by the calendar, time is the same for all — for
the duckling, for its mother, and for the observing man. But unquantified,
apprehended in life and space and motion, time for the duckling, its mother,
and man is very different; each lives in a temporal world of its own.

Space is the medium within which animals live and move. It not only
bounds the places and objects of the present, but is the whole of the world
in which the bird has lived its past, experiences its present, and will live its
future. Space is relative to the perception and the motion of each organism.
Time and space are thus inseparable in the life equation. Just as time is rela-
tive to structure, so is space. Space for the duckling is far more restricted
than for the mother in terms of square feet or miles; yet measured rela-
tively, the world in which the duckling lives is as great and as wide as that
of the mature bird.

We must ever remember that just as time and space are not the same
for the adult and baby duck, so they are not like entities for man and bird.

PART II

Migrations of Waterfowl

'Dark flying rune against the western glow —
It tells the sweep and loneliness of things,
Symbol of Autumns vanished long ago.
Symbol of coming Springs 1"

Pai Ta-shun (Frederick Peterson)

"Home is where one starts from." T. S. Eliot, Four
Quartets

The Cycle of Migration

Ihere come unforgettable evenings in late
August when a soft calm settles over the marsh. The breeze is spent and the
reeds duplicate themselves in perfect reflection. The sky is clear, yet with
sundown comes a refreshing chill. The tinkle of water from the canoe pad-
dle and the rustle of a wren in the tules are the only sounds. Here is the
world as God made it. Deep in the heart of the wheatland is a pristine
wilderness that can differ little from that so loved by the native Cree. This
might be the marsh as seen two centuries ago by La Verendrye. The dark
bulrush, the green cattail, and the tall reed have not changed ; sky and water
are the same; the wren must be a direct descendant of one that chattered
here when the explorer's canoe slipped past this very place. Surely all is the
same except for the tall grain elevator that rises above the oak bluff six miles
to the south.

The peace is broken suddenly by the chuckle of a teal. Who is there so
solemn that he listens to the fall note of the Blue-winged Teal without a
smile? Here is a challenge offered severely, the youngster's exclamation of
its place in this ancient world of bulrush. Hardly before summer becomes
routine, autumn is upon us. These Blue-winged Teal, whose voices break
the tranquillity of the August evening, are birds-of-the-year. Bred in May,
born in June, reared before the wheat is ripe, they are on their way to the
wintering grounds before summer is gone. One evening after supper I flush
a hundred from the cove; the next morning only a dozen are frightened
from the same place. By the equinox the main flight has passed to the south ;
the end of the first week in October finds only a few stragglers remaining,
although there is promise of more fair weather before the shallows close
with ice. Whatever the urge, it surely is not the pressure of frost that sends
the bluewings to their southland. . . .

89

MIGRATIONS OF WATERFOWL

What greater place in life can a man attain than a seat by the fire on
an October evening? What finer thoughts than of bird, of dog, and of gun?
What better companionship than of elder hunters who read aloud from then-
life stories as they gaze into the hearth? However artificial their environ-
ments become, however far from nature they must stray in search of for-
tune, all wise young men seek a place by the October hearthstone.

I have read many books, have spent many days on the marsh, but there
is much I have learned from the words of older hunters. The north wind
was their friend before I could hold my father's gun. In calm and storm they
lived many years on marshland I am just beginning to know. As the birch
logs crackled, I have learned that the Canvasback never wait for the heavy
frost. Come mid-October and the cannies are done with Manitoba. In late
September their numbers crowd the big marshes so that windrows of pond-
weed litter the shore downwind of the feeding places. In early October they
parade daily, passing from their loafing grounds on open water to the sago
beds where they feed. Then, when October is half gone, there comes upon
the birds a wild restlessness. In a flock loafing on the water, one bird after
another raises its body to flex its wings, so that there is a constant fluttering.
Over the marsh, small bands join to form larger flocks. Then the Canvas-
back are gone, all but a few strays lingering on with the scaup.

This I was told, and all this I have found to be true. Fair weather or
foul, the Canvasbacks migrate south before October is finished; they are
gone two or three weeks before the bays are frozen.

Casual as the teal flights may be, early as the Canvasback slip away, the
freeze-up flight of Mallard and Lesser Scaup is quite another thing. They
cling to the northland through October and on into November. Some travel
southward, to be sure, like teal and Canvasback, but vast numbers hold to
the north as long as open water remains. Then comes the time for passage.
The temperature drops and remains below freezing all day; it may touch
zero or fall below that mark. The barometer rises, a stiff wind strikes out
of the northwest, and before noon the skies are clear. On such a day in
November it is the wildfowler's duty to abandon all home ties and go at
once to the marsh. It is usual for little flurries of southbound ducks to ap-
pear early that afternoon. First one, then another, then more and more, un-
til one glance catches many flocks. They come out of the northwest, often
so high that they would not be noticed but for the volume of the flock.
They scurry past without stopping. By four o'clock there is not an instant

90

THE CYCLE OF MIGRATION

without ducks in every corner of the sky. During the heaviest waves, fifty
or sixty flocks a minute may pass over a section of marsh a mile wide ; and
as far east and west as one can see, waterfowl cross over in steady numbers,
small bands and large. The stream of their passage seems endless ; then after
sundown the rosy twilight changes to cold blue, and the last ducks have
passed. Another autumn is gone.

So ends the waterfowl year at Delta. The broad basin of Lake Manitoba
is the home of ducks from April until November frost. There they move to
and from their feeding and loafing places, between territory and nest, from
lakeshore to stubble and return. Day upon day is built the restless activity
of living. The daily chain of travel carries them back and forth across fami-
liar terrain. Then suddenly all this is abandoned. The winter is cold and
deep. The marsh is without waterfowl until the first hardy birds come back
in late March or early April. How do they find their way out of the harsh
northland? What guides them back with the soft winds of spring? These
are the questions eternal.

Migration is the annually repeated cycle of travel that carries waterfowl
away from their birthplace or breeding grounds to temperate wintering
waters, returning them to the familiar homeland with the advent of spring.
It is important that we think of each migration as beginning and ending in
the region of natal experience, with the winter interlude in the south. In
the migrational history of a species, to be sure, we might properly consider
the impetus as coming from the south, the annual cycle carrying a species
to and from its breeding place. For the individual bird, however, the home
range on the breeding ground is the start of all migratory movement; and
this very same place is the final goal which must be attained to complete the
annual cycle. Mayr (1942:240) says that the tendency of birds to return to

91

MIGRATIONS OF WATERFOWL

the same place for reproduction year after year "has been proven by so
many studies that it would be unfair to single out a particular one"; and
Valikangas ( 1933 ) , in his classic experiment, showed how the young of wild
ducks were tied to the region of birth. He brought eggs of English Mallards
to Finland, where they were hatched and where the young were raised and
given migratory freedom. Of 62 birds released, 34 came back to their Fin-
land home after their first trip to the wintering grounds.

Sowls (1949, 1950, 1951, 1955) has presented much evidence to show the
fidelity of the female to her nesting marsh, his experiments demonstrating
that she returns to nest not only in the same meadow, but often in the same
part of that field. After studying five species * intensively by following the
individual histories of nest-trapped, color-marked hens, he concluded that
"they normally return to the original nesting meadow a second and a third
and a fourth year, or so long as they survive and the area remains suitable."
He also found a remarkable return of young females to the home marsh
after their first migration. Of 115 juvenile Pintail hens, for example, 13 per
cent came back to Delta to be individually recorded ( by leg bands ) on the
small pond where they were raised. Sowls discovered the nests of 8 of these
young females only a short distance from the birthplace. Winter matings in
the large aggregations of the southland sometimes join the drake to a fe-
male from a region unfamiliar to him and he cannot go to his own home.
Thomson (1931, 1945) has given the term "abmigration" to movements,
such as those of winter-mated drakes, where a bird native to one region is
"found in a subsequent summer in quite a different area." Banding evi-
dence presented by Sowls (1951) and Cartwright (1952) indicates, how-
ever, that such males may come back to familiar places, sometimes the
natal marsh, after their marital duties are finished.

If we accept the homeland of birth and breeding to be the start and
finish of the annual migration cycle, it is clear that a duck travels away from
a region of learned experience and returns to a familiar range. However
mysterious the act of departure, by whatever guidance it finds its way back,
the familiar home is the start and the finish of each individual's migration ;
the beginning and ending of the annual migration is a learned place.

While the tie to home holds for all waterfowl, we must recognize im-
portant differences in migrational behavior between geese and swans on
the one hand and ducks on the other. In the former there is a strong family
bond, parents and children remaining together during southward migration.

• Mallard, Pintail, Gadwall, Blue-winged Teal, Shoveller.

92

8$\S

The young are attended by both parents during the period of growth. Moth-
er and father molt their wing feathers and are flightless while attending the
young. Children and parents take wing at about the same time in late sum-
mer, and they are all together for the trip southward. Mayr (1942:242)
sums up the evidence to decide that "geese are among the very few birds
in which the family does not break up at the end of the breeding season,
but parents and young stay together for nearly a year. They migrate to-
gether to the winter quarters, they spend the entire winter together, and
they do not separate until after their return to their nesting area." The Elders
(1949) show that the "small goose flock is usually a family and that larger
flocks are frequently multiples of families rather than mere aggregations of
individuals." In our own color-banded, free-winged Canada Geese at Delta
we have seen adults and young-of-the-year depart southward together in No-
vember and return, still as a united group, the next April. Where such kin-
dred ties apply, the immature accompany the experienced elders and do not
pioneer their own first migrations. "There is little doubt that guidance by
older, experienced birds plays a decisive part in the directional flying of such
species" (Mayr, 1952:394).

In North American ducks there is quite a different arrangement. The
father parts company with his mate before the young are hatched,* leaving
the nesting area to join other males that, like himself, are molting into the
eclipse plumage. In the Mallard and other river ducks the mother usually
stays with her ducklings until they are on the wing; then she leaves them to
their own devices while she molts the flight feathers. More often in Canvas-
back and other diving ducks the mother abandons her charges many days
(sometimes several weeks) before they are ready to fly. Once free of ma-
ternal companionship, the young ducks are completely "on their own";
there is no bond of kinship between parent and juvenile after the break-up.

• An exception is the Ruddy Duck, in which the male frequently, but by no means always,
stays for a while with hen and brood. In all other species the drake only rarely is seen with his
family.

MIGRATIONS OF WATERFOWL

In ducks, then, the juvenile behaves independently of parent, and its
movements outward from natal range are pioneerings. These young wander
randomly during late summer, and it is by such explorations that they build
their experience; by such roamings they learn their way about. The Egret
that wanders to Ontario and the Pintail that strays from Delta to Lake Win-
nipegosis have much in common. Like the bird of mythology, they may not
be aware of where they are going, but they learn where they have been. Just
as the downy duckling searches aimlessly for its first food, so must juveniles
explore to find their place in the world.

The summer wanderings of young ducks are random only in terms of
compass direction; this travel is always aimed toward a favorable habitat.*
First, the shift is from water to water ; the many hundreds of young raised
on the scattered potholes of western Manitoba depart from their narrow
ponds and fly to larger places. Small potholes become vacant, larger sloughs
have more birds, while big marshes and lakes boast vast aggregations. The
heaviest movement is from the small waters to the large, but the innate
urge to travel is obeyed by the young of the big marshes too, and every year
bandings show that some Delta juveniles depart elsewhere during August
and September.

The transfer is also of the few toward the many. Sixes become dozens,
dozens become scores, hundreds become thousands until, as old Ernie Cook
used to say, "You couldn't get another duck in the bay with a shoehorn."
However random the peregrinations of youth, these must eventually carry
the youngsters to the mouth of the Saskatchewan, to Lake Winnipegosis, to
Whitewater Lake, Libau, Delta, or some other rendezvous, where, from
August onward, the open waters and shorelines are strewn with ducks of
many kinds. Although forever lost to their parents, many young must eventu-
ally meet with experienced adults before autumn is ended. This is evidenced
by both banding and bag samples, and although the juveniles often greatly
outnumber their elders, it must be the rare young duck that reaches Novem-
ber and the southland without somewhere having joined company with ex-
perienced companions.

In spring, all ducks, juveniles as well as adults, have a background of
experience, and their return to the breeding grounds cannot be classified as
of the unknown, the untried, the inexperienced.

• See Figure 20, p. 145.

94

"It is not true, as Aristotle asserts, that the same
leader heads the migrant column during the whole
of their journey." Frederick II, The Art of Falconry

8

Flight Trails South

The sunrise of October 11, 1951, was bright
and cloudless. Art Paulson sat in the bow with his gun across his knee while
I watched from the stern. There was not a breath of wind. Reflections with-
out a mar. The only birds were a few late bluewings returning now and
again to the reeds. Shortly after seven o'clock we saw a band of ducks com-
ing out of the northwest so high that they appeared only as a thread in the
sky. More followed, and during the next fifteen minutes we counted twenty
flocks. Suddenly the calm broke. Without so much as a breeze for an intro-
duction, a rough wind struck from the northwest, quickly churning the
waters of the bay to whitecaps. Now the volume of the flight increased so
that any glance found at least a dozen flocks. The travelers were strewn far
and wide across the sky, all moving at the same speed, all arriving from the
northwest, all crossing to disappear into the southeast. We identified Can-
vasback and Redhead, Lesser Scaup and Mallard, and there were also Can-
ada Geese. The speed of the wind was measured at twenty-five to thirty
miles per hour on the ground, and the ground speed of the migrants ap-
peared to be more than twice that. Any given group flew quickly out of
sight, but new birds continued to arrive from the northwest so that the flow
was unbroken. Local ducks were put to air by the wind, some flying to pro-
tective shores, others rising to join the migration. James F. Bell, who was
four miles to the east, told me later that he had watched the flight go over
in the same volume, and from other gunners I learned that the movement
crossed over the whole marsh. The passage continued until just before noon,
and, placing our estimates on the number of birds we saw crossing Delta, I
guessed that some 200,000 waterfowl had flown over the marsh in the heavi-
est morning migration I have ever seen.

More typically, these mass migrations go through in the afternoon, at-

95

Figure 10. Standard direction of mass fall migration from Whitewater Lake, Lake Mani-
toba, and Lake Winnipeg marshes. The standard direction from the Delta Marsh is
followed by all ducks, holds the same year after year, and is constant regardless of wind
direction. Stippled area shows the Pre-Cambrian Shield.

taining their maximum intensity near sundown. The outstanding feature of
such avalanches is the uniformity of direction. At Delta, the migrants arrive
from the northwest and depart into the southeast. On any given day all
flocks and all species go this way, the direction is maintained every day of
migration, and the same course is held each year, so that in 1954 the pas-

96

FLIGHT TRAILS SOUTH

sage went to the same point of the compass as I had marked it for the fall
flight in 1938 (Figure 10). While the wind is invariably from the northwest
in these main passages, it seldom blows in exactly the same direction as the
flight so that the course of the birds is often several degrees east or west of
the flow of wind.

With respect to this firmness of direction in the path of autumn migra-
tion, Thomson (1953) reminds us of the "modern view that there is a stand-
ard direction * for the migration of each species, or community of species
. . . This direction leads either straight from the breeding area to the win-
tering area, or to some intermediate area where the direction is assumed to
undergo a change. The capacity to follow such a direction is supposed to be
innate in the bird, as part of its migratory instinct, and this hypothesis
conforms with the experimental findings of Kramer (e.g., 1952) and Mat-
thews (1952) that birds are able to orient their flight in relation to the posi-
tion of the sun, making due allowance for the time of day." Note that Thom-
son refers to the capacity to follow a direction as being innate without im-
plying that a bird is innately bound to a certain direction.

The travelers in these mass passages are most often seen in "waves" of
flocks, with several or many bands within sight at one time. The movement
is always higher than local travel, usually ranging from 500 to about 5,000
feet, with most migrant waterfowl crossing the Delta region between 1,000
and 3,000 feet f (Figure 11). Flock size varies from a dozen or so to strings
of a hundred or more, most bands containing from twenty-five to fifty birds.
During the course of a passage one may see several or many species, but
flocks are seldom mixed, each kind traveling in a group of its own. Individ-
uals of a migrating flock string out in a line forming a blunt arc or, much
less frequently, a sharp-pointed V, each bird thus avoiding the slipstream
of rough air produced by the movement of its companions.

The mass migration over the Delta Marsh moves in a broad sweep. On
a day of a grand passage, hunters scattered over the full width of the marsh
report heavy movements; and on such days at Delta, W. A. Murphy has
told me of spectacular flights over his East Meadow Ranch on the eastern
shore of Lake Manitoba. The width of this passage is probably thirty miles,

0 Thomson's phrase here comes from Geyr von Schweppenburg, who at first ( 1933) used the
term Normalrichtung and later ( 1948 ) Primarrichtung, the latter translated by Deelder ( 1949)
as "standard direction" (van Dobben, 1953).

t All statements of elevation given here are based on estimates of two sorts : ( 1 ) by com-
parison with relative-size standards from exact measurements of duck and goose silhouettes
(Figure 11); (2) by triangulation. Both field techniques are subject to error, but I feel they
are sufficiently in line to evaluate approximate elevations.

97

X

Figure 11. Gauge for judging approximate
elevation of Mallard-sized duck. When the
page is held 20 inches from the eye, the
silhouettes (from top to bottom) show the
relative size of ducks as seen at heights of
^^ 100 feet (good shotgun range), 200 feet

(extreme edge of shotgun range), 500 feet,
1,000 feet, 2,000 feet, and 3,000 feet.

■<*<

"<<-< -*-<-<•<

conforming to the breadth of Lake Mani-
toba.
***** ***+. *+**m Usually the migrants from the north-

west speed over the Delta Marsh without

•-.. hesitation. On several occasions, however, I

"•••• •... have seen them acknowledge their aware-
ness of the marsh by suddenly changing
flight formation and direction. After crossing the lake ridge from the north-
west I have seen members of a flock suddenly crowd together in a tight group,
like a band of blackbirds, appearing suddenly as a dark knot in the sky. These
flocks rise and fall, abruptly changing direction, east, west, and north again,
with stragglers swinging wide behind as in crack-the-whip. Sometimes one
cluster will join another. After some minutes of these gyrations, the groups
head south again, soon reforming into their normal strings. Once, on No-
vember 14, 1944, when a heavy migration arrived at Delta in weather very
cloudy despite a rapidly rising barometer, I saw what amounted to the whole
of an afternoon's migration "pile up" over the Delta Marsh, with hundreds
of bunched flocks flying in every direction, the sky so heavily loaded with
birds that we were sure a collision between bands would certainly occur. At
about six thirty the clouds broke — the first clear sky we had seen in two
weeks * — and the confusion ended, the migration resolving itself into a di-

• The sun had set, but the patch of open sky, bright in twilight color, illuminated the dark
and stormy atmosphere.

98

FLIGHT TRAILS SOUTH

rect southeasterly direction, with all flocks disappearing that way before
dark (Hochbaum, 1944b). (See Figure 12.)

Trautman (1940:89) observed this bunching of migrant ducks at Buck-
eye Lake, Ohio ; and Chris V. Nelson, who has hunted many years on Lake
Christina, Minnesota, writes me that he has seen such behavior in migrating
geese as well as in ducks. On October 21, 1950, for example, he watched a
migrating flock of sixty Canada Geese crossing the lake from the northwest.
"Just as they were leaving Lake Christina, all bedlam seemed to break loose
and they flew about wildly, honking vociferously. They went in circles like a
dog-fight, seeming very upset — some gaining altitude, some losing altitude.
Then, as if responding to a command, they all joined in a perfect V forma-
tion and continued their flight in a southeasterly direction."

4&£

Figure 12. Normal flock pattern of migrating ducks (left), and
"bunching" of gyrating flock

All such gyrations of passage flocks have been seen amongst travelers
that reached Delta when the sky was heavily clouded. The birds appeared
confused, as if they were pressed by two urges, one to stay, one to travel on
despite the unsettled weather. I was thus interested in the observations of
Svardson (1949), who describes similar gyrating behavior in gulls; he con-
cluded that the gyrations developed as a conflict between the "drive-to-go"
and the "urge-to-rest." Waterhouse (1949), who has seen gyrations in mi-
grating Rooks and Jackdaws, suggests that they "occasionally become un-
certain of direction, sometimes on taking off, sometimes in course of flight.
... To the resultant state of feeling — assumed to be a compound of desire-
to-fly and uncertainty-which-way-to-fly — they react by gyrating."

Other great marshes and lakes are the crossing places for the mass
autumn migrations. On the Libau Marsh, at the southeast end of Lake Win-
nipeg, Colonel Arthur Sullivan and George Longbottom, veteran observers
of the fall flight there, tell me the migration is constantly to the southeast in

99

MIGRATIONS OF WATERFOWL

a direction almost exactly the same as we see at Delta. On the Red River,
Thomas Schindler and Nolan Perret have told me of nights that go due
south. At Whitewater Lake, the departure line which Eugene F. Bossen-
maier has plotted for me is slightly more to the south than the direction at
Delta (Figure 14).

There is a heavy crossing of migrants at Buckeye Lake, Ohio, and Traut-
man (1940:90) says that "the ratio between the number of migrating flocks
that were observed flying through the area without stopping and those
alighting on the lake was about three to one." Ray Sickles, Game Protector
for the Pennsylvania State Game Commission, writes me that there is an
annual passage of Whistling Swans over Pymatuning Lake, in northwestern
Pennsylvania, which is always in a southeasterly direction. He observed a
very heavy flight on October 18, 1952, when on night patrol. "Just after mid-
night the air seemed full of migrating birds ... At daybreak this was sub-
stantiated by what was the most concentrated movement of waterfowl I
have ever witnessed. Within an hour several hundred flocks of migrating
swans passed over. One person counted 50 flocks averaging 100 to a flock
within fifteen minutes. From dawn until about 10:30 a.m. it was impossible
to look into the sky without seeing several flocks of swans. By noon the
movement had passed on and only a few straggling flocks could be seen. All
were very high and traveling in a south-by-east direction. I would guess
that 10,000 to 15,000 swans migrated through in that movement and only
about 250 stopped at Pymatuning ... It seems that every time a big mi-
gration of swans occurs, the weather is clear and the sky blue."

Delta, Whitewater Lake, and Buckeye Lake are merely pinpoints of
water on the migration map, but along river valleys the passage may follow
the same watercourse for many miles. Hall (1949:270) recalls a migration
he watched on the Mississippi River about thirty miles south of St. Louis.
"There'd been a blizzard swept down from the northwest, although no hint
of it reached our Missouri countryside. But the waterfowl knew about it and
they came pouring down the river that evening and all through the night
in countless hundreds of thousands, heading for distant feeding grounds in
the warm southland. It seemed to us from our vantage point high above the
river that most of the birds which use the Mississippi flyway must have
passed that afternoon . . . For as far as we could see, both up and down
the river and out across the wide Illinois bottomlands, migrating bands
passed swiftly and at every height. There could be no doubt about it : these
were travelling ducks. Although the long lines verged and crossed, the move-

100

FLIGHT TRAILS SOUTH

ment was steadily southward. Many of the bands flew close enough so we
could easily identify them — Mallards and Pintails and Canvasbacks flying
steadily; teal passing with swift wingbeat; Widgeon and Gadwall, Shovel-
lers and Redheads ; in fact, just about all the ducks which frequent the Mis-
sissippi Flyway. And as the sun dropped toward the horizon, painting the
cloud banks with long streaks of crimson which were reflected in lighter
tones of pink toward the east, we heard the disconsolate crying of Canada
Geese, veering in from westward where they had cut across from the Mis-
souri to avoid flying over the city. High above the ducks and still flying in
bright sunlight, their breasts glistened as the great birds held swiftly and
steadily toward marshlands to the south."

Bellrose (1951:11) says that "most flight routes reach Illinois borders
via the rivers of Iowa — Wapsipinicon, Cedar, Des Moines— which afford
convenient pathways from the northwestern part of the state to the south-
east." Indeed, he has observed river movements from an aircraft, and on
November 1, 1951, traced a large migration of Mallards to its source, the
valley of the Des Moines, whence the birds came down from the northwest
into the Mississippi. In the same breath with which I speak of river pas-
sages, I must mention overland travels as well. Bellrose explains that "water-
fowl do not hesitate to migrate overland if there is no convenient water
course to follow. There are definite routes that ducks follow between the
Mississippi and Illinois Rivers. One route leaves the Mississippi at Savanna,
passes over Annawan, and branches to enter the Illinois Valley at several
points. On November 6, 1948, we saw a pronounced waterfowl movement
along this route. The flight was first noticed at 8:45 a.m. along state high-
way No. 78, three miles north of Annawan.
There was a steady procession of Cormorant,
Pintail and Mallard flocks, along with a few
flocks of Blue and Snow Geese, flying parallel
to the highway from this point to Morrison.
Early in the afternoon, flocks of Mallards
were observed flying down the Mississippi
River above Savanna, leaving the river at
that point." ( See Figure 13. )

Figure 13. Overland pass from the Mississippi

River to the Illinois River followed

by migrating ducks in the fall

MIGRATIONS OF WATERFOWL

Some overland journeys of these mass migrations carry the birds far,
sometimes hundreds of miles, over terrain where we cannot read the pattern
of their flight in the scheme of water areas. Several wildfowlers of Sas-
katchewan and Montana have told me of a late autumn mass movement of
ducks that moves due south across central Saskatchewan and eastern Mon-
tana. Mr. Harry Jensen, of the U.S. Fish and Wildlife Service, told me of a
mass flight he watched pass over eastern North Dakota in the autumn of 1944.
The passage, moving south, lasted one and one-half hours and the birds
were so high that most of them could not be seen without the aid of bin-
oculars.

Waterfowl favor rivers leading from one part of the range to another, but
do not use those crossing this main line of travel. Ducks departing south-
east from Delta have an overland flight of about twenty miles to the Assini-
boine River, which they might follow to the Red River by turning east.
Instead they cross the east-west line of the Assiniboine and continue, to
meet the Red River Valley near the Minnesota border.

The volume of the mass passages is tremendous beyond belief. Rowan
(1929b) describes a November exodus from Alberta when, as one farmer ex-
claimed, the migrants were so numerous that "the sky was black with them,
flying in formation like geese, in bunches of around thirty to forty. As to
numbers, all I can say is that they passed over in thousands." At the peak of
a three-day migration Sowls (1947a) estimated that at least 100,000 ducks,
mostly Lesser Scaup, flew over the Delta Marsh during one hour on Novem-
ber 6, 1947.

These big "pushes" are seldom confined to one marsh region; there is
often a movement of waterfowl over a range that is wide and deep. In 1950
the big freeze-up migration at Delta was on November 8 and 9. Colonel
Arthur Sullivan reported major flights over the south end of Lake Winnipeg
the same days. At Whitewater Lake, Bossenmaier saw the heaviest flight on
the eighth, while at the same time, Merrill Hammond watched the last of
the waterfowl leave the Lower Souris Refuge in North Dakota. At Aberdeen,
South Dakota, Jerry Stoudt observed a major flight of waterfowl going to
the southeast on the eighth, and Warren Nord saw a massive migration of
Mallards and diving ducks near Fergus Falls, Minnesota, that same after-
noon. D. H. Janzen,* traveling in North Dakota, found that the big move-
ment out of that state commenced on November 7 and continued through

0 The accounts by Janzen, Hammond, Stoudt, Bossenmaier, and Lynch are from manuscript
reports supplied by the U.S. Fish and Wildlife Service.

102

«:*§. <^*X^*^

the next two days; he reported that, "for all practical purposes, the hunting
season was over for the State of North Dakota on the evening of the 9th."
In Illinois, Frank Bellrose (1951) described the heaviest passage for 1950
between November 9 and 11. Far to the south, on the Louisiana marshes,
John Lynch found that "new concentrations of ducks, principally Mallards,
showed up on November 8 and for several days thereafter."

The ducks that Nord saw over Fergus Falls on November 8 probably had
crossed Delta earlier the same day and comprised the flight that arrived in
Illinois on the ninth. We estimated the speed of the birds passing over Delta
at from sixty-five to seventy-five miles per hour,' with a tail wind. Traveling
straight through, their schedule would carry them over Illinois the next day.
That such a long journey was taken is suggested by Nord's report, for on

• All estimates of ground speed are by timing migrants over a course of known distance or
when direction and ground speed permit.

103

MIGRATIONS OF WATERFOWL
November 9 he found no ducks remaining around Fergus Falls, and the
area was frozen over except for a few open holes. All the birds of the Cana-
dian prairies and the northern states apparently cleared out in this big push.
The mass migrations we witness at Delta are related to four phases of
the weather: air pressure, wind, temperature, and humidity. Without im-
plying anything as to cause and effect, I have found that a rising barometer,
a falling temperature, a drop in relative humidity, and a wind from the
northwest establish the weather pattern characteristic of the mass migrations.
Indeed, more than once I have predicted the grand passage on the basis of
this weather combination.

In a discussion of these weather characteristics, Robert L. Lillestrand, of
the General Mills Research Laboratories, pointed out how the relation of
winds to the high-pressure (anticyclonic) and low-pressure (cyclonic) air
masses might favor southward migration when a "low" passed Delta and a
"high" arrived. The clockwise movement of air around the high together
with the counterclockwise rush around the low creates a southerly flow of
wind. Lillestrand drew a theoretical weather map to illustrate this situation,
with the high-pressure area located on the western half of the continent and
the low in the east, the trough of winds flowing down the middle between
the two air masses. I then examined the weather maps coinciding with the
major avalanches of fall passage and found that for Blue-winged Teal in
September, Canvasbacks and Redheads in October, and Lesser Scaup and
Mallard in November, every major flight took place when there was such a
west-east opposition of the high- and low-pressure areas. I have selected the
grand passage of November 7, 1947, to illustrate this weather pattern so
favorable to the mass movement of autumn migrants (Figure 14).

With respect to this tie between the weather and migration, Landsberg
(1948:709) believes that migratory birds "have developed a rather remark-
able system of what is called in modern aviation pressure-pattern flying/
This is the system that takes advantage of the maximum possible amount of
tail wind in long-distance flights." Bagg (1948:147) likewise suggests that
there is a strong barometric pressure-pattern in North American weather
that stimulates migration. While the southward flow of wind is perhaps the
outstanding feature of this favorable weather situation, I cannot believe that
it is the only influence starting off these mass movements. I have never
known heavy migrations to start out from Delta during the cloudy, unsettled
weather immediately preceding the arrival of the high-pressure air mass,
even though the wind blew from the northwest, the temperature dropped

104

Figure 14. Weather ideal for mass migration. The map shows the wind and air-pressure
patterns at 7:30 a.m., November 7, 1947. Mass waterfowl migration reached its peak at
Delta just before sundown on November 6, when it was estimated that 100,000 ducks
crossed the Delta Marsh in one hour. At the same time heavy migration was noted on
other Manitoba marshes, and a mass movement over the Madison, Wisconsin, region
was reported by Aldo Leopold (letter). The broad nature of this movement is reflected
in reports of waterfowl biologists, presented at the Ninth Midwest Wildlife Conference,
showing that 1947's heaviest migration down the Mississippi Flyway occurred at this
time: Minnesota, November 6, 7; Wisconsin, November 6, 7, 8; Nebraska, November 6,
8; Michigan, November 8; Illinois, November 7, 8, 9; Indiana, November 9, 10; Ohio,
November 6, 10; Missouri, November 6, 7, 8; Kentucky, November
10, 13; Louisiana, November 11.

MIGRATIONS OF WATERFOWL

and the barometer was on the rise. Thus, on the afternoon of October 30,
1954, the heaviest passage of the year crossed Delta during a period favor-
able in every respect except for repeated snow squalls. But despite the rising
barometer, the northwest wind, and the steady stream of migrants passing
over during most of the afternoon and early evening, none of the local ducks,
concentrated in many thousands, were seen to leave. Next day the weather
cleared and by evening the sky was bright. The local ducks started to mi-
grate at about 4:00 p.m., and by sundown we had seen a tremendous move-
ment away from Delta. The waterfowl that passed over in storm on October
30 no doubt had started from their more northern marshes under the clear
sky of the high-pressure system that did not bring fair weather to Delta until
the next day. I take it from this and from many similar observations that
open sky as well as favorable wind is important at the start of mass migra-
tions.

But then, if clear skies are a prerequisite for the beginning of mass mi-
gration, the passages cany on, nevertheless, to overtake and fly through bad
weather. The speed of migration is the product of the birds' air speed plus
the velocity of the wind ; hence the migrants travel faster than the weather
itself, often, as in the passage of October 30, 1954, catching up with the
region of storm ahead. Many times I have observed ducks arriving at Delta
in bad weather that was followed shortly by the broad edge of cloud intro-
ducing clear skies and fine anticylconic weather. They often passed right on

FLIGHT TRAILS SOUTH

through, as already described; sometimes they stopped, especially if the
storm was severe, leaving hunters to believe that it was the bad weather that
forced them south. When travelers choose to continue on in spite of the bad
weather they may have overtaken, their flights usually carry them through
to some more southern marsh. But the migrants by no means always attain
their destination, and sometimes vast numbers of waterfowl perish when
forced to ground by bad weather. ( See Chapter 12. )

A study of the movements of waterfowl through the autumn reveals that
ducks select anticyclonic weather for the start of their mass migrations, but
that the weather is not in itself the impetus. In September Mallards do not
always migrate with the favorable barometric situation that has a "trigger
effect" on Blue-winged Teal. Most Lesser Scaups and Mallards remain at
Delta through a mid-October anticyclone during which Redheads and Can-
vasbacks vacate the country. In the September and October movements
there is a falling temperature, but this may not even come close to freezing;
and both Blue-winged Teal and Canvasbacks leave a span of fair weather
and an abundance of food behind when they go. And while the November
migration of Lesser Scaups and Mallards coincides with the freeze-up, hard
weather and ice are not in themselves the cause of migration. Some years
large numbers of Mallards remain north in mild Novembers and then fail
to migrate southward when the inevitable deep cold of December and Janu-
ary arrives, sometimes perishing with open water only a few hundred miles
south (Rowan, 1931).

The schedule of the autumn migration is a confusing puzzle, beginning
as it does in August and continuing until November. But when the differ-
ent sex and age groups are studied individually * we find that there is an ar-
rangement of order. At Delta the fall movements have a remarkable regu-
larity from year to year, the exceptions being traceable to extreme weather
variations, drastic water-level changes and late breeding seasons. First to
go in mid- August are the adult drake Pintails ; most of them are on the wing
(after the flightless period of the eclipse molt) by early August and have
departed from Delta by the end of the second or third week of that month.
Following close behind are the adult male Baldpates; so common as flight-
less molters in midsummer, they move away from Delta in late August or
early September and are uncommon for the balance of the autumn. At

•The study of autumn movements has been greatly enhanced by the opportunities of
examining large numbers of waterfowl in banding traps and in hunters' bags along the stopping
places of migration and by the possibility of making completely objective appraisals of the sex
and age composition of these samples (Hochbaum, 1942; Elder, 1946).

107

MIGRATIONS OF WATERFOWL

about the same time as the Baldpates' departure, adult males of Blue-
winged Teal, Shoveller, and Gadwall also go.

The adult Mallard drakes have a coming together in early August, and
these, joined by juveniles, make up the stubble aggregations that remain
through September and most of October. In late September some of the
adult Canvasback and Redhead drakes arrive at Delta from the molting
lakes; the bulk of these species then make their departure in mid-October
at about the same time as the Lesser Scaups arrive in large numbers.

Some of these early movements are directly traceable to the breeding
season. The adult Pintail drakes, for example, depart shortly after they have
their new flight feathers ; and the end of the flightless season, of course, is
related in time to its beginning, which in turn hinges upon the breeding
schedule. It is the same in the Baldpate, and the difference in departure
dates between Baldpates and Pintails is about the same as the difference
between them in breeding schedules. The Baldpate leaves at a later calen-
dar date than the Pintail, but on the same physiological schedule. When
Mallards depart in late October or early November they have completed
their prenuptial molt and are in full breeding plumage; hence the timing
of their migration is one step further removed from the breeding cycle. The
same holds for the Lesser Scaup. Weller (1953a) found that nearly one-
third of the adult Redhead drakes he examined September 19 and 20, 1952,
at Lake Winnipegosis showed some soft primary wing feathers, evidence
of their recent flightless period. Perhaps their late-September arrival at Delta
is linked with their recovery from the wing molt, which comes later in these
diving ducks than in the Pintail. Gotz (1929), noting a general relation be-
tween molt and autumn migration, proposed the idea of a cycle : breeding,
molting, migration. Delayed breeding equals late molt; hence delayed mi-
gration.

Although there seems a close tie between molt and migration in some
ducks, I am not attempting to give evidence showing any cause-and-effect
sequence underlying all fall migration. I simply wish to show how important
passages are hinged in time to certain physiological as well as meteorologi-
cal conditions.

Some of the male aggregations hold together in flocks of their own for
some time after the flightless period of the eclipse, and Dawson ( 1923 ) tells
how adult Pintail drakes reach California during August in bands of their
own sex and age class. At Delta I have seen migrating flocks of Canvasbacks
and Redheads in late September which seemed to be made up wholly of

108

FLIGHT TRAILS SOUTH

adult males. A few adult males in all species join with the juveniles in early
autumn but, except for the Mallard, the adult drake is an uncommon prize
in the hunter's bag on the prairie marshes.

The adult female, which molts later than the adult male and in smaller
companies, does not make up aggregations of her own. When she recovers
flight after the molt of the wing feathers, she joins the young-of-the-year
and, according to the evidence of banding trap and hunter's bag, she migrates
with these juveniles, along with a lesser number of adult males.* Sowls
(1955:164) has summarized the adult-juvenile ratios of all ducks examined
in hunters' bags at Delta between 1938 and 1950 (Table 3). He found a

Table 3. Age Ratios for 10,607 Ducks Examined in Hunters'
Bags on the Delta Marsh, 1938-1950°

Species Adult Juvenile Ratio

Mallard

Gadwall

Baldpate

Pintail

Green- winged Teal.
Blue-winged Teal . .

Shoveller

Redhead

Canvasback

Lesser Scaup

279

2,238

1

1.7

174

370

1

2.1

46

185

1

4.0

173

255

1

1.5

41

96

1

2.3

96

323

1

3.4

97

318

1

3.3

120

981

1

8.2

306

2,307

1

7.5

305

897

1

2.9

* See Sowls (1955:164) for a complete breakdown of sex ratios.

strong membership of adults in the migratory fall populations, species by
species. These samples were taken in late September and through October
each year, of birds shot between, just before, or just after migration. If the
bags erred from the true population ratios, the bias is probably toward a
heavier representation of juveniles, which fly less well and are not so wary
as the adults. I believe the strong ratio of juveniles to adults in Redhead
and Canvasback reflects their greater vulnerability to the gun in early-
season shooting.

Although these hunter samples were taken at random from wild flocks,
it might be argued that adults and juveniles were shot from separate flocks.
It is true, indeed, that one finds bands made up wholly of young birds, while
some adult males keep to groups of their own. But in my hunting exper-
ience I have often taken adults and juveniles from the same flock when

° In an exception to this rule, Mallards, especially their stubble aggregations, may show more
adult males than females in autumn bags ( Hochbaum, 1944 ) .

109

MIGRATIONS OF WATERFOWL

gunning with a companion ; and when an area is vacated by ducks in mass
migration, adults and juveniles inevitably are companions.

This ratio of adults to juveniles varies from year to year because of vari-
ations in reproductive success (Hickey, 1952), but in an annual breakdown
of the Delta bags, and in the more recent bag examinations (Weller, 1953b),
there continues a strong element of adult birds.

It is this regular adult component of the population that must be, I
believe, the directive element in the mass autumn migrations. These pas-
sages are precise, deliberate, orderly, and oriented because of the presence of
the experienced birds. This is social orientation in which the actions of the
experienced set the direction for all. In these grand avalanches, with thou-
sands of birds and hundreds of flocks, each within sight of another, the
individual bird, like a private in a parade, moves with and as his com-
panions. The flock is the individual, "a collective bird, in fact, and however
stretched, straggling and complicated . . . the individual element seems
wonderfully in abeyance" (Selous, 1931:127).

Without documenting the discussion further, it seems fair to arrive at
five conclusions regarding the fall migration of waterfowl :

1. Massive movements of many flocks of ducks traveling at the same
time in the same direction are annual events.

2. The standard direction of these mass flights holds the same from
year to year.

3. These migrations sweeping vast numbers of ducks down the flyways
are regional in character, the shift southward being spread over a range that
is wide and deep.

4. Adult and juvenile ducks travel together in these movements.

5. These passages obey topographic features such as lakes, marshes, and
rivers when these lead toward the wintering grounds, overland routes being
followed when there is no direct watercourse.

Visual observations tell of the regularity of these major movements in
both place and direction, but show nothing of the fidelity of individual
birds to the trails. Does a duck come each autumn to the same places along
the way of migration ? The answer is to be found in the records of banding
stations, and there is no need to go further than McGinnis Slough for evi-
dence. This is a small lake within twenty-one miles of Chicago's loop. Here,
with wise foresight, the Cook County Forest Preserve has created an im-
portant, if small, stopping place for waterfowl moving down the Mississippi
Flyway; and here were banded some 26,415 ducks and coots during the

110

FLIGHT TRAILS SOUTH

years 1940-1945 (Mann, Thompson, and Jedlicka, 1947:206). Of these
banded birds, there were 3,393 recoveries, 659 of which were recaptures at
McGinnis Slough.* Here is the remarkable chronicle of approximately one-
fifth of all recoveries being made at the point of first capture, a stopping
place on the migratory highway. In the Blue-winged Teal, nearly half of
the recoveries were made at McGinnis Slough, and, considering survival
rates, these indicate that a large proportion of bluewings followed a migra-
tory lane that brought them south again by way of the same stop-over (for
Blue-winged Teal do not winter in northern Illinois.

Many other banding stations between the breeding grounds and winter-
ing quarters show the return of experienced waterfowl. Some stray, some
become lost, traveling another route; but the volume of return is sufficient
to establish the repeated visit as typical behavior. This return is typical also
of many other birds, a characteristic prompting Lincoln ( 1935b: 23) to make
the general statement that "many individuals migrate in fall over the same
route, year after year, making the same stops and finally arriving at the
same precise thicket that served them in previous winters."

I think this evidence of banding allows another conclusion regarding the
migration of waterfowl : not only do they start and end the annual cycle of
travel at a familiar home range, but the adults visit familiar stopping places
along the routes of migration. As the young fly in company with the adults
each year, these places and the connecting routes are passed along from one
generation to the next in a traditional manner.

The force of these mass migrations, their volume, their local concentra-
tions, their regional width, and the fidelity of adults to a given route all fit
into a pattern that has been established by field and banding observations in
many places. Let us hasten to admit, however, that this is only part of the
story. Matched against this swift, massive precision of the grand fall pas-
sages are the random travels of juveniles already discussed (p. 94). The
wanderings of young ducks start without the company of adults. As these
vagabonds move from one area to another, we see, by their growing num-
bers, that the dispersals away from home eventually lead to places where
waterfowl concentrate in major numbers, places where the young join com-
pany with all sex and age classes. Here many young take direct passage
with adults in the mass migrations, but we must not conclude that all young
gain the southland in this way.

Nor are wanderings confined to young birds. Records of banding sta-

• This refers only to recaptures in years following the year of banding.

Ill

Figure 15. Evidence of wandering during migration. Map shows northward dispersal

of fall migrant Blue-winged Teal during the same autumn as they

were banded at McGinnis Slough.

tions south of the breeding range indicate that even after ducks have gained
the southland, many individuals, some of them adults, continue their ran-
dom travels. Vogt (1934:268) drew attention to this when he found that
some autumn-banded waterfowl were killed the same season in Ontario,
Maine, and at other places far north of his banding station on Long Island.
Mann and his cooperators (1947) observed the same thing to be happening
with many of the ducks that stopped at McGinnis Slough. Of 141 direct
Blue-winged Teal recoveries,0 28 bluewings, or 20 per cent, were killed
north of McGinnis Slough (Figure 15). Five of these were adults. Pirnie
(1941:258) found that "in their fall dispersal from southern Michigan, some
Black Ducks and Mallards travel as far as two hundred or more miles west,
north or east." Intensely interesting is the "explosion" of Ring-necked Ducks
shown by Duvall (1949). Banded in southern Louisiana in November and
December, some were recovered west in Texas, north in Tennessee, and east
in Georgia and Florida before the end of the same year. Redheads that
were banded during the summer in Utah were found by Robbins (1949)
to fan out into eight more northern states and one Canadian province. Mann
(1950) gives a picture of a spectacular October shift of waterfowl from the

" A "direct recovery" is one in which the band is recovered during the same year the bird
was banded.

112

FLIGHT TRAILS SOUTH

Lower Souris Refuge, in North Dakota, northward into Manitoba, this
amounting to a "reverse migration" involving thousands of birds. During a
mild spell after heavy frost in November 1949, the Delta Marsh, empty of
Mallards and other waterfowl, was repopulated by great flocks of Mallards
which we saw arriving high from the south and southwest. A similar return
of Mallards from the south brought an abundance of "green-heads" to a
nearly empty Delta Marsh in November 1954.

Probably all ducks at least once each autumn partake in a mass migra-
tion sweeping southward over traditional routes, young and old together.
At other times, adults as well as juveniles, wander in all directions from
stopping places along the way of migration.

113

"Homing is a return to a place already familiar.
William Rowan, The Riddle of Migration

Homeward Migration

A small platform rises above the north shore
of Cadham Bay, and another railed perch overlooks the marsh from the
top of Kirchoffer Lodge. Spring evenings we wait at these lookouts to watch
the parade of waterfowl leaving Delta in migration. A few ducks, perhaps,
will reach their destinations before the last tinge has left the sky, but for
many others the evening's flight is but another step in the long journey
home. It is eighteen hundred miles from Delta to the mouth of the Macken-
zie River, where some must go.

The departure in the heaviest passages of spring occurs just after sun-
down. On northern prairies twilight and dusk linger more than three hours
after the late-April sun has set; at eleven o'clock there still remains a faint
sunglow in the northwest on cloudless nights. On evenings of heavy migra-
tion there is a steady flow of birds away from Delta until dark. After dark-
ness has settled completely and through the black hours of morning the
movement of transients may be heard overhead; but this night schedule
never attains the volume of the twilight migration.

In the departure of the travelers there is no circling upward. They take
off from the bays and at once set their course, climbing at a shallow angle.
Birds leaving the north edge of the marsh cross the ridge just above the
trees, while those from the south shore have climbed several hundred feet
by the time they gain the lake. The migrants strike out over the open lake
without hesitation, most of them making the crossing from the marsh at
passes, as described in Chapter 1. From ground level, Lake Manitoba appears
as a wide, frozen sea, the far shorelines below the horizon except during mi-
rage. From the height of one hundred feet, however, the west shore and
Big Point rise into view, and at two or three hundred feet the Riding Moun-
tains may be seen.

114

Flocks of spring migrants divide into smaller units on approaching the marsh.

These April flocks leaving Delta are smaller than the migrant bands of
October, although, as in autumn, it is usual to see several, often many
groups traveling across the sky at the same moment. Sowls (1951:34) found
twelve to be the average for migrating Pintail flocks, and I have never seen
a departing flock of more than twenty birds. The small clusters usually are
made up of birds of one species, although in Mallard and Pintail it is not
uncommon to see both kinds together. Most of the river ducks are paired,
each hen leading her drake, which follows so closely that the pair rather
than the individual makes up the unit of a flock. Some Canvasbacks and
other diving ducks are in groups of twos, but many bands boast only one
female, probably not yet mated, the several male companions undoubtedly
her suitors.

These small companies leaving Delta must join to make larger flocks once
the journey is under way, for on the wheat prairie south of the marsh I have

115

MIGRATIONS OF WATERFOWL

seen arriving migrants in flocks of fifty or sixty, sometimes even a hundred
or more birds. The individual components of these big companies show
themselves when they begin their long, shallow descent to the marsh. Then
the body of travelers breaks up into smaller groups, each making its inde-
pendent arrival at Delta.

