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SANDHILL CRANE STUDY IN THE CENTRAL FLYWAY

'H<^,\

UNITED STATES DEPARTMENT OF THE INTERIOR

FISH AND WILDLIFE SERVICE
BUREAU OF SPORT FISHERIES AND WILDLIFE

SpiciaJ Scientific Report— Wildlife No. 113

United States Department of the Interior, Stewart L. (Jdall, Secretary

Stanley A. Cain, Assistant Secretary for Fish and Wildlife and Parks

Fish and Wildlife Service, Clarence F. Pautzke, Commissioner

Bureau of Sport Fisheries and Wildlife, John S. Gottschalk, Director

SANDHILL CRANE STUDY IN THE CENTRAL FLYWAY

By

Raymond J. Buller, Wildlife Biologist

Special Scientific Report— Wildlife No. 113
Washington • December 1967

CONTENTS

Page

Abstract 1

History of study 2

Objectives 2

Plan of study 3

Results of study 3

Fall migration 3

Peak population at congregation sites 5

Racial composition of migrating sandhill cranes 6

Correlation of fall migration of sandhill and whooping cranes. . 9

Crop depredations by sandhill cranes 12

Management implications of study , . . . . 13

Whooping cranes 13

Greater sandhill cranes 14

Lesser sandhill cranes 15

Summary 15

References 16

ii

SANDHILL CRANE STUDY IN
THE CENTRAL FLYWAY

By Raymond J, BuUer, Wildlife Biologist

Abstract.-Fall-migiating sandhill cranes arrived at congregation sites in southern Canada and in
the States of the Central Flyway between late July and early October. Sandhills peaked at about
100,000 birds at way stations in Saskatchewan during the fall of 1962. A similar peak was recorded at
stateside way stations during the fall of 1964. Footprint measurements indicated that the lesser
sandliill was by far the most numerous subspecies at way stations in Montana, North Dakota, South
Dakota, and Colorado. These measurements also indicated that flocks stopping over in Wyoming,
Kansas, and Oklahoma contained a significant number of the Canadian sandhill or the greater sandhill
or both. A selective collecting program indicated that the footprint measurement technique
overemphasized the incidence of the greater sandhill at way stations in North Dakota and South
Dakota. Whooping cranes and sandhills were occasionally observed together during the early part of
the fall migration. At times, fall-migrating sandhills fed on standing and harvested grain crops in
Canada and in the States of the Central Flyway, but seldom were depredations considered serious.

Cranes (the family Gruidae) are protected
internationally under the migratory bird con-
ventions between the United States and Canada
(1916) and between the United States and
Mexico (1937). Hunting of migratory birds in
the United States is regulated by the Migratory
Bird Treaty Act (40 Stat. 755; 16 U.S.C. 703)
which gives effect to the international treaties.

The treaty with Canada in 1916 listed
"Gruidae or cranes, including little brown,
sandhill, and whooping cranes." Subsequently,
the little brown and sandhill cranes were shown
to be subspecies of a single species (Ober-
holser, 1921), and it was shown also that there
are intermediates between the lesser and
greater subspecies. The "little brown crane"
is now called the lesser sandhill crane and the
"sandhill crane" is now called the greater
sandhill crane. The intermediate population
has been described and named the Canadian
sandhill crane (Walkinshaw, 1965). Another
subspecies in the United States, the Florida
sandhill crane, is outside the concern of this
report.

A general closed season was established on
all cranes in the United States, May 20, 1916,
and remained in effect until January 1, 1961,
when a 30-day season was authorized on lesser
sandhill (little brown) cranes in eastern New

Mexico and western Texas. Sandhill cranes
have been hunted in Mexico for years. During
the fall of 1959, Saskatchewan farmers were
permitted to shoot these birds under general
crop depredation orders.

This report summarizes the results of the
4-year (1962-65) study designed to determine
the feasibility of extending the hunting of
lesser sandhill cranes to other States of the
Central Flyway. An earlier paper summarized
the results of the first 3 years of the study
(Buller and Boeker, 1965).

This report is possible because of the efforts
of many individuals throughout the Central
Flyway who painstakingly collected data for the
study. I am especially grateful to AlexDzubin,
W. R. Miller, and W. J. D. Stephen, Canadian
Wildlife Service, for supplying data from the
Prairie Provinces; to U.S. Game Management
Agents W. Ashton Brann, Harry A. Jensen,
David W. Fisher, R. E.Meyer, Loren J. Bonde,
Charles R. Hayes, H. B. Lyman, and Alfred J.
Robinson, Jr., for coordinating the study within
their assigned districts; to Research Biologist
Jerome H. Stoudt for collecting many of the
cranes; and to numerous national wildlife
refuge managers and State technicians for
supplying fall migration and population data
and footprint (midtoe) measurements.

HISTORY OF STUDY

For many years the Central Flyway Water-
fowl Council requested an open season on
sandhill cranes. In 1960, the National Flyway
Waterfowl Council joined the Central Flyway
Council in its request for consideration of a
limited season on lesser sandhill cranes in
the United States. The Saskatchewan Depart-
ment of Natural Resources and the Canadian
Wildlife Service recommended favorable con-
sideration of the Councils' proposal. Studies
by Aldrich and Burleigh (1958), Huey (1960),
and Allen (1952) concluded that few, if any,
greater sandhill cranes or whooping cranes
occur in the proposed hunting area in eastern
New Mexico and extreme western Texas. In
view of these considerations, the Secretary of
the Interior authorized the first hunting season
on lesser sandhill cranes in these portions of
New Mexico and Texas.

of the hunting area would not jeopardize the
endangered whooping cranes.''"

These internationally famous birds have
been sighted in Montana, North Dakota, South
Dakota, Nebraska, Kansas, Oklahoma, Sas-
katchewan, and Alberta during fall migration.
Sandhill cranes stop over in many of these
same areas.

Another consideration of extending the range
of the lesser sandhill crane hunting season con-
cerned the incidence of the rare greater sandhill
crane. The greater race was present in col-
lections of cranes made by T. D. Burleigh in
the Horsehead Lake region of south-central
North Dakota during the fall of 1959 and I960.
The possibility that this race may be present
in other areas favored by fall-migrating lesser
sandhills was also recognized.

The first lesser sandhill crane season was
held in eastern New Mexico, January 1 to 30,
1961. Texas was unable to participate at that
time since cranes were not classed as game
birds by State statute. This was followed by 30-
day seasons in Alaska (September 1-30) and in
New Mexico and West Texas (November 4-
December 3) in 1961. Similar seasons have
been authorized in succeeding years with
minor changes. The area open to hunting in
New Mexico and Texas was enlarged slightly,
and the hunting period in Alaska was increased
to 45 days during the 1964-65 waterfowl sea-
son. Residents of Saskatchewan and Manitoba
have been permitted limited seasons on sand-
hill cranes each year since 1964.

