THE STORY

OF THE BIRDS

THE LIBRARY

OF

THE UNIVERSITY
OF CALIFORNIA

PRESENTED BY

PROF. CHARLES A. KOFOID AND
MRS. PRUDENCE W. KOFOID

THE STORY OF THE BIRDS

FROM ARCH/EOPTERYX TO BIRD OF PARADISE.

THE STORY OF THE

BIRDS

BEING AN INTRODUCTION TO
THE STUDY OF ORNITHOLOGY

BY

CHARLES DIXON

AUTHOR OF

'RURAL BIRD LIFE," "THE GAME BIRDS AND WILD FOWL OF THE BRITISH

ISLANDS," "BRITISH SEA BIRDS," "CURIOSITIES OF BIRD LIFE," "THE

MIGRATION OF BIRDS," "BIRD LIFE IN A SOUTHERN COUNTY,"

"AMONG THE BIRDS IN NORTHERN SHIRES,"

ETC. ETC. ETC.

WITH FRONTISPIECE BY CHARLES WHYMPER

LONDON
GEORGE ALLEN, 156, CHARING CROSS ROAD

1900

All rights reserved

Printed by BALLANTYNE, HANSON &* Co.
At the Ballantyne Press

PREFACE

THERE are many people who take an intelligent
interest in Birds and their Habits, and would
like to acquire a more extended knowledge of
ornithology were they not discouraged by the
dry and technical manner in which such infor-
mation is usually conveyed. The present volume
has been written with a view to removing some
at least of these obstacles to the acquisition of a
general knowledge of Birds. We have sought to
tell their story simply and in language as free
from technicalities as possible ; to produce a
guide or handbook to the study of birds that
shall be both popular and accurate as we can
make it. We make no pretensions to complete-
ness or finality, for such could scarcely have
been even approximately reached had each
chapter been expanded into a volume ; but we
do claim for our work that no reader can master
its contents without gaining a very general know-
ledge of the avine kingdom. Whilst always

M3663''

vi PREFACE

endeavouring to make the Story popular we
trust we have never done so at the expense of
its philosophic importance.

The Story that the Birds have to tell us is
indeed a fascinating one. Beginning with the
Origin and Descent of Birds during geological
epochs so remote that the mind fails to grasp
or realise the mighty vastness of time that separ-
ates the Then from the Now, we pass on to a
consideration of their salient characteristics in
existing forms, their anatomical features, the
bony framework and internal organs, the pecu-
liarities of their dermal covering, its structure,
colours, and functions. Then we take up the
subject of the various Groups or Orders into
which systematists have divided Birds, the com-
position of those orders, the affinities and pecu-
liarities of the species in them. After which we
trace out the Distribution of Birds over the earth,
and then endeavour to ascertain the conditions
of their Dispersal and the laws that govern their
Migrations. Then comes the subject of the
General Habits and Functions of Birds — their
Flight, terrestrial and aquatic motions, Social
Instincts, Food, and the many methods of obtain-
ing it, the Mimicry of Birds, their Protective
Colouration and Resemblances, Variation and

PREFACE vii

Dimorphism. Our next stage in their Story
brings us to their marvellous methods of Court-
ship, their Love Displays, their bridal Songs and
Cries and Sounds. This is fittingly succeeded by
a scientific study of their Nests and Eggs, which
brings their Story to a close.

CHARLES DIXON.

PAIGNTON, S. DEVON.

CONTENTS

«

CHAPTER I

THEIR ORIGIN AND SALIENT CHARACTERISTICS

PAGES

Diagnosis of a bird — Descent of birds — Archaeopteryx
— Cretaceous Ornitholites — Upper Eocene Orni-
tholites — Miocene Ornitholites — Pliocene Orni-
tholites— Tertiary gigantic birds — New Zealand
Moas — Madagascar yEpyornithes — Miocene tropi-
cal genera in Europe — The feathers of birds —
Contour feathers — Down-plumes — Powder-downs
— Filoplumes — Colour of feathers — Abnormal
colouration — Arrangement and pattern of colour —
Differences in colour due to age, sex, and season
— Colour and environment — Moulting — The avine
skeleton — The anterior and posterior limbs — The
head or skull — Internal organs — Muscular, ner-
vous, and digestive systems — Respiratory organs —
The young of birds 1-53

CHAPTER II

THE PRINCIPAL BIRD GROUPS

The two Primary Divisions — The Carinatae and
Ratitas — Moas and Rocs — Rheas, Cassowaries,
and Emus — Kiwis and Ostriches — The Crypturi
or Tinamous — The Impennes or Penguins — The
Colymbiformes or Divers and Grebes — The