Waterfowl reach Delta from two main directions (Figure 16). Some
come from the southeast, their source being precisely the same direction
into which they departed in the mass migrations of autumn. Others come
from due south. I do not know which of these directions produces the
greatest flow of spring arrivals, but I believe most of the waterfowl come
from the southeast. Surely all the Whistling Swans and most of the diving
ducks are from that direction.

In their evening departure, most ducks start out into the northwest to
a point of the compass that is the same whence they arrived in autumn. Not
all, however, are committed to this standard direction, and flocks some-
times may be seen breaking away to the north. Whistling Swans, like most
of the ducks, migrate into the northwest; Canada Geese go northwest, north,
or north-northeast; Richardson's Geese head north or north-northeast. In
their mass movement away from the prairie country, the Blue Geese and
the Lesser Snow Geese invariably fly to the same point of the compass in
the east-northeast (Figure 16).

Ducks reaching Delta in spring have their March and April rendezvous
in Minnesota and northeastern North Dakota. There, on the lake and marsh
country of the prairies, waterfowl from the east coast meet those of the
Mississippi Valley. Smith (1946) found that most Canvasbacks migrating
through Minnesota make their spring headquarters in the lake region about
Ashby, their heaviest numbers occurring on Lake Christina (Figure 16). On
April 4, 1942, he counted 2,000 Canvasbacks on Lake Christina ; the first Can-
vasbacks did not reach Delta until ten days later that year. The peak of the
Lake Christina population was April 12 and 13, when Smith counted 31,000
and 28,500 Canvasbacks respectively. The next day, April 14, when the first
of this species reached Delta, the Lake Christina population dropped to
12,500. Some Canvasbacks arriving at Delta on the fourteenth no doubt
came from Lake Christina.

The same holds for other ducks; when the time comes to leave Minne-
sota waters they fly directly to the Manitoba marshes. Most of the earliest
arrivals reach Delta during evening twilight. Ducks are seldom seen through
the first mild day of spring; even at sundown none has made its appearance;

116

Figure 16. Standard directions of spring migration for waterfowl and other migrants
arriving in southern Manitoba. Long arrows show direction of approach. Most ducks
and most individuals of many other species, such as hawks, blackbirds, Crows, and
Flickers, continue on into the northwest. But there are important departures from stand-
ard arrival directions at this point, as with the Blue and Lesser Snow Geese, which
arrive from the south, but depart into the northeast (short arrow). The map shows the
relation of Delta to the main breeding range and wintering range of North American
game waterfowl. (Pattern of breeding range compiled from Special Scientific Report:
Wildlife No. 25, published jointly by the U.S. Fish and Wildlife Service and the Cana-
dian Wildlife Service, 1953 ; wintering range from Phillips
and Lincoln, 1930, and Day, 1949.)

MIGRATIONS OF WATERFOWL

but before nightfall the first Mallards, and sometimes Pintails with them,
have made their return. I gather that these birds started out at sundown not
far south, and reached Delta before the light failed. Later on in April, great
numbers of migrants are seen arriving during the morning. If the rule of
evening departure holds elsewhere as it does at Delta, I presume that these
birds have come long distances on an overnight journey.

As in fall, there are "waves" of spring migrants, great numbers moving
away at the same time. The timing of these waves closely obeys the weather.
South wind and rising temperature mark the onset of the heaviest spring
migrations, and a glance at the weather map reveals that this pattern is an
exact turnabout of the autumn one precipitating the mass movements of
October and November ( Figure 17 ) . The high-pressure area is now located
on the eastern side of the continent with the low opposing it in the west,
the clockwise flow of air around the high and the counterclockwise stream
around the low creating the trough of southerly winds moving up the middle
of the continent. This, of course, is the situation so clearly described by
Bagg and his cooperators ( 1950 : 13 ) : "northward movement of migrants in
late winter and spring will normally begin under conditions of a barometric
gradient falling from east to west and of southerly winds typical of the west-
ward portion of a high pressure area (clockwise circulation) moving off to
the east or southeast. . . . When a high pressure area is supplemented by
a low pressure area ( counterclockwise circulation ) originating in the south-
west and moving northeastward, the influx of warm, moist tropical air is
extended and intensified; concurrendy, the northward movement of mi-
grants assumes the proportions of a pronounced onrushing wave in the
warm sector of the low pressure area." Schenk ( 1931 ) has described a similar
weather condition in Europe where, with the "low" over England and warm
air currents moving up from the Mediterranean, the pattern is ideal for
spring migration of Woodcock.

The importance of this meteorological arrangement for mass "pressure
pattern" migration was strikingly manifest during the spring of 1954, when
the east-west juxtaposition of the "high" and the "low" occurred only once
during the whole of April. It was only then that we saw a mass April move-
ment of waterfowl and other birds through the Delta region (Figure 17).
During the balance of the month the weather was dominated by a strong,
stable high-pressure area in northern Canada and, though migration was
not wholly stopped, the travel of waterfowl to and away from Delta was
thin for the balance of the month.

118

Figure 17. Weather ideal for avalanche of spring migrants. The map shows wind and air-
pressure patterns at 7:30 a.m., April 8, 1954. Few migrants had reached southern Mani-
toba by the first week of April. Canada Geese were the only waterfowl in the province,
with most ducks and geese still south of Grand Forks, North Dakota. On April 7 north-
west winds of 25-35 m.p.h. rushed from the "high" centered in northern Saskatchewan,
creating the worst blizzard of the year, with visibility reduced to 20-30 feet in the drifting
snow on the Portage Plains. It was calm and clear by nightfall, however, and the morning
of the eighth was bright and sunny, with mild southeast winds of 15-20 m.p.h Red-winged
and Rusty Blackbirds appeared in numbers by 9 a.m., and through the middle of the day
there was a heavy migration of Rough-legged and Red-tailed Hawks, with lesser numbers
of Sparrow Hawks. Canada Geese were seen shortly after sunup and their passage through
continued all day, one of Delta's biggest goose migrations on record. The first Whistling
Swans and a grand movement of Mallards and Pintails arrived between 3:00 and 4:00 p.m.,
and a few Great Blue Herons passed through before nightfall. South winds and bright,
mild weather continued till about noon on the tenth, with White Pelican, Richardson's
Goose, Shoveller, Sandhill Crane, Yellow-headed Blackbird, and Song Sparrow adding
their numbers to the grand passage. By 3:00 p.m. on the tenth the wind had shifted to
west, then northwest, and the migration ended.

When the nesting grounds are reached, the routes branch again and again to

accommodate each small band until every pair has finally

gained its own home range.

Bagg and his colleagues (1950) point out that favorable arrangement of
the high- and low-pressure areas, "while always of major significance in
spring, may be less absolute in character during the later part of the spring
migration than during the early part." It is thus interesting to observe that
while in late April and early May there was some migration almost every
day, the second biggest waterfowl movement of 1954 left Delta on the eve-
ning of May 4, the second time in 1954 when there was the east-west oppo-
sition of the high- and low-pressure areas in Canada. The third big rush of
waterfowl, which carried the Swans, Richardson's Geese, and wavies away
from Delta, occurred on May 10 and 11, when the high and low next opposed
each other favorably.

The grand movement of ducks into the northwest observed at Delta, is,
in effect, a major "trunk line" of waterfowl. Great masses of travelers go
together, despite their division into small flocks, in the general direction of
their destination. But it cannot be that these birds are swept along with
this movement; each must bend away from the main stream at the correct
time and place for turning. Some Redheads, for example, reach their Minne-
sota stopping place together en route from the Atlantic Coast, but those
destined for Delta must now go differently from companions traveling to-

120

HOMEWARD MIGRATION

ward the Libau Marsh on Lake Winnipeg. With the breeding range of ducks
spread so widely over the northland, the pattern of homeward migration
must eventually show as many divisions as there are pairs in flight. In south-
ern regions there are common channels for many thousands of birds. Then
come major migratory divides where large groups turn toward one or another
breeding region. When the nesting grounds are reached, the routes branch
again and again to accommodate each small band until every pair has finally
gained its own home range. This requirement for division is the reason for
the smaller size of spring flocks.

Some, of course, may take the wrong turn or continue with the main
stream when they should have separated from it. The experience of Sowls
(1955:15) with his color-banded adults, however, is evidence of the effici-
ency of spring passage. His marked ducks arrived on their Delta home range
with the very first flights of spring, the promptness of this return suggesting
a direct passage from the last stopping place.

Awareness of the direction of the destination is suggested by the be-
havior of the Blue Geese and Lesser Snow Geese when they leave the prairie
country in May. They have traveled north up the Mississippi Valley to
Canada ; but they now turn northeast, and if the line of their flight, as seen
in the Delta region, is plotted on a map (Figure 16) it points directly to the
region of James Bay, which is their next stopping place (Soper, 1930, 1942).
Hickey (1943:28) once "enjoyed a mellow April evening with two friends
atop the Palisades along the lower part of the Hudson River near New York
City. Hundreds of scaups began flying over our heads at 5:44 p.m. Leaving
Long Island Sound, a few miles eastward, the birds were headed in a west-
northwest direction over New Jersey's Hills — supposedly for the Finger
Lakes." Bent (1925:131) tells how the May departure of White-winged
Scoters from the New England coast aims for the Canadian prairie breeding
grounds. In 1953 the first Canada Geese seen at Delta flew straight north
over the village, and we learned from Ralph Otto that Canadas reached their
Dog Lake nesting grounds, sixty miles due north of Delta, later the same
day. Probably the birds we watched were headed straight for Dog Lake.

Sometimes we are fortunate enough to witness the actual splitting of a
migration. On the morning of April 20, 1952, I saw a steady stream of
Canada Geese flying northeast across the Libau Marsh near Colonel Sulli-
van's lodge, while at the same time, others of the same kind were flying
northwest. A very interesting split in the migration of Canada Geese north
along the Red River was described to me by J. W. Baldock. Near the town

121

MIGRATIONS OF WATERFOWL

of St. Jean Baptiste, Baldock saw a flock of twenty-seven Canada Geese
coming northward along the Red River Valley, and as he watched, nine of
these broke away from the main flock to fly in a northwesterly direction.
"The remainder of the flock continued north down the Red River. I was
watching them with binoculars when two geese left the main flock before
they reached St. Jean. They circled to the west and finally flew west-north-
west behind the nine which had originally broken away."

The homeward migration is not simply a "north" flight, neither is it con-
stant in direction throughout, nor do all individuals of a species follow the
same course all the way. In its entirety and in its individual segments, the
direction of the vernal passage depends upon the individual place of home.

The main passage of waterfowl through Delta consumes about three
weeks each year, mostly in April; the first week in May brings a close to the
heavy travel except in late springs. The migration period for a given species,
however, is very long when the entire range is considered, and varies ac-
cording to the location of the home nesting grounds. Pintails, for example,
reach Delta in early April (Table 4) and some years have started nesting
before the middle of the month. Others go on to the Arctic, not arriving on

Table 4. Distribution of Arrival Dates during Sixteen Years
(1939-1954) at Delta, Manitoba

Number of Years Total Years

March March 28- April April April April 29- May Recorded
Species 20-27 April 4 5-12 13-20 21-28 May 6 7-14 1939-1954

Canada Goose 5 7 4 16

Mallard 4 6 5 1 16

Pintail 2 5 7 2 16

American Golden-eye 2 1 7 5 15

American Merganser 2 2 10 1 15

Lesser Snow Goose 1 1 4 2 1 1 10

Blue Goose 1 1 4 2 1 1 10

Baldpate 5 7 3 15

Canvasback 5 7 3 15

Redhead 1 4 6 3 1 15

Lesser Scaup 5 6 4 15

Green-winged Teal 4 7 3 14

Shoveller 5 5 5 15

Red-breasted Merganser... 2 2 6 1 11

Ring-necked Duck 2 4 3 1 10

Buffle-head 1 4 4 2 11

White-fronted Goose 1 4 3 1 9

Gadwall '. 3 5 7 1 16

Blue-winged Teal 1 3 10 1 15

Ruddy Duck 1 6 8 1 16

White- winged Scoter 1 4 10 15

122

HOMEWARD MIGRATION

their nesting ranges before the first week in June. Robert H. Smith, who has
made extensive studies of breeding waterfowl in the north, tells me that
Pintails using the delta of the Mackenzie River do not begin nesting there
until early June, fully six weeks after the first Delta Pintails have their eggs
and at a time when a few of the earliest Delta hens have half-grown young.
Some of these Arctic ducks may winter with or near Manitoba Pintails ; per-
haps the two start north at about the same time. But some Delta individuals
are nearly finished with their reproductive activity before the northernmost
birds have started nesting. This same thing, of course, occurs with other
kinds of waterfowl: Arctic breeders are still migrating long after southern
relatives have produced you ig.

The force that impels them to move northward must be the same for
Delta and Arctic Pintails, but the later stages of the sexual cycle are delayed
in the most northern individuals. Wolf son (1942:262), who studied the
breeding cycle and migratory behavior of the Oregon Junco, found that resi-
dent and migrant birds "differ in their gonadial cycles, although they flock
together in the winter and are subjected to the same environmental condi-
tions." These differences were between races or subspecies of the Junco; the
migrants may be distinguished taxonomically from the residents. In Pintail,
of course, Delta and Mackenzie River birds are not racially different. Be-
cause of the hen's fidelity to her home of previous experience, the schedule
of the breeding cycle must be linked to the geographic location of home, Del-
ta Pintails nesting in April and those of the Far North in June. The existence
of innate differences in breeding time is unlikely, because of the blending of
geographical units of population on the wintering grounds, where a Delta
drake might take a Mackenzie River hen for his mate. This mixing of blood
no doubt accounts for the absence of geographical races in the American
Pintail, and is the reason why a variation in time of nesting would not de-
velop as an inborn character in different units of the population. In other
words, the progeny of a June-nesting Mackenzie River Pintail would prob-
ably nest in April in Manitoba if artificially transported there as downy
young. In the Blue and Lesser Snow Geese we find this very thing happen-
ing. Captive geese taken from the wild are nesting at Island Park, Portage
la Prairie, in May, before their free wild brethren have reached the nesting
grounds in the Arctic.

Sowls found the female to be faithful to her breeding place as long as
that area remained favorable for nesting. When, as sometimes happens, a
duck returns to find her homeland unfit for nesting — as when cover is lost

123

MIGRATIONS OF WATERFOWL

to fire, when agriculture has drained sloughs and potholes, or when the
water is gone owing to drought — she must move elsewhere. This happens
sometimes on a grand scale. In 1949 a large portion of the mixed prairie
country of southern Saskatchewan dried out, and thousands of ducks re-
turned to find their breeding grounds untenantable. They evidently settled
elsewhere, and Lynch ( 1949 ) says that "it is quite apparent that some ducks
moved northward out of the dry grasslands and nested in the wetter Aspen
Parklands." Hawkins (1949) detected a late spring influx into Manitoba's
pothole country that same year and attributed these delayed arrivals to the
Saskatchewan dry-out. Prairie ducks are extremely mobile when compelled
to seek new breeding localities, but Hawkins believes that they do not re-
produce so successfully after forced moves as when they breed on their
home range. It is quite possible that some ducks simply refuse to breed
when conditions prove unsuitable, and Kalmbach (letter) suspected this to
be the case with the Canvasbacks he studied in the Prince Albert region of
Saskatchewan when the nesting grounds were shrunken during the dry year
of 1935.

As in the fall, homeward migration moves on a wide front, and when
waterfowl pass over Delta we are aware, by word of cooperators, that similar
passages are taking place over other marshes. Merrill Hammond and I
noted, for example, that in 1949 the first major waterfowl flight of the year
reached Delta, Manitoba, and Upham, North Dakota (150 miles to the
southwest), on April 8. Weather may cause regional variations, however,
and, as there is a tendency for spring to arrive earlier on the western plains,
ducks are sometimes well established in southern Alberta before they have
reached this same latitude in Manitoba.

Each migrant travels homeward with urgency; whatever the barriers
of storm, time, or distance, the bird must bring itself to the homeland for
which it hungers. Its whole being has an appetite for the range where repro-
duction will take place; as the salmon drives relentlessly to the headwaters
of the mother stream, so, with its sexual awakening, a duck or goose must
satisfy its need for the home marsh. This requirement for a special place or
situation falls into the pattern of appetitive behavior (Craig, 1918); "in-
ternal factors, sometimes together with external stimuli, activate a 'drive'
or an 'urge' in an animal" (Tinbergen, 1952:2), this giving rise to behavior
directed toward the attainment of a biological goal.*

0 For a further discussion of goals, "consummatory acts," or "consummatory stimuli," see
Tinbergen (1951) and Bastock et al. (1953).

124

The urge to incubate is satisfied when the clutch is completed.

This drive Thorpe ( 1951b :6) identifies as "the complex of internal and
external stimuli leading to a given behavior." The goal of appetitive be-
havior may be a performance of a particular act, e.g., copulation or egg
laying, or the attainment of a particular relation with something in the
external environment, e.g., incubating a suitable clutch of eggs.

Obviously the whole of the action from the beginning of appetitive be-
havior to goal cannot be carried out on the level of instincts : the bird must
get from the place where a drive is awakened to the special companion,
object, or environmental situation where the appetite is sated. There is an
interval of time and space where learned behavior serves to guide the indi-
vidual. Mallard hens the world over have the same appetites when the ovi-
duct is with egg; universally this hunger is satisfied by egg-laying at the nest.
But each and every Mallard must learn the way to her own nest. It is in
this period between drive and goal "that the adaptive and individual vari-
able responses are found . . . where learning in all its variety enters into
the life-story of the animal. . . . Instinct and intelligence are thus inter-
woven to form the whole pattern of behavior of the individual" (Thorpe,
1951b:7).

Appetites are awakened daily by many drives. There is the everlasting
requirement of food, the need for gravel and water, the urge to bathe and
preen. Such acts are nonsexual, repeated on a daily basis throughout life,
regardless of sexual status. The reproductive drive, on the other hand, is

125

MIGRATIONS OF WATERFOWL

tied to a single period of the annual life cycle. More than this, breeding be-
havior is divided into certain divisions of the reproductive cycle; as spring
advances, there is a sequence of sexual appetites. Some of these may be
given in chronological order: the urge to take a mate, consummated when
the pair is formed ; the appetite for home range and territory, satisfied when
the home marsh is reached; the need to incubate, appeased when the clutch
is completed. Normally the sexual behavior progresses step by step in an or-
derly fashion until nesting is finished and the young reared. Sowls (1949)
showed, however, that if one link in this chain is broken, the duck may
revert to an earlier stage in the cycle. When the nest is destroyed, for in-
stance, the female often returns to egg-laying; if her mate has by then
departed, she may go back still another step and seek another drake as her
partner.

For migratory waterfowl the appetites of the sexual cycle arise on the
wintering waters at a time when the breeding marshes are still in the grip
of frost. The first reproductive goal, taking the mate, may be attained in
early winter or, sometimes in the Mallard, during autumn. Later, drake
and hen migrate together. Her appetites now are for acts that can be con-
summated only at a special place, the familiar home range. He hungers for
behavior which is to be activated only after his mate has settled down on
her home range, part of which becomes his defended territory. In some fe-
males the appetite for the breeding place may be aroused before she selects
her mate, and she migrates unmated, although usually attended by several
suitors.

Eagle Clarke ( 1912 ) , aware of the sexual nature of homing migration,
suggested that "the periodic physiological changes in progress at the ap-
proach of spring in the shape of the development of the reproductive organs,
with their corollary, the reviving instinct of procreation, must prove an over-
powering incentive to seek accustomed breeding haunts." The pioneering
experiments of Rowan (1926, 1929a, 1931) demonstrated the intimate relation
between sexual awakening and homing migration. Inner stimuli of a sexual
nature awaken the appetite for the home, which may be attained only by
migration.* Fundamentally this drive-to-goal pattern of homing migration
differs from other appetitive behavior in the sexual cycle only in terms of
time and space. The distance from loafing bar to nest may be only a few
minutes and yards ; the distance between wintering waters and home marsh

• Since Rowan's original studies there has developed some confusion concerning the exact
endocrine seat of these stimuli; but it is not denied that the migrational homing of spring is a
sexual act. See Farner (1950) for a careful review and bibliography.

126

HOMEWARD MIGRATION

may be many days and hundreds of miles. But only the time and the miles
of travel are different; the appetites within the hen on her wintering
grounds are in the same category as those sensed by the nesting duck on
her loafing bar. In some females, like Mallards that winter and also nest in
Missouri or Colorado, there are few barriers between drive and goal. In
others there may be two thousand miles or more between the first sexual
appetite for the home range and the arrival there. The barriers are in direct
ratio to the distance traveled. Temperature, wind, snow, and rain are factors
in the schedule of travel to the breeding place, the birds staying back in the
face of severe adversities, surging onward in favorable weather. Weather,
however, must be a secondary influence on spring migration, incidental
rather than fundamental.

There are two possible exceptions to this sexual nature of spring migra-
tion of waterfowl to the breeding grounds. In geese and swans, for one ex-
ample, nesting does not take place the first spring, so that in yearlings the
home is not the sexual goal in the same sense as it is in adults. The family
bond is strong enough, however, to carry the young along to the summer
home of the parents, which do travel on a sexual schedule. Once arrived
on their home area, there is intense sexual behavior in these yearlings, even
though it does not attain reproduction (Balham, 1953). There are also some
ducks, such as Bufflehead and the two Golden-eyes, which do not breed
until they are more than one year old. Unlike the geese, the yearlings of
these have no family ties. However, there is evidence that some arrive at
the breeding grounds independently ( Munro, 1942), and we are not entirely
sure that, despite the lack of breeding, there is not some sexual awakening.
At Delta I have seen yearling American Golden-eyes examining nesting
boxes; and for the yearling Barrow's Golden-eye, Munro (1939:272) says
that "there is some manifestation of sexual excitement amongst them and
they go through various performances which in the adults form part of the
reproductive process." Homeward travel for these birds might possibly be
classified as a sexual movement even though reproduction does not follow.

I must not let this discussion end without brief mention of some of the
other migrants. The sweep of spring migration cannot escape the knowledge
of the most casual citizen in Manitoba's April countryside, for the rush of
travelers into this nearly birdless world of winter is a daily reminder of
spring's arrival on the northern prairies. In the latitude of southern Mani-
toba in late April and May, there are less than four hours of darkness com-

127

MIGRATIONS OF WATERFOWL

pletely lacking in sunglow, and in the urgency of their homeward migration,
a great part of the spring transients go through while there is enough light
in the sky for us to see their passage. Most conspicuous of the daytime
travelers are the four species of blackbirds,0 the Bronzed Grackle, all hawks,
swallows, the Crow and Bluejay and the Flicker, which carry on the whole
of their migration with sunlight in the sky. Many others among the shore-
birds, thrushes, finches, and warblers are conspicuous daytime travelers,
although they also migrate heavily after dark.

In all these kinds I have mentioned, the main source of arrival is the
southeast; and in some species, such as the Flicker, the total of the season's
passage apparently comes from that direction. In the blackbirds, some reach
Delta from the straight south, and several times I have followed a flock for
miles as I drove along a north-south highway; but most travel across the
prairie at the same southeast-northwest angle. They come on a broad front.
On the morning of April 27, 1951, Colonel Arthur Sullivan, Premier Douglas
L. Campbell, and I encountered twenty-five flocks of blackbirds along the
forty-five miles between the outskirts of Winnipeg and Portage la Prairie as
we drove westward along highway No. 1. The flocks were rather evenly scat-
tered along the way and most of them were just departing from the wooded
river valley, striking northwest across the White Horse Plains. At the same
time we saw Flickers everywhere along this course, in trees or starting out
to the northwest across the bald prairie. On other days I have seen the
movement of blackbirds and Flickers evenly spread all the way east to
Libau, Manitoba, a distance of about sixty-five miles, and at other times to
Roseneath, seventy miles west of Delta.

When these hawks, blackbirds, Crows, and Flickers cross the marsh and
arrive at the edge of Lake Manitoba, they do not continue over the lake, as
the ducks do, but turn to follow the shoreline westward. There is thus a con-
centrated lane of travel along the wooded ridge, with flocks of blackbirds
sometimes going over the village of Delta at the rate of two or three flocks
a minute. On the morning of April 25, 1951, in a flight lasting from about
6:00 to 9:30 a.m., I estimated that at least 50,000 blackbirds flew over the
village.

In their travels the blackbirds have an air speed of about twenty-five
miles per hour, and the Flicker and the Crow an air speed of about the same.
I have seen blackbirds travel at elevations ranging from a few feet above the
ground to approximately 500 feet. Most going past Delta are between 25

* Red-winged, Brewers, Rusty, and Yellow-headed Blackbirds.

128

..^:

Blackbirds migrating west along the lakeshore

and 200 feet, always flying lower when moving against a wind. Crows fly
at elevations of less than 300 feet, often well within gun range just above
the trees. Flickers go along at treetop level, always as single birds, although
one bird is usually in sight of another. All of the swallows, blackbirds, and
other diurnal travelers that move with flapping flight carry on their heaviest
migrations during the morning, afternoon, and evening hours, resting and
feeding during midday. The soaring kinds, such as the broad-winged hawks,
travel mostly through the middle of the day when thermal currents give
them the greatest lift. I have seen a heavy migration of Rough-legged
Hawks end abruptly as the wind died, almost every lone tree far and wide
across the prairie suddenly boasting two or three, sometimes a dozen or
more, of these big birds.

On a day of southeast wind I found the average ground speed of black-
birds to be thirty miles per hour and the total span of their morning and
evening passage eight hours. Thus many birds may have traveled more than
two hundred miles. If the migration had been about the same all along the
way, those that ended their day at Delta started well south of the interna-
tional border in Minnesota, while those that set out from Delta went at
least a hundred miles across the border into Saskatchewan.

These hawks, blackbirds, Crows, Flickers and others continue westward
around the lake until reaching the mouth of the Whitemud River at the
southeast corner. Thence they branch into the northwest again ( Figure 18 ) .
This deflection away from the west shore of Lake Manitoba leaves an area
nearly vacant of migrants, much as the hiatus described for the north shore
of the Gulf of Mexico (Lowery, 1945; Williams, 1945). For example, be-
tween eight and eleven o'clock on the morning of April 16, 1952, Les Garn-
ham, posted at Delta, counted 137 flocks of blackbirds pass westward. The

129

Figure 18. Deflection of blackbirds around Lake Manitoba, showing migratory divide at
southeast corner of lake and the coastal hiatus on the west shore. All hawks, Flickers,
and all Crows and other passerines follow the same leading lines of the lakeshore, split-
ting their migration to go up the east shore or around the south end of Lake Manitoba
In reverse migration the direction of travel is directly opposite to that shown here.

same morning Pete Ward and I saw them branching away from the lake at
the mouth of the Whitemud River, but when we carefully surveyed about
30 square miles of the farmland along the west shore and on Big Point to
the north we saw not a single blackbird. Moreover, Ralph Thompson, a
farmer on Big Point, told us that so far that spring he had seen only one
flock of blackbirds, although at Delta they had been passing through steadily
for ten days.

Just as there is a steady flow of these migrants westward around the
south end of Lake Manitoba, so there is another concentrated lane of travel
going northwest along the east shore. In short, there is a major migratory
divide at Lake Manitoba where the flight, arriving on a broad front, is split,
some flocks going one way, some the other. This divide is at the southeast
corner of the lake. Peter Ward and I watched this southeast shoreline during
a heavy blackbird migration on the morning of April 26, 1951. Flocks ar-

130

HOMEWARD MIGRATION

rived steadily from the southeast flying directly to the lakeshore. Here they
went one way or the other : some went up the east shore, while others turned
to go around the south end of the lake, this choice requiring them to make
nearly an about-face swing (Figure 18). This splitting of the flight did not
take place sharply at one point of the lakeshore, but occurred over a stretch
about twenty miles long. The result was a two-way flow of birds going in
opposite directions. This migratory divide is the same for Flickers, Crows,
all the hawks, and, indeed, for all the shoreline travelers, and on days when
there is a heavy westward flow at Delta I have seen just as steady a passage
to the northeast along the eastern shoreline.

This turning place at Lake Manitoba is probably only one of several such
decisions the migrants must make during a day of travel. Earlier, there must
be a splitting of the flight when some birds branch north to Lake Winnipeg.
Mr. A. G. Lawrence, veteran Winnipeg naturalist, has made an energetic
search for this turning place of Lake Winnipeg blackbirds and believes there
is a major migrational divide at the bend of the Red River near Morris,
Manitoba, the same bend where Baldock saw the splitting of the Canada
Goose flock (p. 122). Of Flickers I have watched several different flight
lines on the same day, all stemming originally from the main current flow-
ing to the northwest. On April 25, 1951, I saw a steady stream of Flickers
going northeast across the Libau Marsh toward the east shore of Lake Win-
nipeg. Another flight went north up the Red River Valley. A steady move-
ment of Flickers went northwest over the prairie between Lake Winnipeg
and Lake Manitoba. There was a concentrated flow northwest along the
eastern shore of Lake Manitoba and a westward passage over Delta around
the south end of the lake. For individuals with far destinations, the wrong
turn in Manitoba would be as serious an error as that of a Vancouver-bound
railroad passenger boarding the Illinois Central in Chicago.

These diversions of Flickers, blackbirds, and all the other birds from the
main currents of migration, the many separate departures from the standard
direction, are interesting in view of the relation between weather and mi-
gration. The strong southerly flow of winds favors the mass movement of
most birds following the standard direction ; but it is clear that the migrants
are by no means swept along in this current of air. When the turning point
is reached, the travelers bend this way or that, even though they must now
cross the wind rather than go with it. Blackbirds making the turn around
the south end of Lake Manitoba are obliged to face the wind for a while in
order to follow their chosen course. Let us note, too, that while the south

131

MIGRATIONS OF WATERFOWL
wind favors the movement of most ducks going to the northwest, the Blue
and Lesser Snow Geese travel to the northeast, directly across the main flow
of air. Clarke (1912) believed that the clear weather of the high-pressure
configuration influenced the start of heavy migrations, but that the wind
produced by this barometric arrangement did not control the direction of
migration. We must examine other qualities of the anticyclone that influ-
ence migrations. In this respect, we have noticed that among the captive
birds at Delta, during their winter residence in the indoor pens, there is
increased activity — of feeding, fighting, wing-beating and courtship — when
the weather changes from "low" to "high," this despite the fact that they
are protected from the wind.

Lowery (1951:468) points out that "since the general movement of the
air is from the high-pressure area toward a low-pressure area, birds starting
their migrations with favorable tail winds are often ultimately carried to a
region where conditions are decidedly less favorable. In the vicinity of an
area of low pressure the greater turbulence and high wind velocities, com-
bined with the possibly slightly less bouyant property of the air, caused
birds to descend. Since low-pressure areas in spring generally precede cold
fronts, with an attending shift of wind to the north, an additional barrier
to the northward migration of birds is imposed." Very often we see this
effect on the travelers at Delta. All morning there may be a steady flow of
Juncos, blackbirds, and many others past my office window; then suddenly
I am aware that travel has stopped. Great flocks of Juncos are feeding every-
where on the lawn and about the hatchery; the taller trees are loaded with
blackbirds and the thickets with Robins, Tree Sparrows, and other small
birds, many of which now burst forth in song. A cold, damp wind comes in
off the lake, the long cloudline of the front passes overhead, and we know
that the heavy passage has stopped for a while.

The westward direction of the movement along the lakeshore at Delta
is standard except when (as occurs at least once each year) these migrants
turn about to fly steadily in the direction whence they came. I take this to
be a reverse migration, such as is described by Natorp ( 1932 ) , Lewis ( 1939 ) ,
and others. Such reverses seem to be associated with sharp changes in the
weather pattern. On the morning of April 21, 1951, for example, there was a
southeast wind of 5 m.p.h. ; the sky was lightly overcast, the temperature,
38° F. From 5:30 to 7:00 a.m. there passed a steady westward flight of black-
birds, mostly Redwings, which at its peak averaged a flock a minute. This
traffic slowed down shortly after 7:00, after which single flocks went by at

132

HOMEWARD MIGRATION

intervals of from fifteen to twenty minutes. There was a small movement of
hawks, mostly Red-tailed Hawk, and a massive westward drift of Juncos and
Tree Sparrows. About 9:00 o'clock the wind shifted to come from the west,
and all westward travel ended an hour later. At noon the wind was blowing
about 10 m.p.h. from the northwest, there was a heavy, low overcast, and
the temperature dropped below freezing. Shortly after noon I noticed
Juncos and Tree Sparrows drifting eastward; all afternoon they moved
through the thickets and across the clearings in that direction, the volume of
their eastward passage being equal to the morning travel the other way.
Flocks of blackbirds and small numbers of Crows also flew eastward. Next
morning the wind continued from the northwest, but it was bright and
clear. A few Juncos, one flock of blackbirds, and several hawks going west
made up the total of the migration for the day, while the Juncos and Tree
Sparrows remained about the hatchery in their many hundreds. April 23
was cold and cloudy, with a west wind, and there was no migration. The
twenty-fourth broke bright and clear, with a south wind, and there was a
short but heavy westward migration of blackbirds and Crows in the morn-
ing; but the Juncos and their companions did not travel. The twenty-fifth
brought rising temperatures, strong southeast winds, and the heaviest migra-
tion of all species for the year.

When these reverses occur at Delta, I have seen evidence of the turn-
about on the prairie country to the south, where on such days there is a
steady drift of birds to the southeast. Whatever the influence, many birds
over a broad region are induced to turn back on their migratory highway,
retracing their steps several, sometimes many miles.

Though such reverses occur most frequently in the small species, I
have seen similar changes in the flow of waterfowl. On the evening of April
23, 1950, for example, a migration of ducks, mostly Mallards and Pintails,
began soon after 7:00 p.m., the birds all going in their usual direction toward
the northwest. Shortly after the flight started, ducks began arriving on the
marsh from the northwest, and it was apparent that they had turned back
soon after they were out over the open lake. The same evening there was a
reverse movement of blackbirds and Crows; Juncos and hawks had been
going eastward all afternoon. Next morning the prairies were blanketed with
three inches of snow. Sowls ( 1955 : 19 ) describes a reverse in which the ducks
departed completely from the Delta region.

The homeward passage of birds somehow touches the fives of us all; and
yet we have been mainly concerned with these wayfarers when they stop

133

for a while in the course of their vernal journeys. Arrival dates, species by
species, have been faithfully recorded by thousands of observers widely scat-
tered over the land. But we know almost nothing of the timing of the main
flow of migration. There is very little information in North America about
standard directions, as judged by studies of birds in passage rather than as
plotted from banding recoveries. Thomson (1953) says that there has been
a tendency to regard visible migration by day as 'largely a special oppor-
tunity of favored places where spectacular diurnal movements were regu-
larly to be seen ; and this in itself may have given impressions that were in
some respects misleading. In recent years the possibilities of the method
have been more fully appreciated, and this has resulted in a great access of
interest in this aspect of the general subject. Dutch and Swedish observers
have done outstanding work in showing what can be learnt by systematic
study of visible migration, and ornithologists in several other countries are
contributing to the total effort." In the light of Griffin's observations on the
role of ecological factors in migration, and in view of the exciting discoveries
of Kramer and Matthews regarding the influence of the sun, it is important
for North American students to give more time to the study of birds in the
very act of migration.

134

'Spring migration is scarcely completed before there occur
certain summer movements which precede the true autumn
migration." A. Landsborough Thomson, Bird Migration

10

The Classification of Waterfowl Travel

Our word "migrate" comes from the Latin migratus,
the past participle of migrare : "to move from one place to another." It lacks
the element of permanent settlement carried in the word "emigrate" and is
defined by Webster's Dictionary as "to pass or remove from one region or
district to another for temporary residence."

Most of us think of migration as the spring and autumn sweep of birds
to and from their nesting ranges. Many authors, however, have used the
word with reference to other travel occurring between the two main pas-
sages. The literature is thus sometimes confusing; ornithologists seem not
to have found in "migration" so precise a meaning as it still holds for lay-
men. There have been many attempts to correct this situation, like Geyr
von Schweppenburg's suggestion (1933) that we adopt the term Zwischen-
zug, or "between-migration," to distinguish all travel taking place between
spring and fall. I prefer the more recent idea of Wilkinson (1952). He pro-
poses that we refer to the vernal and autumnal migrations to and from the
breeding grounds as anastrophic migration — from the Greek avaarpefoiv, "to
retrace one's steps." All other movement he catalogues as diasporic migra-
tion — from the Greek Siao-Tropa, "dispersion."

The travels of waterfowl come neatly within these two broad classifica-
tions, and placing the various migrations in one or the other category does
much to strengthen our understanding.

ANASTROPHIC MIGRATION
Homeward spring migration

Homeward spring migration carries the bird from the place where its
sexual drives are awakened to the nesting region where the reproductive

135

MIGRATIONS OF WATERFOWL

appetites are consummated. The distance of homeward migration in ducks
varies from a few miles for some individuals which nest near their winter
range, to several thousand miles for others of the same species. In ducks
which take new mates each year, the destination depends upon the experi-
ence of the female returning to her home range. In geese and swans, which
mate for life, the pair annually returns to its familial breeding grounds. In
ducks, parents and children (which in many species are ready to breed their
first spring) are not together as family groups, having separated the previous
summer. In geese and swans the homeward-bound adults are accompanied
by their yearling children. In the Northern Hemisphere this sexual migration
toward the nesting place may begin as early as January for some individuals,
while others do not gain their breeding grounds until June. Birds nesting at
the southern edge of the breeding range may have young before others of
the same species have arrived on nesting places in the extreme north.

The homeward migration of cranes is like that of the geese and swans.
Some other birds, like the Crow and the Barn Swallow, reach their nesting
place in pairs, as do many ducks ; but I do not know whether the female so
strongly directs the course of migration as in ducks. The pattern in water-
fowl, of course, is very different from that in many passerine birds, such as
the Red-winged Blackbird (Allen, 1914), in which the male returns to his
breeding territory before the female.

The impetus of homeward migration is sexual, but the exact schedule, by
days or weeks, is modified by the weather, with the heaviest spring passages
occurring "during the interval between the passage of a warm front through
the region and the subsequent arrival of a cold front" (Bagg et al, 1950).

Mass fall migration

Mass fall migration is the act of experienced birds retracing their steps,
usually over standard directions in direct passage from the breeding or
molting range to the wintering grounds or to traditional stopping places
along the way. Mass fall migrations begin in August, after the adult males
have completed their flightless period of the eclipse molt, and they continue
through the autumn till the final evacuation from the breeding grounds with
the arrival of deep frost. Mass movements may be made up entirely of adult
males of one species, as in the post-molt flight of adult drake Pintails, or they
may be composed of all sex and age classes, with several or many species
represented. When a number of species move in mass, each kind, neverthe-
less, holds to flocks of its own in which juveniles and adults are usually to-

136

CLASSIFICATION OF WATERFOWL TRAVEL

gether. Although young-of-the-year may outnumber adults in direct mass
migration, these passages are essentially the movements of experienced
birds. By this act of travel with the adults, the juveniles, as children (in
geese and swans) or as unrelated companions (in ducks), accept the non-
genetic heritage of the traditional route, which thus becomes ancient be-
yond the experience of any living individual and is passed on to succeeding
generations by social inheritance.

If inexperienced juveniles arrive at the wintering grounds independently
of experienced companions (as some do every August and September), this
probably is the result of the undirected wanderings of young-of-the-year,
vagabond travel that carries other juveniles of the same kind and at the
same time to marshes north or east or west of the natal range.

Mass fall migration accounts for the direct passage of waterfowl by
hundreds, thousands, or, in late fall, hundreds of thousands at a time, moving
over a region many squares miles in extent. By such passages most individ-
uals of a species or, at the time of deep frost, all waterfowl may evacuate their
summer range overnight, leaving only cripples and a few stragglers behind.

The biological impetus for mass fall migration is not understood. In
some birds, like adult drake Pintails, the movement is related to the recovery
from the flightless period of the eclipse ; by links with the molting schedule,
its timing may be traced directly to the breeding period. There is consider-
able variation among species in the time of departure (witness the Septem-
ber passage of Blue-winged Teal and the mid-October departure of Canvas-
back), but each kind shows a calendar regularity that differs little from year
to year. Species migrating in September or early October from the Canadian
prairies leave an abundance of food and a span of fair weather behind them.

Though fall departure occurs at about the same time each year, weather
has a "trigger efEect" which influences the exact day when the mass migra-
tion will start. Regardless of the stage of the autumn — mild September or
cold November — mass fall migrations begin with the arrival of the clear
sky and fair weather of the anticyclone; but once started, migration may
overtake and continue through bad weather.

The mass migrations of waterfowl have been poorly documented in the
literature, perhaps because the passages so often begin late in the day and
move so high that they escape notice. Mass migration is typical of many
other groups of birds, but here again, the record is not clear in the literature,
and I believe we underrate the importance of this type of traditional passage
in the migration of inexperienced young birds.

137

MIGRATIONS OF WATERFOWL
Solitary fall migration

I have never seen a duck migrating by itself without companions. I have
seen lone flocks of ducks, beyond sight of any other traveling groups, fol-
lowing the standard direction to the southeast, as if in migration. No doubt
in higher latitudes where numbers are thin, some migration in ducks begins
with one flock; but such isolated migration is an extreme rarity in the lati-
tude of southern Manitoba.

Nor in the geese have I ever seen a lone migrant. Strays are occasional
in autumn, undoubtedly from flocks which have been broken by hunters.
But these quickly join other flocks. Migrating Canada Geese, Richardson's
Geese, and White-fronted Geese often move en masse, either by themselves
or at the same times as the grand duck migrations. But, much more often than
is found with ducks, single flocks are seen following standard directions in
migration; such aggregations are probably made up of several families
moving as a unit from an isolated range.

In our experience at Delta migration by isolated individuals is nearly as
rare in other species as it is in ducks. During late August and September
there is a drift of Flickers through Delta and across the prairies. These birds
retrace their path of spring migration, going east along the lakeshore past
Delta and southeast across the prairie. In passage, each Flicker is usually by
itself, flying low just over the treetops. But they go in waves, so that as
many as fifty birds have been counted in an hour; and again and again they
stop at places of rendezvous, where several, usually a dozen or more, Flick-
ers may be seen together. I once saw a Bittern take wing just at dusk from
behind my house (surely he must have been the bird that had been there
through the late summer and early fall). He left with a northwest wind of
twenty-five miles per hour and started out alone into the southeast. I watched
him disappear out over Cadham Bay, and am sure he hacLcommitted him-
self to migration. Black-crowned Night Herons usually migrate southward
from Delta in small groups, although I have seen single autumn travelers.
The Goshawk, Sharp-skinned Hawk, and Cooper's Hawk are seen as isolated
migrants at Delta, in contrast to the grand movements of the Red-tailed
Hawk and other Buteos. So, too, the Duck Hawk travels by itself. Among
many of the passerines there is no autumnal period of foregathering. The
Catbird and the Baltimore Oriole in our yard are there today by them-
selves, and gone tomorrow. And yet among the night migrants, if individ-
uals of a kind start out by themselves, there is evidence of mass movements
of different kinds traveling together at night. During nights when passerines

138

CLASSIFICATION OF WATERFOWL TRAVEL

are in passage over Delta we hear the contact calls of birds going over
steadily; and Lincoln (1939:77) gives the account of one observer (watch-
ing with telescope focused on the moon ) who estimated that night migrants
passed his point at the rate of 9,000 birds an hour.

DIASPORIC MIGRATION
The molting shift

The molting shift is the mass transfer of mature ducks, mostly drakes,
from the nesting ranges to marshes or lakes where they pass the flightless
period of the eclipse molt. The journeys begin at the close of the sexual
cycle when the male abandons his incubating hen, and end when he ar-
rives at the locality where the wing feathers are shed. The shift may be to
another part of the same marsh in which he had his breeding territory or
to a place several hundred miles away. The transfer shows no constant geo-
graphical direction; some, like the Pintails that go to the Bear River Marshes
of Utah or the Baldpates that go to Delta, travel toward the winter range,
but others go north or east or west. This is an ecological rearrangement of
the population, with a bias toward large marshes on the part of river ducks
and toward lakes (sometimes the ocean) on the part of the diving ducks.
The shift does not take place in breeding geese or swans, which spend the
flightless period with their young near the nesting place ; but there may be
a molting flight in nonbreeding yearlings and barren adults (Taylor, 1953,
and Scott, 1953, for Pinkf ooted Geese ; Klopman, unpublished, for the Can-
ada Goose).

MIGRATIONS OF WATERFOWL

The timing of this shift shows a remarkable consistency from year to
year. At Delta the first bands of postbreeding Mallard and Pintail drakes
are always seen by the tenth of May, the earliest large flocks by the end of
May, and dropped primary feathers, evidence of the first flightless drakes,
by the middle of June. At Whitewater Lake, Manitoba, Bossenmaier (1953a)
found only a week's difference between the gathering of the first flocks of
Mallard drakes in the very late spring of 1950 and that in the more normal
season of 1951. Baldpate and Green-winged Teal drakes regularly arrive at
Delta in mid-June, and the first cast primary feathers of Canvasback always
drift to the lakeshore in late July. Where nesting has been delayed by ad-
verse spring weather, however, there follows a delay in the peak of the
flightless period.

We mark these events by the calendar, but the birds move on biological
time : the molt and the molting shifts are hinged to the sexual cycle. Drakes
of early-nesting hens are first to molt; males that breed later, molt later. So
it is that during the same week in May one may encounter some groups of
molting Mallard males, while other Mallard drakes, still paired, are in im-
maculate breeding dress. In some species, like Mallard and Pintail, the male
usually abandons his hen during the early stages of incubation. In others,
like Blue-winged Teal and Shoveler, the drake remains on his territory
through most or all of incubation, the postnuptial molt into the eclipse be-
ginning before the marital bond is broken. Although the molt into the
eclipse starts at about the same time as the hen commences incubation
(whether or not the male lingers on the territory nearby), there is yet no
complete understanding of the relation between the postnuptial molt and
reproductive activity. Seligmann and Shattock (1914) observed that the
"seasonal change of plumage in the Mallard is not connected with the sper-
matogenic function of the testicle," a decision recently confirmed by Hohn
(1947).

The postnuptial molt into the drab eclipse plumage progresses gradu-
ally, the loss of the pinions and the flightless period of three to four weeks
coming as a climax ( Figure 19 ) . There is some individual variation in the
timing of the wing molt, however, and I found (Hochbaum, 1944a: 112)
that in old captive Canvasback drakes the flightless period arrived even
though there was not yet a complete change into the eclipse plumage. The
shift of molting drakes to the place where they pass the flightless stage is
likewise gradual. First there is a coming together by twos and threes, such
small bands being seen on the nesting range, the males presumably not far

140

Figure 19. The eclipse molt in the
Pintail drake. The male arrives on
the breeding grounds wearing the
conspicuous white, brown, and
gray nuptial plumage (right). When
he leaves his incubating female in
late April or May, however, he en-
ters the postnuptial molt, donning
a drab, inconspicuous, female-like
plumage (left). When the molt of the
body feathers is nearly complete,
the wing feathers are molted all at
one time, and the bird is flightless
for a period of nearly four weeks.

from their original breeding territories. Then these join to form small flocks
of a dozen or so, the progress of the molt now being apparent to the ob-
server's unaided eye. These flocks may go directly to the place where flight
is lost; or they may move to yet another intermediate rendezvous, where
they join others to make up aggregations of hundreds, and sometimes
thousands.

The major molting marshes and lakes are used year after year by flight-
less adults, and banding returns show that some drakes return to the same
place each summer. Yearling males, ending their first breeding season and
approaching their first flightless period,* may find their way to molting areas
with older drakes, or they may be drawn there by a postbreeding require-
ment for companionship. Some, no doubt, visited these same places in their
juvenile wanderings of the previous summer, for many molting lakes and
marshes are also autumn gathering places for all sex and age classes.