Harvest data obtained during the 1961 lesser
sandhill crane seasons in New Mexico and
Texas (Boeker, Aldrich, and Huey, 1961;
Boeker, Huey, and Uzzell, 1962) prompted the
Central Flyway Waterfowl Council to request
an enlargement of the hunting area at its
August 1962 meeting. The resolution proposed
that the Council and the Bureau explore the
feasibility of extending the season to other
States of the flyway. It was agreed that before
this proposal could be accepted it would be
necessary to firmly establish that enlargement

OBJECTIVES

The objectives of this study were —

1 . To determine the number, time of arrival,
and departure of sandhill cranes through-
out the Central Flyway (New Mexico and
Texas excluded) during fall migration.

2. To locate the major congregation areas
of sandhill cranes in the Central Flyway
during the fall migration.

3. To determine the racial composition of
sandhill crane flocks in the Central Fly-
way during the fall migration.

4. To correlate data concerning the fall
migration of sandhill cranes and whoop-
ing cranes in the Central Flyway.

5. To locate and document crop depredations
by sandhill cranes during the fall migra-
tion.

* The whooping crane is classed as endangered and
the greater sandhill as rare in Rare and Endangered
Fish and Wildlife of the United States, U.S. Bureau of
Sport Fisheries and Wildlife, Resource Publication 34,
July 1966.

PLAN OF STUDY

Standard waterfowl survey techniques were
used to gather data for objectives 1, 2, 4, and
5. Information pertaining to the racial com-
position of fall-migrating cranes (objective 3)
was obtained from a selective collecting pro-
gram and a recently developed field technique
which involves measuring footprint impres-
sions.

In 1960 and 1961, 302 sandhill crane foot-
print measurements were obtained on Bitter
Lake and Bosque del Apache National Wildlife
Refuges in New Mexico (U.S. Bureau of Sport
Fisheries and Wildlife, 1961). Measurements
were made from the posterior edge of the ball
of the foot to, but not including, the claw of
the anterior end of the midtoe. At Bitter Lake,
a known wintering area for sandhill cranes
which are almost exclusively lessers, 160
measurements ranged from 76 mm. to 95 mm.
in length and averaged 86.5 mm. At Bosque del
Apache, a wintering area for sandhills which
are predominantly greater, 142 measurements
ranged from 100 mm. to 123 mm. and averaged
HI mm.

These data suggested that footprint measure-
ments could be used to grossly separate the
greater sandhill crane from the lesser race.
But the Canadian race confounds the issue.
Footprint measurements known to be from
this race are not available. Consequently, the
possibility exists that this subspecies is in-
cluded with either the greater or the lesser
race or both when they are separated on the
basis of footprint measurements alone.

RESULTS OF STUDY

Fall migration

Fall-migrating sandhill cranes were ob-
served at congregation areas (sometimes
called way stations or stopover areas) in south-
ern Canada and in the northern States of the
flyway between late July and early October
(fig. 1). Migration data indicated that first
migrants are erratic and sometimes over-fly
congregation sites in Saskatchewan en route
to sites in McLean, Kidder, and Stutsman

Counties, North Dakota. From there the mi-
gration proceeds in a more orderly fashion to
the wintering grounds in New Mexico and
Texas.

First arrivals reached congregation sites
in Alberta, Saskatchewan, and Manitoba be-
tween early August and mid-September, Ear-
liest observations of migrants reaching the
Grassy Island-Gooseberry-Sound Lake region
near Consort, Alberta, and the Kindersley
District, Saskatchewan, occurred from late
August to mid-September. They were preceded
by migrants reaching the Last Mountain-Quill
Lakes region of south-central Saskatchewan
and the Big Grass Marsh area of Manitoba in
the forepart of August. Fall migrants reached
Montana and southeastern Wyoming 1 or 2
months later.

Migrating sandhills arrived in Kidder and
Stutsman Counties and the Turtle Lake region
of McLean County, North Dakota, between mid-
July and mid-September. That segment of the
population which used the Missouri River
between Montana and the Nisson Bottoms east
of Williston arrived the latter part of Septem-
ber.

Sandhill cranes arrived in the Pollock-
Mobridge area of South Dakota about Septem-
ber 10 each year. The DeGrey area was used
as a way station until it was inundated in 1964
by Big Bend Reservoir. Fall- migrating sand-
hills rarely stopped over in Nebraska.

First arrivals reached Prewitt Reservoir
(Washington County), Bonny Reservoir (Yuma
County), and the Arkansas Valley, Colorado,
between mid-September and mid-October. Ar-
rivals at Kirwin and Quivira National Wildlife
Refuges, Kansas, and Salt Plains and Washita
National Wildlife Refuges, Oklahoma, occurred
between early October and late November.

In most instances the fall migration proceeds
at a leisurely pace, and the numbers found at
congregation sites build up over a period of
several weeks. Sandhills depart Canadian way
stations in mid-October. Departures from con-
gregation sites within the States occurs
throughout November and the forepart of De-
cember. The fall migration is sometimes
hastened by late fall and early winter storms.

V-/ Congregation area or way station

Figure 1. — Sandhill crane arrival dates at congregation sites, 1962-65.

4

Peak populations at congregation sites

Peak populations of sandhill cranes at fall
congregation sites were recorded 3 to 8 weeks
after the arrival of the first migrants (table 1).
Peak numbers differed between years as did the
period of use and length of stopover.

In 1962, an estimated 100,000 sandhills were
recorded at the Saskatchewan congregation
sites the last week of September. Peak num-
bers using the Last Mountain- Quill Lakes
complex fluctuated between 7,000 in 1963 and
35,400 in 1965. Cranes using the Big Grass
Marsh area of Manitoba ranged from 3,200 to
5,000 birds.

The greatest number of cranes stopping
over in Kidder and Stutsman Counties, North
Dakota, ranged between 8,000 and 16,000
birds. Sandhills using the McLean County way
station peaked at 7,000 in 1964.

Migrating sandhills stopping off at way sta-
tions in Montana peaked at 5,000 to 17,500
birds. Departures in 1962 and 1963 ranged
from early November to early December.

Similarly, Wyoming did not host large num-
bers of fall-migrating sandhills. Reservoirs
in Albany, Platte, and Goshen Counties served
as way stations for 1,600 to 6,000 birds.