CONTENTS

PAGES

Procellariiformes or Petrels — The Pelargiformes
or Herons, Storks, Spoonbills, and Ibises — The
Pelecaniformes or Tropic Birds, Gannets, Cor-
morants, Pelicans, Darters, and Frigate Birds —
The Anseriformes or Swans, Geese, Ducks, and
Mergansers — The Gruiformes or Cranes and
allied birds — The Ralliformes or Rails and
Finfoots — The Galliformes or Game Birds — The
Pediophili or Sand-Grouse — The Columbiformes
or Pigeons — The Charadriiformes or Bustards,
Plovers, Sandpipers, Jacanas, Sheath-bills, Crab
Plover, and Seed Snipes — The Lariformes or
Gulls, Terns, Skuas, and Skimmers — The Alci-
formes or Auks — The Falconiformes or Birds of
Prey — The Coraciiformes — The Psittaciformes or
Parrots — The Cuculiformes or Cuckoos and
Plantain-Eaters — The Passeriformes or Perching
Birds . . .... . . 54-102

CHAPTER III

THEIR DISTRIBUTION IN SPACE

The geographical distribution of birds — Views of
Sclater, Huxley, and Wallace — Dr. Sclater's Zoo-
logical Regions — The Palaearctic Region : its
characteristic birds — The Ethiopian Region : its
characteristic birds — The Indian or Oriental
Region : its characteristic birds — The Australian
Region : its characteristic birds — The Nearctic
Region : its characteristic birds — The Neotropical
Region : its characteristic birds — Distribution of
the Moas and Rocs — Distribution of Ratitae birds
— Distribution of Carinatae birds — The Tinamous
—The Penguins— The Divers and Grebes— The
Petrels — The Herons, Storks, Spoonbills, and
Ibises — The Tropic Birds, Gannets, Cormorants,

CONTENTS xi

PAGES

Pelicans, Darters, and Frigate Birds — The
Screamers, Flamingoes, Swans, Geese, Ducks,
and Mergansers — The Finfoots and Rails — The
Cranes, Trumpeters, Screamers, and Sun Bitterns —
The Game Birds— The Sand-Grouse— The Pigeons
— The Plovers and Snipes, &c. — The Gulls, Terns,
Skuas— The Auks — The Birds of Prey — The
Coraciiformes — The Parrots — The Cuckoos and
Plan tain- Eaters — The Passeriformes or Perching
Birds 103-142

CHAPTER IV

THEIR MEANS OF DISPERSAL AND MIGRATIONS

The dispersal of birds — Fortuitous dispersal — Ancient
land-surfaces — Polar dispersal — Equatorial disper-
sal— The law of dispersal — Obstacles to dispersal
— Discontinuous areas of dispersal — Influence
of climate upon species — Species increasing
their range during present time — The migration
of birds — Misconceptions concerning migration —
Transmutation and Hibernation — Migration and
Instinct — Migration not universal in certain species
— The Cause of Migration — Migration due to range
expansion or colonisation — Cause of migration in
autumn — Length of journey variable — The Philo-
sophy of Migration — The wings of migrants —
Moulting of migrants — Course of autumn migra-
tion— How birds find their way on migration —
Migration across seas — General aspects of migra-
tion— Duration of migration — The speed of migra-
tion flight — The height at which migrating birds
fly — The perils of migration — Lost birds at
lighthouses — Various kinds of migration — Vertical
migration — Local movements of birds — Nomadic
migration — Irruptic movements . . . 143-177

xii CONTENTS

CHAPTER V

THE GENERAL HABITS AND FUNCTIONS OF BIRDS

PAGES

The flight of birds— Flightless birds— The fitness of
birds for an aerial existence — Various modes of
flight — Gliding flight : how performed — Flight by
active strokes of the wings : how performed — The
movement of the wings — Soaring or sailing flight :
how performed — Terrestrial and aquatic motion
of birds — Birds unable to progress upon the
land — Running, walking, and hopping move-
ments— Progress in water — The food of birds —
Modifications of the bill — Common to various
distantly related groups — Social, gregarious, or
solitary instincts of birds — Mimicry in birds
— Protective colours and resemblances of birds —
Forest birds — Desert birds — Marsh and swamp
birds — Moorland and mountain birds — Arctic
birds — Variation in birds — Of external structure
and colour — Dimorphism in birds — Sexual dimor-
phism— Dimorphism independent of sex — Struc-
tural dimorphism 178-211