There is strong suggestion of appetitive behavior, the birds moving to
special ecological situations. During the weeks of foregathering, for instance,
many Mallards and other river ducks loaf in large companies on the south
shoreline of Lake Manitoba; but there is no evidence that members of these
species are flightless on the lake as are Canvasback and other diving ducks.
The lakeshore Mallards and their companions always manage to arrive on
the marsh when the flight feathers are lost. Since the pinions may be shed all

* Although the juvenile passes through a change of body plumage its first autumn, in which
it loses the female-like juvenal plumage and takes on the breeding plumage, the flight feathers
of the wing are not lost in the autumn molt. The bird wears its first wing feathers through the
year.

141

MIGRATIONS OF WATERFOWL

at once (sometimes in an instant if the bird is startled) these ducks of the
lakeshore must have some inner stimuli forewarning them to move from
their loafing bars to the special molting environment some time before the
wing feathers are lost. Indeed, there is evidence of their awareness of the
molt: when a Mallard close to the wing molt is flushed, it does not take
off in abrupt rise, as normally, but at a more gentle angle, as if favoring the
wing against extreme exertion.

While the molting shift is mostly of males, it is seldom entirely so. The
late May and June gatherings often contain a few adult females which, for
one reason or another, have abandoned their reproductive attempts for the
year. Sometimes, when the hen, thwarted by predators or other adversities,
abandons nesting while still attended by a drake, these two maintain their
bond as companions and may be seen side by side in the premolting aggre-
gations (Sowls, 1949:270). Unsuccessful females, which accompany the
males most abundantly during adverse nesting seasons, move with the
drakes to their destinations. For the female population as a whole, however,
there is no major shift. The evidence suggests that many hens which have
raised their broods travel only short distances or remain on the same marsh
for the flightless stage. The wing feather molt of the female does not begin
until after she has left her family; hence the flightless schedule is much later
than it is in the male, some females being flightless in October ( Hochbaum,
1944a).

I have observed no pattern of weather governing the timing of molting
shifts, but have noticed that the arrivals and departures of adult drakes in
late May and June usually are made in the late afternoon or during twilight.
In England Coombes (1950) has made a neat study of the Common Sheld-
duck in the act of moving toward its molting place. He found that in July
1949 the molt migration "took place on every evening on which visibility
from the point of departure was 'good' or perfect,' whereas no migration
took place on evenings when visibility was poor or 'bad' . . . Sheld-ducks
fly in the worst of weather at sea and along the coast, but are evidently re-
luctant to face this overland flight except when visibility and weather are
favorable." He found that the migration "takes place during about three
hours only, and the great bulk of it is concentrated into two hours, one
hour before to one hour after sunset."

Ward ( 1953 ) gives evidence of a postbreeding movement of adult male
Coots from the breeding range to such concentration places as the Delta
Marsh, where large numbers pass the flightless season. In the grebes, which,

142

In the twilight hours of early summer evenings, bands of drakes may be
seen arriving at Delta, usually from the northwest.

like the ducks and the Coot, are flightless during the wing-molt, there is a
shift away from small breeding marshes to larger waters. At Delta the large
Western Grebe, which nests in the marsh, moves to the open waters of Lake
Manitoba, where the wing-molt takes place.

In a great many birds which, unlike the ducks, coots, and grebes, molt
the wing feathers gradually and are not flightless, there is, nevertheless, a
regular postbreeding transfer which involves a large portion of the adult
population. Some of these, like the Tree Swallow and the Bank Swallow,
have a postbreeding shift that carries them annually to the same traditional
stopping places. Thus in the first week in July, Tree Swallows reach Delta
to gather in great numbers on pen wires or on trees which, used year after
year, have long ago been killed by the excrement. So, too, some shore birds
and blackbirds gather at Delta in late June or early July. The first arrivals
are adults, possibly nonbreeders or birds thwarted in their nesting attempts.
But later on the old birds are joined by young, so that by the time the mass

143

Yellowlegs and other shore birds return to Delta
from their breeding grounds in early summer.

southward migration takes place, there is
a heavy mixture of birds-of-the-year with
the adults. This mixture, however, may
not be taken as a rule for all kinds. In the
Golden Plover most adults are said to go
south along the Atlantic seaboard, where-
as the young, and some adults, travel
south in a broad movement across the
prairie regions of the continent ( Rowan,
1926).
There are many other kinds of birds, such as Catbird, Baltimore Oriole
and Yellow Warbler, which remain solitary near the breeding territory,
quietly inconspicuous during the molt, but announcing their presence in late
August with autumnal song.

The primary wandering of juveniles

The urge to roam must be innate in young birds, and the random nature
of their travel indicates no awareness of geographic direction (Figure 20).
Thorpe (1944:77) suggests that such juvenile explorations lead to "latent
learning," and he remarks that this is "especially characteristic of animals
which explore their environment without the satisfaction of any immediate
reward, but by their explorations secure information which may afterwards
be of use to them in a number of contexts, for example, in food-getting, in
escape from enemies, or in finding their way home." Such wandering serves
to give the young bird a familiarity with a wide area beyond the birthplace,
and this geographical experience must be an important factor in the homing
orientation of the following spring.

Williams (1944), speaking especially of juvenile Redheads, says that
"the available evidence indicates a vagabond existence for the birds until
they concentrate on the wintering grounds." The extent of the youthful

144

Figure 20. Dispersal of young ducks of seven species (Mallard, Gadwall, Pintail, Blue-
winged Teal, Shoveller, Redhead, and Canvasback) from the pothole breeding grounds
of South Dakota. During the summer of 1954 flightless ducklings were banded on their
home marshes. Spots show where they were shot during October and November of
their first autumn. Ray Murdy, who supervised this banding program, points out that
although the dispersal is random, there is a bias toward the north, east, and south, where
the habitat is more favorable than on the dry plains to the west. Not all birds cleared
away from their birthplaces by the opening of the shooting season, and about one-half
of the returns are from youngsters killed in their home country (large black circle).
(This figure is presented through the courtesy of the South Dakota
Department of Game, Fish, and Parks.)

wanderings hinges, of course, on the time and the latitude of birth. Young
Pintails, some of which are on the wing at Delta by the last week in June,
have more time to explore than young Delta Canvasbacks or Redheads,
which seldom are in the air before August. Redheads hatched in Utah have
far more time to roam than their kin which enter the world in Yukon Ter-
ritory. Some late-hatched young have no time at all to stray before the
arrival of frost, and a few individuals, especially in the diving ducks, never
reach flying stage before the arrival of ice.

No doubt one of the functions of juvenile travel is the refinement of

145

* *■

The first Pintails are on the wing long before the oldest
Canvasback youngsters take flight.

flight technique; another is the strengthening of the flight muscles. After
watching the young color-banded ducks at Delta, I am sure that at least
three or four weeks must pass before the youngsters lose their awkwardness
on the wing. And the effect of flight on the wing muscles themselves is
evidenced by the changes in size and in the color of the flesh.

There is a universal urge for juveniles to use their wings ; and once in
the air, they move out and away from home in what Thorpe ( 1951a:24) con-
siders a "general curiosity about the environment." There is among juveniles
"an aggressive behavior," says Kalela (1954:24), "commonly shown by birds
when they leave their parents, and this leads to the development of undi-
rected wanderings . . ." Here, once more, we find an exception in the geese
and swans, and also in the cranes, in which the family remains united in its
first flights and there is no aimless wandering of the young. This family
grouping also holds with a few passerines. In Manitoba the Arkansas King-
birds move away from the nesting locality in family units a few days after
the young can fly. For a short while afterward these family groups may be
seen scattered widely on roadside wires, the parents still attending the
young; then in two or three weeks they are all gone, not to be seen again

146

Several weeks pass before the young birds lose their
awkwardness on the wing.

until the following year. Manitoba Crow families likewise leave the nesting
places soon after the young are on the wing, young and old joining bands
which eventually make up the large migrant flocks.

By and large, however, the evidence suggests a random scattering of the
young of many species away from the natal range. The true nature of the
scattering is sometimes confused — by ecological barriers, which inhibit
movement in certain directions (e.g., the failure of sea birds to wander over
forested country) ; by human bias in band recoveries (e.g., as between settled
and unsettled districts); or by elements in the weather (e.g., the dominance
of certain air masses, spoken of on p. 208) that may give random travel a
geographic bias in the direction of the dominant flow of air.

Winter vagrancy

However direct the autumn migration, however ancient the wintering
locality, there is strong evidence of vagrant travels by both young and old
birds about the wintering grounds or from stopping places along the fly-
ways of migration. These may be "explosive" movements in any direction,
like those of the Louisiana Ring-necked Ducks or the McGinnis Slough teal
described elsewhere (p. 112) . They may be "weather movements" - south in

147

MIGRATIONS OF WATERFOWL

hard weather, like those of Canvasbacks from the Susquehanna to Curri-
cuck, or north in unseasonably mild weather, like the massive travel of North
Dakota Mallards back into Manitoba. Or they may be cross-country, from
one flyway to another, like the "round-robin" type of movement of Pintails
(Low, 1949).

Bandings show that adults as well as juveniles wander about the winter
ranges in this way; and of Mallards making November arrivals at Delta
from North Dakota, I found both adults and juveniles in hunters' bags. Such
vagrancies, however, do not concern the whole of the wintering population,
some individuals and some large aggregations staying in one place through-
out the winter.

The winter vagrancy ends with the rise of the sexual cycle, when travel is
directed toward the breeding range upon the start of homeward migration.

Homeward spring migration is the relentless drive to the nesting place.
It may consume several or many weeks; there may be interruptions and
lags, usually due to the weather; but it is a persistent and unalterable move-
ment toward the geographic place of home.

On the other hand, in travel from the breeding range to the wintering
grounds, some or many ducks undoubtedly follow vagrant movements be-
fore or between the mass fall migrations. Vast segments of the population
move directly and swiftly over long distances in mass fall migration, and
probably all adult birds and most young waterfowl participate in at least
one mass passage during the course of the autumn. But the random travel
of the young birds (with an ecological and meteorological bias toward the
south in autumn) and the vagrancies of adults are variables of autumn that
are not found in spring.

148

"Nature is pleased with simplicity and effects not
the pomp of superfluous causes." Sir Isaac Newton

"We are accustomed to regard as real those sense
perceptions which are common to different indi-
viduals, and which therefore are, in a measure,
impersonal." Albert Einstein

11

The Dimensions of Travel

T. he problems of avian migration are often ap-
proached from the standpoint of human experience; gauged thus, the
enigma of orientation is insurmountable. A major barrier to objective think-
ing about migration seems to be the great distances that birds travel, dis-
tances that we apprehend as human travelers. We have an understanding
of a bird's movements about the narrow limits of its home range, but its
manner of orientation in migration is unknown. Rowan (1947) has ex-
plained that "when a flicker or a bluebird returns from the south year
after year to the same nesting box, there is no essential difference between
this performance and the return to the same box after a feeding foray,
except in the matter of scale; in the one case the bird travels hundreds (or
thousands) of miles, in the other merely yards." The depth of the mystery
of migrational orientation is in direct proportion to the distance traveled.

We think of migration, and talk and write about it, in terms of miles or
kilometers. Yet a bird has no awareness of a mile as such; neither can a mile
be the same for two species, nor equal for man and bird. The distance of
travel is relative to the traveler : "all movement is relative" ( Bergson, 1911b ) ;
"distance is relative to a particular velocity of the observer" (Eddington,
1930). A journey across a field for a Meadow Mouse is far greater than for
a man, although by yardsticks the trip is precisely the same for both. The
mile for a walking man is longer than for a flying Canvasback; this unit is
simply an arbitrary term of convenience that should be regarded as a rela-
tive rather than absolute measure of travel.

149

All travel of mouse, man, or bird has three dimensions: length, or dis-
tance of travel ; height, the elevation of the eyes that guide travel ; breadth,
the distance between the horizons on either side of the line of travel. These
coordinates vary with every animal because of variations in structure; the
elevation of the eyes is half an inch in mouse, about five and a half feet in
man, and anywhere from a few inches to several thousand feet in the Can-
vasback. The breadth of each individual's travel is relative to its height.*
We are able to understand these values all the better if we contemplate a
ten-mile trip from the level of a mouse, then step into a light aircraft to
experience the same journey as a Canvasback.

There is still another travel coordinate: the motion of the traveler.
Length, height, and breadth merely outline the space within which a jour-
ney takes place, just as the walls of a coop are the chickens' boundaries of
movement therein. Coops may be built according to ten thousand plans,
each with different dimensions. Travel likewise follows many patterns, but
travel implies movement within its three dimensions, and length, height,

• Breadth of travel may be modified by ground haze or other meteorological factors limit-
ing visibility. Breadth is also variable according to variations in acuity. Breadth of vision may
be extended by mountain ranges; but in the absence of these, even under conditions of ideal
visibility, recognizable detail at the horizon approaches zero because of tangential viewing.
Thus, for these several reasons, the exact mathematical measurements of breadth of travel can-
not be given. This, however, does not greatly detract from the importance of this dimension at
elevations normally used by birds in migration.

150

THE DIMENSIONS OF TRAVEL

and breadth have meaning only as they are relative to motion. Thus the
fourth dimension of travel is the velocity of the traveler within the space of
the other three coordinates : time in the space of travel, or time-in-space.

Velocity of travel is commonly measured against two kinds of interval,
one of distance, the other of time. The term miles per hour gives an idea
of the relation between distance and time, but does not relate to the height
and breadth of travel. If we are to study animal movement in a truly objec-
tive manner, we must consider the whole structure of its four dimensions.

Let us now examine a specific problem in bird migration. Evidence sug-
gests that the fall passage of Canvasbacks from Delta to Lake Christina is
made in one flight, a trip of about 300 miles. Canvasbacks have been ob-
served on this course at an elevation of 2,000 feet and at a measured ground-
speed of 60 m.p.h. At this height the breadth of travel is about 118 miles,
or 59 miles on either side of the line of flight. If a tail wind prevails through-
out, the time-in-space of this journey is 5 hours. The dimensions of such a
flight are thus: length, 300 miles; time-in-space, 5 hours; height, 2,000 feet;
breadth, 118 miles. This equation for a Canvasback is compared with the
travel coordinates of a man who walks at 4 m.p.h., * at an eye elevation of
5% feet, and a breadth of travel (in the absence of obstacles) of about 6
miles. Time-in-space, 5 hours, is the common denominator for drawing com-
parisons, with all other coordinates relative to this. With the time constant
for man and bird, the relative value of the man's distance is 20 ; that is, 20
miles is to man as 300 miles is to Canvasback. We of course recognize this
relativity in our daily movements. As I walk over the open prairie to the
marsh a mile away, I see a duck flying in the same direction. The bird's
absolute mile is the same as mine, but its relative distance is much shorter.

The foregoing considered only two coordinates: distance and time-in-
space. These are relative to the height of travel, 2,000 feet for Canvasback,
5)a feet for man. Bear in mind that height is not an isolated point in space ;
it flows with the traveler's motion and is perceived by the eye as movement
of the earth itself, an optical illusion in which the ground beneath the
traveler seems to approach from ahead, pass underneath and to either side,
then recede behind. The velocity of this apparent ground flow is relative to
the height of motion. In human experience, for example, the ground seems
to speed rapidly past in a blur when our aircraft leaves the runway, the
velocity of this ground flow decreasing as the aircraft gains altitude. Air

• Four miles per hour is not an average walking speed for man, but an experienced
walker in top condition can average this on an overland journey.

151

MIGRATIONS OF WATERFOWL

and ground speed may remain constant, but the ground flow is much slower
at 2,000 feet. It is by this apparent motion of the earth that both man and
bird perceive their progress, and the height of the eye is thus of great im-
portance in travel orientation.

A man would find it impossible to direct his journey at 4 m. p. h. if his
eyes were at mouse level. The more rapid the ground flow, the more difficult
the problems of orientation, a fact we human beings acknowledge when we
slow down (or gain altitude in an airplane) when traveling in strange sur-
roundings. To walk at 4 m.p.h., at an eye level of 5& feet, gives a man a keen
and efficient awareness of motion through space. When a Canvasback flies
at 60 m.p.h. at an elevation of 8232 feet, its apparent ground flow is pre-
cisely the same as for the walking man (Figure 21). In short, 4 m.p.h. at
53a feet is to man as 60 m.p.h. at 823£ feet is to Canvasback; the 300 miles to
Lake Christina in 5 hours at an elevation of 8232 feet are to a Canvasback as
20 miles in 5 hours at 532 feet are to a man, the relative values of distance,
time-in-space, and height being the same for man and bird. The Canvas-
back seldom flies so low as this, almost never in migration, and it is immedi-
ately apparent that its ability to gain altitude gives it a tremendous advan-
tage over man. There is no need to resort to mathematical comparisons to
show how the bird is favored at 2,000 feet, but we must understand that not
only is the area seen from this altitude greater, but, because of the relative

Figure 21. Relative travel equality for man and bird. At elevations and
speeds shown above the relative velocity and the apparent ground flow
are exactly the same for man and bird. The bird's relative velocity be-
comes less as it gains altitude, and it may rise so high that the apparent
ground flow becomes almost imperceptible.

152

THE DIMENSIONS OF TRAVEL

reduction in the velocity of apparent ground flow, the bird has much more
time than the walking man for visual examination of any segment of the
landscape over which it travels.

There remains the dimension of breadth. If the other three coordinates
have relative equality, the values of breadth are the same for man and bird.
But as the Canvasback rises above 82& feet it gains a great superiority in its
breadth of perception. Landscape patterns, such as lakes, rivers, and moun-
tains, beyond sight at lower elevations come into view, and errors in course
may be adjusted.0 The increase in the breadth of vision reduces the require-
ment of precision in aerial navigation.

The four-dimensional comparison of man and Canvasback, then, may be
shown as follows :

Travel Altitude Breadth

Velocity Distance of Travel of Vision

(M.P.H.) (Miles) (Feet) (Miles)

Man 4 20 5.5 6

Canvasback 60 300 82.5 24

Man 4 20 133.3 30

Canvasback 60 300 2,000 118

It is only fair, of course, to note that all Canvasback travel does not take
place at 60 m.p.h. or at 2,000 feet, but we must apply the same four-dimen-
sional examination for any speed or altitude if comparisons are to be valid.
For example, if a head wind reduced the ground speed of the Canvasback
to 30 m.p.h., the comparison would be:

Travel Altitude Breadth

Velocity Distance of Travel of Vision

(M.P.H.) (Miles) (Feet) (Miles)

Man 4 40 266.6 42

Canvasback 30 300 2,000 118

Although only the velocity has been changed for the Canvasback, the
relative values of three other coordinates have thereby been altered for
man; 40 miles are now to man as 300 to Canvasback, but the elevation of
the eyes, in a fair comparison, is lifted to the 266.6 feet (as a man might
travel at 4 m.p.h. in a helicopter), and the breadth of vision must be in-
creased to 42 miles.

• "The formula for the distance, d, at which an object h feet above sea level is visible to an
observer h' feet above sea level is approximately: d = 1.317 (v7» + V»') miles" (Griffiin,
1940:65).

153

MIGRATIONS OF WATERFOWL

In a long migration, like the 3,000 miles from the Mackenzie Delta to
the Gulf of Mexico, the relative values for man and Canvasback are :

Velocity
(M.P.H.)

Man 4

Canvasback 60

Travel

Distance

(Miles)

200

3,000

Altitude

of Travel

(Feet)

133.3

2,000

Breadth

of Vision

(Miles)

30

118

Not all birds fly as high or as swiftly as waterfowl. In the Delta region,
for example, blackbirds average 30 m.p.h. at approximately 200 feet, and in
the table below a day's journey of 250 miles for a blackbird is compared
with a man's walk :

Travel

Altitude

Breadth

Velocity

Distance

of Travel

of Vision

(M.P.H.)

(Miles)

(Feet)

(Miles)

4

33.3
250

27
200

14

cbird 30

38

Man

The four dimensions of travel apply to all bird movement, but flight
does not always have a relative advantage over walking. Some small birds,
for example, are known to fly within three or four feet of the land or sea,
and the Penguin migrates with its eyes at sea level.

The importance of the height and breadth of perception in travel is not
always understood. At an elevation of 5& feet, the eyes see a segment of
earth, bounded by the horizon, that is slightly more than 6 miles in diam-
eter. At an elevation of 2,000 feet the diameter between horizons is 118
miles. In terms of miles, the area encompassed by the horizon at 2,000 feet
is nearly 20 times as wide as the circle of vision at 5& feet. But the rela-
tive size of this earth circle is the same at both (and at all) elevations. The
validity of this may be tested by pointing a finger at the horizon, which is
always at eye level, regardless of altitude. No matter if one stands on the
ground or in an airliner at 2,000 feet, the arc of vision between finger and
feet is the same. The universe is divided into earth and sky at the horizon,
and the proportion of the traveler's vision that includes the earth is constant
regardless of his elevation, the relative size of the world remaining un-
changed throughout travel.

We know, of course, that the higher one rises, the farther one sees. This
extension of vision results from a relative shrinking of the earth's dimen-
sions. As one goes up, the miles decrease in relative size as more miles come

154

The horizon is always at eye level.

into view. This phenomenon is so common to human experience that it
needs no further elaboration except to emphasize the point that at higher
elevations the eyes see farther because the relative values of the components
of space become smaller. Thus all parts of the landscape — rivers, hills, fields,
villages, and marshes — are seen in reduction as the eye climbs higher.

As the elevation of travel increases, the complexity of the visual field for
the human air traveler undergoes little change, and, granting differences in
acuity, I believe the same must hold for waterfowl. The details that con-
cern the eye at ground level become reduced as the altitude is increased,
and they are in the field of vision for a longer period of time. Flying at an
elevation of 200 feet, one briefly sees individual trees standing out conspicu-
ously, but at 2,000 feet each tree is lost in the arboreal pattern of the whole
forest, which is viewed with leisure. This relativity of awareness was made
clear to me in a flight with Robert H. Smith from The Pas, Manitoba, to
Delta, in the "Grumman Widgeon" of the U.S. Fish and Wildlife Service.
We left The Pas early on a bright August afternoon and followed the same
course as taken by migrant waterfowl, southeast to the Delta Marsh. Com-
ing down the maze of waterways of the Saskatchewan River, Bob flew at

155

MIGRATIONS OF WATERFOWL

200 feet, where we identified all species of ducks easily, as well as Crows,
Coots, and Canada Jays. We could see the eyes of each Moose. Meadow
and muskeg, spruce tree and waterfowl, were all perceived clearly. Aware-
ness was of details within a limited landscape, each scene viewed for only
an instant. We were lost, however, as regards exact geographical location.
Bob then climbed to 2,000 feet, where we became precisely oriented. Now
spruce trees were not seen individually; we were no longer aware of each
duck, although there were many hundreds below. The plane drifted slowly
over a world of green and blue, of forest and water, the patterns of which
could be examined with leisure despite a ground speed of 120 m.p.h.

The cues or "landmarks" of aerial travel must be relative to height. In
flying from The Pas to Delta at an altitude of 200 feet, there are perhaps
a hundred or more key points in the landscape, identification of which is
important to oriented travel. Miss two or three of these when flying low and
the way is lost. At 2,000 feet, however, there are at most six landmarks
that guide flight for the human pilot flying in reasonably good weather
(Figure 22). Each new cue appears in the distance before the last one has
receded from view behind, so that at this elevation the pilot is never beyond
sight of such guiding features. It follows, then, that the number of cues
required for memory is relative to the height of travel. It is much easier
for the pilot to remember his way across Manitoba's lake country at 2,000
feet than at lower elevations. Were this not so, swift air travel would be
impossible; no pilot (lacking instruments) could fly from Winnipeg to
New Orleans if he had to obey as many cues to orientation as are followed
by a man driving the same course in an automobile. Their behavior sug-
gests that this same relation between height and landscape holds for ducks,
for they precisely follow the patterns of creeks and channels, points and
sloughs, in local movement at low altitude. In higher flights, these details,
so important on the native area, are insignificant segments of the mosaic
of the whole marsh, which the migrant, crossing at 2,000 feet, sees in its
entirety as a single landmark along the way. I suspect that the cues to
oriented travel about the Delta Marsh are no less numerous for the bird
on its home range than are the landmarks required by a migrant during a
day's journey at 2,000 feet.

The perceptual space of the traveler includes not only the surrounding
world, but the sky above, with its sun, moon, and stars. These celestial
bodies are so far from the eye that the traveler does not perceive them as

156

W^7

Figure 22. Travel horizons at 5& feet (small black circles), at 200 feet (smallest open

circle around Delta), and at 2,000 feet (largest circles). In clear weather no more

than six landmarks would be required to guide the way

from Delta to The Pas at 2,000 feet.

In local travel the sun serves as a compass. Both man and bird perceive it, like Joshua,
as being relative to the earth and to time.

being relative to his movement. Instead, the sun, at any moment of travel,
seems to move with the traveler at the same relative velocity. As the mo-
ments of travel become minutes and hours, however, the traveler (like
Joshua) perceives the sun moving relative to the earth. It rises out of the
east, crosses the sky in its arc, then disappears below the western hori-
zon. When in view, the sun serves as a cue to compass direction regard-
less of its position in the sky. Moving about his home valley or along his
village streets, man is guided by the familiar landscape; but as he travels

158

THE DIMENSIONS OF TRAVEL

into strange places, the sun's function as a compass becomes ever more im-
portant. Kramer (1951, 1952) has shown how the sun functions as a com-
pass for birds on the home range. With the sun as their only clue to direction
in the experimental cages, Kramer's Starlings moved with a directional bias
that held constant regardless of time of day. Without the sun, however,
their movements were random, favoring no direction.

The daily change in the sun's position relative to earth and local time,
the change by which the seasons ebb and flow, is too obvious and well
known to merit discussion here. Let us merely recall that on any given day
of the year, the position of the sun varies according to locality. A traveler
who in autumn has moved several hundred miles toward the equator, for
example, perceives that the sun rises at a steeper angle from the east, fol-
lows a higher arc across the sky, and drops more abruptly into the west. The
interval between sunrise and sunset increases slightly, and the points where
the sun strikes the horizon at sunrise and sunset approach more closely to
due east and due west. Because of the more abrupt ascent to sunrise and
the descent after sunset, the duration of twilight is shortened ( Figure 23 ) .

When a traveler moves across degrees of longitude, he perceives no
change in the sun's arc and the length of day; but in eastward travel, sun-

vSUN ftT LOCAL (PE-lTA) NOON t OCT. 15-

&'■ At Dclta

S^Attlk tkave-l due. Cast of Dellta

^3; .. .. .. WL>5T ..

fi* " - " vSOUTH- "

<Sy ■ " £>OUTHE.ft5T * "

Figure 23. Travelers perceive changes in the sun's arc and schedule in direct proportion
to the speed, distance, and direction of travel. A mid-October traveler going from Delta
southeast to Lake Christina in one day would find the sun's arc higher (X-Y:A-B) and
its position (S5) 12 minutes past zenith at Delta noon. From the dotted line it will be
seen that the angle of descent becomes more abrupt as the traveler moves southward.

MIGRATIONS OF WATERFOWL

rise and sunset come earlier (relative to the time at home), and in west-
ward movement, later. A traveler accustomed to breakfast at sunrise, din-
ner at high noon, and supper at sunset would find that if he went several
hundred miles due east overnight, the next day's sun would have topped
the horizon before breakfast, passed its noon peak by dinner time, and set
before supper. If he went west from home, breakfast would arrive before
sunrise, the stomach would call for its dinner before the sun had gained its
zenith, and supper would start with the sun still in the sky ( Figure 23 ) .

These changes in the sun are imperceptible, by men at least, in short
travels from home. It is only when they make long, swift journeys that they
are sensible of a change in the path of the sun relative to earth and time.
The sailor, with the wind behind his sails, was the first to understand how
sun position and schedule were related to his place in longitude and lati-
tude. The Ancient Mariner observed, as his ship sailed southward:

The sun came up upon the left

Out of the sea came he!
And he shone bright, and on the right

Went down into the sea.

Higher and higher every day
Till over the mast at noon —

So it is, the sun serves man in two ways according to the distance and
velocity of travel. In short trips close to home, the sun is a cue to compass
direction. But if a man is lost, displaced from familiar surroundings, the
sun is not a guide to the direction home, even though it still serves as a
reference to north. A given direction may be followed, if the sun is in view;
but one must locate familiar surroundings before perceiving the direction
to home.

As a man goes farther, the change in the sun's position and schedule is
perceived; and awareness of this change is in direct proportion to the dis-
tance and velocity of movement. The farther and faster he goes, the more
keenly is he aware of the sun's changes relative to home. By the sun's arc,
one may tell whether he is north (arc lower) or south (arc higher) of
home. By its schedule, as measured against his clock or, more crudely, by
his metabolic stimuli, he must know the degree of his displacement east
(breakfast late by sun time) or west (breakfast early). By these cues a man,
suddenly shifted several hundred miles from his native range, might deduce
the direction home even when in unfamiliar surroundings.

160

THE DIMENSIONS OF TRAVEL

Matthews (1951a, b; 1952; 1953a, b; 1955a, b)* and Kramer (1952,
1953 ) have shown in pigeons and ( Matthews' studies ) in several species of
gull and shearwater that there is a pattern of orientation toward home when
birds are given freedom in unfamiliar terrain. This direct orientation, Mat-
thews demonstrated, functions only when the sun is in view, and Matthews
has erected a hypothesis of sun navigation that hinges on the traveling
bird's awareness of change in arc and schedule relative to arc and time at
home. Moreover, with pigeons, Matthews (1955b: 78) has shown how this
ability to orient homeward from unfamiliar country varies according to the
distance from home. At a distance of between 20 and 40 miles "there would
seem to be a ring of country," Matthews observes, "in which birds would
have no direct orientation and presumably have to fall back on random
search methods. . . . Beyond 50 miles there is suggestive evidence that the
accuracy of orientation increases with distance, though this is not so firmly
established." This same "distance effect," as Matthews calls it, has puzzled
other workers, like Wodzicki and Wojtusiak ( 1934 ) in a study of swallows,
and Griffin (1943) in a study of terns and gulls. They noticed that birds
released distantly tended to return home more rapidly than others set free
in strange country within a shorter radius of home. This "distance effect"
favors the idea of sun navigation. Although able to perceive direction from
the sun on local range (like Kramer's caged Starlings), birds, like men,
may have no awareness of the change of the sun arc relative to earth and
time when close to home, and they must search for familiar surroundings
if lost. But, so the evidence suggests, the farther birds travel from home,
the more keen their awareness of the ever-increasing change of the sun's
arc and schedule relative to home. Hence, we presume, the longer a bird's
journey, the keener its awareness of the direction homeward even when
displaced from familiar surroundings.

If birds are, indeed, able to navigate by the sun, as the pioneering studies
of Matthews and Kramer suggest, and if awareness of the sun as a nagiva-
tional cue is directly proportionate to the distance and velocity of travel,
then the swiftly flying Canvasback (traveling the 300 miles from Delta to
Lake Christina in 5 hours) has in orienting itself a distinct advantage over
a man on foot (walking 20 miles in 5 hours). Though for the purpose of an
objective study of migration we may make comparisons based on the rela-
tive coordinates of travel, the additional element of sun-awareness, then,

0 See Matthews ( 1955b ) for the complete bibliography of Matthews and Kramer and for a
discussion of sun navigation.

161

MIGRATIONS OF WATERFOWL

may give the migrating bird an advantage that the man going short dis-
tances on foot cannot even comprehend.

The sun, of course, is not always available for reference in travel. We
know that some birds migrate through regions covered by cloud both by
day and night, so that the success of migration may not hinge entirely on
sun navigation. But from the evidence of Delta observations (mass migra-
tions starting under clear sky), it appears that at the start, and at some
periods during residence at the destination or at stopping places along the
way, the sun is visible during segments of the long span of spring and fall
migration and serves as a cue to the direction of home.

In summary, the discussion amounts to this: the distance of travel is
relative to the height, breadth, and velocity of travel. We know this applies
to our own human lives as between man on foot and man in an aircraft.
Avian behavior suggests that this same relativity of motion applies to bird
migration, but that distance is relative not only to height, breadth, and
velocity of travel; problems of orientation and retentiveness are also rela-
tive to these coordinates. If the relativity of motion is applied to bird mi-
gration, the problems may be faced in a truly objective manner. A com-
parative examination makes it clear that the complexity of migrational
orientation is not fairly judged by the miles of travel.

While the four coordinates of travel are always relative, men and birds
may use the sun as a reference for compass direction in local travel, and as
a reference for longitude and latitude in longer journeys. The traveler is
cued by the arc and schedule of the sun and may appraise the general di-
rection of home even when displaced from familiar surroundings. An aware-
ness of the changes in the arc and schedule of the sun varies directly with
the distance and velocity of travel; travelers moving swiftly over long dis-
tances could perceive these changes (hence their position relative to home)
more keenly than those moving only short distances.

162

"There is direct evidence that birds lose themselves
in foggy weather." William Eagle Clarke, Studies
in Bird Migration

12

The Influence of Bad Weather

Ihere persist some hallowed legends about
migration carried from one generation to the next until by the authority of
age they live unquestioned. One such is a belief that migrant birds are able
to navigate through fog to their destinations. Lincoln ( 1950b ) tells us that
"we know that vision is not the sole reliance as some birds fly unerringly
through the densest fog." He cites the observation of Cooke (1915), made
when the latter was on a steamer "en route from Unalaska to Bogoslof
Island in the Bering Sea, proceeding cautiously through fog so dense as to
blot out all objects at a distance of 100 yards. About halfway across, flocks
of murres, returning to their nests on Bogoslof, began to break through the
wall of fog astern, fly parallel to the vessel and disappear into the mists
ahead. The ship, with the aid of compass and chart, was headed directly
toward the island, but its course was no more accurate than that followed
by the birds."

Let us mark first that this was a local movement of sea birds in their
native environment where they traveled from feeding grounds to nesting
place. As they were within sight of the sea, their height was not more than
100 yards, while the breadth of travel was somewhat less than 200 yards.
Unalaska is 60 miles from Bogoslof. The murres were encountered about
halfway; hence their destination was 30 miles from the point where first
seen. In fairness, as they came from behind, let us guess that the whole of
their journey was at least 40 miles. If flying at about 40 miles an hour, their
time on the wing would have been an hour. As such, the flight was com-
parable to a four-mile walk by a man through fog. While admittedly no
"landmarks" were available to the murres, they started from their familiar
feeding place toward the sexual goal at the nest and all the way were in

163

MIGRATIONS OF WATERFOWL

sight of the water's surface, by which they might perceive velocity as well
as wind drift. It is possible that there were ocean swells or waves, although
the account does not tell about this; and when still some distance from
their destination, the sound of bird voices and surf might aid navigation.
Their objective was not a pinpoint of land, but a shoreline several miles
broad which, when reached, could be followed to the nesting place. Perhaps
these coordinates are not entirely accurate, but they are sufficiently in line
to permit a more critical examination of this local travel. The object here
is not to oversimplify such movements ; the flight of murres through fog on
their home range is indeed a complex performance. But it is not migration.

In spring the sky is sometimes clear over the Delta Marsh and the gen-
eral weather situation ideal for migration, but over the ice-covered lake the
blending of moist warm air and cold air brings a heavy fog. At such times I
have seen ducks start out in migration, always to turn back upon striking
the mist. When fog reigns at Delta, the passage of all species comes to a
standstill. On the morning of April 27, 1951, Premier D. L. Campbell,
Colonel Arthur Sullivan, and I, driving westward over the prairie from
Winnipeg, saw many flocks of blackbirds and great numbers of Flickers
flying northwest over the open country toward Lake Manitoba. When I left
my companions at Portage la Prairie and drove north toward Delta, the mi-
gration was still so strong that I was never beyond sight of traveling birds.
On reaching the south edge of the marsh, however, I came suddenly into
a heavy fog that reduced visibility to a hundred yards. Near the north edge
I saw a Flicker perched on a roadside telephone pole and I stopped to
frighten it. At this point the road angled to the northwest and the Flicker
launched north into the gray void. Just as it was about to disappear from
my sight, it turned west to the road, where it alighted on another pole. The
same performance was repeated, but the third time the bird gained sight
of the ridge and flew on to the trees.

At Delta I found Flickers everywhere, perched singly or in clusters in
maple and willow. When flushed, a bird moved only fifty or sixty yards to
alight again. Many Robins and blackbirds were also sitting quietly in the
trees. Peter Ward said that the visibility had been good in the early morn-
ing and that there had been no Flickers or other migrants on the ridge at
8:30 a.m. A strong passage had reached Delta about 9:00 a.m., but the
flight stopped when the heavy fog had closed in soon after. All these birds
remained stationary until the fog lifted in the afternoon, whereupon migra-
tion was resumed.

164

Fog brings migration to an abrupt stop, although local birds may fly about
their familiar home ranges except in the heaviest mist.

Though the migrants remained immobile this foggy morning, there was
some movement of local birds about the home range. Franklin's Gulls, which
had become established at Delta, were on the wing in small numbers,
always within sight of the marsh. Local waterfowl took flight at my ap-
proach, and a pair of nesting Crows flew back and forth between two clumps
of trees which were separated beyond the range of human visibility. In
short, local movements may continue except in the densest fog, but the
migrant delays its journey until the weather clears.

Trautman (1940:96), who watched the migrations so faithfully at Buck-
eye Lake, says that "the one climatic condition which caused birds to alight
was fog. Geese are apparently greatly disturbed or incapacitated for migra-
tion by fogs, and when a fog occurred as the main flight was passing through
the area, many of the birds were forced to earth. A notable example of this
occurred on the night of October 21-22, 1925. A mammoth flight of geese
was caught in a fog which apparently forced many or possibly all of the
birds to alight. On the morning of October 22, individuals and groups of
confused geese were scattered over eastern Ohio. Many had alighted in
cities, where some of the more bewildered ones were found wandering about
the streets, in the ponds of the city parks, and upon the roofs of buildings.
Various observers estimated that the Buckeye Lake area had between five
hundred and five thousand individuals. The geese remained in the area until

165

MIGRATIONS OF WATERFOWL

about 9:00 a.m. on October 22, when the fog disappeared, and they left.
While in the area at least thirty, all Canada Geese, were shot by sportsmen.
The flight consisted primarily of Canada Geese with some Blue Geese and
a few Snow Geese."

Audubon (1840) said that when Canada Geese "are slowly advancing
from south to north at an early period of the season, they fly much lower,
alight more frequently, and are more likely to be bewildered by suddenly
formed banks of fog, or by passing over cities or arms of the sea, where
much shipping may be in sight. On such occasions great consternation pre-
vails among them, they crowd together in a confused manner, wheel irregu-
larly, and utter a constant cackling resembling the sounds from a discon-
certed mob. Sometimes the flock separates, some individuals leave the rest,
proceed in a direction contrary to that in which they came, and after awhile,
as if confused, sail toward the ground, once alighted on which they appear
to become almost stupefied, so as to suffer themselves to be shot with ease,
or even knocked down with sticks. Heavy snowstorms also cause them great
distress, and in the midst of them some have been known to fly against
beacons and lighthouses, dashing their heads against the walls in the middle
of the day. In the night they are attracted by the lights of these buildings,
and now and then a whole flock is caught on such occasions."

Mr. J. H. Yerex, of Clair, Saskatchewan, reports * a weather accident
described to him by a farmer friend, Don Knox. "We had a week of very
foggy weather Nov. 12 to 18 and the trees and fields of stubble were coated
with hoar-frost. The sun was hidden for days and at times it was difficult
to see more than ten feet ahead in daytime. On the evening of the 15th
Mr. Knox decided it would be a good time to burn an old straw stack, so
set it afire about 7:30 p.m. Next morning as he was driving along the road,
he noticed a few dead ducks scattered here and there but thought little
about them as ducks often strike the telephone lines and kill themselves,
but a little later he noticed something unusual going on in his stubble
field and went over to investigate. Mr. Knox was amazed to find hundreds
of dead and dying ducks, some with smashed bodies, some with broken legs
and wings, and others less seriously injured but apparently dazed and un-
able to navigate properly. The stubble was so tall and heavily frosted that
unharmed birds could not take off, but when they were lifted out of the
stubble and thrown into the air, they were able to continue their flight
southward. . . . The ducks were identified as Lesser Scaups, the bluebill

0 In "Chickadee Notes," by A. G. Lawrence, Winnipeg Free Press, December 15, 1944.
166

THE INFLUENCE OF BAD WEATHER

of the sportsmen. Mr. Knox carefully estimated the loss and figures between
five and six thousand ducks perished."

Warrant Officer Clayton Baldwin, of No. 8 Repair Depot, Winnipeg,
writes: "In the fall of 1943, while I was stationed at No. 12 S.F.T.S. at Bran-
don, a similar duck disaster occurred. A heavy ground fog had settled over
the area and aircraft were grounded. In the morning, as airmen proceeded
to work, ducks, mostly Lesser Scaups, with I believe a sprinkling of other
diving ducks, were found dead, dazed or haphazardly wandering around
the Station roads. The Station is at all times brightly lit up and in this in-
stance the ducks, in all probability flying very low, piled into hangers
(which extended from east to west), and those striking head on killed
themselves while the others were more fortunate." °

Such accidents happen in the spring as well, and a passage of diving
ducks meeting fog after dark on April 28, 1955, dashed into buildings, trees,
and wires at McCreary, Manitoba. Some of these were shown to me by Game
Guardian A. M. Lundy: Redhead, Canvasback, Lesser Scaup, and Greater
Scaup, most of them terribly smashed, but two of the scaup with only their
wings broken.

A different kind of tragedy overtook migrating Whistling Swans, Canada
Geese, and ducks in Clarke and Dunn counties, Wisconsin, in early April
1954. These travelers encountered torrential rains and hail: many were
killed, some apparently by hail while they were still awing; and waterfowl
were found dead far and wide over the countryside after the storm. At
least thirty-five dead Whistling Swans were retrieved for examination by
the Wisconsin Conservation Department. "The inspection shows definitely
that they met violent deaths," said Cy Kabat, Chief of Wildlife Research
for the Conservation Department. "They had broken necks, burst livers and
hearts, lung hemorrhages and many bruises all over their bodies and heads
where they evidently had been pelted by big hailstones. We'd guess from
what we know that the hail caught them up high — very high." f

The meteorological factors responsible for the icing of airplane wings, a
severe hazard to human flight, may also act upon birds. Dr. William G.
Sheldon (letter) says that near "Quincy, Massachusetts, I was attracted at
dusk by the chatter of hundreds of Starlings. These birds were scattered
about the ground close to the south shore of Boston Harbor. Approaching
them, I found they had lost the power of flight and were easily caught by

° "Chickadee Notes," Winnipeg Free Press, January 2, 1945.

t News story by Gordon MacQuarrie, Milwaukee Journal, April 23, 1954.

167

MIGRATIONS OF WATERFOWL

hand. Although there was no precipitation, the birds' feathers were heavily
iced. Apparently they had been flying at a higher altitude where there was
sufficient moisture to cause icing."

By and large, most of us think of birds in migration as invincible ( except
at lighthouses), like the Persian messengers of Herodotus for whom "neither
snow, nor rain, nor heat, nor darkness, are permitted to obstruct their
speed." One or two more examples of tragedy in other species will empha-
size the everlasting threat of weather. Roberts (1932:446) tells the fate of
migrating Lapland Longspurs on the night of March 13-14, 1904, which
"was very dark but not cold, and a heavy, wet snow was falling with but
littie wind stirring. Migrating Longspurs came from the Iowa prairies in a
vast horde, and from 11 p.m. until morning, incredible numbers met their
deaths in and about villages by flying against buildings, electric light poles
and wires, and by dashing themselves forcibly onto the frozen ground and
ice." In Worthington, Minnesota, an attempt was made to compute the
numbers lying dead on two lakes with an aggregate area of about two
square miles. "A conservative estimate showed that there were at least
750,000 dead Longspurs lying on the two lakes alone!" The total area on
which dead migrants were found covered approximately 1,500 square miles.

In Nevada, Cottam (1929:80) describes a "shower of grebes." "During
an early morning hour (about 2 a.m.) of December 13, 1928, residents of
Caliente, Nevada, were awakened by a heavy thumping of something falling
on the roofs of their houses. Those who were curious enough to step out-
side and investigate the unusual occurrence found scores of water birds in
the new fallen snow. The next morning, several thousand Eared Grebes
were found on the ground and on flat roofs of business houses throughout
the city." Mr. E. C. D. Marriage, of Caliente, wrote Cottam that "literally
thousands of these birds were found in every portion of the town and out-
skirts . . . they were forced out of the air by the heavy density of the
snow . . . Caliente had the main bunch, but they were scattered for twenty
miles every way." Several himdred grebes dropped in the streets of Enter-
prise, Utah, about forty-five miles east and north of Caliente, and several
hundred more were found in the snow at Uvada and Modena, Utah. "The
evening of December 12," says Cottam, "the air was comparatively warm
and still. By midnight a general anc heavy snowstorm set in. The birds
appeared to be in large flocks and were probably following the Meadow
Valley Wash on their way to the Pacific Coast of southern California or to
some inland lake near there."

168

THE INFLUENCE OF BAD WEATHER

In all these catastrophes the migrants probably started out in fair
weather, but moving faster than the weather itself, they overtook storm.
Once the flight is started, the members of mass migrations seem compelled
to continue on, as if set for a journey of a certain time and length, not to
be cut short by storm. Even where they might stop, as at Delta, they often
continue their flight. The local birds, as we have seen, do not join these
travelers passing over in storm, and I have never known mass migrations to
leave Delta except under fair sky.

On their local range, ducks prefer not to fly in the rain, and a rainy day
is generally a poor one for gunning. A very heavy influx of ducks, mostly
Blue-winged Teal and Baldpate, arrived at Delta during a torrential down-
pour in the late afternoon of September 28, 1954; and then, as these new
arrivals scurried about in search of a resting place, the few wet gunners on
the marsh had fine gunning and bags were filled quickly.

The gyrations of migrants reaching Delta in storm or under heavy cloud
overcast, suggest that the sun or the sun's light (such as the glow of sun-
set) may be important by way of directional reorientation; but we know
that birds do carry on into weather situations in which there is no possibility
of their gaining directional cues from any celestial source. It likewise holds
that migrants may and do travel over cloud, so that they have no reference
to terrestial cues. On the evening of October 17, 1952, Trans Canada Air-
fines personnel reported Blue and Lesser Snow Geese migrating heavily
over North Bay, Ontario, the birds coming from the direction of James Bay
and traveling south. Mr. K. R. Esselmont, T.C.A. Station Manager at North
Bay, writes (letter) that the geese "were first spotted by the Department
of Transport Met. Observer on duty, who saw them approach from the
northeast, flying in a southerly direction. There were three separate flocks
at intervals of perhaps 5 to 10 minutes. The weather was clear from our
station north, and the overcast, consisting of alto cumulus, began just over
head and extended south. The first flock, estimated at close to 200, ap-
proached the station in formation and immediately above they broke forma-
tion, flying in all directions, then reassembling just prior to entering the
overcast, estimated at 8,000 feet. This first group was not seen again. The
second and third groups, not so large in numbers, reacted in the same man-
ner in that, directly over the station, they broke formation and then reas-
sembled. Both these flocks, however, remained below the overcast. There
were two notams on the DOT teletype advising that geese were flying at

169

MIGRATIONS OF WATERFOWL

6,000 to 8,000 feet. These were considered necessary because an RCAF
Mitchell Bomber flew into a flock, damaging the aircraft."

This is a part of a migration which Cooch (1955) traced in nonstop
flight from James Bay, Ontario, to Louisiana, a 1,700 mile trip which con-
sumed about 60 hours. Those electing to go above the overcast would be
aware of the direction and velocity of their travel by reference to the cloud
below. In short trips over cloud, the course of travel would not be greatly
altered; but if they went many miles with cloud as reference, the birds must
become geographically displaced because the clouds themselves are mov-
ing. In this instance the weather records show that the sky was clear over
Ohio and Lake Erie, so that the geese had not more than 200 miles of cloud
ahead.