Table 1. — Peak populations at fall congregation areas

Location

1962

Date

Number

1963

Date

Number

1964

1965

Date

Number

Date

Number

Alberta:

Grassy Island

Saskatchewan:

Kindersley District

Last Mtn. -Quill Lakes

So. Saskatchewan R

Manitoba:

Big Grass Marsh

Montana:

Bowdoin NWR

Medicine Lake NWR

G. M. Russell NTO

North Dakota:

Kidder & Stutsman Cos

McLean County

South Dakota:

Mobridge-Pollock

Nebraska:

Western portion

Wyoming:

Southeastern portion

Colorado :

Prewitt Reservoir ,

San Liois Valley ,

Arkansas Valley ,

Kansas:

Kirwln NWR ,

Quivira NWR ,

Oklahoma:

Washita NWR ,

Salt Plains NWR ,

Red River (Jackson Co.)...<
Cimarron River (Major Co.),

9/23-29
9/23-29
9/23-29

11/9
10/12-18

10/20
10/28

50,000
25,000
25,000

3,200

4,500

2,000

5,000

11,000

10/18

20,300

10/9

9/25-10/2
10/11

9/5

10/20-26
10/23

10/12-22
9/26

10/30

10/30

10/21

11/1
10/20

11/7
11/6

12/6-U
11/6

3,000

13,000
7,000

4,000

5,000
1,000

12-15,000
4,800

12-18,000

3,000

1,600

20,000
2,000

250
810

7,000
2,000

9/3

10/8

10/15

10/11

10/5
11/2

10/17
10/10
10/9

10/4
10/12

10/6

11/25

10/20

11/1-15

11/1-15

5,000

3,000

10,000

4,500

16,000
7,000

9,500

1,200

5-6,000

3,000
500

1,850

15,000
7,900
7,500
2,500

9/6

9/28

10/11
9/25

10/20
9/8

10/15

10/9
9/15
10/17

10/16

10/9

10/20

35,415

4,420

5,000
250

14,000
2,000

3,500
2,750

5,000
3,000
1,000

3,000

2,600

600

Fall migrants using the Mobridge- Pollock
way station in South Dakota peaked at about
18,000 in 1963. In 1965, 3,500 birds was the
greatest number recorded in that area.

Western Nebraska is not an important way
station for fall- migrating sandhills. The peak
number of birds stopping off ranged from
1,200 to 3,000, and then only for a few days.

Sandhills using Prewitt Reservoir, Colorado,
peaked at about 20,000 birds in 1962 and 1963.
In 1962, these birds stopped off for about 1
week, whereas the 1963 migration used this
way station for about 4 weeks. The 1964 and
1965 fall migrations practically bypassed
Prewitt Reservoir, with but 5,000 birds stop-
ping overnight in 1965. Bonny Reservoir and
the Arkansas Valley serve as way stations
for smaller numbers (500 to 2,000) of mi-
grating sandhills. Kansas way stations also
host small numbers of cranes.

Congregation sites in Oklahoma were used
both as way stations and wintering areas by
various segments of the migrating population.
In 1963 and 1965, the sites were used pri-
marily as way stations, and the population
peaked at 2,000 to 7,000 birds. Aerial surveys
conducted between October 1964 and January
1965 indicated that the population peaked at
about 30,000 in early November (Gilliam,
1966). During the last 2 weeks of December
1964, 14,000 cranes were counted in western
Oklahoma. Of these birds, 4,000 wintered on
Washita National Wildlife Refuge.

Population surveys which were conducted 1
to 2 days before the season in those portions
of New Mexico and Texas open to the hunting
of lesser sandhill cranes indicated a popula-
tion ranging from 185,000 to 214,000 birds in
late October, 1962 through 1965.

Racial composition of migrating
sandhill cranes

A total of 3,981 sandhill crane footprints
(midtoe) were measured as an aid to deter-
mining the racial composition. These were
obtained on refuges, lakes, reservoirs,
sloughs, sandbars, mud flats, and grainfields
within the areas of greatest use (table 2). These

measurements indicate that the cranes^ using
the principal way stations in the Central Fly-
way have the following composition:

Bowdoin National Wildlife Refuge and vicin-
ity, Montana (294 measurements): 73% lesser j
27% greater.

Kidder and Stutsman Counties, North Dakota
(960 measurements): 86%lesser; 14%greater.

McLean County, North Dakota (279 measure-
ments): 92% lesser; 8% greater.

Campbell and Walworth Counties, South
Dakota (726 measurements): 97% lesser; 3%
greater.

Goshen County, Wyoming (157 measure-
ments): 59% lesser; 41% greater.

Prewitt Reservoir, Colorado (550 measure-
ments): 100% lesser.

Arkansas Valley, Colorado (147 measure-
ments): 92% lesser; 8% greater.

Kirwin and Quivira Refuges, Kansas (347
measurements): 50% lesser; 50% greater.

Washita Refuge, Oklahoma (200 measure-
ments): 68% lesser; 32% greater.

Salt Plains Refuge, Oklahoma (137 measure-
ments): 50% lesser; 50% greater.

Red River bottoms, Oklahoma (142 measure-
ments): 77% lesser; 23% greater.

Measurements obtained during August, Sep-
tember, and October in Kidder and Stutsman
Counties, North Dakota, were analyzed to
determine whether the races of sandhill
cranes show different migration patterns. Of
277 measurements obtained in August and
September, 18% fell within the range of the
greater race; of 683 obtained in October, 13%
fell within the range of this race. This in-
dicates that the sandhill crane population
that occurs in Kidder and Stutsman Counties
during October may contain fewer greaters
than the August and September population.

^ The number of Canadian sandhills that may be in-
cluded in these measurements is unknown.

Table 2. — Sandhill crane footprint measurements at fall congregation areas

Location

Montana :

Bowdoin NIIVR

10 mi. S. Bowdoin NTO..

North Dakota:

Kidder & Stutsman Cos.

Do

Do

Do

Do

Do

McLean County.

Do

Do

South Dakota:

Can^Jbell & Walworth Cos

Do

Do

Do

Do ,

Wyoming:

Goshen Coimty

Do

Colorado:

San Luis Valley

Prewitt Reservoir

Do

Arkansas Valley

Prewitt Reservoir

Do

Kansas:

Phillips County

Stafford Coimty

Oklahoma:

Custer County

Do

Jackson County

Alfalfa County

Jackson County

Date

Oct. 1963
Oct. 1965

Oct.

Sept,

Oct.

Aug.

Sept,

Oct.

Sept,

Oct.

Fall

1962

1963
1963
1964

196<i
19&i

1964
1964
1964

Sept. 1962
Oct. 1963
Nov. 1963
Sept. 1964
Oct. 1964

Oct. 1963
Oct. 1964

Oct. 1962

Oct. 1962

Oct. 1963

Nov. 1963

Oct. 1964

Oct. 1965

Nov. 1963
Oct. & Nov. 1964

Nov. 1963
Dec. 1964
Fall 1964
Oct. & Nov. 1965
Nov. 1965

Assumed to be-

Lesser sandhills

Number

56
158

262
91

261
7

129
74

136

105
15

112

243

63

17

268

47
45

100
300
135
100
50

20
154

93
43
31
69
78

Range
in mm.