CHAPTER VI

THE LOVE DISPLAYS OF BIRDS

Bird music — Vocal music of birds — Variety in song —
Capriciousness of song — The origin and purpose
of avine song — Individual variation in the song
of birds — Imitation — Do birds sing by instinct
or imitation? — Vocal sounds of birds — The in-
strumental music of birds — Made by ordinary
appliances — Made by special modifications of
the plumage — The drumming of the Snipe —
Modifications in the wings of the Humming-Birds

CONTENTS xiii

PAGES

— In other species — Wing modification in the
Manakins — Sounds made by air sacs or pouches
— The love displays of birds — Aerial displays of
Humming-Birds — Of Tyrant Birds — Love displays
of the Birds of Paradise— Of Bustards— The love-
posturing of the Argus Pheasant — The Bower
Birds — Their curious "bowers" — The dances of
certain Rails — Of the South American Jacana
— Of the Spur- winged Plover — Of certain Ducks —
Parades of plumage — The meaning and purpose
of this display — Sexual selection — The vitality,
excitability, and pugnacity of birds . . 212-242

CHAPTER VII

THEIR REPRODUCTION (NESTS)

The unique character of birds' nests — The architecture
of Ratitae Birds — The nests of the Kingfishers —
The Hornbills— The Swifts— Edible nests— The
nests of the Humming-Birds — Nests of the
Passeriformes — Great variety in the nests of the
Passeres — Variation of nest-type in the same
species — Uniformity in the nests of species — The
architecture of the Wrens — Of the Swallows — Of
the Finches — Of the Starlings, Shrikes, Wax-
wings, Orioles, and Goldcrests — Nests of the
Tropical Oscines— In the Timeliidae— The Tailor
Bird — Nests of the Bulbuls, Cuckoo Shrikes,
Drongos and Greenlets— Of the Birds of Paradise
— Of the Sun-Birds — Of the Flower-peckers and
Sugar Birds — Of the Wood Warblers and
Tanagers — Of the Weaver Birds — Of the Ox
Birds and Hang-nests— Of the Broadbills — Of
the Pittas— Of the Tyrant Birds— Of the Cotingas
and Plant-cutters — The nest of the Oven Birds —
The architecture in the Wood Hewer family— Of

xiv CONTENTS

PAGE

the Ant Thrushes— Of the Lyre Birds— Nest of
the Hammer- Head — Nests of the Mound Birds —
Of the Brush Turkeys— Of certain Coursers— Of
the Rails, Ducks, and Geese — Of the Flamingoes
— The utility of nests — The nest in relation to the
colour of the plumage — Instinct or imitation in
nest-building 243-276

CHAPTER VIII

THEIR REPRODUCTION (EGGS)

Eggs— The development of the shell— The deposition
of the colour pigments — The shape of the mark-
ings— How formed — The two types of markings —
Their distribution — General resemblances amongst
eggs of the same species — Exceptions — Composi-
tion of the colour pigments — The incubation of
the egg — Incubation periods in the various avine
orders — The incubating sex — The texture or grain
of the egg-shell — The colour of the interior of the
shell — The form of eggs — The size of eggs — The
number of eggs produced by species in the various
groups — The colours of eggs — Generic types of
eggs — Variation in the colour of eggs in the same
species — Of the Guillemot — Of the Cuckoo —
Uniformity of colour in other groups — The colours
of eggs hereditary — Eggs of hybrids — The ances-
tral colour of eggs — The utility of colour — White
eggs in covered nests — In open nests — Spotted
eggs in open nests — In covered nests — The pro-
tective colouration of newly hatched birds . 277-304

THE STORY OF THE BIRDS

CHAPTER I

THEIR ORIGIN AND SALIENT CHARACTERISTICS

Diagnosis of a bird — Descent of birds — Archaeopteryx —
Cretaceous Ornitholites — Upper Eocene Ornitholites —
Miocene Ornitholites — Pliocene Ornitholites — Tertiary
gigantic birds — New Zealand Moas — Madagascar ^Epy-
ornithes — Miocene tropical genera in Europe — The
feathers of birds — Contour feathers — Down-plumes —
Powder-downs — Filoplumes — Colour of feathers — Ab-
normal colouration — Arrangement and pattern of
colour *— Differences in colour due to age, sex, and
season — Colour and environment — Moulting — The
avine skeleton — The anterior and posterior limbs —
The head or skull — Internal organs — Muscular, ner-
vous, and digestive systems — Respiratory organs —
The young of birds.