Captain Earl D. Sherman, T.C.A. pilot, tells me that several times he has
observed geese flying above cloud and that late in 1952 a companion pilot,
Captain Don Patry, saw thirteen or fourteen Canada Geese flying south at
an elevation of 7,000 feet between cloud layers near North Bay, Ontario.
In this case clear sky was in sight to the north, but not to the south.
R. C. Hanson, of the U.S. Fish and Wildlife Service, wrote me that at about
10 a.m. on March 12, 1953, he saw Mallards and Pintails migrating over a
layer of cloud that was 300 feet above the ground at the bottom and 1,000
feet above at the top. The ducks were flying northwest up the Mississippi
Valley between Burlington and Muscatine, Iowa. Alvin P. Noltemaier, also
of the Fish and Wildlife Service, has told me that in the process of herding
Canada Geese away from concentration areas with an aircraft, he has seen
them rise to disappear into the overcast above.

Such abundant evidence of above-cloud travel makes it clear that water-
fowl do at times migrate without visual reference to the earth and that, as
in the observation of Captain Patry, they may move between cloud layers
without reference to either earthly or celestial guides. We must not con-
clude from this, however, that such individuals are possessed of the ability
to navigate precisely overland without reference to it. If the birds moved
with the weather, as is usual in migration, their displacement by movement
relative to cloud might not be great. But migration, we know, does not
always carry the travelers unerringly to their destinations, and above-cloud
passage may be one cause of displaced migrants.

Though both spring and fall migrations of waterfowl generally occur
with a favoring wind, they do not always do so. The Lesser Snow and Blue
Geese, going to the northeast, are often seen migrating with a cross wind

170

THE INFLUENCE OF BAD WEATHER

at the same time that many other migrants are traveling northwest with
the southeast wind on their tails. I have seen both ducks and geese flying
against winds of fifteen to twenty miles an hour. At such times the slower-
flying passerines generally remain grounded, but I have watched Crows and
blackbirds migrating against winds of such velocity as to make their ground
speed almost nil.

On April 15, 1954, with Aldo Missio, Weather Forecaster for the R.C.A.F.
MacDonald Weather Station, I departed by car at 10 a.m., going northwest
to Minnedosa, Manitoba. Missio, who had just left his weather charts, ad-
vised me of the approach of a cold front from the northwest; and, indeed,
we could see the long line of cloud ahead that marked the edge of the front.
The wind was from the northwest at about 20 m.p.h. A dozen Red-tailed
Hawks, three flocks of blackbirds, and one flock of Golden Plover were seen
migrating to the northwest between Macdonald and Neepawa, where we
met the front at 11:30 a.m. There was a sudden drop in temperature from
45° to 30° F., a rise in wind velocity to 35-40 m.p.h., reaching 45 m.p.h. in
gusts, with light snow flurries. These conditions of wind and temperature
remained the same all afternoon till dusk. After the front had passed, we
noticed much more activity among blackbirds, Crows, and hawks. In some
this seemed restiessness, as in the blackbirds that rose from a field, settled,
then rose, flying around the brow of a hill, settled again, only to take wing
once more. This restlessness soon resolved into a migration into the north-
west; and as we ranged about the rolling country south of Minnedosa from
noon until 3 p.m. there was a light but steady passage of Red-tailed Hawks,
blackbirds, Crows, and a few Robins. The hawks were lower than we usu-
ally see them; they seemed to take advantage of hills and bluffs of trees,
and often were seen to make their greatest headway against the wind in
long dives, by which they gained speed as they lost altitude. The recorded
velocity of the wind was greater than the ground speed of blackbirds,
Crows, or Robins ; and yet they gained ground against the wind by flying
close to the earth, sometimes only a foot or two high, swinging behind clumps
of trees, around hills and up gullies, reaching an objective, such as a group of
trees, then stopping briefly, only to start on again. Their movements, how-
ever roundabout, always carried them into the northwest. Waterfowl were
seen flying to sheltered situations, but none migrated.

It is not always possible, of course, to judge the relation of wind to mi-
gration. On April 13, 1954, there was a grand arrival of waterfowl from the
south and southeast from 7 a.m. until noon, the birds reaching Delta at ele-

171

MIGRATIONS OF WATERFOWL

vations estimated at 1,000 to 1,500 feet. Throughout the morning we were
aware of a steady flow of wind from the northwest at about 10 m.p.h. ; and
yet the weather records of Macdonald, Manitoba, close by, showed that at
the elevation the birds traveled, the wind was from the southeast.

Birds migrate higher with the wind behind than with the wind in face,
just as in local travel (Deelder and Tinbergen, 1947). It is agreed that
ground friction may reduce the wind near the earth so that in facing the
weather, it is an advantage for the traveler to fly low. I'm sure, however,
that this is not the whole story. I believe that the apparent ground flow has
something to do with the elevation of travel. For example, at an air speed
of 45 m.p.h., the bird with a tail wind of 15 m.p.h. has an awareness of
ground flow at an elevation of 2,000 feet that is precisely the same as that
of a bird at 1,000 feet moving at the same air speed against a 15 m.p.h. wind.
This relativity of awareness may establish the height of the "ceiling" of
migratory flights, for a bird may rise to elevations (as transcontinental air
passengers know ) where there is virtually no perception of ground flow, no
awareness of velocity or wind drift. In this respect we note that, with the
exception of soaring species, the slow fliers, like blackbirds, Crows, and
Flickers, migrate much closer to the ground than swift fliers, like waterfowl
and shore birds.

Weather favorable for diurnal travelers is good for night migrants, and
often, after a heavy daytime passage of blackbirds, Flickers, and others at
Delta, the night sky is alive with the voices of those species that choose to
make their way homeward in darkness. Lincoln (1950a: 29) has pointed out,
as is evident to all who have taken night passage by plane, that "the nights
are rarely so dark that all terrestrial objects are totally obscured, and such
features as coastlines and rivers are just those that are most likely to be
seen in the faintest light, particularly by the acute vision of the bird and
its aerial points of observation." At Delta most waterfowl migration, spring
and fall, begins late in the day. In spring, twilight lingers so long after sun-
set on the northern prairies that in late April and early May there is only
a short period when there is not a sunglow in the sky. In autumn, however,
ducks departing close to sundown strike complete darkness before they are
long on their way.

Lowery (1951) has developed a program for plotting the night migra-
tions of birds by watching their movements against the moon with tele-
scopes. Moon-watching has been followed for years, but this work brings
new techniques for recording and interpreting such observations. This type

172

Nights are rarely so dark that terrestrial objects
are totally obscured.

of study, of course, is limited to fine weather and to periods of the moon.
Lowery reports that "night migrants fly singly more often than in flocks,
creating a remarkably uniform dispersion on a local scale, quite unlike the
scattered distributions observable in the daytime." All our evidence for
ducks, geese, and swans, however, suggests that they hold their flock forma-
tions after nightfall, and that mass movements of flocks remain cohesive
after dark. There are many species which, like the Coot, travel singly; but
these individual birds, nevertheless, make up aggregations of migrants that
apparently fly within hearing distance of one another. The Nevada catas-
trophe of grebes testifies to the grand formations of night migrants; and
once at Ithaca, New York, during an autumn dawn, I saw an armada of
Common Loons coming out of the north, a loose formation of birds that

173

MIGRATIONS OF WATERFOWL

passed for half an hour, a vast aggregation that surely must have traveled
so through the night from some distant starting place in Canada.

By the voices overhead, the contact calls of passerines, I have marked
the migrations of small birds over Delta on spring evenings when there was
no moon and the dark overcast obscured all sunglow in the northwest. I
believe such birds turn west, judging by the drift of their voices, and, like
the daytime travelers, they must be visually aware of the lakeshore to make
this shift. On the evening of April 30, 1951, the moon (but not its glow)
was hidden by an overcast that produced a fine drizzle of rain. It seemed a
poor night for passage, yet not long after twilight had failed, there devel-
oped a heavy Coot migration, made evident by the flight calls of the trav-
elers. I climbed to the observation platform of the Kirchoffer Lodge, where
my eyes, at twenty-five feet, probably were about one-quarter as high as
those of the migrating Coots. From that vantage point, despite the overcast
and the rain, I could see the road four hundred yards away, and such de-
tails as individual trees and buildings were visible more than half a mile
beyond. The south edge of Cadham Bay, two miles distant, was clearly
outlined, and I could see bluffs of trees and the horizon. Many of these Coots
apparently were arriving at Delta from the south; when they reached the
lakeshore they were heard turning back, then alighting on the marsh.

One October evening, about two hours after dark and in the midst of
a driving snowstorm, I heard a flock of small birds, by their voices Snow
Buntings, fly past apparently a few yards above the trees. I cannot believe
this could have been an oriented flight. Another night, jet with overcast and
lack of moon, I was brought out of doors by the yelp of Richardson's Geese
flying very low. Soon their voices told me that they had alighted on the
lake not far from the lights of the village store. The Snow Buntings in the
snowstorm, the geese in pitch darkness, represent movements such as are
all too often considered to be oriented travel ; yet the "note" sections of the
ornithological journals in almost every issue carry reports of "accidentals,"
misplaced birds that have turned up far from their regular beats to delight
the bird-watcher and send him quickly to print with his discovery. "Hold-
ups, side-slips into cul-de-sac, losses of contact will happen. The birds that
settle on the rigging of a ship miles out at sea ; fog-bound stragglers around
a light-house; storm-driven seabirds inland; exhausted migrants dropping
in — all these are evidence of this. These are the unfortunates, the lost, the
grim reminders of the perils and the cost . . ." (Ennion, 1943:63).

Whereas we note such regularities in waterfowl migration as the mid-
174

THE INFLUENCE OF BAD WEATHER

August departure of Pintail drakes, the mid-October travel of Canvasback
and Redhead from the prairies, and the freeze-up passage of Mallard and
Lesser Scaup, every hunter on the southern ranges knows that some years
waterfowl do not come in their regular volume or at their usual time. In
spring, too, there are years when the homeward passage is many days later
than normal.

Major changes in the weather will alter the time, the place, and the
volume of migration. During periods of drought, main flights of birds may
shift to country more abundantly watered, and an unseasonably wet year
may bring concentrations of ducks unusual to a certain region. In 1946 and
1947 there were heavy flights of White-fronted Geese through central Mani-
toba where the species had been uncommon. Hunters farther west in Sas-
katchewan, where the region was drier than usual, reported below-normal
flights of white-fronts. In 1940 winds blew steadily from the southeast at
Delta throughout late September and early October. Arrivals from the north
during this period were so few that the success of the local hunters was
greatly reduced and the small bag was the outstanding feature of the sea-
son. In 1943 south wind was unrelenting during the middle of October
when the Canvasback and Redhead generally leave Delta, and these species
were common until the twenty-second, when the wind abated and the birds
moved southward.

Flights may be deflected by bad weather, as in 1949, when there was
almost no spring migration through Delta, but at the Lower Souris Refuge,
in North Dakota, there was a heavy passage. McCreary (1934) tells how
a change in the normal pattern of winds caused a major shift in the spring
movement of migrants, mostly small birds, in Wyoming. In England, Clarke
(1912) observed that migration from Scandinavia was blocked by north-
west wind, but winds from the southeast were followed by heavy migration.
Over land the direction of migration may follow leading lines, such as rivers
or shorelines or mountain ranges, hence continue its normal course despite
adverse winds. Williamson (1952), however, considers that birds at sea,
especially at night, are far less able to adjust for their wind drift, and then
overseas movements may drift far from the regular course.

After the 1954 avalanche of spring migrants, April 8 to April 10 (see
above, p. 119), the weather in Manitoba was dominated by the Polar Con-
tinental air mass, with a strong high-pressure area in northern Canada and
a stationary Arctic front that held its mean position through the northern
part of Lake Manitoba from April 10 to April 17. Then, for the balance of

175

MIGRATIONS OF WATERFOWL

the month and until May 4, it moved well south of Delta. On May 4 the
front retreated rapidly northward, and on the following days the Arctic
air was pushed beyond the northern boundary of Manitoba. Between April
10 and May 4 there was very little migration of waterfowl or other birds
northward from Delta. There were some massive arrivals from the south, as
on the morning of April 13; and there were times when scattered flocks,
especially of hawks, blackbirds, and Crows, were seen moving northwest
against hard winds. But the whole period was one when there were no great
movements of any kind away from Delta, when scattered travelers were
seen only in small numbers. Through this period of Arctic air dominance,
there was much north wind; the weather was stormy, with occasional rain
and snow squalls. But there were also fine days of blue sky, rising tempera-
tures, and little or no wind. During such fair periods we watched for a
northward movement of ducks, but none passed through. Waterfowl re-
mained in their great concentrations on the marsh and on the flooded fields
in such numbers and so much later than usual that it was the subject of
much comment by local farmers and sportsmen. With the retreat of the Arc-
tic air on May 4, however, there began an avalanche of northbound water-
fowl and many other travelers, the first heavy passage we had seen since
April 9.

What did these waterfowl perceive in the weather that inhibited their
northward travel during the fine days between April 10 and May 4? Had
they gone north of Delta in April, they would soon have reached country
still in the grip of frost. Surely on April's bright days they must have been
aware of some subtile character in the local weather that discouraged their
migration into the frigid region beyond.

176

"Treacherous in calm, and terrible in storm,
Who shall put forth on thee,
Unfathomable Sea?" Percy Bysshe Shelley

13
Overseas Migration

It is one thing to measure the flight of a duck
from Delta, Manitoba, to Lake Christina, Minnesota, and yet quite another to
appraise the migration of Pintail, Shoveller, and other waterfowl from North
America to the Hawaiian Islands. The shortest distance to the first landfall
is at least 2,000 miles over the unbroken ocean, a passage equal to a flight
from Delta to central Mexico. The first step in studying such overseas migra-
tions is to quantify the flight distance in terms relative to the movement of
man, the puzzled observer. In doing this it is only fair to use the most con-
servative combination of travel coordinates. Canvasback and other ducks
have been seen migrating overland at Delta at ground speeds of 60 miles
per hour, and faster; but on the open Pacific, Buss (1946) timed Pintails
at approximately 33 m.p.h. At this rate of travel Pintails might cover the
2,000 miles from the Aleutians to the Hawaiian Islands in 60 hours of flight,
which in relative terms is comparable to a journey of 240 miles for a man
going at a speed of 4 m.p.h. ( Figure 24) .

The Hawaiian Archipelago, as Griffin and Hock (1949) point out,
spreads over 1,600 miles of the Pacific, from Hawaii to Midway, while the
knot of major islands is about 400 miles across. It is thus obvious that mi-
grants are not obliged to navigate precisely to a pinpoint in the middle of
the vast Pacific. Wide errors in course could be allowed and still permit a
landfall upon one part or another of the archipelago, from which travel to
the exact place of previous experience might be made over much lesser
stretches of open water. With relative values of height and breadth of travel
not differing greatly for man and bird, the problem fairly stated is directly
comparable to that involved in a man's journey at 4 m.p.h. going 240 miles
toward a region that has a total width of about 190 miles.

177

Figure 24. Relation of the Hawaiian Islands to continental shorelines of the North Pacific
Ocean. The dotted circles around the easternmost (Hawaii) and westernmost (Kauai)
islands of the main group show the approximate distance at which in clear weather the
tops of the highest peaks appear above the horizon with the observer's eye at sea level.
This point of landfall is extended seaward as the eye is raised above
sea level and as cloud caps rise above the mountains.

Not only is the archipelago broad; the major islands are mountainous.
On Hawaii, at the eastern edge of the group, are Mauna Loa, rising 13,675
feet, and Mauna Kea, 13,825 feet above the sea. In good weather the top
of Mauna Kea is to be seen more than 100 miles to sea, extending the width
of the landfall by so much. On the west the mountains of Kauai rise to
above 5,000 feet, extending the fair-weather landfall at least 60 miles in that
direction. The peaks of islands between lessen the possibility of travelers
passing through without sighting land. To be sure, the sight of the peaks is
not a constant aid to navigation, and, indeed, especially in the northwest,
heavy cloud and rain obscure the islands for long periods of time. The rain,
however, comes from the moist air striking the mountains; hence the clouds

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OVERSEAS MIGRATION

themselves give evidence of land. J. Donald Smith, who traveled about the
archipelago a great deal in his light aircraft, writes me that "Kauai Island,
the northernmost of the main islands, is covered by clouds at one point most
of the year. In fact, Mt. Waielele is supposed to be the wettest spot on earth.
I have no idea how far this can been seen, but I have noted the cloud cover
of Kauai from a distance of 100 miles when flying at 3,000 feet. I would not
consider it reliable for precise navigation, but usable as a general indicator
of land."

In long overseas journeys there is no physical advantage to be gained by
high-altitude flying, and it seems to hold for waterfowl as well as for many
other sea travelers that passages are made at low elevations. The Mallards
and Pintails that Buss observed were 150 to 200 feet above the water; and
since his original observation, he writes (letter) that he has watched the
ocean travel of many more ducks on the open Pacific and their flights have
always been below 400 feet. J. Donald Smith has written me of a flock of
about two hundred and fifty Pintails which he watched depart in northward
migration from Oahu, in January 1951. The birds, bunched and swimming
nervously in close formation, "arose in a mass, circled the pond once, and
took out over the ocean which is separated from the pond only by a beach
ridge. They established a north course and continued on it until I lost them
from sight. They flew just above the water and sometimes disappeared from
sight in the trough." Yocom (1947) presents an interesting account of Pin-
tails on the Pacific, and, while he does not give the actual elevations of the
birds, they apparently were flying much lower than is the rule for overland
migrations.

In their trans-Pacific migrations, then, waterfowl sometimes, perhaps
usually, travel slower and lower than is their custom when moving over
land; but even so, we seriously distort the problem by stating it in terms
of absolute miles. The application of the relativity of motion to such pas-
sages renders the long overseas journeys somewhat less amazing, as the
complexities are appraised by the mind of the human observer.

Besides distance, of course, directional cues are an aspect of the mystery
of overseas migration. What do these birds follow as guides to orientation
in a perceptual space that holds only sky and water? Many writers on bird
navigation have considered the sea to be "trackless," without "landmarks";
and their readers, often without ocean experience, are easily led to accept
this point uncritically. "The sea has no landmarks," so the reasoning goes ;
"hence birds must have some yet unknown sense that guides them over the

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MIGRATIONS OF WATERFOWL

trackless monotony." Yeagley (1947) concluded that "since there are no
'sign posts' of any kind over the ocean wastes, the flights must involve true
navigation."

Yet, however monotonous the seascape, every sailor knows that the
ocean is not wholly a region of sameness. Some of its variations, as where
currents meet, are nearly as stable and well marked as geologic formations
on land. There are differences in color, salinity, air and water temperatures,
plant and animal life, all to be perceived. There is a vast array of evidence
to show how the birds of the sea are aware of these variations even when
they are many miles beyond sight of shore. Murphy (1936:81) shows how
"currents affect every sort of life in at least the upper layers and, in turn,
exercise large control over the numbers and distribution of sea birds." Miller
(1940) tells how the Blackfooted Albatross off the coast of California con-
centrates its numbers over a cold "tongue" of ocean, apparently attracted
there by the abundant food. Carson ( 1951 ) describes the response of some
birds to the movements of fish or plankton. "Capelin gather in the deep,
cold waters of the Barents Sea, their shoals followed and preyed upon by
flocks of auks, fulmars and kitiwicks . . . Out over the plankton meadows
of the North Atlantic the dry twitter of phalaropes, small brown birds,
wheeling and turning, dipping and rising, is heard for the first time since
early spring. The phalaropes have nested on the arctic tundras, reared their
young, and now the first of them are returning to the sea. Most of them will
continue south over the open water far from land, crossing the equator into
the South Atlantic. Here they will follow where the whales lead, for where
the whales are, there also are swarms of plankton on which these strange
birds grow fat."

The border of the Gulf Stream is obvious to the most casual eye; the
water is drab green on one side, richly blue on the other. "The dark blue
water of the open sea far from land is the color of emptiness and barren-
ness," writes Carson ( 1951 ) ; "the green water of the coastal areas, with all
its varying hues, is the color of life. The sea is blue because the sunlight is
reflected back to our eyes from the water molecules or from very minute
particles suspended in the sea. In the journey of the light rays downward
into the water and back to our eyes, all the red rays of the spectrum and
most of the yellow have been absorbed, so it is chiefly the cool, blue light
that we see. Where the water is rich in plankton, it loses the glassy trans-
parency that permits this deep penetration of the light rays. The yellow
and brown and green hues of the coastal waters are derived from the minute

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OVERSEAS MIGRATION

algae and other micro-organisms so abundant there. Seasonal abundance of
certain forms containing reddish or brown pigments may cause the 'red
water' known from ancient time in many parts of the world, and so common
is this condition in some enclosed seas that they owe their names to it — the
Red Sea and the Vermilion Sea are examples. The colors of the sea are only
the indirect signs of the presence or absence of conditions needed to support
the surface life; other zones, invisible to the eye, are the ones that largely
determine where marine creatures may live. For the sea is by no means a
uniform solution of water; parts of it are more salty than others, and parts
are warmer or colder . . . And whenever two currents meet, especially if
they differ sharply in temperature or salinity, there are zones of great tur-
bulence and unrest, with water sinking or rising up from the depth and with
shifting eddies and foam lines on the surface. At such places the richness
and abundance of marine life reveals itself most strikingly."

Brooks (1934) says that when one's ship comes "within a few degrees of
the equator the scattered cumulus clouds become thicker and grayer, a con-
fused swell makes up, rain squalls come and go, and birds appear. At first
there is only a greater abundance of storm petrels, with here and there
petrels of other kinds hunting along utterly indifferent to the ship, or small
groups of tropic birds flying along with the ship, off to one side or overhead.
Then scattered groups of various petrels appear, and finally for an hour or
two there are birds on every hand. If one is not too far from land, a few
hundred miles perhaps, as in the case of the south equatorial drift north of
the Marquesas, one may also see multitudes of sooty or crested terns. Occa-
sionally one sees the grayish blue form of a shark gliding along, or a big
purplish-brown hammerhead lazily twisting around as though trying to get
a better view of the ship. Flying fish, while not so closely localized as the
birds, are breaking the water every few seconds, and bewitch the beholder
by their myriad sizes, shapes and antics, and their bewildering patterns and
shades of deep brown, opal blue, yellow and purple. Then the sun comes
out again, the sea takes on its deep tropical blue, the birds become more
and more scarce and gradually, as the ship moves on, the ocean resumes
its desert aspect ... In the North Atlantic ship lanes the same play is
staged with different actors. Instead of the equatorial currents there are the
Gulf Stream and its continuation, the North Atlantic Drift, and the Arctic
Current; instead of confused swells and squalls of rain there are slicks and
fogs. Tropic-birds are replaced by jaegers and skuas; and different species
of the petrel group, usually here spoken of as shearwaters and fulmars, are

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MIGRATIONS OF WATERFOWL

flying or swimming about, often in great flocks . . . One may pass from the
blue water of the Stream, with floating gulf weed (Sargassum), and perhaps
here and there the iridescent float of a Portuguese man-of-war, into the
gray-green water of the Arctic Current with its thousands of jelly fish, and
in a few hours back again into the Stream. Each time, at the margin, one is
likely to see the surface display of that great abundance of life which has
made the Grand Banks one of the great fisheries of the world."

Preston (1949) points to cloud formations as being constant during some
periods of the year, hence possible cues to ocean travelers. He utters "a word
of warning against the assumption that the ocean is featureless, merely be-
cause it is so shown on a map." Since we men do perceive some of this vari-
ety in the oceanic world, it is within reason to believe that the bird, so much
closer to its wild environment, is aware of these things. Sutton (1934)
speaks of the "Sheenah-cloud" of the North, "a gray cloud that gathers over
open water at the ice-edge." This is a guide to the native Eskimo; it might
be a cue for birds. Wetmore (1926) points out that the green lagoon water
of reefed atolls throws a reflection high above that may be visible before the
land itself is seen. Heyerdahl (1950) likewise speaks of this, saying that "as
the sun rose straight up over the sky astern of us we could see a clear green
glimmer high up towards the misty sky over the island. It was the reflection
of the still, green lagoon on the inside of the surrounding reef. Some of the
low atolls throw up mirages of this kind for many thousand feet into the air,
so that they show their position to primitive seafarers many days before the
island itself is visible from the horizon."

Heyerdahl also writes of the island cloud cap which identifies land long
before it is seen. "With each day that passed, larger flocks of sea birds came
and circled over us aimlessly in all directions. One evening, when the sun
was about to sink into the sea, we noticed that the birds had received a
violent impetus. They were flying away in a westerly direction without pay-
ing any attention to us or the flying fish beneath them. From the mast we

OVERSEAS MIGRATION

could see that, as they came over, they flew straight on exactly the same
course . . . We twisted the steering gear and set our course exactly in the
direction in which the birds had disappeared. Even after it was dark, we
heard the cries of stragglers flying over us against the starry sky on the same
course as that which we were following . . . Next day there were still
more birds over us, but we did not wait for them to show us our way again
in the evening. This time we had detected a curious stationary cloud above
the horizon. The other clouds were small feathery wisps of wool which
came up in the south and passed across the vault of the sky with the trade
wind until they disappeared over the horizon to the west . . . But the
lonely cloud on the horizon to the southwest did not move; it just rose like
a motionless column of smoke while the trade winds drifted by. The Poly-
nesians knew land lay under such clouds. For, when the tropical sun bakes
the hot sand, a stream of warm air is created which rises and causes its
vapor to condense up a colder stratum of air."

One might go on for many more pages, drawing from the literature of
the sea a strong document, evidencing its variation in the eyes of man.
Aware of these characters as we are, we still are not birds. Much more close-
ly in tune with their environment, they may be far more keenly perceptive
of environmental cues than we men.

If the height of overseas travel is truly lower than for overland migra-
tions, I feel there must be good reasons why birds, such as ducks, reduce
their height of travel. There are exceptions, to be sure, especially as ocean
travelers start their journeys. Deelder (1949), for example, observed a
tendency for the Chaffinch to increase its altitude when going out to sea.
Henshaw ( 1910 ) gives evidence that the Pacific Golden Plover may rise to
great heights in its departure from the Hawaiian Islands. By and large,
however, the evidence in the literature suggests the regularity of low ocean
crossings. Wetmore (1926), for example, says that he has "observed autumn
flights of sandpipers crossing the Gulf of Alaska, south of Kodiak Island
and the Kenai Peninsula, at heights of not more than 500 feet above the sea,
with many at only a few yards above the waves. In fact, a Peale's falcon
remained with our ship for a day, perching on a masthead and flying out at
intervals to seize some poor sandpiper that came swinging up to examine
our vessel. . . . Numerous recorders of migrants crossing stretches of open
water note them frequently as passing barely above the waves."

In flying just above the water surface, migrants going into the wind
might benefit as the air current is slowed by friction with the sea; and, as

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MIGRATIONS OF WATERFOWL

Wynne-Edwards (1935) suggests, the waves breaking the surface might
cause an air swell to the travelers' profit. Such advantages, however, would
not be so keenly enjoyed at elevations of 100 feet or so. I believe that the
consistency of low-level flying is also related to the bird's requirement to
perceive its relative velocity. Thomson ( 1942 ) points out that in over-water
passages, flight "without landmarks . . . seems to leave birds without any
means of estimating their lateral drift." Odum (1948), however, believes
that birds perceive their ground speed over water, explaining that ripples,
swells, and whitecaps, although in motion themselves, give a texture to the
water surface that is reference for accurate perception of velocity. "That
this is true is known from the standard procedure of aviation over the ocean
whereby the wing velocity of the air mass in which the plane is imbedded is
told from 'double drift' measurements in reference to the sea surface." An
awareness of velocity and drift from the water depends upon the speed and
height of flight as well as the texture of the surface water. An aircraft can
rise so high that perception of velocity and drift is impossible, in which
case the navigator must drop a smoke flare by which to measure his drift.
And in a complete calm, the air passenger does not perceive relative velo-
city until the plane is almost touching the water surface. Birds, without in-
struments or flares, must keep low enough to the water surface for visual
perception of velocity. The Pintail flying at 33 m.p.h. at 200 feet would be
keenly aware of its relative movement, but at 2,000 feet over the ocean, its
perception of velocity and drift would be reduced to nil. If the sun is an aid
to navigation, as Kramer and Matthews suggest, then sun-awareness and
perception of velocity and drift will be very important cues for the ocean
migrant; but an awareness of the sun without perception of velocity and
drift will make it much more difficult to pursue an established direction.

That overseas travelers do hold to a line of flight is evidenced by the
observations of Paynter (1953), who found a neat consistency of direction
in migrants passing over the Campeche Bank of the Gulf of Mexico. And
Siebenaler (1954), also studying migration over the Gulf of Mexico, made
an extremely important observation of birds adjusting their line of flight to
the wind. "At 10:59 a.m. on October 3, 1952," he writes, "the 'Oregon' was
160 miles north of Yucatan, and it was traveling a true course of 180 degrees
at a speed of 10 knots. At this time heavy flights of warblers and other land
birds were noticed overhead. The wind was from the northeast at speeds of
15 to 18 miles per hour. The birds were not traveling at a uniform altitude,
but those that came near enough to be seen well with the naked eye or

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OVERSEAS MIGRATION

binoculars were all observed to be compensating for the wind speed and
direction by angling their flight and heading approximately 30 degrees to
the east of south. This carried the birds on a true southward course at an
estimated speed of 30 miles per hour. The largest flights were made up of
from 50 to 100 individuals flying in close formation."

Wynne-Edwards (1935) found that the spring migration of the Arctic
Tern across the North Atlantic had a definite trend to the west-northwest,
and he felt that he had evidence that these birds returned over the same
route in the fall. Regarding the fidelity of birds to regular migration paths
over the ocean, Lloyd (1954) observed on May 10, 1950, a remarkable
flight of Long-tailed Jaegers in migration at 53° 19' N., 26° 45' W., in the
North Atlantic. This location is only 200 miles from that where seventeen
years earlier, on May 23, 1933, Wynne-Edwards (1935) encountered a
migrating flock of the same species. By such deliberate attempts as those of
Paynter and Wynne-Edwards to search out birds at sea for a study of their
movements, and through the alertness of ornithologists like Lloyd, Yocom,
and Buss during ocean crossings, we shall accumulate, bit by bit, much
more information to explain the travels of the overseas migrants.

No problems of ocean passage have been solved here, no explanations
established. But it seems certain that some of the mysteries of sea migra-
tions (as these are mysterious to the inquiring mind of man) are generously
diluted when certain fundamentals are marshaled for open-minded ap-
praisal. Surely the complexity of pelagic journeys has been deepened by
our human evaluation of distance and by our sense of the monotony of the
ocean. The problem is faced in a much more rational manner when dis-
tances are approached as relative and when ecological variations at sea are
critically assayed as possible avian cues for travel.

185

"There is recent evidence that many birds find their way
not by relying on a special 'sense of direction or other
unique sensory mechanism, but rather by an ability to
perceive environmental cues which are within the scope
of the receptors common to all higher vertebrates." Don-
ald R. Griffin and Raymond J. Hock (1949)

14

Magnetic and Radio Fields

Since the twelfth century man has depended so on
the compass that some students quite naturally have attempted to explain
the homing of birds as a biological awareness of the magnetic pole ( Viguier,
1882). Thomson (1942:176) points out that "no evidence of any magnetic
sense has ever been obtained, however, despite a good deal of experiment."
Rowan (1931:84) remarks that 'magnetic sensibility is an intriguing hy-
pothesis, but the best we can say for it is that it never has been disproved.
There is no evidence in its favor." Griffin's attempts (1944:25) "to train
three homing pigeons to respond to a magnetic field were entirely negative,
although the field was of considerably greater intensity than the earth's
field." Henderson (1948) serving on a Canadian minesweeper during the
last war, had abundant opportunity critically to observe the behavior of
gulls, ducks, and other migratory birds exposed to intense magnetic fields
set up by the vessel, and he found that "birds appeared to be supremely
indifferent to magnetic field, even at the sudden beginning of magnetic
pulsing." Yeagley ( 1947, 1951 ) conducted experiments testing the homing
ability of pigeons wearing small wing magnets but found no "indication
that the experimentally induced pulsing magnetic field moving across the
birds' bodies in flight confused them insofar as navigation was concerned."
Van Riper and Kalmbach (1952), in a meticulously planned experiment,
found homing pigeons unaffected by wing magnets. Matthews (1951a)
and Kramer (1949, 1950) likewise had negative results with magnetic tests,
as did Gordon (1948) in his earlier studies.

Besides the lack of evidence in favor of a magnetic awareness, there is

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MAGNETIC AND RADIO FIELDS

another circumstance making the theory less attractive. Even if a bird
could sense magnetic force, successful orientation would still have to de-
pend heavily upon visual geographic orientation. A Canvasback traveling
to Delta from the Chesapeake Bay, for instance, directs its flight first to
intermediate points such as Lake Erie and Lake Christina. Migrants from
the Atlantic Coast would be obliged to appraise magnetic force in terms of
directions relative to Lake Erie and each of the other stopping places on
the long route homeward.

A more elaborate theory has been set forth by Ising ( 1945) and Yeagley
(1947), who propose that birds may be aware of the Coriolis force. Yeag-
ley's hypothesis implies an avian sensitivity "to the effect of motion through
the vertical components of the earth's magnetic field and to the effort ex-
erted to overcome the Coriolis forces due to the earth's rotation. Each of
these influences provides a set of lines joining points of equal intensity and
together forming a navigational gridwork. The theory is that by correlating
its instantaneous land speed with the two effects, a bird can fly to its home
which is a unique point in this gridwork, or to related conjugate points ex-
isting in the gridwork, at a position other than its home" (Thorpe, 1949:92).
While Yeagley believes that this theory clarifies the "age-old mystery of bird
migration" and considers it "the first working hypothesis to explain homing
pigeon navigation," his experiments seem most important because their
results appear to be essentially negative.*

Watching the homing behavior of his pigeons from an aircraft, Yeagley
(1951:755) observed that they often detoured to fly over towns, usually
circling the larger towns several times. He suggested that this town-interest
might be due to the birds' response to power stations located there. Even be-
fore electricity arrived in Delta, however, and when the greatest electrical
force was in automobile batteries, racing pigeons were seen each year over
the village, the birds usually dropping down to alight on a house or barn.
A displaced pigeon might be expected to react positively to a town as a lost
duck turns to a lake or marsh.

Griffin (1944:25), in his classic discussions of the sensory basis of bird
navigation, remarks that "there has recently been much rumor in popular
publications about interference with the homing of pigeons and migrations
of wild birds by radio stations (Brown, 1938; Casamajor, 1927; Darling,
1940; Aymar, 1935; and Maurain, 1926). The writer knows of no statistically

• For reviews of the Yeagley studies, see Slepian, 1948; Varian, 1948; Davis, 1948; Odum,
1948; Thorpe, 1949; Wilkinson, 1949; Drost, 1951; Matthews, 1955.

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MIGRATIONS OF WATERFOWL

significant data supporting such opinions, and it seems appropriate to neg-
lect them until they are adequately tested." From the radar research of the
armed services come casual reports of birds, especially waterfowl, respond-
ing to radar pulsations. Poor (1946:631), reporting on the work of W. H.
Doherty, of the Bell Telephone laboratories, says "he had noticed that when
a radar transmitter was directed at a flock of flying birds, the birds appeared
to become confused, with the flock often breaking up and the birds wander-
ing aimlessly. Single birds also seemed to be disturbed." I have permission
to quote from a letter written by Brigadier General Homer Case, of the U.S.
Army, to Mr. Frederic C. Lincoln, of the U.S. Fish and Wildlife Service:
"The antiaircraft units of this command are equipped with high power
radars with a wave length of 10 centimeters. They conduct target practices
near Bethany Beach, Delaware, and flights of wild geese frequently pass
over that area. It is an interesting fact that when the beam of a radar is
aimed at a flight of geese, the 'V or other formation breaks up and the
geese fly off in all directions. As soon as the beam is moved away the geese
return to their original formation."

"In the fall of 1943," writes Knorr ( 1954), "I was in charge of a group of
military personnel engaged in tracking aircraft over the ocean off the east
coast of the United States. The radar set was emplaced in the dunes not far
from the high tide line. During a lull in operation, a large flock of scaup
(Aythya sp.) and scoters (species?) was seen flying parallel to the coastline
a few hundred yards off shore and approaching our position. Having nothing
better to do at the moment, we idly swung the parabolic antenna around
and pointed it directly at the flock. The result was immediate and dramatic.
The once orderly group of birds became a bewildered mass of individuals
which flew in circles, missed wingbeats, and performed many unbirdlike
gyrations. Some observers later insisted that a few birds accomplished loops
and rolls, although I never observed this. As the beam was diverted by
elevating the antenna, the flock regrouped and proceeded down the coast
in the original direction. To verify this unusual behavior as being caused by
radar, the experiment was repeated several times on subsequent occasions.
In each case the result was essentially the same, the response of the stimu-
lated flock coinciding with the incidence of the beam upon the birds, the
cessation of response coinciding with the diversion of the beam."

I hoped that we might study the problem at Delta,* and a radar set was

• Our interest was stimulated by Dr. R. B. Roberts, of the Carnegie Institution, who observed
what appeared to be avian responses to radar during his wartime researches.

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MAGNETIC AND RADIO FIELDS

established there, from April 21 to May 1, 1949, through the cooperation of
the Royal Canadian Air Force.* This was a small aircraft type ADS operat-
ing on a 3-cm. band with a peak output of 50 kw. The scanner was set up
on the roof of a garage at the edge of the Station, with the rest of the
equipment inside, except for the generator operating beside the building.

The location was under a heavily used migration pass, and the calendar
period was for the usual peak of the spring migration. It so happened, how-
ever, that the weather was unfavorable for waterfowl migration throughout
the test, and fewer ducks passed over during the whole period than would
be expected in one evening. During the eleven days, the radar was directed
at only fourteen flocks of ducks migrating over the pass. These bands of
Mallard, Pintail, and Lesser Scaup arrived from the southeast, crossed over
at an elevation of 150 to 300 feet in swift, direct flight into the northwest.
The radar was directed at these oncoming flocks when they were 100 to
300 yards away.

Twelve times out of the fourteen opportunities with migrants we ob-
served unexplained actions that took place the instant the radar was aimed
at an approaching flock: there was a marked quickening of wingbeat, the
birds abruptly altered their direction, and the formation was disrupted. In
each instance the disturbance lasted but an instant, then the flock reformed
and continued on its way. The radar scanner could be swung around, the
ducks held in its beam, but no further responses were noticed as the dis-
turbed flock flew past. The behavior of the birds was hardly different from
that of a flock fired upon with a shotgun, and I have never seen ducks behave
in this manner except under gunfire. The noise of the generator might have
disturbed them, as might the movements of observers. But migrating ducks
have not before nor since been abruptly frightened by people or motors in
the village. There was little wind throughout the tests and on several eve-
nings, no wind at all, hence air currents were not responsible. Four migrant
flocks passed directly over the radar when the generator was running, but
the radar not operating; these birds showed no variation in their direct pas-
sage over the equipment. Unfortunately, no observations were made with
the radar operating and the generator silent; and there were not enough
birds to check on disturbed and undisturbed flights with and without radar.

In one instance, however, all other influences seemed to be ruled out. On

* I am especially grateful to Squadron Leader J. Hudson, who arranged for this test, and
to Leading Aircraftsmen Douglas Hudson and Robert Stamm, who set up the radar at Delta
and operated it throughout.

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MIGRATIONS OF WATERFOWL

the evening of May 1 at 7 p.m. a pair of Shovellers flying at about 100
feet came directly toward the radar, and when they were at a distance of
about 150 feet, the radar was directed upon them. The birds literally col-
lapsed in midair, dropping at least twenty feet as if shot; then, regaining
flight, they altered their direction to go away at right angles to the original
course. This was a dead-calm evening, and the observers were well hidden.
In any event, had the birds been disturbed by the watchers they should
have swung upward rather than dropping. The same evening a band of
four Shovellers flying toward the scanner dropped nearly fifty feet out of
the sky the moment the radar was directed at them, almost reaching the
ground before regaining controlled flight.

All the foregoing observations were made of ducks coming toward the
radar and flying over it. There were many daily opportunities to direct the
radar at local ducks going east or west along the shoreline of Cadham Bay,
but no response was ever observed in any of these waterfowl crossing the
beam. Nor did we detect any response in the wild and tame ducks and
geese at rest in the Station enclosure to suggest that they were aware when
the radar was directed at them, as it was for many minutes at a time.

Although few waterfowl crossed over the radar, hundreds of the four
species of blackbirds migrated toward and over as they traveled west along
the ridge. The radar was aimed at every crossing flock, such birds sometimes
coming within fifty feet; but there was never a single response in more than
a hundred tests. The same held true for heavy numbers of Tree Swallows,
Franklin's Gulls, Juncos, and Flickers that crossed close to the scanner beamed
in their direction. Drost ( 1949 ) also found specific variations in the response
to radar; Kramer ( 1951 ) reported negative results with Red-backed Shrike;
Matthews (1951a) saw no evidence of awareness in homing pigeons released
in a radar beam. We do not understand the reasons for these differences,
much less how the radar pulsations are perceived by some waterfowl. The
whole subject offers an interesting and important field for continued re-
search.

So far we know only that some birds, such as ducks, under certain situa-
tions apparently respond to radar pulsations in much the same manner as
they do to a shotgun blast. But, as Drost explains (1951), "we do not sug-
gest that birds are guided by waves, if we mention the fact that migrants
show a positive reaction to ultra-shortwave (radar) transmission (Drost,
1949); we shall only mention that birds are able to react in cases where
men are unable to do so." In his recent review of the studies of bird naviga-

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MAGNETIC AND RADIO FIELDS

tion Griffin (1952a: 368) says that the "responses of birds to pulsed, high
frequency, radio waves (from radar transmitters) have been observed both
in the United States and in Europe (Drost, 1949), and these observations
are cited by Yeagley as 'rapidly increasing evidence' for theories of bird
navigation based on electromagnetic phenomena. As Schwartzkopf (1950)
has pointed out, however, the density of the energy flux in a pulsed radar
beam is probably sufficient to exceed known thresholds for biological effects
of electromagnetic radiation. One such effect, described by Barlow, Kohn
& Walsh (1947a, b), is the production of visual sensations when the human
eye is stimulated either by weak alternating currents (0.2 mA. at 60 c.p.s.)
or by the electric current induced by an alternating magnetic field of 500
gauss at 60 c.p.s. This magnetic-field strength is approximately 1000 times
that of the earth's field. In fact both the radar beams and the artificial mag-
netic fields employed by Barlow et al. gready exceed any known intensity
of terrestrial magnetism or its electrical by-products. On quantitative
grounds it thus appears most unsound to erect theories of bird navigation
based upon these observed responses of birds or men to intense electromag-
netic stimuli."

Let us not be dissuaded from the continuation of intensive studies of the
influence of radio and radar waves on the behavior of birds; the subject de-
mands further investigation. In the light of current knowledge, however, any
electrostatic sensitivity in birds appears to be no more useful to regional
orientation than sound waves from a shotgun, to which they respond in a
similar manner.

191

"It is curious that although human navigators have for
centuries been obtaining their position in unknown areas
from the sun's co-ordinates, it is only in the last few
years that the possibility of birds doing likewise has been
considered." G. V. T. Matthews, Bird Navigation

15

Awareness of Direction

Ihe manner in which birds find their way in migra-
tion is one of the oldest mysteries to mankind. With each migrant is the se-
cret, discoverable because it is there, yet undiscovered. Many like to believe
this ability stems from a special sense — a "sixth sense," writes Chapman
( 1916: 138), that "has been called a sense of direction. The sense of sight we
know to exist in the eye, and the sense of hearing in the ear, and in the
nerves leading from these organs to the brain. But no one knows where the
sense of direction is situated."

While a few modern ornithologists still believe with Chapman in this
undiscovered sense, we now realize, of course, that the so-called five senses
are not discrete, that sensory awareness of the outer world is not separable
into special components of perception. It is thus "a confused gesture of de-
spair to dispose of the problem by calling for a sixth sense — or a sixteenth"
(Griffin, 1953:215).

Some have turned to the travels of man to find evidence of a sense of
direction, like Lincoln (1950a: 28), who says that "man recognizes this sense
in himself, though usually it is imperfect and frequently at fault." To be
sure, there are abundant testimonials in favor of a human sense of direction,
these offered by or concerning people who found their way home or to camp
under adverse conditions. But the subjects seldom are aware of how such
orientation is accomplished; the best Hudson could offer ( 1922 ) by way of
explaining his homeward "hunches" was "a nerve in the brain," which he
considered to be active in animals but usually latent in man. There seems
to be no scientific evidence of such a sense in man. Indeed, man has spent
far more time and money studying the orientation of birds than of the prob-

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AWARENESS OF DIRECTION

lem in his own human race. Gregg ( 1939 ) made a wide review of the liter-
ature to find that there have been very few studies of spatial orientation in
humans. More recently (1953) Witkin said that "despite its importance to
human adaptation, orientation has not been extensively studied at the
human level. ... It is particularly noteworthy that the specific way in
which sensory factors contribute to human orientation has been given rela-
tively little attention, even though in many instances the relevant sensory
mechanisms have received considerable study."

Those crediting human beings with a special sense contend that it is
more highly developed in native aborigines, guides, or woodsmen. Jaccard
(1931), however, who reviewed many accounts of homing in man, con-
cluded that all possess the same endowment for orientation, regardless of
their station in life; there is no appreciable difference between the sensory
capacities of different human races or occupations. Dwellers of the city are
amazed at the Indian who travels so effortlessly about his wilderness; yet
he, in turn, does not understand how a child can enter the subway in New
York or London and emerge minutes later to find its way home through
the maze of streets and buildings all so alike. "Admittedly in ordinary
speech," says Thomson (1942:177) "we often talk of a person as having a
'good sense of direction' ( or perhaps *bump of locality' ) but by this, how-
ever, we merely mean that the individual has his wits about him in the par-
ticular respect of finding his way, and that he is observant and has good
conscious or unconscious memory for places seen, distances covered and
turns taken. If we stop to think about it, we realize that we have no inten-
tion of crediting him with possession of any special sense unknown to physi-
ology."

Some students have referred to a "magnetic sense," an "inherited mem-
ory," or a "hereditary knowledge" by which birds are guided; and it is often
implied (if not clearly stated) that in young birds there must be an innate
foreknowledge of the geographic destination. The term "instinct" has been
very loosely used in the literature on migration, there being implied an in-
born awareness of the geographic destination and the direction thereto.
And now Huxley (1954:106) tells us that "several zoologists have recently
begun to consider psi as a possible explanation for the . . . extraordinary
and hitherto inexplicable performances of migrating birds and fish." * But
"if we concede it a scientifically legitimate sort of proceeding," writes Lor-
enz (1950:231), "to bridge any arbitrarily chosen gap in our present knowl-

* Psi is the term used by parapsychologists in reference to a paranormal faculty.

193

MIGRATIONS OF WATERFOWL

edge by an obliging little wonder, then all scientific research becomes a pure
farce."

All through the ages of wondering, man has conceived the idea that the
answer to this mystery of avian orientation might be found in a single ex-
planation, like a magnetic awareness, a compass-like sense, a delicate per-
ception of the Coriolis force, or some other discrete sensory capacity by
which the geographic direction to home is perceived. This insistence on the
complete efficiency of one directive source is set forth by Huxley ( 1954 ) as
he dismisses the idea that birds may rely on the sun as a guide to their
travel. "There is," he says, "the hypothesis that pigeons navigate by the sun.
If they do, they must possess, built into their nervous systems, the equiva-
lents of a chronometer, a sextant, navigational tables and a calculating
machine for correlating the solar data observed at the point of release with
those at the loft. ... All in all, solar navigation seems just as untenable
as the canal theory or the magnetic theory."

But neither Matthews nor Kramer claims the sun to be the sole factor
in orientation. Matthews (1955:98), after having discovered that his pi-
geons, gulls, and shearwaters had a direct homeward orientation when re-
leased at an unfamiliar place on a sunny day, and having shown that this
direct homeward orientation broke down when the sun was hidden behind
cloud overcast, demonstrated "that when Pigeons are very familiar with a
release point, after six previous releases there, overcast conditions have no
effect at all on initial orientation." In short, Matthews' work shows that ex-
perimental birds orientate directly homeward from strange regions with the
sun in view, are confused in strange regions with the sun hidden, but can
orientate homeward without the sun on familiar range. The sun may thus
play a role in the travels of birds as it does with men: if the way is familiar
by previous experience, the sun is not necessary to homeward orientation,
but if the way is not familiar, the sun is fundamental.