80-95
71-91

74-95
71-95
71-95
76-91
63-95
72-95
68-95
73-90
78-92

68-92
68-95
74-95
73-93
68-95

70-95
87-95

74-95
72-95
59-95
74-95
74-97

74-94
81-95

73-95
85-95
81-95
80-95
76-95

Average
in mm.

90.7
81.6

85.8
86.3
86.1
84.4
82.6
88.8
85.1
82.6
85.9

80.5
82.5
86.3
85.9
85.7

87.1
92.6

85.4
85.6
84.5
85.0
85.0

89.6
91.2

87.8
92.2

90.0
89.0

Greater sandhills

Number

78
2

23

12

32

1

37

31

17

5

1

12
2
3
6

3
62

42

12

89
84

7
57

7
68
26

Range
in mm.

96-116
96

96-103
96-105
96-103

97
96-110
96-103
96-104
97-99
100

96-103

98
96-98
96-100

98
96-115

95-113

96-104

96-114
96-106

96-98

96-112

96-128

95-119

95-130

Average
in mm.

103.3
96.0

101.8
98.9

100.4
97.0

100.2
98.7
99.2
98.6

100.0

100.6
98.0
96.6
97.1

98.0
101.1

102.3

99.8

102.2
98.6

96.7
100.1

100.4
104.0

The possibility that the footprint measure-
ment of juvenile greater sandhills might fall
within the range of those of the lesser was
also investigated, since this could render the
footprint measurement technique invalid for
separating races. At Monte Vista National
Wildlife Refuge, Colorado, midtoe measure-
ments were obtained from 11 greater sandhills
hatched from eggs gathered at Malheur National
Wildlife Refuge, Oregon. Measurements ob-
tained at 49 to 57 days of age ranged from 97
to 108 mm. (average 103.6 mm.). At 79 to 88
days of age, the measurements ranged from 98
to 112 mm. and averaged 106.4 mm. (Knoder,
1964). It was concluded, therefore, that the

footprint measurement technique can be used
to grossly distinguish juvenile as well as adult
greater sandhill cranes from lesser sandhills.

Stephen, Miller, and Hatfield (1966) con-
cluded that there was too much overlap in the
measurements (mean weights and mean values
for total length, tarsus, midtoe, bill, and
culmen) between adult females and adult males
taken at Last Mountain Lake, Saskatchewan,
to make these values useful in sex determi-
nation. Moreover, they concluded that sex
differentiation was essential for taxonomic
purposes. I agree that sex determination as
well as diagnostic measurements are desirable

for classification purposes, but this in no
way detracts from the fact that midtoe meas-
urements provide a usable field technique for
the gross separation of greater and lesser
sandhill cranes. This contention is supported
by the midtoe measurements obtained at
Monte Vista, Bosque del Apache, and Bitter
Lake Refuges.

Data on the racial composition of fall-
migrating sandhill cranes are also available
from a selective collecting program during
and preceding the study. Birds were collected
with a high-powered rifle equipped with a
telescopic sight, and the collector was in-
structed to take only the "larger-appearing
birds." Therefore, the birds collected during
the study do not represent a random sample
of the population. This selective technique
probably resulted in the collection of propor-
tionately more greater sandhills than normally
occur in this population.

Because of these collections, the diagnostic
characters (sex, weight, age, and measure-
ments— wing chord, tarsus, midtoe, and cul-
men) of 93 birds were made available for
racial determination purposes (table 3).
Eighty- eight birds were collected during the
study, and five were illegally killed. They
were distributed as follows: North Dakota,
61 in Kidder, Stutsman, McLean, and Ramsey
Counties; South Dakota, 22 from the Pollock-
Mobridge area; Oklahoma, 4 from Washita
National Wildlife Refuge and 3 confiscated
from goose hunters in the vicinity of Salt
Plains National Wildlife Refuge; Colorado, 3
from Prewitt Reservoir. Thirty-three of the
birds from Kidder and Stutsman Counties,
North Dakota, were collected in 1965 for a
food habits study (Madsen, 1966).

Racial determinations made by Dr. John W.
Aldrich, Staff Specialist of the Bureau, indicate
that of birds from Kidder and Stutsman Counties

Table 3. — Racial composition of large sandhill cranes, selectively collected, 1962-65

Date

Racial composition

State and area

Lesser

Canadian

Greater

Unclas-
sified

North Dakota:

10/16-19/63
9/8-12/64

10/19-23/64

9/23-24/64

10/21/64

10/2-3/64

9/22/65

10/3-29/65

11/2/65

9/26-10/5/62
10/14-18/63

9/11/64
10/22/64

10/10/65

10/10/64
10/28-11/18/65

4

4
4

1
3

1
4
4
1
1
1
7
20
2

2

1

Do

Do

^ 1

McLean County

Do

Devils Lake, Benson Co

Kidder County

Do

Do

-

Subtotal

South Dakota:

Mobridge

Pollock

Do

Do

16

3
6
2

4

41

1

3
1

3

1
2 2

Subtotal

15
3
3

5
2

0
2

2

Colorado:

Prewitt Reservoir

Oklahoma:

Salt Plains tlWR

Washita !fflR

Total

37

48

5

3

•"■ Typical greater if female; questionable greater if male.

^ Body condition did not permit distinction between Canadian and greater races.

8 were typical lessers, 38 were Canadian
sandhills, 2 were greaters, and 1 was a ques-
tionable greater. Of 10 birds collected in
McLean County, 8 were judged to be lessers
and the other 2 were Canadian sandhills. The
Ramsey County birds were identified as a
Canadian and a greater. Of the cranes taken
in South Dakota, 15 were lessers, five were
Canadian sandhills, and 2 could not be clas-
sified, because of body condition. Oklahoma
birds were identified as follows: Salt Plains
Refuge, 3 lessers; Washita Refuge, 2 Cana-
dians and 2 greaters. The Colorado birds
were judged to be lessers.

Of 13 sandhills collected between October 27
and November 3, 1959, by T. D. Burleigh in
Kidder and Stutsman Counties, North Dakota,

9 were identified as lessers, 3 were judged to
be Canadians, and 1 was a greater. Of 12 taken
by T. D. Burleigh in this area September 9-12,
1960, 10 were identified as Canadians, and 2
were greaters.

Footprint measurements obtained in Sep-
tember indicate that the flocks found in North
Dakota at this time may contain fewer lessers.
This is supported by the collection program
during the study and the collections by T. D.
Burleigh in 1959 and 1960, which suggest that
the lesser race is more numerous in October
than in September, whereas the greater race
is more numerous earlier in the season.

Of the sandhills that were selectively col-
lected during the study, 5 were identified as
greaters, 48 were judged to represent the
Canadian race, and 37 were lesser sandhills.
The condition of 2 birds did not permit clear
distinction between the greater and Canadian
races, and another was placed in a question-
able greater category because its sex organs
were destroyed when it was collected.

Correlation of the fall migration of sandhill
and whooping crones in the Central Flywoy

The most important consideration in ex-
tending the lesser sandhill crane season to
States other than New Mexico and Texas is
the possibility of jeopardizing the endangered
whooping crane. To resolve this problem, all
reported sightings of fall-migrating whooping

cranes (table 4) were checked for authenticity
and correlated with the sandhill migration.

Five verified, three probable, and four un-
confirmed sightings of whooping cranes were
recorded between August 23 and November 30,
1962 (Boeker, 1963). One verified report was
received during the fall of 1963. Seven verified
and three probable sightings were received
between the dates of September 11 and Novem-
ber 3, 1964. Four verified and five unconfirmed
sightings were received between September 26
and November 18, 1965. The location of these
sightings and the verified and probable sight-
ings of migrating whooping cranes during the
fall of 1959, 1960, and 1961 (Boeker, 1960,
1961, and 1962) are shown in figure 2. The
principal congregation areas used by migrating
sandhill cranes are included.

Figure 2 shows that several congregation
sites or way stations are used by both whoop-
ing cranes and sandhill cranes, and these
species occurred simultaneously at several
of the way stations. Following are the way
stations used by all species and the dates of
the earliest and latest observations of whoop-
ing cranes from 1959 through 1965:

Last Mountain Lake-Quill Lakes, Saskatch-
ewan— September 15 and October 20.

Medicine Lake Refuge, Montana — September
26 and October 18.

Missouri River near Williston, North
Dakota — October 18-26.

McLean County, North Dakota — September
21 and November 1.

Kidder and Stutsman Counties, North
Dakota — September 22 and October 4.

Mobridge- Pollock area. South Dakota — Sep-
tember 11 and October 7.

Kirwin and Quivira Refuges, Kansas — Octo-
ber 19 and November 1.

Salt Plains Refuge, Oklahoma — September 26
and November 8.

Table U. — Dates and locations of reported sightings of whooping cranes
during the fall of 1962, 1963, 1964, and 1965

Date

Location

Cranes

Nature of report

1962

Meath Park, Saskatchewan
Snake Creek NWR, N. Dak.
Hampden, Ramsey Co., N. Dak.
Eldridge, Stutsman Co., N. Dak.
Lenore Lake, Saskatchewan
Chappell, Deuel Co., Nebr.
Williston, McKenzie Co., N. Dak.
Garden City, Finney Co., Kansas
Hill City, Graham Co., Kans.
Concordia, Cloud Co., Kans.
Williston, McKenzie Co., N. Dak.
Bevaria, Saline Co., Kans.
Dover, Shawnee Co., Kans.

10 mi. SE of Williston, N. Dak.

4 mi. N. of Huron, S. Dak.

Pollock, Campbell Co., S. Dak.

Des Lacs NWR, N. Dak.

Salt Plains NWR, Okla.

Lake McConaughy, Nebr.

10 mi. N. of Mandan, N. Dak.

Kirwin NWR, Kans.

Vicinity Snake Creek NWR, N. Dak.

Quivira NWR, Kans.

Salt Plains NWR, Okla.

Medicine Lake NWR, Mont.
Vicinity Long Lake NWR, N. Dak.
Vicinity Salt Plains NWR, Okla.
20 mi. SE Medicine Lake NWR, Mont.
13 mi. N, 3 mi. W Alliance, Nebr.
12 mi. N, 5 mi. E, Bassett, Nebr.
Kirwin NWR, Kans.
Quivira NWR, Kans.
Vicinity Panhandle, Carson Co. , Tex.

u

Probable.

1

Verified.

1

Unconfirmed

2

Probable.

7

Probable.

6

Unconfirmed

8

Verified.

9

Unconfirmed

1

Verified.

2

Verified .

4

Verified.

3

Unconfirmed

3

Unconfirmed

3

Verified.

5

Verified.

2

Verified.

3

Probable.

1

Verified.

4

Verified.

3

Probable .

3

Verified.

6

Probable .

3

Verified.

3

Verified.

3

Verified.

1

Unconfirmed

?

Unconfirmed

3

Verified.

1

Unconfirmed

3

Unconfirmed

2

Unconfirmed

3

Verified.

3

Verified.

Fall-migrating whooping cranes have been
observed at several sandhill crane way sta-
tions since 1833. Allen (1952) reported the
earliest and latest observations at sandhill
crane congregation sites in Saskatchewan,
North Dakota, and Kansas thus:

Last Mountain Lake-Quill Lakes, Saskatch-
ewan— Fall and November 3.

Missouri River near Williston, North
Dakota — September 22.

McLean County, North Dakota — September.

Kidder and Stutsman Counties, North
Dakota — September 1 and October 25.

Stafford County (Quivira Refuge), Kansas —
Fall and October 26.

Allen's tabulation includes three historical
records of whooping cranes in the vicinity of
the Mobridge- Pollock, South Dakota, sandhill
crane way station. He cited two from Edmunds
County immediately east of Walworth County.
One is a museum specimen taken October 19,
1883, and one was a bird which was killed in
September 1885. The third bird, from near

10

BRITISH
COLUMBIA

IDAHO

UTAH

ARIZ.

•. •

•SASKATCHEWAN

ALBERTA

MANITOBA

(S)

#

MONTANA

NORTH
ITA

WYOMING

SOUTH DAKOTA

o

NEBRASKA

COLORADO

^

KANSAS

0.

p

NEW MEXICO

OKLAHOMA

TEXAS

MINN.

IOWA

MO.

ARK.

• WHOOPING CRANE OBSERVATIONS SANDHILL CRANES ©FALL H WINTER ^SPRING

Figure 2.— Location of verified and probable sightings of fall migrating whooping cranes, 1959-65, and

sandhill crane congregation areas, 1962-65.

11

Mobridge, is also a museum specimen, but
the date it was taken is lacking. Other his-
torical fall records of whooping cranes in
South Dakota occurred in September and Oc-
tober 1889 and 1890, and September and No-
vember 1891; however, these were in Douglas
County which is about 200 miles southeast of
the Mobridge- Pollock way station.

Allen's historical records do not show fall-
migrating whooping cranes from or near the
present day Medicine Lake Refuge, Montana,
or Salt Plains Refuge, Oklahoma.

Sandhill crane congregation areas lying en-
tirely outside the historical and the 1959-65
fall migration route of whooping cranes in-
clude those on or in the vicinity of Bowdoin
Refuge, Montana; Albany, Goshen, and Platte
Counties, Wyoming; and the San Luis Valley,
Colorado.