Griffin ( 1952a, 1953 ) has described three types of homing, these apply-
ing to experimental birds set free by students of avian navigation and also
to free birds in the wild:

Type I. Reliance on visual landmarks within familiar territory and the
use of exploration or some form of undirected wandering in unfamiliar ter-
ritory.

Type II. The ability to fly in a particular direction, even in unfamiliar
territory.

Type III. The ability to head for the home locality even when released

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AWARENESS OF DIRECTION

in unknown territory and when the correct direction of the homing flight
bears no relation to directions that have been previously adhered to in
training nights or migrations.

Type I navigation is "contact" flying, the bird being guided by visual
reference to the earth. Such orientation on the local range is commonly
considered to be within our comprehension; we wonder only how birds
find their way on the longer journeys. Watson and Lashley (1915), among
others, have distinguished between proximate orientation, as where the goal
itself directly and immediately stimulates the animal, and distant orienta-
tion, as where the goal is beyond the perception of any known receptors.

But in Type I navigation, where the bird orientates itself entirely by
visual contact with the world over which it travels, I feel that it is mislead-
ing to judge the complexity of the problem in terms of distance. If we dis-
regard the relative values of the travel coordinates, then the artificial prob-
lem in the mind of the human investigator must become vastly more com-
plex than it can ever be to the bird in passage. We must not make a clear-cut
distinction between proximate and distant orientation, for in all travel,
whether of bird in migration or of human child to kindergarten, the distant,
unperceived objective is attained only by passing through a series of proxi-
mate situations. In our human travel we "cross our bridges" as they are
reached. Brown (Gregg, 1939:69), who studied human behavior in a maze,
tells us that "few subjects, when they are able to tread the maze correctly,
can recoimt the turns as 'right,' left,' 'right,' etc. Almost invariably, after
giving a few turns thus verbally, the subject will say, T don't know what
comes next; J have to be there before I can tell you.' " I suspect it may be the
same with ducks and other birds. As Mallards cross the passes day after day
en route to stubble, or return to the home marsh spring after spring, they
may be ever aware of the proximate situations as these make the path to
the distant and unseen goals.

At two or three weeks of age, the duckling travels in an oriented manner
about its slough, where the forest of reeds stretching far above its head ex-
tends in all ways in confusing monotony. The grain fields to this bird are a
world unknown, as unreachable as the moon itself, as far beyond compre-
hension as America was to Aristotle. Eight weeks later, however, when
the youngster takes wing, relative distances become shorter, and prairie
farms are soon a part of a wide, familiar realm. First to near fields, then to
far, until the young Mallard is feeding many miles from home by mid-
August. Come October and it has reached Minnesota or North Dakota or

195

The grain fields are a world unknown to these young Mallards,
as unreachable as the moon.

some other distant land; by the end of its first year it has experienced half
a continent. Where, as this circle of experience grows outward from the
natal slough, is the dividing line between proximate and distant orientation?
So, as its life develops, the young duck gains within a few weeks after
birth a traveler's perspective of the world that man could not achieve
through all the eons of his existence until this present moment of history.
Not until he understood the relativity of motion, nor until he had viewed
the earth as an airman, could man comprehend the world as a bird awing,
or understand how the realm of migration, like the narrow home range, be-
comes familiar through the experience of travel.

Although a bird comes and goes about a range that is familiar to it,
there is evidence of Type II navigation, where a direct course is followed
in the absence of landmarks to guide the way. Kramer (1951, 1952) has
shown how the sun serves as a cue to compass direction. Studying the ac-
tivity of caged Starlings, he found that during the migration season, their
movements had a strong bias in one direction, and this orientation de-
pended upon the sun. Such solar influence was tested by manipulation of

196

AWARENESS OF DIRECTION

sunlight with mirrors and by an artificial sun; and it was demonstrated that
with the sun obscured, as by overcast of cloud, the cage movements were
random, without directional bias. Kramer's Starlings were not merely aware
of the sun as division between night and day, nor simply as the cue to east
and west, morning and evening. These experimental birds related their
position to the sun in both time and space as it moved in its arc across
the sky.

So convincing are Kramer's experiments that we must conclude that
wild birds, like his caged Starlings, perceive the sun as a cue to direction.
Santschi (1923) has shown how the sun is used as a compass by ants, and
in a wonderful little book Von Frisch (1950) tells us of the role of the
sun in the orientation of bees. Ants, bees, birds, and men perceive the sun
only as an accessory guide when traveling about their homes; but when
they are following a course beyond the limits of familiar surroundings, the
sun becomes a primary cue to direction.

In the absence of the sun or of landmarks, as in overseas passages, the
texture of the water may serve as a cue to direction. Because of their
great inertia, waves may continue in a certain direction long after the wind
has changed. "Once the flight direction relative to this rather long-lived
system of parallel lines is established (from the bearing provided by the
sun, or by some other means), it is possible to use them over a period of
many hours as an indicator of direction." * Clouds may serve as a cue to
direction, either by their texture overhead or on the horizon where cloud
caps show above islands or mountain peaks. Flying above cloud, birds
may perceive their velocity and wind drift relative to cloud texture, but
of course they must become displaced over the land to the extent of the
cloud movement.

Hitchcock (1950, 1952) has succeeded in training pigeons to fly in cer-
tain directions, which were followed by some of his trained birds when
released in strange territory. Kramer observed that, besides maintaining
their standard migrational direction in captivity, his Starlings could be
trained to move in certain ways. This suggests not only a retentiveness for
direction, but that such awareness may develop from a learning process.

The ability to hold a course accounts for the migration of waterfowl
along standard directions during periods of heavy overcast. But the gyra-
tions of travelers over Delta during unfavorable weather suggests that they
seek some cue to direction to continue with a movement under adverse condi-

• Robert L. Lillestrand, "The Flight of Birds in the Wind" (unpublished manuscript).

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MIGRATIONS OF WATERFOWL

tions of visibility. And of course the great waves of misplaced birds, as re-
ported by Williamson ( 1952 ) , make it clear that migrants cannot invariably
hold a track throughout a journey in bad weather.

Banding records demonstrate that birds come back again and again to
the same stopping places and winter destinations every year; and we gather
that migrants are familiar with these regions of annual return. But it must
not be assumed that every bird homing in spring flies every mile of the
way by retracing a route learned in the fall. Like Pintails going south via
California and homing north through the Mississippi Valley, or ducks flying
part of the way over cloud, or birds of many kinds blown far off course by
unseasonable wind, or migrants obliged to cross vast stretches of open
water, there are many individuals which annually must rely on an aware-
ness of the direction home for at least a part of spring migration. In short,
Type III navigation, where the traveler in strange surroundings perceives
the direction toward home, must be fundamental in spring migration. Such
homeward awareness in strange regions has been observed with many
kinds of birds released under experimental conditions: Noddy and Sooty
Tern (Watson and Lashley, 1915), Swallow (Wodzicki and Wojtusiak,
1934), Song Sparrow (Manwell, 1936), Alpine Swift (Schifferli, 1942),
Homing Pigeon (Matthews, 1951a; Griffin, 1952b; Hitchcock, 1952; Kramer,
1952), Herring Gull, Lesser Black-backed Gull, and Manx Shearwater
(Matthews, 1952, 1953a).

With Swallows, Wodzicki and Wojtusiak (Wojtusiak, 1949) found that
in many of their experiments "there was noticeable a characteristic be-
havior of the birds at the moment of their release. The Swallows soared
up into the air, described one circle or several, and then started to fly in
a direct line toward their nesting site." Griffin's pigeons, when released at
points 72 and 100 miles from their loft, "took the correct initial direction
within two miles of the release point." Kramer (1952:284), after studying
the direct homing of his pigeons, concluded that "some sort of astronomical
navigation is suggested by the fact that the pigeons seem to be orientated
even before starting." Matthews (1955b: 94) found that this initial orienta-
tion* toward home functioned only when the sun was in view: the "home-
ward orientation shown by pigeons in critical releases in sunny weather
deteriorates markedly in conditions of heavy cloud and breaks down com-

• "Initial orientation" is that observed at the point of release. Not all individuals making
initial orientation homeward have equal success in reaching home. See Matthews (1955b: 26)
for a summary of homing success.

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AWARENESS OF DIRECTION

pletely with overcast skies. . . . The homeward orientation of Lesser Black-
backed Gulls in sunny conditions gave place to disoriented scatter in
heavily clouded and overcast conditions." Matthews found disorientation
under cloud in the Manx Shearwater, and he says that "it was possible to
show, further, that the same individuals which gave good orientation in
sunny conditions would scatter at random with overcast, and vice versa."

This initial orientation does not hinge on the bird's familiarity with
the range about its home. Matthews (1953b) observed an awareness of
the direction home in untrained young pigeons which had been allowed
to fly only in the immediate neighborhood of their loft. Set free one by
one at distances of 50 to 75 miles from home, they showed an awareness
of the direction home that was but little inferior to that of experienced
birds, although their success in returning was not so high as that of birds
with training. Kramer and Saint-Paul ( 1954 ) went a step further, keeping
their pigeons in large aviaries within which they had limited flight experi-
ence. Given their freedom 320 kilometers (about 200 miles) from home,
these inexperienced birds showed a direct homeward orientation at the
point of release, although, like Matthews' birds, their homing success was
not so great as that of trained individuals.

There is before us, then, the evidence that some birds are able to orien-
tate directly homeward from strange locations and that such direct initial
orientation operates only when the sky is not hidden by cloud. The impli-
cation is clear that the sun serves as a cue to the direction toward home.
If this is so, the displaced bird must be aware of the arc angle and sched-
ule of the sun as these are relative to the situation at home.

It has been observed in many homing experiments that some birds re-
leased in strange country, far from home, orientate homeward more pre-
cisely and return at a greater rate of speed than others set free at lesser
distances from home. Wojtusiak (1949) felt that the birds that were closer
came back at a proportionately slower rate because of their self-confidence
within the range of familiar surroundings. Griffin (1943), noting the poor
homing of Herring Gulls when released close to home, said that "if this is
a consistent effect it might conceivably offer a clue to the fundamental
problems of homing." In the light of Matthews' sun-navigation hypothesis
this failure of birds to return from strange but near places might be due
to their inability to perceive changes in the arc angle and schedule of the
sun close to home. Perhaps birds, like men, must travel some distance be-
fore they become aware of the sun's changes. Until they have been car-

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MIGRATIONS OF WATERFOWL

ried past this critical distance in homing experiments, they must search
randomly* for familiar cues, consuming their time in wandering rather
than in loitering.

When they have passed this critical point, birds may perceive the
changes in the sun's position, then becoming aware of the direction home,
which they adopt at once. Using two teams of experienced pigeons, Mat-
thews (1955b: 77) found that: (1) In birds released 10 miles from home,
"a coarse orientation resulted which could be clearly attributed to memory
of landmarks since it became generally better at closer distances." (2) In
birds released 35 miles from home, there was a "near random scatter, as-
sociated as in the other nonorientated releases with slow returns." (3) When
released at 50 miles from home, "good orientation has been achieved by
these and many other pigeons." Perhaps 50 miles is near the critical point
in this "distance effect" for pigeons. In the Swallow, Wodzicki and Wojtu-
siak (Wojtusiak, 1949:101) determined that 120 kilometers (74.5 miles)
was the critical point. Griffin's homing experiments with Leach's Petrel
(1940:72) showed that birds released at 65 miles and 85 miles from their
nesting places came home much less efficiently than those set free 135
miles away. No doubt the critical point may vary with the species, with
seasons, and with latitude, but the evidence suggests that it may rest
roughly between 50 and 100 miles from home.

One wonders why migrants, such as petrels and swallows, if they find
their way home to a familiar range in spring, become lost only 30 or 50
miles away when artificially displaced. We must remember that the dis-
placement in the homing experiment breaks the thread of continuity link-
ing past with present. For birds released at a great distance, the direction
home in terms of the sun is perceived, and they approach home in the
same manner as migrants. Those set free at closer range may be cued only
to compass direction and, without awareness of the way home, must wan-
der. In our own human experience, the whole of a range is often more
familiar than its parts. Regardless of how I approach the vast Delta marsh
from a distance, I can always perceive the way home. But more than once
I have become lost within the marsh, not far from familiar landmarks.

Hitchcock (1952:285) points out that this distance effect may support
the Coriolis theory of navigation. "If one makes the assumption that a
homing bird wants to return at once," he says, "poor homing performance
at short distances is difficult to explain on the basis of visual orientation

• See Griffin ( 1952a) and Wilkinson ( 1952) for a discussion of random movements.
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AWARENESS OF DIRECTION

involving recognition of landmarks. Such performance is not incompatible
with theories of homing based on terrestrial magnetism or Coriolis force.
According to these theories the stimuli for orientation at nearby points
would be too similar to those at the loft to be differentiated, but those
at a distance could be differentiated clearly." The distance effect is certainly
evidence of a type of "grid navigation," but it does not obtain without the
sun. The experiments of Kramer and Matthews are so amenable to quanti-
tative analysis and tie in so closely with observations of wild migratory
behavior that, in the face of present evidence, this distance effect favors
the case for sun navigation. The challenge now is for other workers with
other species in other places to repeat and test.

In one of the few orientation experiments human beings have con-
ducted upon their own kind, Gregg (1939) found that a man will move in
the direction of his thoughts without being aware of doing so. His experi-
ments were set up very much like those of Kramer's with birds. Instead of
being caged, the human subjects sat within an enclosure encircled by cur-
tain. When a man, with motion-recording devices attached to his head or
to certain muscles, was instructed to think of "north" or "sunset" or some
other point of the compass, there was bodily motion or muscular activity
(of which the subject was unaware) in that direction. "To entertain a
thought of geographic location," concluded Gregg, "is to make overt or
covert response in the perceived direction." When Gregg's human subjects
were disoriented by being turned back and forth on their turn-table plat-
form—when they were "lost" within their curtained enclosure— they showed
no directional bias in their movements. Like Kramer's Starlings without the
sun, their actions showed a random pattern.

We may step from Gregg's experiments into our daily lives to under-
stand how a man directs his actions with his whole being. Here I sit com-
fortably in the parlor reading, until hunger sensations impel me to walk
to the kitchen for a snack. Back to the easy chair for a while, then a yawn
or two and off I go to bed. These actions are conducted thoughtlessly, yet
precisely, so that I do not go to the bedroom when the stomach signals
hunger, nor to the kitchen or bathroom when I am tired.

Such travel to kitchen and bedroom must be on a level of activity simi-
lar to that of a female duck with distended oviduct moving to her nest,
or of hungry stubble Mallards flighting out to the grain fields. For both
man and bird there is a pattern of appetitive behavior. For the man, the

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MIGRATIONS OF WATERFOWL

way to the bedroom is a learned route; he is directed there by the whole
body to satisfy the appetites arising from inner stimuli. The appetite is
not for the bed, but for the instinctive act of sleep. In the same way the
hen moves to her nest, not hungering for the nest itself, but to complete
the act of egg-laying. By the same pattern, man goes to kitchen or bed-
room, bird to slough or gravel bar, neither hungering so much for the
geographic place as for the completion there of instinctive acts.

In man, for all his intelligence, this orientation within the home environ-
ment is conducted without conscious organization; oriented movements
develop with the same spontaneity as words flowing together to make the
spoken sentence. "We seldom think of this experience with space," says
Katz (1953:99), "except when we have some special reason to be aware
of it. . . . This mechanism of orientation is easy to use when one does not
think about it, but seems to resist deliberate manipulation."

Gregg's experiment concerned only compass direction. We know very
little about man's awareness of the sun or other celestial bodies, except as
their place in navigation is taught to him. The early mariners relied heavily
on the sun and the stars in their voyages. In modern celestial navigation,
computation of a "line of position" from the stars is a complicated process
involving spherical trigonometry (if prepared tables are not at hand), and,
besides, there must be a sextant and a chronometer set to Greenwich Mean
Time. Yet, with no understanding of trigonometry, without charts, with-
out sextant or chronometer, the Polynesians followed the stars in their
travels about the South Pacific, the navigational techniques delivered from
one generation to the next by tradition. They "considered the stars as mov-
ing bands of light that passed across the inverted pit of the sky, and they
sailed toward the stars which they knew passed over the islands of their
destination" (Carson, 1951:211).

We human beings are so concerned with the paraphernalia of civiliza-
tion that it is difficult to appraise our awareness of the sun with respect
to regional orientation. Two of my children, at the ages of seven and nine,
independently observed and commented upon the change in the sun's
schedule and position after a five-day trip from Delta, Manitoba, to Wash-
ington, D.C., in November. I find myself always conscious of the sun's
change of position and schedule when traveling away from Delta, and I
maintain an awareness of the location of Delta which I believe to be re-
lated to the sun. I also find it difficult to adjust immediately to "daylight
saving time," clinging for several days to the sun's rather than the clock's

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AWARENESS OF DIRECTION

signal for bed time. But we should test human beings in displacement ex-
periments as Matthews has done with shearwaters, gulls, and Pigeons.

Robert H. Smith and Edward G. Wellein, pilot biologists for the U.S.
Fish and Wildlife Service, have had much experience with low-level fly-
ing over the Arctic, where charts are often in error, the compass unreli-
able, and the landscape monotonous. Both contend that the sun is an im-
portant cue to navigation and that they are aware of the variation in arc
and schedule as they move across degrees of latitude and longitude, so
that by the sun they maintain an awareness of their relation to their base of
operations. Wellein tells me that on several occasions he has sensed his
position relative to the sun but followed his compass — and has found that
his own awareness of position was the truer guide to position.

But the sun, especially in some regions of the Arctic during the sum-
mer, is not always available as a cue, and men, like birds, must make refer-
ence to the world about them. Robert H. Smith says (letter): "An inex-
perienced pilot is frequently lost because he can't pinpoint himself on the
map at a given time. As experience is acquired, he worries less about the
exact position, and is more concerned with the broad features of the ter-
rain—drainage patterns, mountain ranges, large lakes, coastlines and dis-
tinctive features of culture. There is hardly any place where one is not
bracketed in by a combination of these — and this is all that is really im-
portant on long cross-country flights. I believe I could fly from Aklavik,
Northwest Territories, to Mexico City by following my usual routes, without
charts, radio or compass, using my knowledge of details of terrain and cul-
ture near places where I must land for fuel, and relying on broad land-
marks for the areas between. To do this would require flying at a reason-
able height with good visibility."

Home, in all its individual and geographic varieties, means the same
thing to every man in terms of his inborn appetities for those acts and
stimuli of parenthood (or childhood) that for each human being can be
satisfied at only one place: this territory of home. Wherever he is, how-
ever modern his age, the home, grand or humble, is the ultimate goal in
the travels of all mankind.

As with birds, the circle of geographic learning extends outward from
the home. The corner store is the edge of the universe for the two-year-
old who cannot comprehend the father's travels. And yet in due course,
in the natural way of lif e that no elder can ever explain to a child, the wide
unknown becomes familiar. Modern transportation methods, guiding instru-

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MIGRATIONS OF WATERFOWL

ments, books, maps, all have modified the problem of human orientation,
but there is always the awareness of and the inborn hunger for home.

Man is impressed by the superiority of his intelligence to that of birds
and mammals; and yet this homeward orientation — which had to be effi-
cient in the dark, unknown ages before man began his climb up the intel-
lectual ladder — may still be at a primitive level. However much we have
learned to improve our homes and the trails leading there, the organization
of our activities relative to home is apparently very close to the homing
behavior of the lower animals. At dusk the bird flies home, the dog trots
home, and the man drives home, perhaps listening to the radio all the
way. Wherein lies the essential difference?

In man, orientation on his home range is fundamental. Surely such
behavior must have developed early in his evolution ; and upon this ability
to find his way about is built the higher level of activity upon which civi-
lized behavior is established, both in the evolutionary scale for the human
race, and in the life story of each individual.

For the bird the satisfaction of innate hungers is life itself — but no less
or more so than for man. And at this level of behavior where movement
in space assists in the satisfaction of innate appetites, man and bird have
much in common. To study the homing behavior of one is inevitably to
learn something of the other.

Instead of a "sense of direction" in man, there appears to be an aware-
ness of direction. This does not result from the funption of one sense but is
probably a product of all the sensory apparatus, with the eyes, no doubt,
most important. This awareness exists without the requirement for a
knowledge of its existence; it functions as long as a man maintains con-
tinuity with his environment. It ceases to have reality the instant the pres-
ent is disconnected from the past; then a man is lost. Awareness of direction
is thus not inborn but hinges on personal experience with the environment.

In birds there appears to be a similar awareness of direction, effective
as long as the continuity of life's flow remains unbroken, ineffective when
the continuous sensory contact with the surroundings is disrupted and the
bird is displaced from all environmental cues. In birds and in men the sun
is the basic cue to orientation. In local travel it serves as a guide to direc-
tion; beyond a certain point from home, changes in its position and its
time may be cues to the direction of home. In the absence of the sun, man
and bird must read their position in terms of the world about them, wan-
dering if displaced from familiar surroundings.

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AWARENESS OF DIRECTION

In the flow of life, a bird faces familiar places on all sides. The direction
in which the bird moves, that with the greatest valence, depends upon
the appetites impelling travel. On the local range the bird may go toward
nest, gravel bar, or slough according to the stimuli of oviduct, gizzard, or
crop. In the same manner, the Manitoba Mallard hen wintering in Texas
must be driven by her newly awakened sexual appetites to respond to her
awareness of the direction toward Manitoba. We do not know what appe-
tites awaken an awareness of familiar wintering places in autumn. But in
each of these situations where migration is concerned, the valence of cer-
tain directions depends upon appetitive behavior, and the travel of migra-
tion differs from movement on the home range only by the relative meas-
ures of time and space.

Where waterfowl migrate homeward along flight lines of standard di-
rection, we see great numbers going the same way ; but the travel is not to
a common destination. The spring navigation homeward (except for the
mated drake, or the young of geese and swans) is an individual problem
which must be faced separately by each bird. The female duck may start
from Texas with many others of her kind, but eventually there comes a time
when she, like each companion, must bend away from the direction of the
group and take her own course to the familiar nesting place. Leadership
in spring migration cannot be entrusted to casual companions, or else the
arrival home would be a remote chance indeed.

In the same way, molting movements of adults and the swift, direct
passage of mass fall migration hinge upon an awareness of direction toward
destinations that have been visited before. But in these nonsexual migra-
tions, the whole body of birds moves together as a social group to the
common destination without the requirement of individual separation.

To understand this awareness of direction, as it is cued by the sun and
by the surrounding world, would be to understand how the duckling learns
to know its mother, or how it so rapidly takes its familiar place within the
complex range of its natal slough. The evidence suggests that each bird
gains familiarity with its mother, with its home pond, and with the great,
wide world beyond, by virtue of its experience; but to explain this process
of rapid learning and retentiveness would be to unravel the whole mystery
of memory itself.

Such awareness of direction founded upon experience is, of course, thin
soup for those who fail to distinguish between the orientation of adults

205

MIGRATIONS OF WATERFOWL

and juveniles or who cherish the oldest and fondest of all migration mys-
teries, the idea of an inborn awareness of the direction and the route to
the wintering grounds.

In any analysis of migrational orientation, I am sure we must distin-
guish between experienced adults and inexperienced juveniles just learn-
ing their place in the world. The primary dispersals of ducks from the natal
ranges carry youngsters toward rendezvous areas where they gather to-
gether, not only with many of their own age, but with adults as well. As
already discussed in Chapters 8 and 10, vast numbers of juvenile ducks
make part or all of their final autumn journey to the wintering grounds
with experienced adults in the traditional mass migrations. Juveniles that
accompany their elders, whether they are children, as in geese and swans,
or merely companions, as in ducks, may learn the flyways and standard
directions, which thus become traditional.* But however many young reach
the wintering grounds in this way, some juvenile waterfowl (and in some
species of birds, perhaps all young-of-the-year) gain the wintering places
without the companionship of experienced adults.

An analysis of juvenile travel in autumn must first distinguish between
an ecological and geographical goal. Because the immature bird arrives at
an ecologically suitable situation on its winter range, the literature often
assumes an innate awareness of that place. When a young duck finds a sago
bed on the far side of its natal pond, nobody claims there is an inborn
guidance to that special location, nor to the stubble fields ten miles south
of the home marsh, nor even to another marsh in the home province. When
the juvenile eventually arrives in Minnesota or North Dakota, we credit
it with no innate tie to these places. But somehow, when a young bird
finally attains a wintering area a thousand miles or more from its birthplace,
this feat is often explained by assuming an innate bond to that geo-
graphic location.f

* In ducks I found the existence of mass migrations poorly documented in the literature,
and I believe this holds for many other species. While it may be true that in some kinds all
young-of-the-year arrive on the wintering grounds independently of adults, I believe that mass
autumn migrations are greatly underrated as the vehicle for the autumn travels of inexperi-
enced juveniles. Simmons ( 1951:406), discussing raptor migration, says, "I feel the significance
of socially-facilitated behavior has been under-estimated. There is a definite tendency for the
birds to follow the movements of their companions, thus effecting general movement in the same
direction." To show that large numbers of young in many species regularly travel part or all of
the way to the wintering grounds en masse with adult companions is not to explain all juvenile
travel. But this type of movement must account for the winterward passage of great numbers of
young birds in many species.

t In some European species, like the Stork, European Sparrow Hawk, Starling, and Hooded
Crow (Mayr, 1952), and in the American Crow (Rowan, 1946), certain experiments have been

206

AWARENESS OF DIRECTION

Such assumptions are often embellished with the suggestion that the
young bird went with precision to this place. If the wintering area has been
used by a particular species for many years, or if the adults have arrived
earlier, some by a different route, these circumstances are given as further
evidence that the tie between bird and place is innate. Science has yet to
describe an inborn awareness of a proximate geographic location, and it
seems unreasonable to believe that such an awareness exists for some dis-
tant place beyond the realm of experience. A female may have an inborn
urge to nest in a rather narrow ecological pattern of environment; but each
and every female must explore to find the geographic place of her nest.
In the same way young waterfowl and juveniles of many other species ap-
parently have an innate awareness of environmental patterns, but the exact
locations of these places they use their first autumn and winter must be
found in the course of their juvenile explorations.

Some young ducks reach the wintering range in their primary wander-
ings, getting there before many adults have arrived. Other vagabonds,
at the same time, find their way north or east or west. As long as these
youngsters have no experience of the land over which they wander, they
are under certain environmental influences. By their innate response to
water, the early movements carry the young ducks from one lake or marsh
to another. They follow rivers and shorelines ; and when they move over-
land, their stopping places are marshes and lakes. In this random travel
the wind inevitably is a major influence on the pattern of their wanderings.
Without geographic goals the over-all trend of nomadic flight will be in
the direction of the air flow, and it is most important that we understand
the relation of the wind to the wandering juvenile. When a bird, young
or old, moves about on its familiar range, flying to and from familiar ob-
jectives, the wind modifies the timing but not the direction of these move-
carried out which have produced results accepted by some as evidence of an inborn awareness
of the direction of autumn migration. In several of these studies, pure groups of young birds
were used, but there was no analysis of the weather prevailing during the period of study.
Others studied the weather, but could not rule out the possibility of young meeting experienced
adults. Nor has the role of tradition been thoroughly examined, as where local birds moved by
tradition, while the experimentals, released later, might have been influenced by major air mass
flow. When we assume something so vastly fundamental as genetic influence on geographic
direction, I believe experimental investigations must insist on: (1) Studies to be carried out
only with birds in which the history is known from birth. (2) A thorough assay of "ecological
factors in the broadest sense, including air mass characteristics, wind direction, the apparent
structure assumed by convection currents in the air, ocean currents, ocean wave patterns and
the possibility that the sun or resulting sky-brightness pattern could serve as a directional cue"
(Griffin and Hock, 1949:196). (3) No opportunity for experimental birds to join experienced
wild companions. ( 4 ) A study of the role of tradition in the migration of the wild stock against
which the experiments are being compared.

207

In their juvenile wanderings, young ducks move from one marsh to another.

merits, as discussed in Chapter 5. Once the bird leaves the familiar range,
once it has no geographical goal, once it wanders at random, the over-all
trend will be in the direction of the wind (Figure 25). In their explora-
tions, the juveniles may travel part of the time against the wind, some-
times for prolonged periods, for the bird is not passively at the mercy of
the wind as a leaf or wisp of spider's web. But as long as the travel is ran-
dom, the total product of a day's or a week's wandering will be in the
direction in which the air mass flows, just as surely as a ship wandering
in the Gulf Stream moves with the ocean currents.

This is a small matter when the flow of air in any one direction is of
short duration. But with the advent of September in central Canada and
the north central United States, the flow of air, when measured by weeks,
is predominantly from the northwest. There are periods of calm, days when
the warm autumn air moves up from the southeast; but when the whole
of the air movement from mid-September through November is measured
for any year, the major trend across the heart of the continent is from the
northwest (U.S. Weather Bureau, 1952) (Figure 26).* However far north-
ward the inexperienced juveniles may have wandered in August, the domi-

° Although the dominant November flow of air over the main waterfowl breeding range is
from the northwest, the patterns of high- and low-pressure areas give some interesting variations.
Winds moving counterclockwise around the Aleutian low (Figure 26) create a westerly flow over
the Pacific Ocean from the Aleutian Islands to the continent; and there is evidence here ( such as
that presented by Yocom, 1947 ) of an oceanic migration of waterfowl and other northern birds in
autumn. The eastward flow of winds from the Greenland low suggests a reason behind the autumn
migration of Greenland birds toward Europe; and it may be with this same current that the Arctic
Tern takes its flight across the North Atlantic in the first leg of its long autumn migration. The
intercontinental flow of wind around the Aleutian and the Greenland lows may be the medium of
transportation by which North American waterfowl regularly drift to Siberia and to Europe.

Figure 25. When a bird flies at random,
it must inevitably move in the direction
of the wind. Here the speed of the wind
is 15 m.p.h. from the northwest. The air
speed of the bird is 30 m.p.h. If it flew
one hour directly northwest into the wind,
one hour southwest, one hour southeast,
and one hour northeast, the product of
the four hours' travel would be 60 miles
southeast of the starting place.

nance of the Polar Continental Air Mass in September and October must
make for a southeasterly movement of these young birds, just as the blind-
folded bird, flying in circles, drifts downwind. I believe that all young
waterfowl which do not join mass migrations are inevitably destined to
travel toward the equator in autumn by the dominant flow of the air mass
in which they move. Williamson (1953) explains "that in the case of Green-
land-Iceland populations down-wind drift, without dependence on an in-
nate sense of orientation, provides the surest method of reaching the west-
ern sea-board of Europe in autumn."

We find evidence of this influence of the wind in other places with
other birds. In summer there is a flow of air to the northeast along the
Adantic Coast (Trewartha, 1937:88). Young herons of several species,
wandering aimlessly from their birth range in the southern United States,
arrive in regions far to the north in August and September. Broley (1947),
studying the movements of immature Bald Eagles he banded in their natal
state of Florida, found a similar trend northward along the Atlantic Coast.
Hoar (1953:440) has shown how the Chum Salmon fry move with the
current during the night when in darkness they lose their visual orienta-
tion,* and he points out that "it is not necessary to assume that fish trans-
ported in this way will move at the same rate as floating objects." He goes
on to say that "the downstream movement of juvenile and spent fish, em-
phasized by Russell (1937), is recognized as a part of the migratory be-
havior of a great many fish. Cod, salmon, herring, mackerel and flatfish
may be mentioned as a few of the important species showing such be-

• See p. 69.

209

Figure 26. Normal weather chart for November (U.S. Weather Bureau, 1952). The
solid lines show the pattern of sea-level air pressures (millibars), and the thin solid
arrows mark the flow of winds near the earth's surface. The weather for the whole of
November, of course, does not remain stable on a day-to-day basis, there being a regu-
lar progression of migratory lows from the northwest to the southeast across the con-
tinent. Behind each mobile low there follows a ridge of high pressure, usually starting
just east of the Canadian Rocky Mountains (see the weather map for November 7,
1947, on page 105). The tracks of these high-pressure cells flow almost exclusively from
the northwest to the southeast, as shown by the heavy black arrows (Berry, Owens, and
Wilson, 1952). The broken lines and arrows indicate the contour and wind flow at the
700 millibar surface (approximately 10,000 feet above sea level). At this height, where
weather is less under the influence of surface variations, the predominance of Novem-
ber's northwesterly movement of wind over the whole of North America becomes more
apparent.

210

The rock and spruce country of the Pre-Cambrian Shield
is avoided by most migrant waterfowl.

havior." Whether the current is of air or water, the animal moving ran-
domly must travel with the flow of the medium in which it wanders.

Just as a boatman in a great current may avoid shoals by steering
around them, so juvenile birds are ecologically selective in their travel
within the air mass. If the movements of waterfowl were in complete
obedience to the flow of air, there would be a mass passage of western
ducks over the inhospitable spruce forests of the Pre-Cambrian Shield, for
this vast region is southeast of important duck-breeding grounds. While
there is, indeed, some crossing of the Shield, we find the major trend of move-
ment holding to the prairies. Sigurd Olson, who has lived many years
within the Spruce Forest of northern Minnesota, writes me that he has
"observed the flight of ducks in the Pre-Cambrian Shield from the Lake of
the Woods to Lake Superior for 35 years and can say that there is no
comparison with the flight over the prairies to the west. Along the western
edge of the Shield there is a transition area where the flight may be fairly
heavy, but as one penetrates more deeply into the Shield country, the
numbers become appreciably less." In the same way, autumn juveniles may
avoid drought areas or congregate in regions abundantly supplied with
water or where there is a profusion of preferred food.

However the young waterfowl arrives on its wintering grounds — in
company with experienced companions, or in the course of its wander-
ings—the juvenile's vernal return to the nesting place is to the familiar
range of youthful experience. In view of the return of the young to the
marsh of their first liberation (as in the experiments of Valikangas, 1933;

211

Long journeys are carried out in the absence of the sun or other celestial guides.

Williams and Kalmbach, 1943; McCabe, 1947; Foley, 1954b) there can be
no inborn awareness in waterfowl of the direction of home. The course
of homeward migration must be founded on experience of the world.

This discussion is not presented as an explanation of migrational orien-
tation, but merely attempts to organize the problem, especially with respect
to waterfowl. The evidence at hand suggests that adult waterfowl travel
as experienced birds over a familiar range. By reference to the sun, as
to a compass, or to environmental patterns, like those presented by waves,
they may hold a direct course for some distance without visual reference
to a familiar landscape. The studies of Matthews and Kramer (yet to be
repeated with waterfowl) suggest that the sun may serve as the cue to
the direction of home when the bird is displaced from familiar surround-
ings, but that such awareness hinges on the bird's distance from home.
Long journeys are carried out in the absence of the sun or other celestial

212

AWARENESS OF DIRECTION

guides, but the gyrations in stormy weather suggest that ducks seek re-
orientation when traveling under adverse weather conditions. There is
ample evidence that migration does not always carry migrants to their
destinations; in bad weather they may be blown far from their course or
meet their destruction by accident. In the fall migration of juveniles toward
the wintering grounds, vast numbers travel with experienced adults. Other
young birds, still wandering randomly, gain temperate regions and win-
tering companions under the influence of the air mass in which they travel,
such air flow showing a southward trend in autumn; and some few each year
drift to Europe or to Siberia, carried there by the streams of wind flowing
around the Greenland and the Aleutian low-pressure areas, the transoceanic
air currents linking North America with the continents to its east and its
west.

21G

PART III

Traditions of Waterfowl

'It is by means of a sort of tradition that the migra-
tory birds transmit to each other from generation to
generation the knowledge of the airy paths they
follow."

G. Reynaud, The Laws of Orientation
among Animals

"The role of tradition in evolution should not be so
lightly dismissed without better evidence, for such
dismissal tends to discourage further attempts to
learn the facts of the case." John E. Cushing ( 1944)

16
Biological Traditions

In the summer of 1951 a crate of young Pin-
tails traveled to New York State by rail. These ducklings had been hatched
at Delta from eggs taken from wild nests in nearby stubble and meadow-
land. They were half-grown when they left Delta and had seen no country-
side beyond the narrow view from the hatchery window. Their travels
ended in central New York, where they were banded and released on
Spicer's Marsh. Next spring, a survivor of the first autumn and winter, iden-
tified by her leg band, migrated back from the southland to nest and rear
her young on Spicer's Marsh. This place had not known nesting Pintails
in modern times. With all the wide northland to visit, she was faithful to
the marsh of her maidenhood.

All week the wild geese passed over Delta, each flock going beyond the
horizon to destinations we knew not where. Then, on the evening of the
eighth day of April, there came thirty-six birds flying straight for the Sta-
tion pond. They circled only once before alighting on their home waters.
These were birds we had raised and to which we had presented freedom
the November previous. The parents came back to their home; their chil-
dren were with them.

I live on the prairies, but when I dream it is of mountains. Often, when
there is a dark cloud bank in the west, I squint my eyes and pretend it is
the Rockies. When soft spring winds blow, they feel like Chinooks to me.
My parents are from Illinois, but I was born within sight of Long's Peak;
and, however wonderful the prairie sunsets, I think of the mountains
beyond.

217

Often when there is a dark cloud bank in the west, I squint my eyes
and pretend it is the Rocky Mountains.

Many songs are of places for which some men have great attachment:
songs of the prairies, the hills and the rivers of home. Homeland has been
inspiration for the poet; the artist paints this land he knows best. When
a man hears the melodies, reads the poetry, or sees pictures of home, he
cannot suppress nostalgia; for no matter where this place may be, all man-
kind has an inborn attachment to the region of early experience.

Crossing the Susquehanna at Havre de Grace was always the highlight
of my ride home from college at the Christmas holidays. Usually some
Canvasback were in sight of the bridge, and once they were strewn down
the river as far as I could see. Every wildfowler knows of the Susquehan-
na's Canvasback, and Heilner (1939) says that in the old days they some-
times "looked like plumes of smoke when they got up." A century earlier

218

BIOLOGICAL TRADITIONS

(1831) Alexander Wilson had written that "on the first arrival of these
birds in the Susquehanna near Havre de Grace, they are generally lean;
but such is the abundance of their favorite food, that toward the beginning
of November they are in pretty good order. They are excellent divers, and
swim with great speed and agility. They sometimes assemble in such mul-
titudes as to cover several acres of the river, and when they rise suddenly,
produce a noise resembling thunder. They float about these shoals, diving
and tearing up the grass by the roots which is the only part they eat. They
are extremely shy, and can rarely be approached unless by strategy." In
those days, as now, the Susquehanna was a major wintering place for the
Canvasback; then, as now, it gave the best of Canvasback gunning. In
Wilson's time the Chesapeake market gunners claimed that their bird was
of a finer breed and "boldly asserted that only their waters were favored
by this species, and all other ducks, which seemed to claim affinity, were
a spurious race, unworthy of consanguinity. Hence at the same time when
a pair of legitimate Canvasbacks, proudly exhibited from the mail coach,
from Havre de Grace, readily sold for two dollars and fifty cents, a pair
of the identical species, as fat, as heavy, as delicious, but which had been
unfortunately killed in Delaware, brought only one dollar." *

The regularity of the Canvasbacks' return to the Susquehanna is but
one example of the tie between waterfowl and their wintering grounds.
As surely as the arrival of frost, the Greater Snow Geese come each year
to Cap Tormente, Quebec, until all their worldly numbers are together
there. Every autumn finds thousands of Redheads settling down on the
Laguna Madre off the east coast of Mexico. The coming of Greater Scaups
to Cayuga Lake in New York is an event of annual interest to upstate
waterfowlers. Earlier in the discussions I have dwelt upon the return of
ducks to McGinnis Slough, and there is no reason to burden this chapter
with further testimony to the fact that ducks, geese, and many other birds
come back to the same wintering places year after year, generation after
generation.

What link ties them to their wintering quarters? To be sure, they have
selected a habitat that provides suitable food and rest, the kind of en-
vironment to which we believe they have some innate attachment. With
respect to the geographical location, however, there can be no genetic
bond; the Canvasbacks have no inborn guidance to the Susquehanna, nor

• Mr. Glenn Martin told me that many Maryland wildfowlers still consider the Susquehanna
Canvasbacks distinct - heavier and better eating than Canvasback shot elsewhere.

219

TRADITIONS OF WATERFOWL

the Blue-winged Teal to McGinnis Slough. Our present understanding of
innate behavior accounts for no inherited relation between a bird and a
special geographic place. I believe that once a Canvasback has come to the
Susquehanna, a Redhead to the Laguna Madre, or a Snow Goose to Cap
Tormente, these same birds must find their way there again during an-
other fall migration. And when juveniles travel southward in company
with experienced adults, the Susquehanna, the Laguna Madre, and Cap
Tormente are delivered from one generation to the next as traditions. True,
some young stray; some do not go directly; some travel without the com-
pany of adults. But where such neophytes chance upon birds that have
come to use a place regularly, they take this into the realm of their exper-
ience. In this way, the link between the Susquehanna River and the
Canvasbacks that use it lives in the action of experienced birds, a tradi-
tion that ties the wintering behavior of modern birds to their ancestors of
Wilson's time and long before.

In our everyday use of the word, tradition refers to story or verse or
rule of family and community that has been handed down from our ances-
tors. Essentially, tradition is the delivery from father to son or from an-
cestors to posterity of knowledge, experience, and custom, carried through
the years without written memorial. Many songs have come to us this
way; tales of the frontier have reached us by word of mouth. On sidewalks
and in schoolyards we listen to children repeating doggerel that no child
ever reads.

We generally think of traditions as carried vocally, yet it is clear that
the verbal link is not essential. For example, some rituals, such as the
handshake or the tipped hat, survive in action alone. To be sure, some
mothers must prompt their children, but instruction is often absent. Neo-
phytes follow the actions of the experienced as when rising for the hymn
in church; all do the same thing at the same time with no cues other than
the direct movements of companions. Other human traditions are carried
by symbol, as the lapel buttonhole and cuff buttons on a man's suit. Without
a word, the young accept the customs of the fathers, eventually to see their
own progeny following the same traditions, so that no son ever asks for
cuff buttons, nor does he order a coat without these ornaments. The paths
of our pioneers were followed by others, and the original routes have be-
come traditional; many trails of the frontiersman are the roadways of to-
day. In cities we follow by walk and curb the traditions of generations
gone. Surely our daily lives are ruled far more closely by tradition than

220

BIOLOGICAL TRADITIONS

we generally realize. Although ancestors have not consciously directed us
and we have not sought their guidance, we the moderns cannot escape
the force of the traditional influences in the actions of living from day to
day, from youth to old age.

The welfare of our daily lives is broadly influenced by this social in-
heritance. Health measures, safety procedures, the design of our homes,
live by tradition. So it is that most North Americans own a toothbrush,
and automobiles keep to one side of the road. Many traditions are of bio-
logical importance to the human race, and the pattern of social life is es-
sentially a nongenetic inheritance passed from father to son or from elders
to young. We realize the strength of this force on our lives when examin-
ing the mating behavior of human beings in different parts of the world.
Monogamy is traditional for a large segment of the human race, but it is
by no means universal; there are numerous patterns of marriage customs
according to race and region. "No man ever looks at the world with pris-
tine eyes. He sees it edited by a definite set of customs and institutions
and ways of thinking. Even in his philosophical probings he cannot go be-
hind these stereotypes ; his very concepts of the true and the false will still
have reference to his particular traditional customs . . . The life history
of the individual is first and foremost an accommodation to the patterns
and standards traditionally handed down in his community. From the mo-
ment of his birth, the customs into which he is born shape his experience
and behavior. By the time he can talk, he is the little creature of his cul-
ture, and by the time he is grown and able to take part in its activities,
its habits are his habits, its beliefs his beliefs, its impossibilities his impossi-
bilities" (Benedict, 1946:4). These customs from the cradle onward have no
biological transmission; they are nongenetic; they are a part of our heritage,
but they are not genetically heritable.

Any study of human behavior, any searching investigation into our
ethology, must give deep and careful examination to tradition. So too, in
the animal world, where there is learned behavior, where individuals live
in companionship, where there are communities and biological societies,
there is the nongenetic link of intelligent action between one generation
and the next. This being the case, it may be said that tradition is a proper
biological term of special reference to behavior that is delivered by ances-
tors to progeny nongenetically.

When a bird learns from the behavior of its experienced companions,
the objects, places or actions thus learned become traditional. Cushing

221

TRADITIONS OF WATERFOWL

(1944) discusses the role of tradition in the feeding habits of birds and
comes to the conclusion "that all evidence so far available favors the con-
tention that the differences in specific food habits of various species of
raptors are maintained much more through non-heritable factors passed on
by the interaction of parental behavior with that of the offspring than they
are through specifically heritable factors." He goes on to say that "there
is abundant evidence that tradition may play an important role in the food
habits of a great variety of birds besides raptors."

When a wild bird feeds on a cultivated domestic crop, there must be
some link of tradition that carries this new food habit from one generation
to the next. In the Mallard and Pintail, the habit of eating cereal grains
is certainly traditional, and this likewise holds for ducks that feed on let-
tuce fields in the Far West or on rice in the southland. More obviously
traditional, perhaps, is the acquired habit of opening milk bottles in the
Great Tit and at least ten other British birds. Fisher and Hinde (1949)
show how this milk-robbing has "become widespread in many parts of Eng-
land and some parts of Wales, Scotland, and even Ireland." These authors
concluded, after careful study, that "this source of food was actually dis-
covered de novo by only a small proportion of the tit population, and was
then passed on in some manner to other individuals." In such feeding tradi-
tions pioneers discover new sources of food by trial-and-error learning, per-
haps as some human beings first learned to relish tomatoes. Companions
eventually repeat their actions until the habit is acquired by many. Miller
(1942) says that "habits and associations with respect to environment and
particular landmarks are passed on nongenetically from generation to gen-
eration. Cultures or societies are formed in the higher vertebrates, as indeed
in humans, and temporary barriers set up. Perhaps the hill-dwelling Song
Sparrows of San Francisco Bay do not associate with those of the salt flats,
figuratively and literally on the other side of the railway tracks, because
of their upbringing." Snyder (1948), who discussed avian traditions in
some detail, shows how a transplanted population of Mallards established
a traditional breeding area in Ontario. Lorenz (1952), speaking of his be-
loved Jackdaws at Altenberg, tells how the modern birds "follow loyally all
the traditions which reigned in the first colony, and which were trans-
mitted to the present by Redgold."

Mayr (1942:53) speaks of the Yellow Wagtail of Europe, which "is
nearly always a ground-nesting bird. About 1915 Schiermann (1939) found
a little colony of these birds in which all individuals (eight or nine pairs)

222

BIOLOGICAL TRADITIONS

had built their nest off the ground on Artemisia plants. The birds came back
year after year and built the same kind of nests, until the habitat was de-
stroyed. It is extremely unlikely in this case ( and many similar ones ) that
some sort of mutation had occurred which resulted in the changed habit.
It is much more likely that one bird started the new fashion and others
learned' from him, until the entire population had acquired' the new habit.
Such new habits are usually lost as quickly as they are acquired, unless
they add measurably to the survival value of the species." On the Delta
Marsh, the Redhead usually nests over water in emergent vegetation, but
some few individuals nest on dry land, sometimes quite far from water, in
situations where one would expect to find Mallards. I have found such land
nests of Redheads in loose groups, with more than one in the same restricted
area. This looks like traditional nesting behavior.

Nice (1943:150) decided that in the Song Sparrow, the pattern of song
"is innate, but the quality may be imitated. Particular songs may be impro-
vised, or may be adopted from some other Song Sparrow." Mayr (1942:54)
says that "it has been known to the field ornithologist for a long time that
in some birds the song varies from district to district. . . . The most re-
markable geographic variation of song and call-notes that has been de-
scribed occurs in the European Chaffinch. Promptoff (1930) called attention
to the fact that this species tends to break up into a number of geographic
song races. Sick (1939), who gives a general survey of the literature on
geographic variation of song, found that the so-called 'rain-call' of the Chaf-
finch is subject to an even more remarkable localization. This call, whose
exact biological significance is still somewhat obscure, is uttered by the
male within his breeding territory. In the township of Stuttgart, southern
Germany, three sharply characterized rain-calls occur, of which one is re-
stricted to the three-hundred-year-old park which extends along the valley
floor for a distance of three kilometers. The second call is restricted to the
hills to the west, and the third to the hills to the east of the town. A 'hybrid-
zone' is found where two of these dialect districts meet, but distributional
barriers, such as railroad yards, prevent such hybridization in other places,
so that districts of pure call notes approach each other occasionally within a
distance of only five hundred meters. Much circumstantial evidence indicates
that these call notes are not genetically fixed, but conditioned. The young
Chaffinch learns these call notes from his father and from the neighboring
males and he either stays at or always returns to the locality where he was
born. The exact history of the parks of Stuttgart is known, and it is evident

223

TRADITIONS OF WATERFOWL

that a period of three hundred years was available for the development of
the striking park dialect.' The significance of such nongenetic changes as
contributory factors to isolating mechanisms is evident (see also Cushing
1941)."

Thorpe ( 1954) studied the pattern of the Chaffinch song by means of the
sound spectrograph and from this concluded that the normal song "has a
very restricted inborn basis." Some learning of song takes place during the
bird's early fife, but the final song form is acquired during a period of a few
weeks during the first spring.

Nice (1943:264) says that "apparently the Song Sparrow recognizes
enemies by both inborn and learned patterns. In nature, the behavior of
the adults must be of great importance in the forming of conditioned pat-
terns in the young." She concludes that "experience may be handed down
non-genetically from generation to generation particularly in matters re-
garding protection from enemies." All evidence suggests that wild ducks
leam the nature of their relationship with man, fear or lack of fear being
transmitted from the experienced to the inexperienced. Hunters claim the
Mallard as the "wildest" of all ducks in autumn, the wariest, the most diffi-
cult to approach with gun. When young from wild eggs are reared in cap-
tivity, however, they are "tame" in the presence of man, showing no fear
of him.° This awareness of man as a "friend" is transmitted from one bird
to another, from flock to flock, until each year the number of fearless birds
of wild origin in the Delta pond is increased. We note the companion in-
fluence when a small band of Blue-winged Teal alights near the tame ducks.
As I approach these wild birds, they make departure movements. But when
their companions, who know me as a friend, show no escape reactions, the
wild birds remain; and although they are obviously more nervous, they
usually do not take flight. In a few days they may be approached on the
pond as closely as any of the old residents and are completely "settled
down."

Surely some birds are tied traditionally to certain places. Not far from
Delta are the dancing grounds of a band of Sharp-tailed Grouse, which local
farmers recall as having been in regular use for at least sixty years. Al-
though many generations of grouse have come and gone, the living link of
action ties modern birds to the same plot of prairie as was used by their

"And yet there is such a thing as "heritable wildness" (Leopold, 1944) in waterfowl.
When Mallard and Baldpate are hatched from wild eggs and reared by man in captivity, the
Baldpate, according to my experience at Delta, never becomes as tame or fearless of man as
the Mallard.

224

BIOLOGICAL TRADITIONS

ancestors more than half a century ago. In New York State, Emlen (1938)
found that in 1932 the locations and boundaries of winter Crow territories
were essentially the same as those reported twenty-five, fifty, and, in one
case, one hundred and twenty-five years before. Austin (1949) describes
Japanese netting places that have been used by wild ducks from time im-
memorial. The ponds where the ducks rest are kept as sanctuary, the birds
captured in cast nets at passes as they arrive and depart each morning and
evening. At one pond, netting privileges are still held by a guild estab-
lished more than a hundred years ago. One of the best known traditional
ties is that of the Whooping Crane, with the last few coming back from
the north each autumn to the Aransas Refuge in Texas. Cushing (1941b)
discusses the regular return of Ravens to their roosting place and says that
"it is probable that an individual acquires rather than inherits its special
attachment for a particular roosting site, even though it probably inherits
the ability to form this attachment." Hamerstrom (1942:35) believed that
in the continuity of winter territories of the Chickadee "the key lies in
tradition. Instead of repeating this random building up from a fresh start,
the territory begins its second winter with a nucleus of old-timers." Moffitt
(1937) tells of a group of Western Canada Geese that used the same winter-
ing quarters in northwestern California for at least fifty years. Stresemann
(1934) refers to Palmen's (1874) hypothesis that some birds hold strongly
to certain migration routes that are handed from one generation to the next
in a traditional manner.

In some mammals, certain traditions such as the game trail are handed
down by record. An Elk need never see another to follow the traditional
route that generations of its ancestors have taken out of the high country
each autumn. At Delta the White-tailed Deer arrived in the late 1930s.
Before this no big game trails had survived from pristine times, and the first
deer pioneered their way about the marsh. Now, eighteen or twenty years
later, with none of the original stock alive, the modern White-tails follow
in the footsteps of their forefathers, and the main deer trails are those estab-
lished by the first deer. Some birds leave records for tradition, such as the
bulky nest of the Osprey, the chalkings of the Peregrine Falcon, or the mud
workings of the Cliff Swallow. Mostly, however, avian traditions are carried
in action alone. Such passing of experience by action may be local and brief,
like the opening of milk bottles. Or the experience may be long and regional,
like the flight of the Whooping Crane to Texas or the Canvasback to the Sus-
quehanna. There is no intent upon the part of the elders to "teach" the

225

TRADITIONS OF WATERFOWL

young or the inexperienced. Yet the directness of experienced behavior is
the medium by which one bird learns a custom or a region that another bird
has used, and by this unconscious delivery, the cultures and traditions,
new and old, are handed down through the ages.

As we examine the traditions of food and place, we are aware of cer-
tain characteristics that distinguish this inheritance from the innate. Firstly,
a tradition may have spontaneous beginning at any time in the life of any
individual, as genetic mutations cannot. Secondly, as Mayr (1942) points
out, traditions may be "lost as quickly as acquired." A tradition may have
its beginning today and its ending next year, after delivery to but one gen-
eration ; or a habit acquired this afternoon by an individual or a group may
live for many years, perhaps for centuries. Traditions that have lived for
unknown generations beyond the beginning of history may die forever
overnight. Errington (1941:99) postulated for the Bob-white that "tradi-
tions die along with populations during periods of great mortality." The link
is always in the actions of experienced individuals. When these are lost or
killed or no longer active, the tradition is ended. It is this nonheritable spon-
taneity of tradition that permits the establishment of a breeding colony
of Canada Geese almost anywhere a man may choose for the starting of
young birds.

We observe that there are two ways of delivering avian traditions. There
is, first, the direct tie between parent and offspring. In numerous species, like
the ducks, the parent-child relationship is short and family traditions are
thus weak. In others, such as the geese and cranes, where the family holds
together for a long time, family traditions are strong. Second, there is the
companion bond whereby group or community traditions are delivered
from one experienced bird to another, although there may be no blood
relationships. The use of a sanctuary and the feeding travel to grain fields
are examples of such social inheritance. We of course are aware of these pat-
terns of inheritance in our own human lives, how each family has its indi-
vidual codes of behavior passed on from father to son, while every com-
munity maintains traditions of action that concern all its families. So it is
that in man and in many of the lower animals, certain cultures, habits and
actions are delivered nongenetically from one generation to the next and,
as Cushing and others have suggested, we may properly refer to such non-
heritable actions as traditions.

226

'The pioneer that carries the range a little further for-
ward starts from a base where it has associated with
companions and found food plentiful ; and when the im-
pulse to live in society again asserts itself, it not only
repeats its former experience but hands on the habit
thus acquired to those of the next generation that hap-
pen to accompany it." Eliot Howard (1920)

17

Building New Traditions

To the Mission San Juan Capistrano, in California,
come Cliff Swallows each March, returning to build their gourdlike nests
under the Mission's eaves. The pastor, the Reverend Vincent Lloyd-Russell,
wrote me that the pioneer swallows first took residence on the buildings in
1776. Originally, the Cliff or Eave Swallow was confined in its nesting to
natural features of the land such as cliffs and overhanging walls. With the
coming of civilization, the structures of man offered ideal nesting situations ;
barns and other buildings were quickly accepted so that, as Bent (1942:
465) points out, the swallows "multiplied and spread from place to place
where they were never seen before." Far and wide over the land they
claimed new homes, deep over the prairies, far into the woodlands, miles
beyond their pristine nesting range. Lewis ( 1939a ) tells of a Nova Scotia
farmer who dates the history of a barnside colony back "ninety or a hundred
years," and he mentions another colony with a history going back to at least
sixty years. Grinnell (1937) believed that the pioneers were yearlings; and
in the colony starting on the Life Sciences Building, in Berkeley, California,
there was a span of six years between the completion of the building and
the establishment of the first swallow nests thereon. At Assessippi, Mani-
toba, however, Thompson (1891:608) noted that "although the carpenters
have scarcely finished the new mill, and hotel, over three hundred pairs of
Cliff Swallows have begun to build under the eaves." Buss (1942) traced
the history of a Wisconsin Cliff Swallow colony which started with one
nest on the barn of Cory Bodeman in 1904; the birds returned each year in
increasing numbers, until by 1942 there were 2,015 nests.

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TRADITIONS OF WATERFOWL

Equally interesting in its pioneering is the Arkansas Kingbird. This is
not a member of the original fauna of Manitoba and is not mentioned in
Thompson's (Seton) 1891 list "The Birds of Manitoba." The first record is
from Oak Lake, Manitoba, in 1907; this kingbird reached Winnipeg in
1912, and by 1921 it was breeding commonly in southern Manitoba.0 Now,
forty-five years after its arrival, it is a typical bird of Manitoba's agricul-
tural region; there is hardly a farmstead without at least one pair. In a
similar way it has invaded Minnesota (Roberts, 1932) and Saskatchewan.

Such enlargements of range frequently go hand in hand with environ-
mental changes. f In some species, such as the Cliff Swallow and the Ar-
kansas Kingbird, the breeding area is occupied only during the spring and
summer, the birds migrating back to their wintering grounds after the
young are reared. In others, like the Prairie Chicken and the exotic Eng-
lish Sparrow, new ranges are held through the year. Many hunters think
that this pinnated grouse is a native of Manitoba, but Coues (1874) said
that "I have no reason to believe that it occurs at all in northwestern Min-
nesota or northern Dakota ... I have met with no indication of its oc-
currence north of the United States boundary," an observation in which
Thompson (1891) concurred. Leopold (1940) traced the spread of the
Hungarian Partridge in Wisconsin, where it moved "by slow overflow into
the vacant territory." Kessel ( 1953 ) has traced the far-flung pioneerings of
the European Starling in North America. In Manitoba, where the Hungarian
Partridge is a recent arrival, its spread now has covered the agricultural
region of the province, and locally its coveys have developed traditional
territories where the birds may be found in the same places year after year.
That is to say, the history of a covey in a locality is older than any members
of the band. Similar pioneerings are well known in the Cottontail Rabbit
and in the White-tailed Deer.

In waterfowl, Hochbaum (1946) pointed out that the river ducks are
the most rapid pioneers, the Canvasback, Redhead, and other diving ducks
enlarging their ranges more slowly. In the Mallard, Pintail, and other river
ducks, the young are on the wing by early summer, hence have time to gain
broad geographical experience. Moreover, there is a wide tolerance of nest-
ing situations in these species, so that as long as there is water, they may
settle down to find nesting cover somewhere nearby. In the diving ducks,

* A. G. Lawrence, "Chickadee Notes," Winnipeg Free Press, May 30, 1952.

f Mayr (letter) points out that "range changes are sometimes due to changes of the habi-
tat, sometimes independent of it, such as the fantastic range expansion of Streptopelia decaocto,
the Collared Turtle Dove, in Europe."

228

In ducks the parent-child relationships are short, and family traditions are thus weak.

Redhead ducklings, such as these, are often abandoned by the

mother several weeks before they can fly.

the young mature later in the summer, thus enjoying a shorter period of
breeding-ground experience their first year. Moreover, they are much less
tolerant of variations in the nesting cover, and they do not pioneer into a
region for several years because of the slower development of a suitable
habitat. When water comes to the dry prairies of Saskatchewan, or when a
new lake is established, Mallards and some other river ducks are often there
as nesters the very next year, but the arrival of the diving ducks is delayed
until their nesting cover has become established. In 1945 the surface water
remained on the farmlands of the Portage Plains and Red River Valley
through the spring and summer for the first time in at least a decade. Mal-
lards and Pintails and, less frequently, Shovellers and Blue-winged Teal
settled down on these areas, and breeding pairs were scattered over country
that had seen no nesting ducks for several waterfowl generations. None of
the diving ducks moved to these new waters, which were lacking in emer-
gent vegetation. In the same way, large numbers of Pintails invaded south-
western Saskatchewan, where there was an abundance of new water in the
spring of 1952 (Gollop, Lynch, and Hyska, 1952). Bue, Blankenship, and
Marshall (1952) have shown how the waterfowl advanced to occupy the
new stock-watering ponds of western South Dakota. In such range exten-

229

TRADITIONS OF WATERFOWL

sions there may be a previous history of waterfowl breeding in past years,
but often the period of drought is longer than the life-expectancy of ducks ;
hence the regions are entirely new to the modern generation that moves
in during a wet cycle.

New areas often remain wet for only a few years ; then water and ducks
are gone again. On the Portage Plains most of the sloughs of 1945 held
water and nesting ducks each year until 1950, a span of six consecutive
breeding seasons. By 1951 some had become dry and duckless; by 1952
most were dry. With ducks there is an ebb and flow of breeding populations
at the edge of permanent ranges. Many large marshes, such as the Delta,
never lose all their water or their ducks. The sloughs and potholes of the
true prairie are relatively stable. But in the western mixed prairie, water and
ducks, like agricultural crops, fluctuate severely.

The degree of pioneering in ducks, it seems to me, depends on the
proximity of new areas to established nesting grounds. In the Dakotas and
the prairie provinces of Canada there is a large and established breeding
population in the marshes and smaller water areas of the true prairie. In
years when the water comes to the shallow depressions of the western
plains region, the shiftings of breeders originates from the dense popula-
tion centers not far away. Farther south and east on less densely populated
breeding grounds, there are fewer waterfowl centers of abundance from
which birds may overflow. In the Delta region I have noticed that ducks
pioneer more quickly and more abundantly to new ponds within ten miles
of the marsh than to new waters beyond that range. I presume that most
such pioneers are young birds approaching their first breeding season.
Pioneering does not contradict the homing behavior of young females that
may establish themselves near their natal marsh or in an area learned dur-
ing juvenile wanderings.

The story of the Gadwall, on the other hand, shows breeding populations
and probably recent pioneerings on the Atlantic Coast, far from the major
nesting range, which lies northwest of the Mississippi Valley (Griffith, 1946).
Certainly the new nesting groups of this species on Long Island (Sedwitz
et ah, 1948) and in Maryland (Springer and Stewart, 1950) are pioneer-
ings. Most of these records are for refuge marshes, where nesting conditions
have been made favorable for the species and where shooting has been con-
trolled. Robert A. Wells writes me that there are recent pioneerings of the
Ring-necked Duck in small lakes of the Adirondack Mountains, the bird now
breeding on waters where it was unknown before.

230

BUILDING NEW TRADITIONS

In the Canada Goose there is not the same pioneering as in ducks, in
breeding situations at least. The close family and group ties hold birds to
given locations from which they expand slowly. Despite the existence of
large regions of prime goose-breeding habitat, much of this is not occupied
by geese. Such vacancies cannot be explained entirely in terms of ecology,
for where we introduce a flock of Canada Geese, such as the plantings at
Delta or the Lower Souris Refuge, the flocks thrive in the new locations.
Hawkins, Wellein, and Crissey (1950) covered a large part of the West
shore of the Hudson Bay in an aerial waterfowl survey during the breed-
ing season, and they found that "goose ranges continued without interrup-
tion, so far as we could tell, from Wawa Lake southwest of Moosonee to
Eskimo Point. Along this entire strip, however, the only place where
Canadas appeared to be nesting in large numbers was on Akimiski Island.
Otherwise, the population appeared to be widely scattered." I take it that
faithfulness to the breeding place and reluctance to pioneer to new regions
are evidence of the strength of family traditions in the Canada Goose.

Faithful as they are to their home range, however, geese are elastic in
their use of migration routes and wintering quarters. Jack Miner's sanctu-
ary, in southern Ontario, gives the history of a new goose tradition, the
birds being few in the beginning and increasing in the lifetime of one man
to many thousands more. Such also was the modest start of goose traditions
at Horseshoe Lake, Illinois. "Originally, Horseshoe Lake was an Oxbow of
the Mississippi River, but its present location is about two miles from the
river channel," writes A. S. Hawkins (letter). "During floods, the river still
spreads over it. More recently this was a swamp, which early in the present
century became dry enough so that a fire burned deep holes in its bed.
Horseshoe Lake resulted, and today a dam holds the water at a fairly con-
stant level. Old-timers report that Horseshoe Lake used to offer good duck
hunting but not good goose shooting. For at least 50 years, Horseshoe Lake
Island has been farmed, although during one period, brush claimed it for
a few years. Probably geese have fed on Horseshoe Lake Island as long as
it has been farmed, but they did not use the lake until the dam was built
Formerly a hunting club, Horseshoe Lake became a refuge in 1927. The
first estimate in wintering numbers places the 1928-29 population at be-
tween 1,000 and 1,900 (Leopold, 1931:206); by 1953 the mid-winter inven-
tory of the flock showed a total of 143,000." Originally the feeding places
around Horseshoe Lake had no superiority over other parts of the valley.
When the refuge offered protected resting grounds, however, an element

231

TRADITIONS OF WATERFOWL

of advantage was added. Despite heavy and ever increasing gun-pressure
between refuge and feeding places, the protected rest area attracted more
and more geese till, as Hanson and Smith ( 1950 ) pointed out, about 50 per
cent of the Mississippi Valley population came to roost on Horseshoe Lake.

At Jack Miner's and at Horseshoe Lake, formerly gooseless places have
become the rendezvous of tens of thousands, the many following the trails
of the original few. These famous gathering grounds continue to hold their
numbers. Elsewhere are records of broken traditions. Grant's Lake, Mani-
toba, was the last stop of the Lesser Snow and Blue Geese before their
long journey to James Bay. Here they gathered in such great numbers that
Greshem (Soper, 1942) could describe nights where "the leading birds of
the flock were dropping into the lake while the tail of the flock was still out
of sight." Then suddenly all of this ended: Grant's Lake dwindled and
dried; the geese came no more; where the clangor was once deafening, the
land was now silent of wavies except in May, when they flew over en route
to James Bay. The habit of unrecorded generations came to an abrupt close.*

The geese of Horseshoe Lake and Grant's Lake seem to offer firm evi-
dence that there is no inborn tie of waterfowl to the geographic parts of
their continental ranges. Here are the beginnings and the endings of tra-
ditions, built recently at Horseshoe Lake, dying over winter at Grant's Lake.
Attachments to place live with the birds from generation to generation,
growing as the advantages of use remain constant, ending when the places
are no longer useful or tolerable.

Successful explorations and rapid extensions of the breeding range im-
ply a constant population pressure. For centuries the force of this internal
stress in the Cliff Swallow and the Arkansas Kingbird was met with inhos-
pitable breeding conditions ; but within a few years after man altered the
face of the land in their favor, some individuals overflowed into new envi-
ronments to take occupancy. So rapid were these invasions, sometimes, that
human settlers believed the birds had always been there. A careful study
reveals pioneerings of many kinds of birds which we now casually accept
as part of the native fauna. In regions once forested, the opening of wood-
land for agriculture favored the Meadowlark, Bobolink, Vesper Sparrow,
and many others that ventured into country which never before had held
nesting populations. Where trees and thickets invaded prairies, woodland
birds enlarged their ranges in the same way. For southern Wisconsin, Schor-

0 There is local disagreement on this point, some contending that the geese abandoned the
area in the face of the abundance of aircraft from wartime training centers.

232

BUILDING NEW TRADITIONS

ger (1941:105) says "it may be stated in general that the Crow was dis-
tributed sparsely in the State prior to 1855, became common in the south-
ern portion by 1875, and abundant by 1890." As the land changed, pioneer-
ing Crows and Meadowlarks, Robins and Song Sparrows moved in to take
residence in country their kind had never occupied before, migrating to
and from these new places and delivering the traditions to their progeny,*
so that now these regions are firmly established within the natural ranges
of the species.

When the Arkansas Kingbird moved into Manitoba, it extended its mi-
gratory range northward by at least two hundred miles, to such an outpost
as Lake St. Martin, f Even though this bird was not a member of the native
fauna, it is now among the most regular of spring and fall migrants. Here,
within the span of a few years, we have the evolution of a migration carry-
ing many individuals hundreds of miles into land their race never used be-
fore. The urge of these Arkansas Kingbirds to migrate must be sexual and
inborn, regardless of the newness of the places to which they migrate. The
recent origin of the migration, however, seems to give further evidence
that the route is learned ; the short time these kingbirds have lived in Man-
itoba cannot have been sufficient to permit the establishment of inborn ties
to their new geographic locations. This same thing, as suggested by Mayr
and Meise (1930), must have taken place in response to the ecological
changes in the wake of receding glaciers. As Allen (1880) wrote, "Such mi-
gration must have been at first 'incipient and gradual,' extending and
strengthening as the cold-wave Ice Age receded and opened up a wider
area within which existence in summer became possible." There is strong
evidence, then, that the length of migrations was extended by ecological
changes following the recession of glaciers in the same way as new migra-
tions accompanied the changes wrought by man. In the first instance, the
pioneerings of birds must have been slow; in the modern example of the
Arkansas Kingbird, the deep advance into new migratory range has been
accomplished in a twinkling of history. Probably both slow and rapid
pioneerings became established in the same way, as the actions of experi-

0 We must point out that there are some species, of limited number to be sure, that
seem to have no ties to the land, birds that pioneer to new breeding places one year, never to
appear there again for many seasons, wanderers such as the Pine Siskin, the crossbills, and the
Evening Grosbeak, which, as Roberts (1932:365) points out, are possessed of a "gypsy-like
wanderlust" that takes them "now here, now there and only irregularly and seemingly by
chance back again to the same locality." These "eccentric creatures" are pioneers leaving be-
hind no followers, explorers delivering no traditions except of wandering.

t A. G. Lawrence, in "Chicadee Notes," Winnipeg Free Press, May 29, 1953.

233

TRADITIONS OF WATERFOWL

enced birds carried new traditions from one generation to the next. Many
hundreds of years elapsed in the recession of glacial Lake Agassiz before
the Upland Plover arrived on the prairie border of modern Lake Manitoba,
and yet these plovers have traditional rather than genetic ties to this land
in the same way as the Arkansas Kingbirds which arrived on the neighbor-
ing farmsteads only a few years ago.

Salomonsen (1951), among others, has presented evidence of the re-
sponse to changes of climate taking place in our time. "Recent climatic
change in the arctic and temperate zones of the Northern Hemisphere," he
says, "has caused an amelioration of the conditions of life of many animals
and plants. It is a well-known fact that the breeding-area of a number of
birds belonging to the Mediterranean, European or the Siberian Taigoa
fauna has been pushed to the north in the last decades." He describes in
detail the immigration of the Fieldfare to Greenland; and Gudmundsson
( 1951 ) discusses the relation between climatic changes in Iceland and the
arrival of pioneers establishing new breeding ranges there. It is interesting
that the pioneers to Iceland and Greenland have come from Europe rather
than from North America; and, indeed, Salomonsen (1951:519) shows
how the movement of the Fieldfare to Greenland was related to the favor-
able flow of winds blowing from Europe around the "top" of the Greenland
low-pressure area. °

Students of tradition will study the transplantings of game species to
learn something of the artificial establishment of pioneers. Leopold (1933:
87) points out that "transplantation of game is as old as civilization," and
with some kinds, such as the Pheasant in Great Britain, the originally
exotic species has become established as a part of the native fauna, with
a local history running back centuries. By and large, artificial introductions
have been most successful with nonmigratory species, but Delacour (1954:
161 ) tells us that the Canada Goose was introduced into Europe from North
America in the seventeenth century. "It soon became well established and
hundreds are still living in a feral state in Great Britain today." Although
not of themselves inclined to pioneer new breeding colonies, geese respond
well to artificial transplantings. In North America there have been many
successful "seedings" of Canada Geese, breeding colonies having been es-
tablished on new ranges or in areas where the original populations were
killed when the country was settled. New colonies of geese may be started

0 For other discussions of pioneerings see Cowan ( 1937), Fisher ( 1951 ), Keve and Udvardy
(1951), Salomonsen (1948), Svardson and Durango (1951), and Valikangas (1951).

234

A Pintail hen, hatched at Delta, Manitoba, and released as a flightless duckling on a

New York marsh, returned to the New York range of her juvenile

experience, there to nest and raise her family.

with pinioned, hand-reared pairs whose progeny are allowed to migrate, or
with wild-trapped birds set free on a new range before they are fledged.
The object is to start with young birds that will have their first flight experi-
ence at the site of the new colony. Old birds used as breeding stock must
be fully pinioned, not simply wing-clipped; else they will fly home when
the next wing molt is completed, taking their young along with them.

The transplanting of ducks is a technique by which breeding popula-
tions of such species as Redhead or Gadwall may be restored as native
breeders to ranges where the original populations have been "burned out."
Young, hand-reared juveniles are released on new marshes before they are
able to fly, at five to seven weeks of age, and the females surviving the first
hunting season and fall migration may be expected to return in spring to
these places of first flight experience, there to rear their young, like the Spicer
Marsh Pintail mentioned on page 217 (Foley, 1954b). The success of such
plantings hinges on the willingness of local sportsmen to delay the opening
of their wildfowling season until the breeding females and young birds
have dispersed from their home marshes. "If there is practical value to be
derived from the release of hand-reared stock other than satisfying the local
gunner on an immediate basis," Brakhage says (1953:474), "it must be
realized through the return of birds to nest. If the surviving individuals re-
turn to their marshes of liberation to nest in the following years and thus

235

TRADITIONS OF WATERFOWL

replace a 'burned out' breeding population or colonize a new area, a long
term value may be realized. But it cannot be considered sound management
to stock birds which do not survive long enough to reproduce."

In the Mallard, heredity apparently plays an important role in the suc-
cess of plantings. The wild Mallard is the source stock from which the
"call" ducks and most domestic varieties originated, and the mixing of wild
and domestic blood may take place on game farm ranges. Such birds may
fail to survive or to migrate when released in a wild environment, and the
experience with such mixed strains prompted Lincoln (1934:81) to say
that "efforts to restore marshes with artificially produced Mallards are
doomed to failure." More recent investigations (Benson, 1939; Brakhage,
1953; Foley, 1954a; and Wells, 1954) suggest, however, that when hand-
reared Mallards are planted on wild ranges, the survivors of the first hunt-
ing season may migrate in a pattern not different from that of wild-bred
birds. At Delta we have found that hand-reared females return with un-
handed, wild-bred drakes as their mates.

It is unfortunate that more attention has not been given in North
America to the artificial re-establishment of breeding traditions in some of
of the rarer species. The Trumpeter Swan, when reared by hand, breeds
well in captivity, and young from such hand-reared stock might be used
to repopulate locations where favorable breeding habitat still remains. The
species was captive-bred for many years in Europe, but unfortunately in
its own country there never has been a reservoir of hand-reared stock. And
I feel that it is only through captive-breeding that the Whooping Crane
can be saved from extinction, for the hazards of the long, traditional jour-
ney may be too dangerous for the few young that are produced each year.
The old birds, of course, must be left to follow their migration to and from
their northern breeding grounds, for adults would not breed in confinement.
But some young stock of these wild birds must be brought to captivity at
the earliest possible age and, under the care of trained "keepers," raised
where they may grow to maturity in a favorable, yet protected, environ-
ment. If this is done in time — if, at the rate of two or three young each
year, a captive breeding stock may develop in a protected situation — then
eventually some full-winged progeny of these long-lived birds may be set
free with the wild adults to learn from them the traditional flyways to and
from their ancestral breeding grounds. By captive-breeding the Wildfowl
Trust has given substantial increase to the numbers of the rare Hawaiian
Goose (Scott and Boyd, 1951, 1954, 1955).

236

'Bird systematics is no longer merely the study of
specimens in the museum." Ernst Mayr (1942)

18
Tradition and Racial Isolation

On every hand is evidence that groups of ani-
mals isolated from each other will vary. Poultry, cattle, and hunting dogs
have been divided into their many domestic varieties by the artificial iso-
lation of selected breeding stock. In the same way, many kinds of barnyard
ducks have stemmed from the wild Mallard. Similarly, over a vastly greater
period of time, natural isolation has divided many species of wild animals
into distinct races; and it was this that gave Darwin his inspiration con-
cerning the pattern of evolution. Before Darwin a species was generally
believed to be a distinct creation, with the specific characters showing no
variation from a certain type. As specimens from many regions were exam-
ined, however, it was found that there often occurred differences in size
and color, and this discovery led to the description of geographical races or
subspecies. The Song Sparrow is a good example of this regional variation;
the A.O.U. Committee on Classification and Nomenclature now recognizes
thirty-one subspecies for North America (F. C. Lincoln, letter), ranging
from the large, dark Aleutian Song Sparrow of the Alaskan islands to the
small, pale Desert Song Sparrow of the southwestern United States.

Geographical isolation is the most widely recognized and probably the
most important factor separating different units of population. Ford (1949:
92 ) reminds us that geographic isolation is established not only by "barriers
such as water or land (to terrestrial or aquatic forms respectively), or those
due to altitude, but that mere distance will prevent a free interchange of
hereditary material between individuals at opposite extremes even of a
continuous range." Mayr (1942:106) defines the subspecies as a "geograph-
ically localized subdivision of the species, which differs genetically and
taxonomically from other subdivisions of the species."

In many birds, such as the Downy Woodpecker, Song Sparrow, Robin,
and Yellow Warbler, to name only a few, there are numerous races which

237

TRADITIONS OF WATERFOWL

are separated more by space than by sharp geographical barriers, and their
many subspecies blend together from one region to another without abrupt
divisions between two races. Where space is the major isolating factor, we
have what Mayr (1942:244) calls "subspeciation by distance." "The forma-
tion of local races in the absence of distributional barriers will occur," Mayr
tells us, "whenever the combined effects of recurrent local mutations and
of selection pressure outweigh the effect of the interchange of individuals
between local populations."

Free as the wind to fly wherever it will, a Song Sparrow wintering in
Georgia could just as easily fly northeast to the Atlantic Coast as northwest
to central Canada ; but by force of experience it travels to its former breed-
ing place in Manitoba, where it is geographically isolated from some win-
ter companions that migrated to Maine. Its tie to Manitoba can hardly be
considered a genetic bond. The return is to the place of experience; and
this, as Nice ( 1937 ) has shown for the Song Sparrow, is the region of youth,
often near the birthplace. Manitoba is the birthright of its Song Sparrows;
their inheritance of Manitoba experiences is traditional. The homing be-
havior which brings the migrant back to traditional breeding grounds estab-
lishes the geographic isolation upon which racial subdivision depends. To
put it another way : if Song Sparrows did not return to their home region
year after year, if they spread their breeding ranges widely without regard
to birthplace, there would not be the same degree of geographical isolation
that now exists, and we could not expect the same racial variation. Cushing
(1941a: 107) observes that "if we are to consider the homing reaction as a
potential isolating mechanism, it may be classifiable as on par with geo-
graphic isolation (see Dobzhansky, Genetics and Origin of Species, 1937:
230 ) , although itself physiological in nature. Such non-genetic mechanisms,
while presumably of a relatively temporary nature, theoretically precede
the rise of genetic isolation within populations." So it may be that in some
species the primary factor in isolation is the tie to the home breeding range.

In species with broad ranges we might expect those kinds possessing
the strongest traditional ties to have the greatest racial variations. This
holds with the geese. With their firm regional and family traditions, the
geese follow a pattern of behavior which must encourage the development
of variation. Mayr (1942:242) says that "no other arctic or subarctic bird
breaks up into so many pronounced races as the geese. The Canada Geese
of the genus Branta have some 6 to 9 geographic races in North America,
some of which are so different that some authors propose to put them in 3

238

TRADITION AND RACIAL ISOLATION

or 4 different species." Mayr (1951:97) notes further that in the Canada
Geese "it occasionally happens that neighboring nesting colonies differ in
body size, voice (honking vs. cackling), nesting site (sea-coast vs. island),
nest (mound vs. scrape), migration season and other features." Delacour
(1951 ) recognizes only one species, Branta canadensis, which, however, he
divides into twelve subspecies. All of these have the white cheek patch,
black head and neck "stocking," and similar body patterns ; but they vary
widely in size, voice, darkness of plumage, and behavior. The brant of
North America show three distinct subspecies (Delacour 1954), while the
Snow Goose and the White-fronted Goose each have two.

It is quite another story for North American game ducks.* Taxonomists
recognize subspecific variation in only one species, the Florida Duck.f
All the other game ducks show no racial divisions on this continent. More-
over, some North American species are quite the same as those of northern
Europe, and Mayr (1942:241) says that "many of the Holarctic ducks, such
as the Gadwall (Anas strepera), Shoveller (Spatula clypeata) and so forth,
have no subspecies, or only one or two very slight ones, in spite of their
wide circumpolar distribution." This monotypic pattern apparently stems
from the absence of traditional ties in the male. In the gregarious societies
of winter there is opportunity for the meeting of males and females from
widely separated breeding places. In such matings, the male, faithful to
his bride, follows her wherever she may go, spreading hereditary material
widely, allowing no true isolation. Thus taxonomists cannot distinguish a
Minnesota-bred Pintail from one hatched in Alaska.

This monotypic characteristic in ducks is evidence that the waterfowl
flyways of North America, described by Lincoln (1935a), are not strictly
isolated entities. There must be free genetic mixing of populations from dif-
ferent flyways, and evidence of this overlap is shown in the patterns of
dispersal reported by Aldrich et at. (1949), such as the "round-robin" mi-
gration of the Pintail, and in the winter vagrancies of the Ring-necked Duck.
In the light of the wide winter movements of most ducks, the narrow
range of the Florida Duck seems significant. This is not a migratory species,
and, though there is a seasonal shift from one place to another, the breeding
grounds and wintering range are approximately the same (Bent, 1923:72,
75). The eastern race of the Florida Duck, Anas fulvigula fulvigula, has

° All North American ducks except the eiders and tree ducks.

t The "Red-legged Black Duck" (Anas rubripes rubripes), once regarded as a distinct race,
is now known to be the adult male of the Common Black Duck ( Shortt, 1943 ) .

239

TRADITIONS OF WATERFOWL

both its breeding and wintering range in the state of Florida, whereas the
western race, A. f. maculosa, lives the year round in Texas and Louisiana.
Within these restrictions there is no wide dispersal of males in winter,
hence little chance for the cross-mating of birds from widely separated
breeding places. Consequently the geographic division between eastern
and western birds has been sharp ; the genetic changes recognizable to the
taxonomist have developed from this spatial isolation.

Among the Eiders of the genus Somateria, four closely related kinds
are recognized : the American Eider, the Hudson Bay Eider, the Northern
Eider, and the Pacific Eider. The American, Hudson Bay, and Northern
Eiders are so closely related as to be considered subspecies of one another,
and the Pacific Eider is just enough different to be given specific recognition
by some authorities. Bent (1925:94) points out that there is an overlapping
of range in the American and Northern Eiders, but this is slight, and the
main breeding and wintering places of the Northern Eider are well to the
northeast of the ranges used by the American Eider. The Pacific Eider is
still further separated in its winter and summer ranges; and despite the
possibility of some overlapping with the summer range of the Northern
Eider, matings with the American Eider could result only by rare chance.

In considering the distribution of the Florida Duck and the Eiders,
the relation between geographic isolation and subspecific differences seems
to be one of cause and effect. The variation could hardly occur if Florida
Ducks mixed thoroughly on the winter ranges or if all Eiders shared the
same wintering places. Whether or not this regional isolation is genetic or
traditional, however, is a question we will not try to answer here; for in
these instances it may be impossible to separate the genetic and traditional
inheritances.

Tradition may have been a factor in establishing the geographic races
in the crane family. Cranes, as already noted, are like geese in their strong
family bonds during migration and in their firm regional traditions. Taxono-
mists recognize four subspecies of the brown crane of North America, the
Little Brown Crane of the far north, the Sandhill Crane of the middle
latitudes, the Florida Sandhill Crane, and the Cuban Sandhill Crane. The
Coot, a close relative of the cranes, is more like the ducks in its habits. Its
breeding range is spread widely over North America, being much the same
as that of our game waterfowl; and it joins in large gregarious bands on
the wintering grounds. Present evidence suggests that some Coots pair
on the wintering grounds, thereby effecting the same genetic mixing as

240

The nesting habitat of Mallard and Pintail on the treeless plains is nothing
like the environment used by these species in Manitoba.

occurs in ducks. Taxonomists recognize the Coots nesting in Ontario as the
same race that breeds in California.

The weight of the discussion has been placed on waterfowl, which, it
must be acknowledged, have patterns of behavior quite different from those
of many other kinds of birds. For example, the family unity in migration,
which builds such strong traditions for the geese and cranes, is found only
in a few other groups. Not many species accomplish their pairing in gre-
garious winter companies, as do the ducks. More typical is the behavior
of the passerines, in which the family usually dissolves soon after the young
are able to take care of themselves and in which pairing takes place at or
near the nesting area, often on the territory proclaimed by the male before
the arrival of the female. The tradition of birthright is strong in such birds,
however, as both sexes migrate back to breed near the place of youthful
experiences. Thus a wide gene-flow from one region to another is prevented.

In these migratory perching birds there are only a few, such as the
Magpie and the Barn Swallow, that have one geographical race spread over

241

TRADITIONS OF WATERFOWL

most of the continent. Most of the rest are divided into several subspecies,
and some, like the Song Sparrow, show abundant racial variation. This
point is important to our thesis because it appears that, within certain
limits, ecological patterns as well as geographical locations are the tradi-
tional birthright of subspecies whose distribution is limited to certain hab-
itats. Marshall (1948:252) says (in reference to races of the Song Sparrow
in the San Francisco Bay area) that "habitat preferences, based merely on
the impulse of the individual to stay in the kind of environment in which
it was raised and with which it is familiar," may serve to effect the eco-
logical isolation of a race; and that "it should be evident that such prefer-
ence would be unlikely to be fixed genetically." It seems to me that Marshall
has neatly expressed this fine difference between the inborn and the non-
heritable response to the environment. At Delta some Song Sparrows live
their whole reproductive lives in stands of Phragmites far from shrubby
edges. But close by, and over much of the prairie country, other Song Spar-
rows (which taxonomists recognize as the same subspecies) nest in brushy
edge cover. This local variation in breeding area I take to be the nonheredi-
tary habitat preference to which Marshall refers. It is interesting to note
that since there are no outstanding singing posts in the Phragmites, the
males with marsh territories regularly make towering song-flights, which
are not characteristic of nearby shrub-dwelling Song Sparrows.

The same sort of thing is seen in ducks. On the Delta Marsh the pre-
ferred nesting of the Canvasback is bulrush, but in the pothole country
around Minnedosa many Canvasbacks nest in cover types entirely unlike
anything used by the species at Delta. The nesting habitat of Pintail and
Mallard in the farming country of Manitoba is quite different from the
nesting environment of these species on the treeless plains of Alberta. In
Manitoba the Canada Goose nests on fish boxes mounted on poles at Ren-
nie, on open islands at Dog Lake, and on Muskrat houses at Delta.

Waterfowl and many other birds apparently have an inborn urge for
the homeland of birth, where each individual selects the environmental
patterns most closely meeting its innate breeding requirements. From this
instinctive attachment to home may arise the isolation upon which mor-
phological variations are founded, even in the absence of geographical bar-
riers to the flow of genes. However innate the homing behavior, the geo-
graphic place of home is inherited, not genetically, but by birthright and
experience.

242

"We may read indignantly of the Great Auk and
the Passenger Pigeon and say complacently that
such a thing could not happen nowadays, but only
by the narrowest margin is the Trumpeter Swan of
North America, the largest of all waterfowl, still in-
cluded in the avifauna of the world." Peter Scott,
Wild Chorus

19
Broken Traditions

The Passenger Pigeon is gone beyond recall.
Oaks live whose branches held their nests ; much of the pigeon environment
is still here on earth; but the last pigeon is long since dead.

The Canada Goose is a living part of our native fauna, a passage mi-
grant with numbers strong enough to give the modern hunter a share in
the annual harvest. On part of its range, however, it is as dead as the Pas-
senger Pigeon. Many regions of the United States and Canada once knew
the clarion call of the goose on its breeding territory. It bred in Illinois,
Indiana, and Iowa (Cooke, 1906). In Minnesota, Roberts (1932) tells us
that it was "formerly a common summer resident, nesting throughout the
State." Manitoba old-timers, such as Stuart Criddle, of Treesbank, remem-
ber nesting geese where there are none today. Cooke, writing in 1906, said
that "a hundred years ago the species bred commonly in all the northern
third of the Mississippi Valley and not uncommonly to the latitude of St.
Louis." McClanahan ( 1940) shows that its breeding range reached to north-
western Mississippi. Now this region is barren of its original stock; the
native geese of the Mississippi Valley and their breeding traditions have
vanished with the Passenger Pigeon.

Despite drainage, places still remain in the Middle West where geese
might nest, marshes as fine for reproduction as are to be found in the
north country. It must hold that the Canada Goose has left the Mississippi
Valley as a breeder not simply because all its nesting habitat is gone, nor
because of the encroachments of civilization, but because all geese with

243

Trumpeter Swans still raise their families in
some regions of the Northwest.

local breeding experience (like all Passenger Pigeons) are dead and gone.
The breeding traditions for this region died with the geese that once nested
there. No matter how many fly north along the Mississippi in spring, all
modern geese have nesting or family experiences beyond the northern hori-
zon; when the time comes, they continue on to their more distant homes.
The Giant Canada Goose, which Delacour and Moffitt (Delacour, 1951)
considered a distinct subspecies, is forever gone from the Mississippi Val-
ley.*

The Trumpeter Swan tells another story of total regional losses. Roberts
(1932:206) gives convincing evidence that this great bird of the prairies
bred at Heron Lake, Everson Lake, Swan Lake, and other places in Minne-
sota until the 1880s. Bent (1925:293) says that "when the great Central West
was wild and uncultivated it was known to breed in the uninhabited parts
of many of our central states, even as far south as Missouri." It nested in
Iowa as late as 1883. Trumpeters still raise their families in Wyoming, Mon-
tana, Alberta, and British Columbia; but their traditions of the Middle West
are gone with the pigeons.

Why have the geese and swans departed from so much of their original

• Wild breeding flocks of Canada Geese have been re-established in several parts of the
Middle West, as mentioned in Chapter 17, but this transplanted stock is not the same as the
one that originally bred in the region.

244

But their traditions of the Middle West have
gone with the Passenger Pigeon.

range? Some, of course, left because their homelands were spoiled, but
this is not the whole story. Some say they left because civilization pressed
too closely upon the nesting places. If it is implied that these wildfowl
moved away because they could not tolerate the close presence of man and
his activities, this cannot be true, for today in some parts of their present
range, wild Trumpeter Swans and Canada Geese thrive within sight of
human dwellings. It must be that during settlement and in the lush days
of gunning, local breeders and their young were gradually taken. One by
one, pair by pair, family by family, the geese and swans of Minnesota and
the Middle West were used for food. An old-time resident of Heron Lake,
Minnesota, told Dr. Roberts (1932) that Trumpeter Swans "used to breed
there in fair numbers and that men from the east came to the lake, rounded
up the cygnets in the open water before they could fly, and shipped them
to eastern parts." Delacour (1944) points out that "Trumpeters used to nest
and to winter well within areas which became settled by man when the
country was opened up. Consequently they were slaughtered quickly and
easily." Unlike the Whistling Swan, which calls the Arctic its home, the
breeding places of the Trumpeter Swan were in lower latitudes early set-
tled by man. When domestic duties held swans to a small locality, voice
and action soon disclosed their presence to men, who came to take what
they believed to be their rightful harvest.

245

TRADITIONS OF WATERFOWL

Locally, the numbers of swans and geese killed probably were small.
Here were a pair on this pond, there several at a nearby lake, a few more
in waters beyond. In the settler's mind a modest harvest of local birds did
not seem beyond reason in view of the great flights that passed through,
spring and fall. * In a few years, however, such predation gradually thinned
nesters down to widely scattered birds. When the last families were taken,
their traditions were dead. The lakes, many of them, the rushy borders, and
the muskrats upon whose houses these wildfowl nested, have survived to
please the settlers' grandchildren; but the native geese and swans are
gone.

In other species we find similar endings of breeding traditions — some-
times complete, as where the Carolina Paroquet and the Heath Hen have
been exterminated, sometimes only regional, as where the Raven has gone
from southern Wisconsin, the wild turkey from New England, or the Prairie
Chicken and Sandhill Crane from many places. Some, like the Raven, dis-
appeared in the face of intolerable environmental changes. For many kinds,
however, favorable environment remains, but local breeders have been
killed.

Tracing the histories of lost species, we note, as with the Trumpeter
Swan and the Canada Goose, that the end came quickly for those that were
vulnerable on their breeding range. For some, however, the nesting grounds
were beyond the reach of man, and it was on the flyways and the wintering
places that whole breeding populations were shot out, none surviving to
go north. Forbush points out (1912:552) that where northern-breeding
species are regularly over-shot along certain flyways, there may be no
birds to return to their Arctic nesting places the following seasons. He
suggests that, as in the olden days of shorebird gunning, a few families
"reared in the same locality in the far north, start down the Atlantic coast
in their migration. Gunners in the Bay of Fundy first decimate the birds,
which then cross to Cape Cod, pass a blind occupied by an experienced
gunner, who gets nearly all of them, and the next gunner a little farther
down the beach kills what is left. There will be no more birds coming down
the Atlantic coast from that nesting place for some time." Meinertzhagen
(1935) saw the results of heavy shooting on the coast of Syria. "The stream
of migrants which used to pass north up the coast no longer does so . . .
which would indicate that particular communities of birds use especial mi-

• Owen Wister (1955), in the diary of his western trips, tells how the flightless young of
Canada Geese were chased down as food for camp supper.

246

BROKEN TRADITIONS

gratory routes, and that the persistent persecution of that community on
that especial route will eventually exterminate that community."

This, no doubt is what happened to the Eskimo Curlew, which was
killed heavily through much of its migratory and winter range. Carroll
(1910) says that in Labrador, "the Hudson's Bay Company's people at Cart-
wright annually put up large numbers of hermetically sealed tins for the
use of company's officials in London and Montreal. I have seen as many as
2,000 birds hung up in their store as the result of one day's shooting by
some 25 or 30 guns." In Nebraska, as Swenk ( 1915 ) tells it, "hunters would
drive out from Omaha and shoot the birds without mercy until they had
literally slaughtered a wagonload of them, the wagons being actually filled,
and often with sideboards on at that. Sometimes when the flight was un-
usually heavy and the hunters were well supplied with ammunition, their
wagons were loaded too quickly and easily filled, so whole loads of the birds
would be dumped on the prairie, their bodies forming piles as large as a
couple of tons of coal, where they would be allowed to rot while hunters
proceeded to refill their wagons."

Bogardus ( 1899 ) , the great wing-shot of his time, says that when "two
or three of the plover or curlew are crippled, the others will circle round
them and often offer chances for capital shots. . . . On one such occasion
I remembered having killed forty-two golden plover and curlew, all shot
on the wing, before I picked up one of them. Many a time I have killed
as many as fourteen or fifteen without lifting a bird, there being opportuni-
ties to load and fire again and again while the plover swept and circled
over the dead and wounded of their own flock. ... Of late years I have
generally killed from fifty to two hundred plover and curlew a day." The
days of Captain Bogardus are gone forever, and so are the great flocks of
Eskimo Curlew.