Two of the Colorado sandhill crane way
stations — Prewitt and Bonny Reservoirs — are
50-100 miles north, and another, the Arkansas
Valley, is 40-50 miles south of a historical
fall whooping crane sighting. This observation
occurred October 13-17, 1941, on the Kit
Carson Refuge, Cheyenne County, which was
abandoned in 1952.

Crop depredations by sandhill cranes

Recording crop depredations by cranes was
an objective of the coordinated study. Sandhill
crane depredations on grain crops have pre-
viously been documented by Smith and Boeker
(1958), Timmerman (1958), Munro (1950),
Linduska (1949), Sperry (1939), Sooter (1943),
Nelson (1961), and Mackay (1962). In 1959,
Saskatchewan farmers were permitted to shoot
sandhill cranes in the vicinity of Last Mountain
Lake under general crop depredation orders.
The 1961 experimental crane season in New
Mexico and Texas was authorized to alleviate
crop depredations in Saskatchewan and the
northern States of the flyway by reducing the
size of the crane population. The New Mexico
and Texas seasons were followed by limited
seasons in Saskatchewan and Manitoba begin-
ning in 1964.

In 1962, a mail questionnaire survey, which
was conducted throughout the Prairie Prov-
inces of Alberta, Saskatchewan, and Manitoba,

showed that sandhill cranes fed on standing
and harvested cereal crops in the Kindersley,
Last Mountain-Quill Lakes, and Big Grass
Marsh areas (Stephen, 1967). Sandhill cranes
fed on grain crops in the Kidder-Stutsman
County area of North Dakota, but the nature and
extent of the depredations were not learned.
It was also reported that no depredation con-
trol was practiced by farmers during the
goose season in this area, since these control
activities have a dispersing effect upon the
geese. Approximately 30 farmers reported
moderate to heavy crane depredations on corn,
sorghum, and winter wheat and rye in the
Mobridge- Pollock area. South Dakota.

Crop depredations by cranes in Canada dur-
ing the 1963 fall migration were again localized
in the Last Mountain Lake-Quill Lakes area.
The lack of depredation complaints in the U.S.
was attributed to mild, clear weather which
permitted farmers to harvest their crops be-
fore the peak of the fall migration. One com-
plaint of crop depredations by cranes was
registered in the San Luis Valley, Colorado.

In 1964, no complaints of crop depredations
by cranes were registered in the flyway.
Cranes were reported to have fed on swathed
grain in Kidder and Stutsman Counties, North
Dakota. A killing frost in early September
caused farmers to "chop"their corn for silage.
A late August frost and a dry fall accelerated
the grain harvest in South Dakota. Cranes
stopping off in the Mobridge- Pollock area fed
in cornfields containing livestock. In Kansas,
sandhill cranes were observed to feed occa-
sionally in winter wheatfields, but no depreda-
tion complaints were registered. In Oklahoma,
several complaints of damage to winter wheat-
fields were registered in the vicinity of Washita
National Wildlife Refuge. Scarecrows were
effective in controlling depredations.

Several complaints of depredations on
swathed wheat were registered in the Horse-
head Lake area of Kidder County, North Dakota,
in 1965. A permit was issued to combat crane
depredations on cereal grains in the San Luis
Valley of Colorado. In Oklahoma, one complaint
of damage to sprouting winter wheat in the
vicinity of Washita Refuge was registered, but
a storm caused the birds to migrate before
depredations became serious.

12

Sandhill cranes sometimes feed in standing
or harvested cereal grains and sprouting win-
ter wheat. Because of harvest practices, crop
depredations by sandhills are more extensive
in Canada than in the States of the Central
Flyway. In the States, depredations are related
to weather conditions before and during the
harvest period. Depredations are negligible
during years of mild, clear weather which per-
mits farmers to harvest their crops before
the peak of sandhill crane migration. Stephen
(1967) reported that a measure of control over
crane damage at Last Mountain Lake, Saskatch-
ewan, was achieved by the use of acetylene
exploders and lure crops. Too, the number and
frequency of complaints arising from crane
damage in eastern New Mexico and west Texas
have decreased since crane hunting was per-
mitted in 1961. Scarecrows effectively con-
trolled depredations on winter wheat in Okla-
homa. Complaints received during this study
indicate that crop depredations were common
throughout the Central Flyway, but were not a
major problem anywhere.

MANAGEMENT IMPLICATIONS OF STUDY

This study resulted from a proposal that
the Central Flyway Waterfowl Council and the
Bureau study the feasibility of extending the
hunting of sandhill cranes to States of the fly-
way other than where the hunting of these birds
is now permitted. It was recognized that a
decision to extend the sandhill crane season
should be governed primarily by (1) its effect
on whooping cranes during the fall migration,
and (2) the racial or species composition of
sandhill cranes using the principal fall con-
gregation sites.

One of the most important considerations in
extending the hunting of lesser sandhills con-
cerns the endangered whooping crane, and its
population status need not be reviewed here.
Any extension of the hunting season should in-
clude provisions to insure that not one whooper
is lost because of a crane season in the United
States.

The second consideration concerns the rela-
tively rare greater sandhill crane. As recently
as 10 years ago, it was believed that the west-

ern segment of the greater sandhill crane
population numbered about 1,700 birds. Sand-
hill cranes wintering on Bosque del Apache
National Wildlife Refuge, New Mexico, num-
bered 5,500 birds on December 11, 1964, and
these are believed to represent the greater
race predominately. Although the western
population of greater sandhills is larger than
earlier information indicated, the incidence of
the greater race at the principal congregation
sites used by fall-migrating sandhill cranes
was an important facet of the study.

Whooping cranes

The fall migration of the whooping crane is
sometimes coincident with that of the early
migrating sandhills, and during the past 7
years (1959-65) whooping cranes have been
observed at sandhill congregation sites in
Saskatchewan, northeastern Montana, North
Dakota, South Dakota, Kansas, and northern
Oklahoma. No whooping cranes have been
observed during the past 7 years at sandhill
crane congregation areas in north-central
Montana, southeastern Wyoming, eastern Col-
orado, or western Oklahoma.

During the 1959-65 period, whooping cranes
were observed coincidently with sandhill cranes
in Kidder and Stutsman Counties, North
Dakota, between September 22 and October 4,
and McLean County between September 21 and
November 1. Similar sightings were made in
the Mobridge- Pollock area. South Dakota, be-
tween September 11 and October 7. Sightings
were made at Salt Plains National Wildlife
Refuge, Oklahoma, between September 26 and
November 8. If it can be assumed that the
latest sighting dates represent the final ap-
pearance of fall-migrating whooping cranes,
it is also reasonable to assume that sandhill
crane hunting seasons in these areas of con-
current use held after these dates would not
jeopardize the whooping crane. A delay of 1 to
2 weeks would serve to safeguard any whooping
cranes that do not follow the migration pattern
exhibited during the 1959-65 period.