The Golden Plover was spared, and so, too, has been the Upland Plover
of our prairies. Roberts (1932:487) says that "to recite the history of the
Upland Plover in Minnesota is to tell a sad tale of wanton destruction of
a valuable and once abundant bird that resulted in its almost complete
extermination. Sixty years ago it was present all through the summer every-
where in the open country in countless thousands. ... In May, 1893, the
writer visited Jackson and Pipestone counties, and the Upland Plover was
present everywhere on the prairies. A return visit was made in 1899, and
it was largely gone — the incessant and musical qua-a-aily, qua-a-aily of the
hovering birds was a tiring of the past." Roberts tells of the heavy market

247

TRADITIONS OF WATERFOWL

hunting that took place in southern Minnesota during the nesting season
and he concluded that it was doubtful whether "the remnant can be saved
even with careful protection." The passage of years has shown, however,
that protective action came in time so that in Minnesota and many other
prairie states and provinces, the Upland Plover is still a member of the
native fauna, in some places showing steady increase.

Another story of the salvation of threatened birds, and perhaps the most
remarkable one, is that of the American Egret and Snowy Egret. Brought
so close to extinction early in this century by the plume-hunters, these
herons are once more abundant on their breeding grounds, from which
some wander each summer north to southern Canada.

Forbush (1912:516) concluded that "when North America was first set-
tled, wildfowl bred more or less abundantly throughout most of the region
now known as the United States." This still holds today, for a study of the
summaries of the annual breeding ground surveys shows that at least sixteen
states ° claim to have from nine to sixteen breeding species of ducks with-
in their boundaries. A dozen more have from four to eight, and each of
the remaining states have two or three. Thus in terms of species, the roll
call of breeding ducks in the United States may not have changed greatly
since early times.

This shows the potential for waterfowl within the United States ; but of
course, while there may be a fine list of nesting species, state by state, some
regions have lost most of their native ducks. Some populations have disap-
peared entirely with the rise of cities and intensive farming. As a young
man, my Grandfather Hochbaum knew places, now deep within Chicago,
where several kinds of ducks bred; and when marshes, like the great Kan-
kakee, where he went wildfowling, were drained, large units of breeding
range were lost. Far and wide across the Middle West, waters were spilled
forever from marshes large and small, and these places were withdrawn
from the realm of wildfowl. Even where water itself was not lost, certain
agricultural practices so altered the reedy edges that they no longer served
some kinds. Where grazing destroyed emergent vegetation and shoreline
cover, some, like Canvasback and Redhead, could not stay on.

0 Michigan, Wisconsin, Minnesota, North Dakota, South Dakota, Nebraska, Iowa, Colorado,
Wyoming, Montana, Idaho, Utah, Nevada, California, Oregon, and Washington claim from
nine to sixteen of the following species: Mallard, Black Duck, Gadwall, Baldpate, Pintail,
Blue-winged Teal, Green-winged Teal, Cinnamon Teal, Shoveller, Wood Duck, Redhead, Ring-
necked Duck, Canvasback, Lesser Scaup, American Golden-eye, Barrow's Golden-eye, Buffle-
head, Harlequin Duck, Ruddy Duck (surveys published by many authors in Special Scientific
Report - Wildlife No. 25, published jointly by the U.S. Fish and Wildlife Service and the
Canadian Wildlife Service).

248

BROKEN TRADITIONS

In the North American way of life, most of us are brought up with
strong ideas of right and wrong, good and bad. We have been taught, for
one thing, that it is not good for the country that water be drained too
quickly into the valleys. This lesson, which most school children must still
learn, is not taught entirely in the interest of preserving the fish, furbearers,
or waterfowl. We learn that the upland waters must be held to protect
the land and the people from drought and flood. And yet generation after
generation sees the shrinkage of marshland. Having done away with many
of the big marshes, the drainage programs now seek to empty the smaller
places. The prairie land of eastern South Dakota and western Minnesota is
spangled with sloughs and potholes, scattered here, there, and everywhere
at the rate of five or six to more than a hundred per square mile, many
thousands of them covering only a fraction of an acre. For mile after
mile, traveling across this rolling prairie, one is seldom beyond sight of
ducks or farmsteads. Here is some of the best farming country in the
world; and here, also, is a part of the finest duck -breeding range in the
whole of North America. Pintail and Gadwall nest close to main roads, Can-
vasback and Redhead in farmyard sloughs, Ruddy Duck and Blue-winged
Teal in village ponds. This region produces well of both waterfowl and
agricultural crops.

Drainage of these marshy places has been going on for many years, and
by 1935 the loss of waterfowl habitat in some districts was severe. After
World War II better machinery and more Federal funds made the drainage
programs still more efficient. Conservationists set upon a steady program
of protestation and deploration, and the subject has been raised at least
ninety-three times before the annual meetings of the North American Wild-
life Conference, often by some of our most distinguished citizens; but the
argument for water conservation carries no weight with the ditching agen-
cies. In 1949 Schoenfeld (1949) found that 1,400 potholes had been drained
from Day County, South Dakota, "not simply due to the chance initiative
of individual farmers, but also to calculated financial and technical aid from
three Federal agencies. What is happening in Day County," said Schoen-
feld, "is only a portion of what is going on in the 5,000 square miles of
prize duck pothole country in eastern North and South Dakota." By 1952
Evans and Nord ( 1952 ) found an annual loss of 7 per cent of Day County's
potholes; and from 1946 to 1950, Peterson tells us (1952:126), "at least
10,700 potholes were wiped out and habitat for an equal number of ducks

249

TRADITIONS OF WATERFOWL

is gone forever" from South Dakota. The exclamations against the loss
gained in vigor, but the drainage forges ahead.

As the marshlets lose their water, the waterfowl breeding traditions
are broken forever. In another human generation, the people of the land,
wildfowlers and farmers alike, will be unaware of this heritage lost, as un-
knowing of the legions of Canvasback and Pintail once nesting here as the
present generation is unaware of swan and pigeon. The landplanners who
advise and subsidize the farmers to spill the water from their holdings tell
us their eyes are on the future, on the years ahead, when the human popu-
lations of the 1980s and 1990s will require the returns of a greater agri-
cultural productivity. "Get the potholes out of the way now," they say,
"and the land will be ready for the wheat and corn our children and grand-
children will need."

What about waterfowl for the grandchildren; what about wildfowling
in 1990? The economists, if they are thinking of ducks at all, count on the
north for the birds of the future. The north always has been the horn of
plenty for the wildfowler. However badly the home marshes have fared,
however thin local populations have become, there is the everlasting hope
for a grand north flight. But we must understand that the north country
cannot supply all the waterfowl now and forevermore. Despite the vast,
pristine northland, much of the finest waterfowl-breeding grounds in all
North America remains within the realm now used by man. This is espe-
cially true for many of our most important game species. Some of the best
breeding grounds — particularly the true prairie country of eastern Saskatch-
ewan, Manitoba, the Dakotas, Minnesota, and Wisconsin — is also some of
the best farmland. In 1953 careful breeding-season estimates by transect
sampling revealed that North and South Dakota together held nearly
2,500,000 breeding ducks.* These included some of our finest game species :
Mallard, Gadwall, Baldpate, Blue-winged Teal, Pintail, Redhead, Canvas-
back, Lesser Scaup. In that same year another survey by experienced biolo-
gists flying transects over several thousand miles of the lake-studded wilds
of western Ontario (which on a map looks like a waterfowl paradise) and
northern Saskatchewan showed that on some 400,000 square miles of this
north country, there were approximately 1,181,000 breeding ducks (Wellein
and Newcomb, 1953a). The combined area of the two Dakotas is 147,712
square miles. Thus a parcel of Ontario and Saskatchewan wilderness al-

•The 1953 index figure for North Dakota waterfowl was 1,459,839 ( Fashingbaur, 1953:
188). The 1953 index figure for South Dakota was 1,021,000 (Murdy and Anderson, 1953:192).

250

BROKEN TRADITIONS

most three times as big as Dakota farmland accommodates less than half
the Dakotas' supply of ducks. What is more, half these northern birds were
mergansers or other nongame species.

We know, of course, that this spruce and muskeg country of Ontario
and northern Saskatchewan is not the finest of the wilderness breeding
grounds, hardly comparing with the Yukon's Old Crow Flats or the Macken-
zie delta. A 1953 aerial survey of the finest waterfowl range in the Yukon
and Northwest Territories of Canada gave an estimate of a breeding popu-
lation of 2,267,000 ducks on 235,000 square miles (Smith and Sutton, 1953).
Thus the best of the north country requires twice the area to accommodate
the same number of ducks that breed in the Dakotas. There are vast regions
of the Arctic — the Barren Grounds away from the seacoasts and the river
valleys — where waterfowl numbers average less than one duck per square
mile (Wellein and Newcomb, 1953b). It would take an area of such country
ten or twelve times the size of the Dakotas to hold the same number of
breeding ducks.

Take the potholes out of the Dakotas and Minnesota and we have cut
a major slice from the wildfowling of the future. Schoenfeld ( 1949 ) pointed
out that in Day County alone, the loss from drainage up to 1949 had de-
stroyed a waterfowl range that was ten times as productive as Manitoba's
famed Delta Marsh. Whichever side of the international border the drain-
age occurs on, both Canadian and American wildfowlers must mourn the
loss together. And wildfowlers of the United States must realize that in
Canada the waterfowl range "is more limited than would first appear. Many
sites which provide accommodation for ducks also provide attractive areas
for the growing of crops and, with continuing agricultural expansion, are
being withdrawn from natural waterfowl habitat" (Colls, 1951). Speaking
of the prairie and parkland region of Saskatchewan, Gavin ( 1953 ) says that
"when settlers first moved into these areas, lakes, sloughs and potholes
were in abundance. Loss of much of these breeding areas has been a major
blow to waterfowl. . . . Traveling through these areas today and trying to
compare them with the older large-scale maps provides a shock that can-
not be adequately described."

Pothole country is the finest of all breeding ranges because the scat-
tered water areas let the pairs spread far and wide over the land. Gregarious
through most of the year, ducks isolate themselves, much in the same way
as Robins and Song Sparrows, during the nesting season, each pair keep-
ing separate from others of the same species. The small sloughs and pot-

251

The prairie land of Minnesota and the Dakotas is spangled with sloughs and potholes.
Here is some of the finest waterfowl breeding range in North America.

holes create the ideal pattern for the kind of dispersal the breeding pairs
like best. Farming country, spotted with marshlets, may hold as many ducks
per square mile as do the great marshes like the Delta, or even more, and
over vastly many more square miles. The big marshes function as gathering
places, spring and fall, as molting areas and summer rendezvous; but they
comprise but a fraction of the total nesting range.

Many regions, like the lake country of Ontario and parts of the Arctic,
have a favorable spacing of small waters, but the acid or thin soils do not
produce the food or nesting cover plants so attractive to the waterfowl of
the prairies. Thus, while the lake country of Ontario or eastern Minnesota
may have only two or three breeding ducks to a square mile, the prairie
pothole range only a short distance west may attract a hundred or more
breeding ducks per square mile. Years ago, Leopold (1931) pointed to
this variation, showing how the duck breeding range is to be evaluated not
so much by acreage as by quality. The quality breeding range for many
of our finest game ducks is on rich land that is also good for man. The
millions of acres of slum range can never supply the wildfowling of the
future if today's potholes must grow wheat and barley for the next genera-
tion. To save this range is going to take better arguments than we have

252

BROKEN TRADITIONS

been able to put across during the past quarter-century. We who wish to
keep these breeding grounds must act with the same conviction, with the
same intelligent planning, as the drainage agents. For the wildfowler drain
age is more than a matter of good or evil, drought or flood, feast or famine :
drainage is the process by which succeeding generations, however rich in
wheat and barley, must lose their heritage of Canvasback, Gadwall, or Red-
head.

Man, of course, is not by any means the only force changing the face of
the world. In the regular cyclic rise and fall of waters by which the levels of
Lake Manitoba and the Delta Marsh vary, there are important changes in the
marsh pattern, influencing waterfowl activity. In the most recent rise the
water of the Lake Manitoba basin has reached record-breaking elevations.
As a result the shallows at Archie's Point where the Whistling Swans fed
through so many Aprils have flooded so deeply that the swans can no longer
reach the bottom with their long necks, and they come there no more. Berg-
man (1951) tells how a traditional spring resting place of the Old Squaw
was changed because of a variation in ice conditions. Either flood or drought
may bring to a close nesting traditions of many generations.

Besides the loss of breeding range, waterfowl have suffered from the
same kind of heavy gun pressure and market interests as shore birds. In
Ohio, Trautman (1940:47) described the techniques of market hunters who
combed "the swampy fields with dogs in order to capture the larger duck-
lings and adults in flapper stage." Richard Harker, a market gunner from
Spirit Lake, Iowa, recalls that "the law on ducks was out about the 15th
of August and we shot from then until freeze-up. ... It seemed that when
we were market hunting, every year ducks were just a little harder to get"
(Musgrove, 1949:198).

The killing of local stock seemed unimportant in view of the vast num-
bers during migration. Even so great a conservationist as Theodore Roose-
velt (1927:41) wrote that flightless young ducks were "as tender and deli-
cious birds for the table as I know ... In these small ponds with little
cover round the edges the poor flappers are at a great disadvantage; we
never shoot them unless we really need them for the table. But quite often,
in August and September, if near the place, I have gone down to visit one
or two of these pools, and have brought home half a dozen flappers." The
tug of conscience was not strong enough to deter E. L. Brown, pioneer of
northern Minnesota, who wrote that he "flushed a duck from her nest, but
did not shoot her from a confused notion against shooting the females;

253

TRADITIONS OF WATERFOWL

but afterwards went over where she lit and missed her when she rose,
but dropped her with the second shot, a gray duck. The nest was prettily
placed at the edge of the bank, seven eggs all clean and fresh." * When
acted upon annually, the philosophy that to take only a few from the home
marsh is harmless must surely have accounted for a considerable loss of
breeding stock in some parts of the range. Ducks continued to pass aplenty
in migration ; but once the native birds with local breeding traditions were
killed, flights went through each spring with few or none stopping to nest
in some localities.

We speak with contempt of the carefree, heavy gun pressure of the
past; yet even in our time, early-season wildfowling and careless gunning
on the breeding marshes threaten some late-maturing waterfowl like Can-
vasback and Redhead. In some parts of the nesting range the season con-
tinues to open on marshes where many young diving ducks and adult
females are still flightless or barely on the wing. Evidence of bag studies
shows that in some early-season openings, more Canvasback and Redheads
are killed in one or two days of gunning than are raised locally in a season
(Sowls, 1946; Hochbaum, 1947). In such early-season shooting, the careless
waste is sometimes quite unbelievable. On the opening day of the 1946
season on the Delta Marsh, a hot, windy September 16, it was estimated
that about half of the 4,000-bird bag spoiled and was thrown aside. Kit
Kitney, Winnipeg columnist, wrote that "heavy losses were due to the fact
that birds carried all day in the car, spoiled and had to be discarded . . .
We took only nine birds. This was fortunate, because we were too tired
to do anything about our game when we arrived home Monday, and on
Tuesday night they were too far gone and had to be thrown out."t On
September 17, 1946, in routine bag study, I saw a pile of more than two
hundred and fifty ducks, mostly Canvasback and Redhead, which were
being thrown away as spoiled, these on the kitchen floor of an Indian
woman who had contracted to process the birds for shipment.

Besides spoilage, the products of early-season gunning on breeding
marshes are often cast away as too thin or pin-feathery. Frequently on the
Delta Marsh young Redheads have been left behind by hunters as not
worth taking home. The adult drake bagged in October is as fine and as
wary a bird as any Canvasback; but the little Redheads just on the wing
in September are thin-breasted, flabby birds, innocent of all experience

0 Diaries of E. L. Brown, 1889-1901. Typed manuscript, Minnesota Historical Society,
t "Sportsmen Afield," Winnipeg Tribune, September 21, 1946.

254

BROKEN TRADITIONS

with shot and gun, so different from the adult that some local gunners
contend that they are of a separate species. Others believe that the light
little birds are sickly, and for this reason do not keep them. In early season
shooting, when birds are abundant and bag-limits small, it is a common prac-
tice, during the course of a day's shoot, to discard the smaller ducks, like
Blue-winged Teal, or less desirable kinds, like Shoveller, replacing these
with larger Mallards and Canvasbacks. Ducks scattered and lost in the
reeds by novice hunters, or ducks thrown away by city shooters as spoiled
or too small to take home, are just as dead as those the market hunter packed
in ice.

Of course, one cannot wholly blame the hunter if his seasons are set so
that he is likely to shoot birds so immature that they are all but worth-
less as food. To most hunters the young Redhead just on the wing is not
readily distinguished from an adult until it is dead. I am sure that as we
find out more about the life histories of waterfowl, there must stem from
this understanding a new pattern of gunning regulations. At present all
ducks are shot under a common plan. Even though many Canvasback and
Redhead are not strongly on the wing until late September, their shooting
season opens at the same time as it does for young Mallard and Pintail,
which are flying by midsummer. Even though many adult females are still
flightless on the breeding marsh at the start of autumn, gunning on the
marsh starts on the same day as it does on upland fields or open lakes,
where drakes and strongly-flying young have been feeding for many weeks.
It is unreasonable to set laws which require the hunter to recognize the
legality of killing one species but not another in the same environment. But
by certain zoning regulations, hardly more complicated than now exist for
upland game, the season might open early on grain fields for strong-winged
Mallard and Pintail; shooting could be delayed on the breeding marshes,
and the pressure there thus relieved, until after the young diving ducks and
adult females had had a chance to become strong of wing and had dis-
persed from the home range.

This, of course, is no place to discuss the modern pattern of wildfowl-
ing, for it is a subject yet unstudied. We know almost nothing of the cus-
toms of hunters or of the impact of their practices on native populations of
northern marshes. The throwing away of spoiled birds or the waste of young
Redheads in September shooting may be of little consequence. The whole
subject of the influence of the hunter on the waterfowl population awaits
careful study and analysis. But it is the hunters themselves who say that

255

TRADITIONS OF WATERFOWL

some great Canadian marshes are already overshot and "burned out." The
gunner is moving ever northward.

Shooting, when it begins before the close of summer, may be respon-
sible for the existence of good marshes that lack breeding ducks. Where
the young and adult females are killed heavily enough on their native
range, local traditions may be broken to the point where, despite plenty of
migrants passing through, there are not enough birds with local experience
to fill some marshes. Leopol (1931), in his surveys of the North Central
states, found that while "only 10 percent of the original marshlands remain
in existence, possible only five percent are actually used to any extent."

During our most recent duck depression, in the middle 1940s, similar
vacancies reached deep into Canada. In 1947 Soper (1948:54) found places
where "numerous favorable small bodies of water were conspicuously un-
derpopulated by waterfowl; and in many tracts, eight or nine sloughs out
of every ten, though provided with plenty of water and duck food, had
no ducks." In Manitoba's famous Minnedosa pothole region, less than half
the water areas had breeding pairs in 1947 (Hawkins, 1948:44). Since the
pothole country was not heavily shot (the young and adults most seasons
having departed to larger waters before the advent of gunning) the thin
nesting populations, as in the case of the shorebirds, may have resulted
from overshooting on the flyways.

An important advantage held by waterfowl over the shorebirds and the
Passenger Pigeon is the larger clutch. The Passenger Pigeon laid one, some-
times two eggs ( Schorger, 1955 ) , and the standard clutch size in the shore-
birds is only four. While there is some variation between species, duck
clutches range from eight to twelve eggs, the over-all average being per-
haps ten. Thus in successful seasons these waterfowl are able to recover
their numbers at a much faster rate than the shorebirds, and the pigeons
were at a disadvantage greater still. Moreover, the evidence of Sowls's
studies ( 1949 ) is that among the river ducks, at least, there is a persistent
drive to renest in the face of early nest loss ; and such renesting may carry
the bird to a third attempt after a second catastrophe. The ability to re-
cover numbers is shown in the surveys of the Newdale-Erickson district
of Manitoba's Minnedosa pothole country, where the breeding population
climbed from 26 ducks per square mile in 1947 (Hawkins, 1948) to 81
ducks per square mile in 1949 (Hawkins, 1949). By 1953 there were 100
ducks per square mile in this district (Kiel, 1953).

If the number of waterfowl of Minnedosa could be trebled in two years,

256

BROKEN TRADITIONS

it is possible that populations of more southern marshes might show a simi-
lar capacity to expand when more ducks are available. In 1951 the Waubay
pothole region of South Dakota held 124 ducks per square mile (Evans,
Mann, and Black, 1951:162), a resident breeding population five times as
dense as that of the similar Canadian pothole country in 1947. In 1950 the
State of North Dakota held a nesting population averaging 19.7 ducks per
square mile, a number greater than the over-all average for Alberta (11.5
ducks per square mile) (Hjelle, 1951:149; Smith, 1951:30). I suspect that
the breeding grounds in the true prairie country of the Dakotas, Minnesota,
Wisconsin, and Manitoba may serve as security range during seasons when
parts of the more western plains dry out to the point of being untenable to
nesting ducks. This does not imply that birds move east to breed success-
fully the first year of a drought; but during dry periods lasting several years,
the marshes of the true prairie hold water longer, then providing the main
part of the breeding grounds in the middle latitudes.

I have spoken mainly of the United States breeding grounds of the
north central region because they are potentially so fine and so immedi-
ately threatened by4drainage. There are other great breeding ranges in the
United States, such as the sandhill country of Nebraska, the plains of Mon-
tana, the Great Basin country of Utah and Idaho, and the marshes of the
Klamath basin of California and Oregon, to mention only a few. Some of
these western ranges not only have many species of game ducks, but are
heavily productive of Canada Geese. If we are to plan for the wildfowling
of the future as carefully as we plan for barley, we must count heavily on
these breeding grounds within the settled regions of North America.

In token of the importance of this resource, a technical program for
waterfowl investigations has been launched far and wide across the land.
At last we have grasped the idea that we cannot manage waterfowl as a
renewable resource unless we know more about ducks and geese, species
by species, region by region. And during the past ten years we have learned
more about these birds than in all our previous history. University gradu-
ate departments, biological stations, provincial and state game branches,
and central government agencies are studying waterfowl in many ways
and in many places. Some seek to understand such fundamental problems
as the natal range of ducklings in Manitoba (Dzubin, 1954), or the effect of
spring rainfall on nesting Mallards in California (Mayhew, 1955). Others
set about to find ways of restoring birds to new or empty ranges, as by
transplanting flightless juveniles from old to new marshes (Wells, 1954;

257

TRADITIONS OF WATERFOWL

Foley, 1954b). Bright young men in every corner of the land search for
information aimed at a better understanding of this great resource. An-
nually an international team, composed of more than fifty biologists rep-
resenting many different agencies, surveys the waterfowl breeding popula-
tion from the central United States north to the Arctic Ocean and beyond,
so that the pattern of the harvest may be fairly planned. Another team
appraises waterfowl on their wintering grounds each January.

For all this new interest, however, for all the technical advancements,
for all the many pounds of published facts about life histories, numbers,
ranges, food habits, territorial requirements, for all the new dams and im-
poundments, we have not learned how to draw a compromise with the
economists who are doing away with the breeding range faster than it can
ever be restored. Perhaps we have learned more about the behavior and
living requirements of ducks than of ourselves. The time when we start
saving the prairie marshes may arrive when we somehow realize that we
need these wetlands for our own human race, when we understand that the
real concern is not for ducks, but for the people themselves : can we con-
tinue to be strong and healthy on this North America after we have let
the gems of upland waters drain to the valleys?

The real concern is for us, the people. We who wish to keep marshes and
their waterfowl must study ourselves and our human society. We are at the
threshold of an era we cannot comprehend. But surely we know that each
nation must find its strength in the land. The people of North America can-
not remain always strong if the value of our prairie land is measured wholly
in terms of wheat and barley.

Bibliography

Ihe following titles, all but a few of which are cited in the text, are
those that I have used in writing this book. For anyone wishing to read further in
the very extensive literature on bird migration, I suggest the excellent reviews by
Drost (1951), Griffin (1944, 1952a), Matthews (1955b), and Schiiz (1952), all
of which contain fine bibliographies listing many important titles that I have been
unable to include here.

In this book I have not dealt with the stimuli responsible for migration, and as
an introduction to this subject one might start with Farner's careful review paper
( 1950 ) and the works of Rowan and Wolf son cited below.

Bagg, Imhof, Salomonsen, and Williamson, together with a few others men-
tioned in their papers, are making important observations on the relation of
traveling birds to moving air masses; I consider their publications extremely
important for all to read. Nor can the modern student of bird migration afford to
overlook "Normal weather charts for the Northern Hemisphere" (U.S. Weather
Bureau, 1952).

Concerning migration North American ornithologists have recorded many inci-
dents and arrival dates. But there has been little attempt to study the behavior of
birds, in the way that Lack, L. Tinbergen, and their colleagues in Europe have
studied it, in the very act of passage. As an introduction to important papers and
bibliographies on visible migration, the April 1953 issue of the Ibis ( Volume 95 ) ,
is a logical starting place. Matthews ( 1955b ) has a full review and a bibliography
of studies that have been made on avian relation to the sun, work that has been
carried out almost entirely in Europe.

In regard to learning and instinct, the student may refer to Lorenz (1935,
1937), Thorpe (1951a), and N. Tinbergen (1951), studying at the same time the
critique by Lehrman (1953). Although the important role of tradition has been
suggested by numerous writers over a long period of years, such as Palmen
(1874), Reynaud (1898), and Howard (1920), in the modern literature available
to me the subject is treated only briefly and often self-consciously (with abundant
apologies for anthropomorphic interpretations ) . But I found the work of Cushing
to hold original, straightforward discussions of traditions, and Mayr (1942) and
Nice (1943) have offered a number of stimulating ideas and observations.

259

TRAVELS AND TRADITIONS OF WATERFOWL

All through my review of the literature on behavior and migration, I have found
evidence of friendships between European and North American authors and of a
broad exchange of ideas and observations that are bound to result in a fuller
understanding of the subject.

Acworth, Bernard

1946. The cuckoo and other bird mysteries. London: Eyre and Spottiswood.
Aldrich, John W., and others

1949. Migration of some North American waterfowl. U.S. Fish and Wildlife Service,
Special Scientific Report (Wildlife) No. 1, pp. 1-49.
Allee, Warder C.

1951. Cooperation among animals. New York: Schuman.

, and Karl P. Schmidt

1937. Ecological animal geography. London: Wiley.
Allen, Arthur A.

1914. The Red-winged Blackbird: A study in the ecology of a cat-tail marsh. Proc.
Lirmaean Soc. of New York No. 24-25, pp. 42-128.

1931. The Canvasback. Bird-lore 33:347-360.
Allen, Francis H.

1939. Effect of wind on flight speeds. Auk 56 (3) :291-303.
Allen, J. A.

1880. Origin of the instinct of migration in birds. Bull. Nutt. Ornith. Club 5:151-154.
Armstrong, Edward A.

1947. Bird display and behaviour (rev. ed.). New York: Oxford.
1954. The behavior of birds in continuous daylight. Ibis 96 (1) : 1-30.

Audubon, John James

1840. Birds of America, from drawings made in the United States and their terri-
tories. Philadelphia: Chevalier.
Austin, Oliver L., Jr.

1932. The breeding of the Blue-winged Teal in Maryland. Auk 49 (2): 191-198.

1949. Waterfowl of Japan. General Headquarters, Supreme Commander for the
Allied Powers, Natural Resources Section, Report No. 118.

Aymar, Gordon C.

1935. Bird flight. New York: Dodd, Mead.
Baerends, G. P.

1950. Specializations in organs and movements with a releasing function. Symposia
of Society for Experimental Biology No. 4, Physiological Mechanisms in
Animal Behavior. Cambridge, England: Cambridge Univ. Press.

Bagg, Aaron Moore

1948. Barometric pressure-patterns and spring migration. Auk 65 ( 1 ) : 147.
, W. W. H. Gunn, D. S. Miller, J. T. Nichols, Winnifred Smith, F. P. Wolfarth

1950. Barometric pressure-patterns and spring bird migration. Wilson Bull. 62
(1):5-19.
Balham, Ronald W.

1954. The behavior of the Canada Goose (Branta canadensis) in Manitoba. Unpub-
lished thesis, Univ. of Missouri.
Barlow, Horace B., Henry L. Kohn, and E. Geoffrey Walsh

1947a. Visual sensations aroused by magnetic fields. Amer. J. Physiol. 148:372-375.

260

BIBLIOGRAPHY

1947b. The effect of dark adaptation and of light upon the electric threshold of
the human eye. Amer. J. Physiol. 148:376-381.
Barnett, Lincoln

1948. The universe and Dr. Einstein. Harpers 196:303-312 (April), 465-476 (May),
525-539 (June).
Bastock, M., D. Morris, and M. Moynihan

1953. Some comments on conflict and thwarting in animals. Behavior 6 (l):66-84.
Beecher, William J.

1951. A possible navigation sense in the ear of birds. Amer. Midland Naturalist 46
(2):367-384.

1952. The unexplained direction sense of vertebrates. Scientific Monthly 75 (1):
19-25.

Bellrose, Frank C.

1951. Waterfowl flight. Illinois Wildlife 6 (4):10-11.

1953. Housing for Wood Ducks. Illinois Natural History Survey Circular 45:1-47.
Benedict, Buth F.

1946. Patterns of culture. New York: Pelican Books.
Bennett, Logan J.

1938. The Blue-winged Teal. Ames, Iowa: Collegiate Press.
Benson, Dirck

1939. Survival studies of Mallards liberated in New York State. Trans. 4th North Amer.
Wildlife Conference, pp. 411-415.

Bent, Arthur Cleveland

1923. Life histories of North American wild fowl. U.S. National Museum Bull. 126.

1925. Life histories of North American wild fowl. U.S. National Museum Bull. 130.

1929. Life histories of North American shore birds. U.S. National Museum Bull. 146.

1942. Life histories of North American flycatchers, larks, swallows, and their allies.
U.S. National Museum Bull. 179.
Bergman, Goran

1951. Om isforhallandenas inverken pa anfagelns, Ckingula hymalis (L.), rastvanor
under varen. Ornis Fennica 28 (3) : 62-65.

Bergson, Henri

1911a. Creative evolution (tr. by Arthur Mitchell). New York: Holt.

1911b. Matter and Memory (tr. by Nancy Margaret Paul and W. Scott Palmer).
New York: Macmillan.
Berry, F. A., George V. Owens, and H. P. Wilson

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1951. The sea around us. New York: Oxford.
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1955. Owen Wister's West. Atlantic Monthly 195 (5):29-35.
Witkin, H. A.

1953. Space orientation in man. Mimeographed report, American Museum of Natural
History Conference on Orientation in Animals, Feb. 6-7, 1953.
Wodzicki, K., and Wojtusiak, R. J.

1934. Untersuchungen liber die Orientation und Geschwindigkeit des Fluges bei
Vogeln, I — Experimente an Schwalben (Hirundo rustica L.). Acta Ornithol.
Mus. Zool. Polon., p. 1.
Wojtusiak, Roman J.

1949. Polish investigations on homing in birds and their orientation in space. Proc.
Linnean Soc. of London, Session 160, Part 2, pp. 99-108.
Wolfson, Albert

1940. A preliminary report on some experiments on bird migration. Condor 42 (2):
93-99.

BIBLIOGRAPHY

1941. Light versus activity in the regulation of the sexual cycles of birds: The role
of the hypothalamus. Condor 43 (3) : 125-136.

1942. Regulation of spring migration in Juncos. Condor 44 (6):237-263.

1945. The role of the pituitary, fat deposition, and body weight in bird migration.

Condor 47 (3): 95-127.
1948. Bird migration and the concept of continental drift. Science 108 (2793) -.23-30.
1952. Day length, migration and breeding cycles in birds. Scientific Monthly 74 (4) :

191-200.

1954. Weight and fat deposition in relation to spring migration in transient White-
throated Sparrows. Auk 71 (4):413-434.

1955. Origin of the North American bird fauna: Critique and reinterpretation from
the standpoint of the continental drift. Amer. Midland Naturalist 53 (2):353-
380.

Woodcock, Alfred H.

1940. Observations on Herring Gull soaring. Auk 57 (2):219-224.
Woodrow, Herbert

1951. Time perception. In S. S. Stevens, ed., Handbook of experimental psychology.
New York : Wiley.
Wright, Bruce S.

1954. High tide and an east Wind. Harrisburg: Stackpole and Heck.
Wynne-Edwards, V. C.

1935. On the habits and distribution of birds of the North Atlantic. Proc. Boston Soc.
of Natural History 40 (4): 233-346.
Yeagley, Henry L.

1947. A preliminary study of a physical basis of bird navigation. J. Applied Physics

18 (12): 1035-1063.
1951. A preliminary study of a physical basis of bird navigation, II. J. Applied
Physics 22 (6):746-760.
Yocom, Charles F.

1947. Observations on bird life in the Pacific Ocean off the North American shores.
Condor 49 (5): 204-208.

283

Nomenclature of Birds

Ihis is the list of birds mentioned in the foregoing discus-
sions. These fall into three categories : those observed as transients, those to
which other authors have referred, and those I have studied intimately. It would
be quite improper to give exact racial identification for the first two categories,
and I have been as conservative as possible in the binomial listing. In the water-
fowl, however, I have tried to be precise and modern, following the classification
suggested by Delacour and Mayr (1945) as presented by Scott (1951), acknowl-
edging Delacour's (1954) more recent treatment of the geese.

Throughout the text I have capitalized the common name as given in the
A.O.U. Checklist of North American Birds, 4th edition, 1931, with only a few
modifications. I have referred simply to Junco and to Flicker, rather than to
Slate-colored Junco and Northern Flicker, as there has been visual evidence that
not all these abundant migrants are of the same race. Nor have I held to the
geographic adjectives, such as American Coot, where Coot alone seemed clear
and sufficient. Every school child in Manitoba knows the Red-winged Blackbird,
but only a few citizens are aware of the Giant Red-wing; hence I have held to the
older name. In general, the common name has been more stable than the Latin,
but even here there are some puzzles. Moffitt (1937) wrote of the White-cheeked
Goose, which is the Western Canada Goose of Scott and the Vancouver Canada
Goose of Delacour. Should Shoveller be spelled with two Ts, as by Delacour and
Mayr (1945) and by the Canadian Wildlife Service, or with one I, as by Scott
( 1951 ) and the U.S. Fish and Wildlife Service? Shall Wigeon (for Anas penelope)
retain its European heredity, which lacks the d; or when speaking of the bird as
North Americans, shall we hold with the American Ornithologists' Union and call
it Widgeon?

On page 239 of the text I mentioned that only one North American game duck
showed subspecific variation. This may not be entirely true as things now stand.
The Green-winged Teal apparently has a subspecies on the Aleutian Islands,
Anas crecca nimia, while there may be a Pacific and an Atlantic race of the White-
winged Scoter, Melanitta fusca dixoni and M. /. deglandi. Balancing these minor
divisions there is the conservative revision of the Harlequin Duck, whereby the
birds of the eastern and western ranges are now considered to be of one and the

284

NOMENCLATURE OF BIRDS

same race. The Black Duck is currently considered to be merely a race of Anas
fulvigula (Delacour and Mayr, 1945; Scott, 1951). The Black Duck travels in
winter as far south as the winter quarters of both the Mottled Duck and the
Florida Duck, evidence, perhaps, that the isolating mechanism by which the
races of fulvigula remain distinct may not be so simple as set forth in the text.
But it does hold that most of the Black Duck population winters north of these
sedentary relatives.

NORTH AMERICAN BIRDS

Common Loon Gavia immer

Eared Grebe Colymbus caspicus

Western Grebe Aechmophorus occidentalis

Black-footed Albatross Diomedea nigripes

Leach's Petrel Oceanodroma leucorhoa

White Pelican Pelecanus erythrorhynchos

Great Blue Heron Ardea herodias

American Egret Casmerodius albus

Snowy Egret Leucophoyx thula

Black-crowned Night Heron Nycticorax nycticorax

American Bittern Botaurus lentiginosis

Whistling Swan Olor columbianus

Trumpeter Swan Olor buccinator

White-fronted Goose Anser albifrons frontalis

Lesser Snow Goose (Blue Goose) Anser cserulescens cserulescens*

Greater Snow Goose Anser caerulescens atlanticus

Hawaiian Goose Branta sandvicensis]

Canada Goose Branta canadensis interior

Giant Canada Goose Branta canadensis maxima

Western Canada Goose Branta canadensis occidentalis

Richardson's Goose Branta canadensis hutchinsi

Pintail Anas acuta

Green-winged Teal Anas crecca carolinensis

Mallard Anas platyrhynchos platyrhynchos

Florida Duck Anas fulvigula fulvigula

Mottled Duck Anas fulvigula maculosa

Black Duck Anas fulvigula rubripes

Gadwall Anas strepera

Baldpate ( American Widgeon ) Mareca americana

Blue-winged Teal Anas discors

Cinnamon Teal Anas cyanoptera

Shoveller Spatula clypeata

• Following Delacour ( 1954:125), the Blue Goose being merely a color-phase of this species,
t Extra-limital, not appearing on the North American list.

285

TRAVELS AND TRADITIONS OF WATERFOWL

Canvasback Aythya valisineria

Redhead Aythya americana

Ring-necked Duck Aythya collaris

Lesser Scaup Aythya affinis

Greater Scaup Aythya marila nearctica

Wood Duck Aix sponsa

Pacific Eider Somateria mollissima v-nigra

Northern Eider Somateria mollissima borealis

American Eider Somateria mollissima dresseri

Hudson Bay Eider Somateria mollissima sedentaria§

White-winged Scoter Melanitta fusca deglandi

Harlequin Duck Histrionicus histrionicus" *

Old Squaw Clangula hyemalis

Barrow's Golden-eye Bucephala islandica

American Golden-eye Bucephala clangula americana

Bufflehead Bucephala alheola

Red-breasted Merganser Mergus serrator

American Merganser Mergus merganser americanus

Ruddy Duck Oxyura jamaicensis jamaicensis

Goshawk Accipiter gentilis

Sharp-shinned Hawk Accipiter straitus

Cooper's Hawk Accipiter cooperii

Red-tailed Hawk Buteo jamaicensis

American Rough-legged Hawk Buteo lagopus

Bald Eagle Haliasetus leucocephalus

Marsh Hawk Circus cyaneus

Osprey Pandion halisetus

Duck Hawk Falco peregrinus

Pigeon Hawk Falco columbarius

Sparrow Hawk Falco sparverius

Heath Hen Tympanuchus cupido cupido

Prairie Chicken Tympanuchus cupido pinnatus

Sharp-tailed Grouse Pedicecetes phasianellus campestris

Hungarian Partridge Perdix perdix

Whooping Crane Grus americana

Little Brown Crane Grus canadensis canadensis

Sandhill Crane Grus canadensis tahida

Florida Crane Grus canadensis pratensis

Cuban Sandhill Crane Grus canadensis nesiotes \

Coot Fulica americana

§ Auk 63 (3) -.429 (July 1946).

°* "Histrionicus histrionicus pacificus Brooks is now considered inseparable from the eastern,
nominate, form. The Harlequin Duck thus reverts to binomial status . . ." — Auk 71(3) :310 (July
1954).

286

NOMENCLATURE OF BIRDS

Golden Plover Pluvialis dominica

Black-bellied Plover Squatarola squatarota

Woodcock Philohela minor

Wilson's Snipe Capella gallinago

Eskimo Curlew Numenius borealis

Upland Plover Bartramia longicauda

Lesser Yellow-legs Totanus flavipes

Long-tailed Jaeger Stercorarius longicaudus

Franklin's Gull Larus pipixcan

Arctic Tern Sterna paradissea

Sooty Tern Sterna fuscata

Noddy Tern Anous stolidus

Domestic Pigeon Columba livia

Passenger Pigeon Ectopistes migratorius

Carolina Paroquet Conuropsis carolinensis

Great Horned Owl Bubo virginianus

Flicker Colaptes auratus

Downy Woodpecker Dendrocopus pubescens

Arkansas Kingbird Tyrannus verticalis

Tree Swallow lridoprocne bicolor

Barn Swallow Hirundo rustica

Cliff Swallow Petrochelidon pyrrhonota

Canada Jay Perisoreus canadensis

Blue Jay Cyanocitta cristata

Magpie Pica Pica

Raven Corvus corax

Crow Corvus brachyrhynchos

Black-capped Chickadee Parus atricapillus

Catbird Dumatella carolinensis

Robin Turdus migratorius

Starling Sturnus vulgaris

Yellow Warbler Dendroica petechia

English Sparrow Passer domesticus

Bobolink Dolichonyx oryzivorus

Western Meadowlark Sturnella neglecta

Yellow-headed Blackbird Xanthocephalus xanthoceplialus

Red-winged Blackbird Agelaius phoeniceus

Baltimore Oriole Icterus glabula

Rusty Blackbird Euphagus carolinus

Brewer's Blackbird Euphagus cyanocephalus

Bronzed Grackle Quiscalus quiscala

Cowbird Molothrus ater

Evening Grosbeak Hesperiphona vespertina

Pine Siskin Spinus pinus

287

TRAVELS AND TRADITIONS OF WATERFOWL

Vesper Sparrow Focecetes gramineus

Slate-colored Junco Junco hyemalis

Oregon Junco Junco oreganus

Tree Sparrow Spizella arborea

Song Sparrow Melospiza melodia

Lapland Longspur Calcarius lapponicus

Snow Bunting Plectrophenax nivalis

EUROPEAN BIRDS

Manx Shearwater Procellaria puffinus

Common Sheld-duck Tadorna tadorna

Pink-footed Goose Anser arvensis brachyrhynchus

Wigeon ( European Widgeon ) Anas penelope

Sparrow Hawk Accipiter nisus

Pheasant Phasianus colchicus

Ringed Plover Charadrius hiaticula

Woodcock Scolopax rusticola

Lesser Black-backed Gull Larus fuscus

Herring Gull Larus argentatus

Collared Turtle Dove Streptopelia decaocto

Alpine Swift Apus melba

Swallow Hirundo rustica

Hooded Crow Corvus comix

Rook Corvus frugilegus

Jackdaw Corvus monedula

Great Tit Parus major

Fieldfare Turdus pilaris

Robin Erithacus rubecula

Chaffinch Fringilla coelebs

Yellow Wagtail Motacilla flava

Red-backed Shrike Lanius collurio

288

Acknowledgments

This is the fifty-first technical dissertation (and third book0)
resulting from the cooperative studies of the Delta Waterfowl Research Station.
The scientific program at Delta, Manitoba, was founded in 1931 by James F. Bell,
of Minneapolis, who established the buildings and equipment necessary for
biological research at the edge of a great breeding marsh. For the opportunity of
using these materials in an ideal wild location, within an atmosphere of complete
academic freedom, and for countless courtesies, I am grateful to Mr. Bell.

From 1931 to 1939 the Station was operated by Edward Ward, of Delta, who
pioneered many new techniques in the captive-breeding of wild ducks. In 1938
the American Wildlife Institute joined to share sponsorship with Mr. Bell, and at
this time, under the counsel of Professor Aldo Leopold, Dr. Miles D. Pirnie, and
Dr. William Rowan, the plan of research by university graduate students was
established. A heavy debt of gratitude is due these gentlemen.

Sponsorship was transferred to the Wildlife Management Institute in 1945; then
in 1950 the North American Wildlife Foundation, with its international Board of
Directors, assumed responsibility for sponsorship, the Wildlife Management
Institute remaining the administrative organization. To the directors, officers, and
members of these two organizations my colleagues and I at Delta are grateful
for the opportunity of continuing studies under an expanding program, with
improved living and working facilities. Especially helpful have been Max
Mcgraw, of Chicago, President of the North American Wildlife Foundation;
Colonel Arthur Sullivan, Q.C., of Winnipeg; Robert M. Gaylord, of Rockford;
Glenn L. Martin, of Baltimore; W. A. Murphy, John B. Richardson, and H. E.
Sellers, all of Winnipeg; and Herbert J. Symington, Q.C., and R. Howard Web-
ster, both of Montreal.

The Station has depended heavily upon the ready counsel of the Canadian
Wildlife Service and has appreciated the annual grants of permits for special
studies. The Manitoba Department of Mines and Natural Resources and the
Manitoba Game and Fisheries Branch have been generous with manpower,
equipment, and services. The National Research Council of Canada has con-

• H. Albert Hochbaum, The Canvasback on a Prairie Marsh, 1944; Lyle K. Sowls, Prairie
Ducks, 1955.

TRAVELS AND TRADITIONS OF WATERFOWL

tributed funds to this and to other Delta studies. The Royal Canadian Air Force
has given the Station assistance of a very specialized kind. The National Film
Board of Canada, the Canadian Broadcasting Corporation, and the Manitoba
Museum have supplied manpower and equipment. The U.S. Fish and Wildlife
Service has worked closely with the Station since its beginning. We have bene-
fited from the close association with Ducks Unlimited over a period of many years.
The Severn Wildfowl Trust (now the Wildfowl Trust) has had a profound
influence on my own studies and upon Delta operations as a whole. The Manitoba
Federation of Game and Fish Associations has been a continual source of informa-
tion and support. Canadian Industries Ltd. has been an enthusiastic participator
in the Delta program. The New York State Conservation Department and the
Wisconsin Conservation Department have been collaborators during several
seasons. Borden Productions and the Moody Bible Institute have been our fellow
workers. All but one of these agencies have stationed a man at Delta to carry out
special projects, some for only a part of a season, others each spring for many
years. Cornell University, Illinois College, and the universities of Alberta, Bristol,
British Columbia, Manitoba, Minnesota, Missouri, and Wisconsin have carried
out postgraduate investigations of various phases of waterfowl biology.

In addition to these organizations, every individual member working at Delta
has in some way or other contributed to the development of this book. The task
of making individual acknowledgments for the help and criticism that have been
given so freely by so many over such a long period is therefore overwhelming.
The book was started ten years ago after a series of separate discussions with
James F. Bell, Dr. William Rowan, of the University of Alberta, Robert H. Smith,
of the U.S. Fish and Wildlife Service, Peter Ward, of Delta, and Dr. Lyle K.
Sowls. Especially important has been the generous and detailed advice of Robert
L. Lillestrand, of General Mills Research Laboratories, to whom I owe a great
deal for the development of the discussions on the physics and aerodynamics of
flight. The original Delta investigations of Lyle Sowls on the homing behavior of
waterfowl have given foundation to important sections of the book, and the keen
field ability of Peter Ward has been the source of much original material.
Margaret M. Nice, of the Wilson Ornithological Club, gave me the first critical
review; I owe her much for this and for the help she gave me during her years
at Delta. The manuscript grew from critical readings by Dr. Walter J. Brecken-
ridge, Dr. William H. Marshall, and Dr. Dwain W. Warner, of the University of
Minnesota; Dr. John E. Cushing, University of California; Dr. Ira N. Gabrielson,
Wildlife Management Institute; Dr. Donald R. Griffin and Dr. Ernst Mayr, Har-
vard University; and E. R. Kalmbach, U.S. Fish and Wildlife Service. Dr. Rowan
read the manuscript at many stages from start to finish, and I have depended
heavily upon his lucid, stimulating criticisms. Dr. Frank McKinney, of Delta,
helped me organize the final copy for publication. I am heavily in debt to these

290

ACKNOWLEDGMENTS

friends for the time they have spent and the clear and detailed guidance they
have given me.