Historical records as well as recent records
of fall-migrating whooping cranes are fre-
quently cited when sandhill crane hunting sea-
sons are being considered. Such records may

13

be used to deny hunting seasons, while the
lack of historical whooping crane observations
are often cited as justification for sandhill
hunting seasons. Historical whooping crane
records are of limited value since the birds
these observations represent disappeared from
the population 25-50 years ago, and changes
in habitat have reduced the attractiveness of
many of the areas formerly used as rest stops.
Recent records of fall-migrating whooping
cranes can be misleading, for it is obvious that
(1) all the whooping cranes are not observed
during the annual fall migration, and (2) all the
rest stops made by fall-migrating whooping
cranes are not recorded.

From 1959 through 1965, the first fall-
migrating whooping cranes to reach their
wintering grounds (Aransas National Wildlife
Refuge) arrived between October 9 and 30.
During the 1940-58 period, the earliest "first"
arrivals reached the refuge October 4 (1949).
The latest date whooping cranes were first
recorded during this period was November 11
(1946); however, this cannot be considered an
arrival date because road conditions prevented
earlier observations.

The fall migration of the whooping crane is
reasonably predictable. The big cranes and
their young usually begin their trip from the
breeding grounds in late September. Adults
with young make frequent rest stops of one or
more days, whereas adults without young make
longer flights with shorter rest stops. Allen
(1952) described the flight from the breeding
grounds to winter quarters thus: "The fall
migration . . . appears to develop in successive
'waves, ' single birds and pairs without young
migrating in the first two or three waves,
followed by the family groups at a later date.
Family groups containing young-of-the-year

' As this report was being readied for publication,
reports on the 1967 fall migration of whooping cranes
showed the following: Three whooping cranes (2 adults
and 1 young) were on Medicine Lake National Wildlife
Refuge, Montana, on October 17, 1967. An identical
group was on the Kirwin National Wildlife Refuge,
Kansas, on October 24, 1967. Seven whooping cranes
reached the Aransas National Wildlife Refuge on that
date. By November 1, 1967, 38 adult and 9 young
whooping cranes were on Aransas; another adult
bird arrived between November 1 and November
11.

apparently leave their nesting region by late
September and the Provinces between October
1 and 10."

Greater sandhill cranes

Track measurements indicate that 27% of
the sandhills using Bowdoin National Wildlife
Refuge, Montana, as a way station during the
1962-65 fall migration may represent the
greater race. No track measurements were
obtained at Medicine Lake National Wildlife
Refuge, nor were any sandhills collected at
either refuge.

Track measurements from Kidder and
Stutsman Counties, North Dakota, indicate that
about 14% of the fall- migrating sandhills that
use this way station may represent the greater
race. At this congregation site 74 sandhills
were collected from 1959 to 1965; 5 were iden-
tified as greater sandhills and another as a
typical greater, if a female. The greater was
not represented in the 10 birds collected in
McLean County. Footprint measurements in-
dicated that only 8% of the birds using this
congregation area apparently represented the
greater race.

Representatives of the greater race were
rare in the Mobridge- Pollock, South Dakota,
congregation area also. Footprint measure-
ments indicated that 3% probably represented
the greater race. Only 2 of 22 birds collected
at this site were classed as "possible
greaters;" body condition did not permit a
clear distinction between the Canadian and
greater races.

Although no cranes were collected in the
Wyoming fall congregation sites, a limited
number of footprint measurements imply that
the greater uses these sites during the fall.

Footprint measurements and crane collec-
tions indicated that the greater race did not
use Prewitt Reservoir, Colorado, as a way
station during the study.

A limited number of footprint measurements
from Salt Plains National Wildlife Refuge
(Alfalfa County) and the Red River Bottoms
(Jackson County), Oklahoma, suggests that the

14

greater race may occur at these way stations.
Three cranes confiscated from goose hunters
in the vicinity of the refuge were identified as
lessers. Track measurements indicate that
about one-third of the sandhills that use
Washita National Wildlife Refuge may also
represent the greater race. Two of four birds
collected at this site were identified as
greaters; the remaining birds were placed in
the Canadian race.

The breeding range of the lesser sandhill
extends from northeastern Siberia across
Alaska and Arctic Canada to the region of
Baffin Island, and south into the Northwest
Territories (Walkinshaw, 1949). Although an-
nual recruitment in the population may be as
low as 11% (Stephen, Miller, and Hatfield,
1966) this race can withstand additional har-
vest under proper management.

Analyses of the footprint measurements ob-
tained during the study and the racial com-
position of sandhills selectively collected from
1959 to 1965 indicate that the lesser race is
much more numerous at North Dakota and
South Dakota congregation sites in October
than is the greater race. Moreover, the se-
lective collecting program undoubtedly em-
phasized the incidence of the greater race.
Thus, late October or early November hunting
seasons in these States would not seriously
jeopardize the rare greater sandhill.

The incidence of the greater sandhill at
congregation sites in Wyoming and Oklahoma
was not adequately determined during the
study — additional measurements are needed
in these States.

Lesser sandhill cranes

Recreational hunting of sandhill cranes in
the United States was prohibited between 1916
and 1961 by the Migratory Bird Treaty and the
prevailing idea that the species could not
stand a harvest. This idea was based on the
knowledge that some races of the sandhills
were relatively scarce, although the lesser
sandhill crane population was known to ex-
ceed 200,000 birds. Recurring depredations
on cereal crops in Canada and the United
States by sandhills and the growing conviction
among game managers that this migratory
game bird could withstand harvest under
proper management led to the first lesser
sandhill crane seasons in the United States
in 1961. This was followed by limited seasons
in Manitoba and Saskatchewan in 1964. These
hunting seasons now result in an annual har-
vest of less than 5,000 birds and provide about
10,000 man-days of recreation.

SUMMARY

The 1961 lesser sandhill crane hunting sea-
sons in New Mexico and Texas prompted the
Central Flyway Waterfowl Council to propose
that the Council and the Bureau explore the
feasibility of extending the season to other
States of the flyway. This resulted in a co-
ordinated study to obtain information on the
chronology of the fall sandhill and whooping
crane migrations, peak populations and areas
of greater use, racial composition of fall-
migrating sandhills, and crop depredations by
sandhills in the Central Flyway.

1. With slight variations in time and geog-
raphy, the vanguard of the fall migration of
sandhill cranes reaches congregation areas in
Canada and North Dakota between mid-July
and mid- August; in Montana, Wyoming, and
South Dakota between the first week of Sep-
tember and the first week of October; in Col-
orado and Nebraska between mid-September
and mid-October; and in Kansas and Oklahoma
between the first and last weeks of October.