The chapters on perception and memory lean heavily on discussions with J.
Ford Bell, Jr., of Minneapolis, and Dr. Robert Galambos, of Walter Reed Medical
Center. J. Donald Smith, of the U.S. Fish and Wildlife Service, helped with the
chapter on oceanic migration. Glenn L. Martin and G. S. Trimble, Jr., of the
Glenn L. Martin Company, read the chapters on "The Aerial Environment" and
"The Dimensions of Travel," presenting a number of important suggestions.
Edward G. Wellein, of the U.S. Fish and Wildlife Service, also assisted me with
these chapters. The original studies of blindfolded birds were made by William
Carrick, of the Royal Ontario Museum. Aldo Missio, of the Royal Canadian Air
Force Weather Station, Macdonald, Manitoba, advised me on the interpretation
of meteorological data. The shape of the final discussion in chapters 11 and 15
was greatly influenced by the 1955 visit to Delta of Dr. G. V. T. Matthews, of
the Wildfowl Trust. Dr. John E. Cushing and Peter Scott, M.B.E., D.S.C., inspired
many ideas developed in the chapters on tradition. Robert M. Gaylord and
Arthur S. Hawkins gave me good advice for Chapter 19. Dr. Herbert Friedmann,
of the U.S. National Museum, Dr. M. D. F. Udvardy, of the University of British
Columbia, and Mrs. Nice guided me to important European literature. The fol-
lowing persons have all given me critical readings and detailed suggestions:
Bessie Schenck Bunten, Washington, D.C.; Eugene F. Bossenmaier, University of
Minnesota; Dr. Warren W. Chase, University of Michigan; Dr. Nicholas E.
Collias, Illinois College; Graham Cooch, J. Bernard Gollop, and Nolan G. Perret,
Canadian Wildlife Service; Dr. Ian McTaggart Cowan, University of British
Columbia; Dr. William H. Elder, University of Missouri; C. R. Gutermuth and
James B. Trefethen, Wildlife Management Institute; Merrill C. Hammond and
John C. Lynch, U.S. Fish and Wildlife Service; Dr. Eckhard H. Hess, University
of Chicago; Dr. J. J. Hickey, University of Wisconsin; A. G. Lawrence, Winnipeg
Free Press; G. W. Malaher, Manitoba Game and Fisheries Branch; H. W. Murdy,
South Dakota Department of Game, Fish and Parks; Dr. H. T. Odum, Yale Uni-
versity; Father P. M. Plunkett and Father C. C. Ryan, St. Paul's College,
Winnipeg; Carl D. Shoemaker, National Wildlife Federation, and Walker Van
Riper, Colorado Museum of Natural History. But I must not carry this list further,
for there are many more who have helped, these having been mentioned in the
text or thanked personally.

I thank Doris E. Franklin and Jane McCarthy, of the University of Minnesota
Press, for the warm and sympathetic manner in which they have shaped the
book from manuscript and drawings. Aileen Burton, Pat Martin, and Doris Weller
typed parts of the many manuscripts. Beverly Dillon, Brenda McKinney, and
Dorothy Richardson, together with Dr. Fred Cadham, helped me with the proof.
I am indebted to members of the Station staff, especially Norman Godfrey, Nan

291

TRAVELS AND TRADITIONS OF WATERFOWL

Mulder, Ray Burton, and Les Garnham, and their families. The members of the
Hutchinson, Loucks, and MacDonald families, together with numerous other
friends in the Village of Delta, have been always helpful. Many sportsmen and
farmers in the city and rural municipality of Portage la Prairie, in Winnipeg, and
throughout the province have been a continual source of information about the
waterfowl of Manitoba.

Finally, I am ever grateful to my wife Joan and to my children, who, together
with my parents and members of the Ward family, have encouraged me toward
the completion of this book. Nor, in spring, summer, and fall, could I have
learned half so much about the waterfowl of the Delta Marsh without good old
faithful Tim, a Black Labrador Retriever.

292

Index of Authorities

Acworth, B., 57; Alford, A. A., 82; Allen, A.
A., 136; Allen, F. H., 58; Allen J. A., 233; Arm-
strong, E. A., 80; Audubon, J. J., 166; Austin,
O. L., Jr., 225; Aymar, G. C, 187

Baerends, G. P., 42; Bagg, A. M., 104, 118, 120,
136; Baldock, J. W., 121; Balham, R. W., 127
Barlow, H. B., 191; Barnett, L., 29; Bastock
M., 124; Bell, J. F., 95; Bellrose, F. C, 101,
103; Benedict, R., 221; Benson, D., 236; Bent
A. C, 121, 240, 244; Bergman, G., 253; Berg
son, H., 54, 149; Black, K., 257; Blankenship
L., 229; Bogardus, A. H., 247; Bossenmaier, E
F., 73, 102, 140; Brakhage, G. K., 235, 236
Broley, C. L., 209; Brooks, S. C., 181; Brown

E. L., 253; Brown, J. E., 187; Bue, I. G., 229
Buss, I. O., 177, 179, 227

Cadham, F., 8; Cadham, R., 78; Campbell, D.
L., 50, 128, 164; Carrick, W. H., 62, 71; Car-
roll, W. J., 247; Carson, R., 180, 202; Cart-
wright, B. W., 92; Casamajor, J., 187; Chapman,

F. M., 192; Clarke, W. E., 126, 132, 163, 175;
Colls, D., 251; Cooch, G., 170; Cooke, M. T.,
57; Cooke, W. W., 163, 243; Coombes, R. A.
H., 142; Cottam, C, 168; Coues, E., 228;
Cowan, I. M., 234; Craig, W., 124; Criddle, S.,
243; Crissey, W. F., 231; Cullen, J. M, 80;
Cushing, J. E., Jr., 50, 217, 221, 222, 224-226

Darling, J. R., 187; Darwin, C, 237; Davis,
L., Jr., 187; Dawson, W. L., 108; Day, A. M.,
117; Deelder, C. L., 45, 97, 172, 183; Delacour,
J., 234, 244, 245; Dobben, W. H. v., 97;
Doherty, W. H., 188; Drost, R., 187, 190, 191;
Durango, S., 234; Durant, W., 46, 86; Dzubin,
A., 50, 257

Ebbinghaus, H., 49; Eddington, A. S., 149;
Einstein, A., 149; Elder, N. L., 93; Elder, W.
H., 93; Emlen, J. T., Jr., 225; Ennion, E. A. R.,
174; Errington, P. L., 226; Esselmont, K. R.,
169; Evans, C. D., 50, 249

Fabricius, E., 22, 39, 50; Farley, F. L., 42;
Farner, D. S., 126; Fisher, J., 222, 234; Foley,

D., 212, 235, 236, 258; Forbush, E. H., 23,
246, 248; Frederick II, 95; Frisch, K. v., 77, 197

Gavin, A., 251; Gerard, R. W., 47; Geyr von
Schweppenburg, H. F., 97, 135; Gibson, J. J.,
57; Gotz, W. H. J., 108; Gollop, J. B., 229;
Gordon, D. A., 186; Gregg, F. M., 193, 195,
201, 202; Griffin, D. R., 36, 45, 134, 153, 161,
177, 186, 187, 190, 194, 199, 200, 207; Griffith,
R. E., 230; Grinnell, J., 227; Gudmundsson, F.,
234; Gulliksen, H., 49

Hall, L., 100; Hamerstrom, F., 225; Hammond,
M. C, 102, 124; Hanson, H. C, 232; Hanson,
R. C, 170; Hawkins, A. S., 18, 124, 231, 256;
Heilner, V. C, 218; Heinroth, O., 49; Helm,
L. G., 82; Henderson, G. H., 186; Henshaw,
H. W., 183; Heyerdahl, T., 182; Hickey, J. J.,
110, 121; Hinde, R. A., 222; Hitchcock, H. B.,
197, 200; Hjelle, B. V., 257; Hoar, W. S., 69,
209; Hochbaum, H. A., 107, 140, 142, 228,
254; Hock, R. J., 177, 207; Hohn, E. O., 140;
Howard, H. E., 85, 227; Hudson, W. H., 192;
Huxley, A., 193, 194; Hyska, W., 229

Ising, G., 187

Jaccard, P., 193; Jack, A., 58; Janzen, D. H.,
102; Jeans, J., 38; Jedlicka, J., Ill; Jensen,
H., 102

Kabat, C, 137; Kalela, O., 146; Kalmbach, E.
R., 36, 124, 186, 212; Katz, D., 202; Kessel, B.,
228; Keve, A., 234; Kiel, W. H., 256; Kitney,
K., 254; Klopman, R. B., 140; Knorr, O. A.,
188; Kohn, H. L., 191; Kramer, G., 37, 45, 77,
84, 97, 134, 151, 152, 184, 196-201

Lack, D., 45; Landsberg, H., 104; Lashley, K.
S., 54, 195, 198; Laven, H., 43; Lawrence, A.
G., 131, 166, 167, 233; Leopold, A. S., 224;
Leopold, Aldo, 55, 105, 228, 231, 256; Lewis,
H. F., 56, 132, 227; Lillestrand, R. L., 31, 104,
197; Lincoln, F. C, 47, 111, 139, 163, 172,
188, 192, 236, 237, 239; Lloyd, H., 185; Lloyd-
Russell, V., 227; Longbottom, G., 99; Lorenz,

293

TRAVELS AND TRADITIONS OF WATERFOWL

K., 16, 19, 20, 22, 42, 49, 50, 51, 193, 222;
Lowenstein, O., 62; Lowery, G. H., Jr., 129,
132, 172; Lynch, J. C, 33, 103, 124, 229

McCabe, R. A., 212; McClanahan, R. C, 243;
McCreary, O., 175; MacQuarrie, G., 167; Mann,
G. E., 112, 257; Mann, R., Ill; Marshall, J. T.,
Jr., 242; Marshall, W. H., 229; Martin, G. L.,
219; Matthews, G. V. T., 45, 84, 85, 134, 161,
184, 186, 187, 190, 192, 194, 198-201; Mau-
rain, C, 187; Mayhew, W., 257; Mayr, E., 40,
91, 92, 206, 222, 223, 226, 228, 233, 237-239;
Meinertzhagen, R., 246; Meise, W., 233; Menner,
E., 36; Miller, A. H., 180, 222; Miner, J., 231;
Missio, A., 171; Moffitt, J., 225, 244; Munro,
J. A., 127; Murdy, R., 145; Murphy, R. C, 180;
Murphy, W. A., 97

Natorp, O., 132; Nelson, C. V., 99; Newcomb,
W., 250; Nice, M. M., 77, 79, 223, 224; Nolte-
meier, A. P., 170; Nord, W., 102, 249

Odum, H. T., 184, 187; Olson, S., 211

Palmen, J. A., 225; Palmgren, P., 79; Paton,
D. N., 62; Patry, D., 170; Paynter, R. A., Jr.,
184; Peterson, E., 249; Pettingill, O. S., Jr., 79;
Phillips, J. C, 117; Pirnie, M. D., 112; Poincare,
H., 29; Poole, E. L., 69; Poor, H. H., 188;
Preston, F. W., 182; Promptoff, A. N., 223;
Pumphrey, R. J., 32, 33, 35, 36, 81

Queeny, E. M., 55, 60, 64, 79

Ramsay, A. O., 50; Reynaud, G., 12, 215; Rob-
bins, C. S., 112; Roberts, T. S., 168, 233, 243,
244, 245, 246, 247; Roosevelt, T., 253; Rowan,
W., 47, 81, 102, 107, 114, 126, 144, 149, 186;
Russell, E. S., 39, 209

Saint-Paul, U. v., 199; Salomonsen, F., 234;
Santschi, F., 197; Schenk, J., 118; Schiermann,
G., 222; Schindler, T. H., 81; Schoenfeld, C,
249, 251; Schorger, A. W., 233, 256; Schwartz-
kop£F, J., 191; Scott, P., 82, 139, 243; Sedwitz,
W., 230; Seligmann, C. G., 140; Selous, E., 110;
Seton, E. T., 85 (see also Thompson, E. E.);

Shattock, S. G., 140; Sheldon, W. G., 167
Sherman, E. D., 170; Shortt, T. M., 239; Sick
H., 223; Sickles, R., 100; Siebenaler, J. B., 184
Simmons, K. E. L., 206; Slepian, J., 187; Smith
A. G., 257; Smith, J. D., 116, 179; Smith, R. H.
12, 123, 155, 203, 232, 251; Smith, S., 58, 59
Snyder, L. L., 222; Soper, J. D., 121, 256
Sowls, L. K., 19, 42, 46, 81, 92, 102, 115, 121
123, 126, 133, 142, 254, 256; Springer, P. F.
230; Steinmetz, P., 73; Stewart, R. E., 230
Stoudt, J., 102; Stresemann, E., 225; Sullivan
A., 46, 99, 128, 164; Sutton, G. M., 182
Svardson, G., 99, 234; Swenk, M., 247

Taylor, J., 139; Thompson, D. H., Ill; Thomp-
son, E. E., 227, 228 (see also Seton, E. T.);
Thomson, A. L., 92, 134, 135, 186, 193;
Thorpe, W. H., 14, 15, 18, 19, 40, 51, 125,
144, 146, 187, 224; Tinbergen, L., 45, 172;
Tinbergen, N., 12, 15, 25, 42, 124; Trautman,
M. B., 12, 79, 100, 165, 253; Trewartha, G. T.,
209; Trimble, G. S., Jr., 63

Udvardy, M. D. F. v., 234; United States
Weather Bureau, 210, 218

Valikangas, J., 92, 211; Vanderplank, F. L.,
36; Van Riper, W., 186; Varian, R. H., 187;
Viguier, C, 186; Vogt, W., 112

Walls, G. L., 32, 33, 34, 36; Walsh, E. G., 191;
Ward, P., 9, 24, 130, 142; Waterhouse, M. J.,
99; Watson, J. B., 195, 198; Wellein, E. G.,
203, 231, 250, 251; Weller, M. W., 108, 110;
Wells, R. A., 230, 236, 258; Wendt, G. R., 62;
Wetmore, A., 182, 183; Wildfowl Trust, 236;
Wilkinson, D. H., 135, 187, 200; Williams,
C. S., 144, 212; Williams, G. G., 132; William-
son, K., 175, 198, 209; Wilson, A., 219; Wister,
O., 246; Witkin, H. A., 193; Wodzicki, K., 161,
198, 200; Wojtusiak, R. J., 36, 161, 198, 199,
200; Wolfson, A., 123; Woodcock, A. H., 60;
Woodrow, H., 80; Wynne-Edwards, V. C,
184, 185

Yeagley, H. L., 180, 186, 187; Yocom, C. F.,
179, 208

294

Subject Index

Abmigration, 92

Accidents, 165-168

Acuity, visual, 34-36, 150

Adirondack Mountains, 230

Aerodynamics of flight, 55-72

Age: as determinant in migra-
tion, 92-94, 107-110, 144-
147, 205-213; of independ-
ence, 93, 145, 228; of breed-
ing, 127

Air speed, 57-59, 67

Airplane, compared with bird,
33, 57, 63-64, 151, 155-157

Alarm, 24

Albatross, Black-footed, 180

Alberta, 102, 103, 242, 244, 257

Alighting, 55, 61, 66-72

Alpine Swift, 198

Altitude of flight: relative to
other travel dimensions, 11,
60, 82-83, 150-156, 172, 177;
of blindfolded birds, 71; in
fall migration, 97-98, 137; in
spring migration, 114, 128;
over water, 177, 179, 183-184

American Bittern, 138

American Crow. See Crow,
American.

American Egret, 248

American Eider, 240

American Golden-eye, 122, 127,
248

American Merganser, 122

Anticyclone. See Atmospheric
pressure.

Appetitive behavior, 124-126,

201-205
Arctic breeding grounds, 251

Arctic Tern, 208

Arkansas, 79

Arkansas Kingbird, 228, 232-

233
Arrival of spring migrants, 3—4,

81, 116, 121, 122, 128
Artificial transplanting, 222,
234-236

Assessippi, Manitoba, 227

Assiniboine River, 102

Atlantic Ocean, 180-181, 185,
208

Atmospheric pressure: fall, 104-
107, 137, 207-213; spring,
118-120, 136, 171, 175-176;
and migration, 207; Aleutian
low-pressure area, 208, 210,
213; Greenland low-pressure
area, 208, 210, 213, 234. See
also Weather.

Auditory cue, 24

Auslbser, 42

Autumn migration. See Fall mi-
gration.

Awakening time, 77, 79

Awareness: of time, 73-82, 86,
159-161; of space, 82-86; of
direction, 121-123, 192-213,
206-207; of velocity, 151-
155, 172, 183-184. See also
Perception.

Bag tally, 107-110

Balance, 61-64

Bald Eagle, 209

Baldpate (American Widgeon),

52, 107-109, 122, 139, 140,

169, 224, 248
Baltimore Oriole, 138
Barn Swallow, 62, 66, 136, 241
Barrow's Golden-eye, 127, 248
Bathing, 78
Bear River Marsh, 139
Bees, 77, 197
Bering Sea, 163
Big Point, Manitoba, 130
Birthright traditions, 238, 241-

242
Bittern, American, 138
Black Duck, 75, 112, 239, 248
Black-bellied Plover, 12
Blackbird, Brewer's, 128-133,

190
Blackbird, Red-winged, 62, 66,

71, 77, 119, 128-133, 136,
171, 190

Blackbird, Rusty, 119, 128-133,
190

Blackbird, Yellow - headed, 13,
62-70, 119, 128-133, 171,
190

Black-crowned Night Heron, 12,
21, 138

Blindfold, flight with, 61-72

Blue Goose. See Goose, Blue.

Blue Heron, Great, 119

Blue Jay, 127

Bluebill. See Scaup, Lesser.

Blue- winged Teal. See Teal,
Blue-winged.

Bobolink, 232

Brant, 239

Breeding behavior: pair forma-
tion, 16, 92, 236, 239; and
valence, 40-42; territory, 40-
41, 85, 126, 140; species com-
pared, 92-94; and migration,
107-108, 122-127; remating,
126; renesting, 126, 256; age
of breeding, 127; traditions,
222-223, 226-230, 233-236,
238, 239-258; and pioneer-
ing, 228; and subspecies, 239-
241

Breeding range, 228-231, 243-
252, 256-258; map, 117

British Columbia, 244

Broad-front movements, 102-
103, 105, 124, 128, 137

Bronzed Grackle, 62, 77, 128-
133

Brood. See Duckling.

Buckeye Lake, Ohio, 12, 99,
100, 165

Bufflehead, 122, 248

Bunting, Snow, 174

Calculated course, 58
California, 180, 198, 222, 225,
227, 242, 248, 257

295

TRAVELS AND TRADITIONS OF WATERFOWL

Canada Goose. See Goose, Can-
ada.

Canada lay, 156

Canvasback, 6, 8, 10, 14-18, 20,
23, 26, 37, 40, 46, 248: food
of duckling, 16-18; nesting,
39, 242; juvenile environment,
39; migration, 90, 95, 104,
107-109, 115-116, 122, 137,
140-141, 145, 149-156, 167,
175; nonbreeding, 124; win-
tering grounds, 218-219; pio-
neering, 228-229; hunting of,
254-255

Cap Tormente, Quebec, 219

Capistrano Mission, San Juan,
227

Captive-breeding, 236

Carolina Paroquet, 246

Catbird, 62, 138, 144

Cedar River, 100

Chaffinch, 223-224

Chesapeake Bay, 6

Chickadee, 225

Chronometer, 194. See also
Navigation, Time.

Cinnamon Teal, 248

Classification of migration, 135-
148

Cliff Swallow, 225, 227, 228,
232

Climate, influence of changes in,
234

Cloud, as travel guide, 84, 197.
See also Overcast.

Clutch size, 256

Coastal hiatus, 129-130

Collared Turtle Dove, 228

Color, perception of, 36

Colorado, 248

Communication, social, 20-28

Compass, sun's function as, 84,
156-160, 196-197, 212

Consummatory act, stimuli, 124

Contact call, 21-22

Cooper's Hawk, 62, 138

Coot, 21, 33, 142, 173-174, 240

Coriolis force, 187, 194, 200

Courtship behavior, 16, 20, 40

Cowbird, 62, 66, 70

Crane, Cuban, 240

Crane, Florida, 240

Crane, Little Brown, 240

Crane, Sandhill, 119, 240, 246

Crane, Whooping, 225, 236

Crow, American, 62, 117, 128-
133, 147, 165, 171, 172, 206,
225, 233

Crow, Hooded, 206

296

Cuban Crane, 240

Curlew, Eskimo, 247

Currituck Sound, 148

Cycle: migratory, 89-94; repro-
ductive, 107-108, 122-127

Cyclone. See Atmospheric pres-
sure.

Day length, 73, 114, 127, 159-
160, 172

Decoy pipe, 51-52

Deer, White-tailed, 225, 228

Defense flight, 40-41

Deflection of migration: by Lake
Manitoba, 130-131; by bad
weather, 175, 198; by ecolo-
gical barriers, 211

Delaware, 188

Delta Marsh: description, 3-13;
map, 9

Density of breeding population,
249-252

Des Moines River, 100

Dihedral, 63

Direction: standard, 96-97, 110,
116, 117, 128-130, 205, 206;
awareness of, 121-123, 192-
213, 206-207

Dispersal: of juveniles, 94, 112,
144-147, 207-213; of adults,
233

Display, sexual, 16, 20, 40

Distance: relativity of, 83, 86,
149-156, 177, 185, 195-196;
traveled in a day, 103, 116,
129, 161; to horizon, 150-
157, 177-178; perception of,
233

Distance effect, 159, 199-201

Diurnal migration, schedule: in
waterfowl, 95-96, 114, 116-
118; in other birds, 129

Divide, migratory, 121, 130-131

Diving ducks, compared with
river ducks, 93. 139, 228-229

Dog Lake, Manitoba, 121, 242

Domestication, 236, 237

Dove, Collared Turtle, 228

Downy Woodpecker, 237

Drainage of breeding grounds,
249-250

Drake: relation to natal range,
92; different departure sched-
ules, 107-109; molting shifts,
139-144

Drift, migrational: with bad
weather, 175, 198; with air-
mass movements, 208-213,
234

Drive, 125-127

Drought, effect on breeding dis-
tribution, 124, 230
Duck, Harlequin, 248
Duck, Mottled, 239-240
Duck, Ring-necked, 112, 122,

147, 230, 239, 248
Duck, Ruddy, 93, 122, 248
Duck Hawk. See Hawk, Duck.
Duck pass, 5-6, 8-13, 101
Duckling: first flights, 15, 17,
145, 228; food habits, 15-17;
natal environment, 39, 50-52,
83, 86, 195-196, 257; over-
land travel, 79; transplanting,
234-236
Duffer's course, 58-59

Eared Grebe, 168

Eagle, Bald, 209

East Meadow Ranch, Manitoba,

97
Eclipse plumage and molt, 7,

24, 107-108, 136-137, 139-

144
Ecological cues to orientation,

82-86, 154-156, 179-183,

194-205
Ecological isolation, 242
Ecological selectivity, 40, 206,

211
Egg: failure to identify, 19, 42;

laying, 125, 202
Egret, American, 248
Egret, Snowy, 248
Eider, American, 240
Eider, Hudson Bay, 240
Eider, Northern, 240
Eider, Pacific, 240
Enemies, reaction to, 24-25, 35,

37-38, 40-41, 43-44
English Pheasant, 234
English Sparrow. See Sparrow,

English.
Equator, 159, 180
Equilibrium, 61-64
Eskimo Curlew, 247
Ethics, shooting, 253-256
Europe, drift of North Ameri-
can birds to, 208, 213
European Robin, 79
European Sparrow Hawk, 206
European Swallow, 198, 200
European Woodcock, 118
Evening Grosbeak, 233
Everson Lake, Minn., 244
Experience, 14-49, 94, 205-206,

242, 254
Experiments: in flight behavior,

62-72; in orientation, 171,

193-202
Extirpation of species, 244-246
Eye, 29-38; diagram, 30, 34

Falcon. See Hawk, Duck.

Fall migration, 89-91, 95-113,
136-139, 148, 151-156, 165-
170, 172, 174-175, 177, 205-
213, 218-220, 231-232, 235-
236, 255: mass, 81, 80, 95-
111, 136-137, 173, 206; goal
of, 91-92, 206; standard di-
rection of, 96-100, 110; flock
size, 97; weather during, 97-
99, 104-107, 137, 207-213;
gyrations during, 98-99, 197;
adult-juvenile ratio in, 109-
110; return to familiar stop-
ping places, 110-111; solitary,
138

Family bond, 49-50, 93-94,
127, 206, 226, 240, 241

Fannestelle, Manitoba, 82

Fatigue, 78-79

Feigning, 24-25

Fieldfare, 234

Finger Lakes, 121

Flicker, 117, 128-133, 164, 172,
190

Flight, 55-72: instinctive, 15;
learned aspects, 17; of air-
craft, 33, 56-57, 63-64, 151,
155-157; defense, 40-41; of
blindfolded birds, 61-72; in
fog, 83, 163-167; in rain,
167-169, 174; over cloud,
169-170. See also Altitude of
flight.

Flightless period, 7, 24, 107-
108, 136-137, 139-144; kill-
ing for market during, 245,
253

Flocks: size in fall, 97; compo-
sition, 109-110; size in spring,
115-116

Florida Crane, 240

Florida Duck, 239-240

Fog, 83, 163-167

Food habits, 16-18, 26, 30

Franklin's GuU, 12, 165, 190

Freeze-up migration, 90, 102-
104, 107

Gadwall, 19, 23, 235, 239, 248:
migration, 92, 108-109, 122,
145; pioneering, 230

Game farm, 236

Geographical goal, 193, 206

Geographical races, 123, 237-

238
Glacial recession, 233
Golden Plover, 144-171, 183
Golden-eye, American, 122, 127,

248
Golden-eye, Barrow's, 127, 248
Gonadal cycle, 123
Goose, Blue, 4, 42, 44, 116, 117,

121, 123, 132, 166, 169, 170
Goose, Canada, 22, 25, 26, 43,

61, 79, 82: stubble flights, 77;

family bond, 93; migration,

99, 116, 119, 121, 138, 165-

166; new colonies, 226, 234,

244; pioneering, 231; racial

divisions, 238-239; nesting,

242, 245; former range, 243-

245
Goose, Giant Canada, 243-244
Goose, Greater Snow, 82, 219
Goose, Hawaiian, 236
Goose, Lesser Snow, 4, 42, 44,

116, 117, 121-123, 132, 166,

169, 170
Goose, Pink-footed, 139
Goose, Richardson's, 116, 119,

120, 138
Goose, White-fronted, 122, 138,

175
Goshawk Hawk, 138
Grackle, Bronzed, 62, 77, 128-

133
Grant's Lake, Manitoba, 232
Great Blue Heron, 119
Great Britain, 222, 234
Great Horned Owl, 62
Great Tit, 222
Greater Scaup, 167, 219
Greater Snow Goose, 82, 219
Grebe, Eared, 168
Grebe, Western, 143
Greenland low-pressure area,

208, 210, 213, 234
Green-winged Teal. See Teal,

Green-winged.
Grosbeak, Evening, 233
Ground speed, 57-59, 60, 63,

67, 95, 103, 151, 177
Grouse, Sharp-tailed, 224
Gulf of Mexico, 129, 184
Gulf Stream, 208
Gull, Franklin's, 12, 165, 190
GuU, Herring, 12, 77, 198-199
Gull, Lesser Black-backed, 198-

199
Gun pressure, 243-248, 253-256
Gunners' bags, 107-110
Gyrations, 98-99, 197

SUBJECT INDEX

Habitat, awareness of favorable,

39-40, 211
Hail, 167

Harlequin Duck, 248
Hawaiian Goose, 236
Hawaiian Islands, 177-179
Hawk, Cooper's 62, 138
Hawk, Duck, 34-35, 64, 138,

225
Hawk, European Sparrow, 206
Hawk, Goshawk, 138
Hawk, Marsh, 13, 62
Hawk, Pigeon, 34, 35
Hawk, Red-tailed, 119, 133, 171
Hawk, Rough-legged, 119, 129
Hawk, Sharp-shinned, 138
Hawk, Sparrow, 119
Hazards of migration, 163-176
Heath Hen, 246
Heritable wildness, 224
Heron, Black-crowned Night,

12, 21, 138
Heron, Great Blue, 119
Heron Lake, Minn., 244-245
Herring Gull, 12, 77, 198-199
Home range, 82, 85, 121
Homing, 46, 50, 92, 121, 126-
127, 193-205, 211, 230, 238,
242
Homing Pigeon, 186-187, 190,

197-201
Hooded Crow, 206
Horizon: distance to, 150-157,
177-178; elevation of, 154-
155
Horned Owl, Great, 62
Horseshoe Lake, 111., 231
Hudson Bay, 231
Hudson Bay Eider, 240
Hudson River, 121
Hudson's Bay Company, 247
Hungarian Partridge, 228
Hunting: decoys, 42; bag com-
position, 107-110; market,
219, 243-248, 253; opening
dates, 235, 254-256; prac-
tices, 243-248, 253-256; ef-
fect on migrants, 246-248

Iceland, 234

Idaho, 248, 257

Illinois, 18, 101, 110, 111, 112,

147, 231, 243
Illinois River, 100
Imagery, 47
Imprinting, 49-52
Incubation, 19, 125
Independence, age of, 93, 145,

228

297

TRAVELS AND TRADITIONS OF WATERFOWL

Indiana, 105, 243
Infra-red radiation, 36
Instinct, 14-18, 40, 193
Iowa, 170, 243, 248, 253
Ithaca, N.Y., 173

Jackdaw, 42, 99, 222

Jaeger, Long-tailed, 185

James Bay, 121, 169, 232

Jay, Blue, 127

Jay, Canada, 156

Junco, Oregon, 123

Junco, Slate-colored, 132-133,
190

Juvenal plumage, 141

Juvenile: in fall migration, 92-
94, 109-110, 144-147, 205-
213; homing of, 92, 127, 211-
212, 230, 238; wandering of,
111-112

Kentucky, 105
Kill. See Hunting.
Kingbird, Arkansas, 228, 232-
233

Labrador, 247

Laguna Madre, 219

Lake Agassiz, 234

Lake Christina, Minn., 6, 99,
116, 117, 152, 160, 161

Lake Dauphin, 6, 9

Lake Erie, 6

Lake Manitoba, 6, 9, 84, 128-
133, 141, 143, 234

Lake of the Woods, 211

Lake St. Martin, 233

Lake Superior, 211

Lake Winnibago, 8

Lake Winnipeg, 6, 9, 84, 96,
99, 102, 121

Lake Winnipegosis, 6, 96, 108

Landing, 55, 61, 66-72

Landmarks, 82-85, 101-102,
154-156, 178-179, 222

Latitude and longitude, sun as
cue to, 159-162, 192, 198-
204

Leach's Petrel, 200

Leadership, in migration, 110,
206, 220

Learning, 14-28: definition, 14;
to eat, 16-18; to fly, 17; iden-
tity of eggs and young, 19,
42; from companions, 26-28,
110, 206, 217-236; location
of nest, 42-43; identity of
mate, 42, 52; identity of
mother, 49-52, 205; latent,
144

298

Lesser Black-backed Gull, 198-
199

Lesser Scaup. See Scaup, Less-
er.

Lesser Snow Goose. See Goose,
Lesser Snow.

Libau Marsh, Manitoba, 6, 96,
99, 121, 128, 131

Little Brown Crane, 240

Long Island, N.Y., 112

Longspur, 168

Long-tailed Jaeger, 185

Loon, Common, 173

Louisiana, 103, 105, 147

Lower Souris Refuge, 102, 112,
175

Macdonald, Manitoba, 171

McGinnis Slough, 111., 110-112,
147

Mackenzie River, 123

Magnetic awareness, 186, 191,
193

Magpie, 241

Mallard, 5, 8, 10, 18, 21, 23, 24,
26, 27, 35, 59, 60, 62, 79,
248: vocabulary, 22; reaction
to enemy, 24, 35, 37-38; eye
construction, 29, 30, 34; ju-
venile environment, 39; terri-
torial defense, 40; prospective
actions, 53-54; stubble flights,
73-78, 82, 195; migration, 90,
92, 95, 101, 104, 107-113,
115, 118-119, 122, 125-127,
133, 140-142, 145, 148, 179;
restocking, 222, 236; wildness,
224; pioneering, 228-229;
nesting, 242; domestic strains,
236, 237; hunting of, 255

Man: air flights, 33, 57, 63-64,
151, 155-157; memory, 47-
49; awareness of sun, 156-162,
202; sensitivity to magnetic
field, 191; orientation of,
192-193, 201-204; orientation
experiments with, 195, 201;
traditions of, 220-221

Manx Shearwater, 198, 199

Maps: Delta Marsh, 9; standard
fall directions, 96; overland
pass, 101; weather, 105, 119,
210; wanderings of Blue-
winged Teal, 112; standard
spring directions, 117; deflec-
tion of migrants around Lake
Manitoba, 130; dispersal of
young ducks from South Da-
kota, 145; Manitoba travel

horizons, 157; North Pacific
Ocean, 178

Marsh Hawk, 13, 62

Maryland, 230

Massachusetts, 167

Mating. See Breeding behavior.

Maturation, 15-17

Meadow Mouse, 13, 149

Meadowlark, 233

Memory, 46-54, 156, 162, 205

Merganser, American, 122

Merganser, Red-breasted, 122

Metabolic cue to time, 75-77,
80, 160

Michigan, 105, 248

Migration: nocturnal, 21, 103,
114, 116, 118, 137-138, 165-
174; homing, 46, 92, 121,
126-127, 198, 200, 205, 211,
230, 238; abmigration, 92; di-
urnal schedule, 81, 95-96,
114, 116-118, 129; cycle, 89-
94; broad front, 102-103, 105,
124, 128, 137; distance, 103,
116, 123, 129, 136, 161;
"pressure-pattern," 104-106;
in snow, 106, fog, 163-167,
and rain, 167-169, 174; and
breeding cycle, 107-108, 122-
127; traditional, 111, 137,
206, 207, 217-258 passim;
wandering during, 111, 113,
207-213; reverse, 112-113,
132-133; deflection of, 130,
131, 175, 198, 211; definition,
135; anastrophic, 135-139;
diasporic, 135-146; molting
shifts, 139-144, 205; dimen-
sions of, 149-157; hazards of,
163-176; over cloud, 169-
170; oceanic, 177-185; radar
influence on, 189-191; of fish,
209; of captive-reared ducks,
236. See also Age as deter-
minant, Altitude of flight,
Atmospheric pressure, Fall
migration, Navigation, Orien-
tation, Sex as determinant,
Spring migration.
Migrational drift: with bad
weather, 175, 198; with
movement of air masses,
208-213, 234
Migratory divide, 121, 130-131
Minnedosa, Manitoba, 171, 256
Minnesota, 6, 99, 102, 105, 116,
117, 120, 129, 152, 160, 161,
168, 195, 228, 243-248, 250,
251, 253, 257

Mississippi Valley, 100, 121,

170, 198, 243, 244
Missouri, 105, 127, 244
Molting shift, 139-144, 205
Montana, 248, 257
Morris, Manitoba, 117, 131
Mottled Duck, 239-240

Natal environment, 39, 50-52,
83, 86, 195-196, 238, 241-
242

Navigation, 192, 194-205: by
reference to sun, 37, 84, 156-
162, 192, 197-204, 212; in
wind, 55-61, 97, 184; by cal-
culated course, 58; by duf-
fer's course, 58-59. See also
Migration, Orientation.

Nebraska, 105, 247, 248, 257

Neepawa, Manitoba, 171

Nest, nesting behavior: build-
ing, 16; identity of eggs, 19,
42; incubation, 19, 125; mov-
ing of nest, 19; requirements
for cover, 39, 42, 242; of cap-
tive-reared birds, 39, 235-
236; territory, 40-41, 85, 126,
140; orientation, 43, 53-54,
202; schedule, 123-124; ap-
petitive behavior, 124-126;
renesting, 125, 256; clutch
size, 256. See also Breeding
behavior, Breeding range.

Netley Marsh, Manitoba, 6, 82

Nevada, 248

New York State, 112, 121, 173,
217, 225, 230, 235

Newdale-Erickson district, Man-
itoba, 256

Night migration, 21, 103, 114,
116, 118, 137-138, 165-174

Noddy Tern, 198

Nomenclature of birds, 284

North Dakota, 102, 116, 119,
124, 148, 195, 248-251, 257

Northern Eider, 240

Northwest Territories, 251

Oak Lake, Manitoba, 228

Ocean: migration over, 177-
185; Pacific, 177-179, 181-
183, 202, 208; Atlantic, 180-
181, 185, 208

Ohio, 12, 99, 100, 105, 165

Old Squaw, 253

Ontario, 211, 250

Oregon, 248, 257

Oregon Junco, 123

Orientation, 30, 82-86, 110,

151-162, 177-185, 192-213:
of duckling, 39, 50-52, 83,
86, 195-196, 257; of nesting
hen, 43, 53-54, 202; of blind-
folded bird, 64-72; of man,
192-193, 201-204. See also
Awareness of direction, Mi-
gration, Navigation, Percep-
tion.

Oriole, Baltimore, 138, 144

Osprey, 225

Otolith organs, 62

Overcast, influence of: on flight
schedule, 73; on orientation,
98, 104, 106, 161-162, 194,
197-201

Owl, Great Horned, 62

Pacific Eider, 240

Pacific Ocean, 177, 179, 181-
183, 202, 208

Pair formation, 16, 92, 236, 239

Paroquet, Carolina, 246

Parallax, 32-33

Parent-child relation, 17, 19,
49-52, 92-94, 127, 206, 226,
240

Partridge, Hungarian, 228

Passenger Pigeon, 243, 256

Pecten, 34, 36-37

Pelican, White, 119

Pennsylvania, 100

Perception: of companions, 20-
28, 40-45; of depth and dis-
tance, 30-34; of color, 36; of
movement, 37-38; of specific
environment, 39-42; of wind,
55-72, 197, 205-213; of
guides to travel, 82-86, 154-
156, 179-183, 194-205; of
magnetic pole, 186, 191, 193;
of radar and radio waves,
186-191; of Coriolis force,
187, 194, 200. See also Aware-
ness.

Perceptual world, 29-45, 73-86

Petrel, Leach's, 200

Pheasant, English, 234

Pigeon, Domestic (Homing),
186-187, 190, 197-201

Pigeon, Passenger, 243, 256

Pigeon Hawk, 34, 35

Pine Siskin, 233

Pink-footed Goose, 139

Pintail, 5, 8, 18, 21, 22, 26, 62,
66, 68, 248: juvenile environ-
ment, 39; nesting, 39, 242;
stubble flights, 75, 222; mi-
gration, 107-109, 115, 118,

SUBJECT INDEX

119, 122-123, 133, 136, 139-
142, 145, 177, 179, 184, 198,
239; transplanting, 235; hunt-
ing of, 255

Pioneering, 52, 227-236

Plover, Black-bellied, 12

Plover, Golden, 144, 171, 183

Plover, Binged, 43

Plover, Upland, 234, 247-248

Plumage. See Eclipse plumage
and molt.

Polynesians, 202

Population, breeding densities,
249-252

Portage la Prairie, Manitoba,
123

Portage Plains, Manitoba, 119,
229

Post - breeding dispersal, 107-
109, 139-144

Pothole region as breeding
range, 249-252

Prairie Chicken, 228, 246

Pre-Cambrian Shield, 96, 211

Pressure-pattern flying, 104. See
also Atmospheric pressure.

Prospective behavior, 53-54

Psi, 193

Pymatuning Lake, 100

Babbit, Cottontail, 228

Bacial variation, 237-242

Badar and radio, influence on
birds, 186-191

Bandom movement, 200. See
also Wandering.

Baven, 246

Bed Biver of the North, 102,
121, 131, 229

Bed-backed Shrike, 190

Bed-breasted Merganser, 122

Bedhead, 8, 22, 24, 26, 62, 66-
68, 79, 234, 248: juvenile en-
vironment, 39; migration, 95,
104, 108-109, 120, 122, 144,
167, 175; wintering grounds,
219; nesting, 223; pioneering,
228-229; hunting of, 254-255

Bed-tailed Hawk, 119, 133, 171

Bed-wing. See Blackbird, Bed-
winged.

Belativity: of space, 86; of time,
86, 151-156; of motion, 86,
149-156, 172, 177, 183-185

Beleasers, social, 22-27, 42-45

Bemating, 126

Benesting, 126, 256

Bennie, Manitoba, 242

Beproductive cycle, 107-108,

299

TRAVELS AND TRADITIONS OF WATERFOWL

122-127. See also Breeding

behavior.
Restocking, 222, 234-236
Retentiveness, 46-54, 156, 162,

205
Retina, 33-37
Reverse migration: spring, 132-

133; fall, 112-113
Richardson's Goose, 116, 119,

120, 138
Ringed Plover, 43
Ring-necked Duck, 112, 122,

147, 230, 239, 248
Rivers, as migratory route, 101-

102
Robbing of milk bottles, 222
Robin, 132, 164, 171, 233, 237
Robin, European, 79
Rook, 99

Rough-legged Hawk, 119, 129
Ruddy Duck, 93, 122, 248

St. Jean Baptiste, Manitoba, 122
Salmon, Chum, 69, 209
San Francisco Bay, 222, 242
Sandhill Crane, 119, 240, 246
Saskatchewan, 124, 129, 166,

175, 228, 229, 250-251
Saskatchewan River, 155
Scaup, Greater, 167, 219
Scaup, Lesser, 8, 10, 26, 61,
248; migration, 90, 95, 102,
104, 107-109, 122, 165-167
Scoter, White-winged, 23, 121,

122
Semicircular canal, 62
Sense: of time, 81; of direction,

192; sixth, 192
Sex, as determinant in differen-
tial migration, 92, 107-109,
139-144
Sexual cycle, 107-108, 122-127
Sharp-shinned Hawk, 138
Sharp-tailed Grouse, 224
Shearwater, Manx, 198, 199
Sheld-duck, Common, 142
Shooting season. See Hunting.
Shoveller, 92, 108, 109, 119,
122, 140, 145, 177, 189, 229,
239, 248
Shrike, Red-backed, 190
Siberia, drift of North Ameri-
can birds to, 208, 213
Signals, 24-28
Siskin, Pine, 233
Slate-colored Junco, 123
Snipe, Wilson, 62, 66
Snow, migration during, 106
Snow Bunting, 174

300

Snowy Egret, 248

Social inheritance. See Tradi-
tion.

Social releasers, 22-27, 42-45

Solar cue to time, 75, 160

Song, traditional aspects of,
223-224, 242

Song Sparrow. See Sparrow,
Song.

Sooty Tern, 198

Sound spectrograph, 224

South Dakota, 102, 248, 249-
251

Sparrow, English, 62, 65, 66,
67, 69, 70, 71, 228

Sparrow, Song, 119, 198, 222,
223, 224, 233, 237, 238, 242

Sparrow, Tree, 132, 133

Sparrow, Vesper, 232

Sparrow Hawk, 119

Speed of migration, 103, 116,
118, 177. See also Relativity
of motion.

Spicer Marsh, N.Y., 235

Spiral instability, 63

Spring migration, 3-8, 52, 114-
134, 135-136, 148, 164-165,
167, 170-176, 185, 189-190,
198, 200, 205, 211, 229-236,
238: arrival, 3-4, 81, 116,
121, 122, 128; departure, 5,
114-116, 175, 176; flock size,
115-116; standard direction
of, 116-117, 128-130; weath-
er during, 118-120, 127, 131-
133, 136, 164-165, 171-176;
goal of, 126; sexual nature of,
124-127, 205

Standard direction, 96-100, 110,
116-117, 128-130

Starling, 77, 159, 161, 167, 196,
197, 206, 228

Stubble flight, 7, 8, 10, 18, 39,
54, 75-78, 82, 195, 222

Subspecies, 237-242; definition,
237

Sun: as cue to time, 74-77; as
compass, 84, 156-160, 196-
197, 212; as cue to longitude
and latitude, 159-162, 192,
198-204
Susquehanna River, 148, 218,

219
Swallow, Barn, 62, 66, 136,

241
Swallow, Cliff, 225, 227, 228,

232
Swallow, European, 198, 200
Swallow, Tree, 143, 190

Swan, Trumpeter, 236, 244-

246
Swan, Whistling, 3, 22, 31, 53,

100, 116, 119, 120, 122, 167,

253
Swan Lake, Minn., 244
Swift, Alpine, 198
Syria, 246

Tameness in wild ducks, 224,
236

Teal, Blue-winged, 22, 24-25,
46, 59, 62, 67, 69, 248, 255;
migration of, 89, 92, 104,
107-113, 122, 137, 140, 145,
169

Teal, Cinnamon, 248

Teal, Green-winged, 23, 33, 62,
66, 109, 122, 140, 248

Temperature, 107, 137. See also
Weather.

Tern, Arctic, 208

Tern, Noddy, 198

Tern, Sooty, 198

Territory, 40-41, 85, 126, 140

The Pas, Manitoba, 155, 157

Time: awareness of, 73-82, 86,
159-161; relativity of, 86,
151-156

Tit, Great, 222

Tolling, 27

Tradition, 111, 137, 206, 207,
217-258: of food habits, 222;
and song, 223-224, 242; de-
livery of, 226, 238; pioneer-
ing, 227-236; and subspecies,
237-242

Trumpeter Swan, 236, 244-246

Upland Plover, 234, 247-248
Urgency of spring migration,

124
Utah, 139, 168, 248, 257

Vagrancy, winter, 112, 147-148.
See also Wandering.

Vagrants, 233

Valence, 39-45, 205

Vesper Sparrow, 232

Vision, 29-45; binocular, 30;
breadth of, 30, 150; monocu-
lar fixation, 31-33; acuity,
34-36, 150; night, 35; color,
36

Vocabulary, 22-24

Wagtail, Yellow, 222
Waking light, 69
Wandering: of young, 94, 112,
144_147, 207-213; of adults,

112, 147, 148; of nomadic
species, 233

Wapsipinicon River, 101

Warbler, Yellow, 13, 237

Washington, 248

Waterfowl breeding range, 228-
231, 248-251, 256-258; map,
117

Wavie. See Goose, Blue, and
Goose, Lesser Snow.

Weather: during fall migration,
97-99, 104-107, 137, 207-
213; maps, 105, 119, 210;
during spring migration, 118—
120, 127, 131-133, 136, 164-
165, 171-176; during molting
shift, 142; movements, 147;
bad, 163-176; cold front,
171; deflection of migration
by, 175- 198; November pat-
tern, 210; influence on pio-
neering, 234

Western Grebe, 143

Whistling Swan. See Swan,
Whistling.

White Horse Plains, Manitoba,
128

White Pelican, 119

White-fronted Goose, 122, 138,
175

Whitemud River, Manitoba, 78,
129-130

Whitewater Lake, Manitoba, 6,
9, 102, 140

White-winged Scoter 23, 121,
122

Whooping Crane, 225, 236

Widgeon, 18

Wildness, 224

Wilson's Snipe, 62, 66

Wind: perception of, 55-72,
197; during migration, 97,
104-107, 116-120, 131, 170-
172, 175, 184, 207-213; in-
fluence on travel dimensions,
151, 153; rdation to pressure

SUBJECT INDEX

areas, 104-107, 118-120,

207-213, 234
Wing load, 69
Wing slot, 64
Winglet, 64-65
Wintering grounds, 206, 207,

218-220, 225, 238-240; map,

117
Wisconsin, 8, 107, 167, 233,

246, 248, 250, 257
Wood Duck, 18, 248
Woodcock, 79
Woodcock, European, 118
Woodpecker, Downy, 237
Wyoming, 244, 248

Yearling, 127, 227
Yellow Wagtail, 222
Yellow Warbler, 13, 237
Yellow-legs, Lesser, 144
Young birds. See Duckling, Ju-
venile, Parent-child relation.
Yukon Territory, 251

301

NATURE

Travels and Traditions of Waterfowl

by H. Albert Hochbaum

With the combined talents of naturalist, writer, and artist,
H. Albert Hochbaum captures the varying moods of earth
and sky and spirit of flight. For many years as director
of the Delta Waterfowl Research Station in Manitoba, Can-
ada, he has observed the ways of the waterfowl. In this book
he portrays and discusses the flights and habits of the
birds he has watched in that vast marsh country — the wild
ducks, geese, and swans of North America.

"The entire work is in lay language with a delightful
blend of the experiences of the naturalist and hunter with
those of the scientist." Science,

This book is the winner of a publication award of the
Wildlife Society. It is recommended by the American Asso-
ciation for the Advancement of Science in its A A AS Sci-
ence Book List for Young Adults,

UNIVERSITY OF MINNESOTA PRESS

Minneapolis