2. Fall- migrating sandhills reach peak num-
bers at Canadian way stations between the first
week of September and the second week of
October. Populations peak at way stations in
Montana, North Dakota, South Dakota, Wyoming,
Colorado, Kansas, and Oklahoma between the
first week of October and the first week of
November.

3. Crane numbers reached 100,000 in the
principal Saskatchewan congregation sites dur-
ing the fall of 1962. A minimum of 100,000
birds was present at way stations in the United
States during the fall of 1964. During the study,
185,000 to 214,000 sandhills reached the prin-
cipal wintering grounds in eastern New Mexico
and west Texas by late October.

15

4. Sandhill cranes usually depart from Ca-
nadian way stations in mid-October. Depar-
tures from principal fall congregation sites
within the States occur throughout October,
November, and early December. Generally,
the fall migration proceeds at a leisurely
pace except when mass movements are trig-
gered by cold fronts.

5. The fall migration of the whooping crane
is occasionally coincident with the sandhill
crane migration. Historically and during the
past 7 years (1959-65), whooping cranes were
observed at sandhill crane congregation sites
in Saskatchewan, northeastern Montana, North
Dakota, South Dakota, Kansas, and northern
Oklahoma. No whooping cranes have been ob-
served at sandhill crane way stations in north-
central Montana, southeastern Wyoming, east-
ern Colorado, or western Oklahoma; nor were
the two species observed together after No-
vember 8 anywhere in the flyway north of
Texas.

6. Cranes using the Prewitt Reservoir,
Colorado, way station were found to be the
lesser sandhill. This race also dominated
in the Montana (Bowdoin Refuge), North Dakota,
South Dakota, and the remaining Colorado
way stations — Bonny Reservoir and the Ar-
kansas Valley. Footprint measurements imply
that fall- migrating sandhills using way stations
in Wyoming, Kansas, Oklahoma, and the San
Luis Valley, Colorado, contain relatively
higher proportions (32% to 100%) of the greater
race.

7. Of 74 sandhills selectively collected in
Kidder and Stutsman Counties, North Dakota,
from 1959 through 1965, 5 were identified as
greaters. No greaters were included in 10
birds preferentially collected in McLean
County, North Dakota. Only 2 of 22 birds dis-
criminately collected in the Mobridge- Pollock
area. South Dakota, could be classed as pos-
sible greaters; body condition did not permit
distinction between the greater and Canadian
races. The greater race was not represented
in birds collected at Prewitt Reservoir, Col-
orado, or in the cranes confiscated from goose
hunters in the vicinity of Salt Plains Refuge,
Oklahoma.

8. Footprint measurements and the collec-
tion of specimens in September indicate that
the first migrating flocks to reach the prin-
cipal way stations in North Dakota contain
unknown numbers of the greater race, and
that these are gradually replaced or diluted
by the more numerous lesser race.

9. Sandhills were observed to feed on stand-
ing and harvested grain crops in Canada and
throughout the States of the flyway. Control
measures were not practiced in the principal
North Dakota congregation area during the
goose season, since farmers believed that
these measures had a dispersing effect upon
geese. Scarecrows effectively alleviated crane
depredations on winter wheat in the vicinity of
Washita Refuge, Oklahoma.

REFERENCES

Aldrich, j. W., and T. D. Burleigh.

1958, Geographical variation in sandhill cranes,
U.S. Bureau of Sport Fisheries and Wild-
life, Typewritten report,

Allen, R. P.

1952, The whooping crane. National Audubon So-
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Boeker, E. L.

1960. Whooping cranes in 1959, U,S. Bureau of
Sport Fisheries and Wildlife, Mimeographed
report. 9 p.

1961. Whooping cranes In 1960. U.S. Bureau of
Sport Fisheries and Wildlife, Mimeographed
report. 19 p.

1962. Whooping cranes in 1961. U.S. Bureau of
Sport Fisheries and Wildlife, Mimeographed
report. 12 p.

1963. Compilation of whooping crane data during
calendar year (1962-63), U.S. Bureau of
Sport Fisheries and Wildlife, Mimeographed
report. 8 p.

Boeker, E, L., J. W. Aldrich, and W. S. Huey.

1961. Study of the experimental sandhill crane
hunting season in New Mexico during Jan-
uary 1961. U.S. Fish and Wildlife Service,
Special Scientific Report— Wildlife No. 63,
24 p.

Boeker, E. L., W, S. Huey, and P. B. Uzzell.

1962. Study of Texas-New Mexico lesser sandhill
crane hunting season — November 4-Decem-
ber 3, 1961. U.S. Bureau of Sports Fisheries
and Wildlife, Mimeographed report, lip.

16

Buller, R. J., and E. L. Boeker.

1965. -Coordinated sandhill crane study in the
Central Flyway. Transactions of the
Thirtieth North American Wildlife and
Natural Resources Conference, p. 100-113.

Gilliam, C,

1966. Little brown crane study. Oklahoma Wild-
life Conservation Department, Completion
Report, Project W-32-R-15, Job 12. 7 p.

Huey, W. S.

1960. Sandhill crane investigations. New Mexico
E)epartment of Game and Fish, Completion
Report, Project W-91-R-3, Job 14. 5 p.

Knoder, E.

1964. Personal communication, August 18, 1964.

linduska, J. P.

1949. Sandhill crane observations — 1949, Texas
and New Mexico. U.S. Bureau of Sport
Fisheries and Wildlife, Unpublished report,
8 p.

Mackay, R, H.

1962. The current status of crop depredation con-
trol in Western Canada. Proceedings 25th
Federal-Provincial Wildlife Conference
(Ottawa, Canada), 1961, p. 48-53.

Mads en, C.

1966. Personal communication, April 6, 1966,

Munro, D. A.

1950. The economic status of sandhill cranes in
Saskatchewan, Journal of Wildlife Manage-
ment, vol. 14, p, 276-284,

Nelson, J. L,

1961. Waterfowl depredations control in Saskatch-
ewan. Wildlife Branch, Saskatchewan De-
partment of Natural Resources, Mimeo-
graphed report, 6 p.

Oberholser, H. C.

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17

* U.S. GOVERNMENT PRINTING OFFICE : 1968 O— 290-445

The Department of the Interior, created in 1849, is a Department of
Conservation, concerned with management, conservation, and develop-
ment of the Nation's water, wildlife, fish, mineral, forest, and park and
recreational resources. It has major responsibilities also for Indian and
Territorial affairs.

As America's principal conservation agency, the Department works to
assure that nonrenewable resources are developed and used wisely, that
park and recreational resources are conserved for the future, and that
renewable resources make their full contribution to the progress, pros-
perity, and security of the United States, now and in the future.

UNITED STATES

DEPARTMENT OF THE INTERIOR

FISH AND WILDLIFE SERVICE

BUREAU OF SPORT FISHERIES AND WILDLIFE

WASHINGTON. D. C. 20240