" WHAT is a man ? " asks Galatea of Pygmalion
in Mr. Gilbert's famous play. " What is a
bird ? " the curious reader may ask, and possibly
ask ninety-nine people out of every hundred
without obtaining any satisfactory definition of
such a well-known and familiar creature. Birds
are familiar to all of us. To almost every kind

2 THE STORY OF THE BIRDS

of scene they impart an ever-welcome sense of
life ; whilst of all organisms they are as a class
the most beautiful, the most tuneful, and we
may even add the most widely and generally
interesting. The old proverb that "A bird is
known by its feathers" amounts to a strictly
scientific diagnosis of the class Aves, for feathers
are otherwise unknown in the animal kingdom,
and therefore become the most important char-
acteristic of a bird. There can be no reason-
able doubt that birds are more closely related
to reptiles than to any other class of animal
life. The close propinquity of the two classes —
reptiles and birds — was unreservedly recognised
by Huxley, that great comparative anatomist
associating both under the term Sauropsida,
the two combined forming one of the three
primary groups into which he divided vertebrated
animals.

It might reasonably be thought that as birds
are so obviously closely related to reptiles, the
descendants in fact of one common ancestor
from which both classes of organisms (Reptilia
and Aves) have sprung, there would be definite
evidence in existence, in a fossil form, to indi-
cate the line of their descent. But although
we may be practically certain that birds and

ORIGIN AND CHARACTERISTICS 3

reptiles are more closely related to each other
than either is to all remaining forms of vertebrate
life, nothing displaying nearer affinities with birds
than those gigantic reptilian forms known as
Dinosaurs have yet been discovered. Casts of
footprints found upon the Triassic sandstone
in the valley of the Connecticut in New England
were long supposed to be those of birds, but
palaeontologists appear now to be generally
agreed that these impressions were made by the
feet of Dinosaurian reptiles. Some of these
footprints, measuring as many as seventeen
inches in length, indicate creatures of vast size
with a stride of about eight feet ! Dr. Hitchcock
enumerates the footprints of as many as twenty-
three species of what he termed Ornithichnites
— a Greek compound, signifying fossil footprints
of birds, and which of course in the light of
modern opinion now becomes obsolete. From
the Bunter Sandstein of the Triassic system to
the Solenhofen slate formation of the Jurassic
system constitutes a vast period of geological
time, and yet this separates these reputed Orni-
thichnites from the first really fossil bird respect-
ing the identity of which authorities are in no
doubt. This, the earliest known avine form, is
the Archaeopteryx (a second species has lately

4 THE STORY OF THE BIRDS

been described from the same locality), a crea-
ture which, although presenting not a few
reptilian characteristics, was unquestionably dur-
ing life a feather-clad bird. The Archaeopteryx
was a bird about the size of a Crow, with a short
blunt bill. The upper jaw was furnished with
thirteen and the lower jaw with three conical
teeth on each side, each embedded in a distinct
socket. This curious bird was also furnished
with a long lizard-like tail composed of twenty-
one vertebrae, from each of the first twelve of
which grew a pair of feathers. The three free
digits of the wing were armed with claws. Of
course nothing can be said with certainty re-
specting the habits and mode of life of the
Archaeopteryx, but the structure of the feet
suggest a possible arboreal existence.

The next known bird forms (Ornitholites)
appear in the Cretaceous epoch. All these, so
far as is known, still continue to present the
character of teeth, but the lizard-like tail com-
pletely disappears. Many of the remains found
in the deposits of this epoch, and formerly
believed to be Ornitholites, have been shown
to be those of Pterodactyls (bat-like reptiles).
However, in 1858, undoubted avine remains (of
a form believed by some authorities to be allied

ORIGIN AND CHARACTERISTICS 5

to the modern Divers) were discovered by
Barrett in the Upper Greensand of Cambridge-
shire ; others obtained from the chalk forma-
tion of South Sweden have been described by
Professor Dames. A much more extensive series
of Ornitholites (referable to no less than seven
genera) from the Cretaceous rocks of North
America have been described by Professor
Marsh. Two of these, from the shales of Kansas,
formed his distinct sub-class Odontornithes, but
as all Cretaceous birds are believed to have
been toothed the term has more recently been
employed to embrace all Ornitholites of that
epoch. The list of Pre-Tertiary Ornitholites is
comparatively a small one. As might naturally
be inferred Ornitholites become much more
numerous in Tertiary deposits. Avine evolution
must have been progressing upon a vast scale
during the closing ages of the Cretaceous and
the early eras of the Tertiary systems ; and not
only do we find a much greater and most
significant wealth of avine fossils, but a steady
progress towards those types which dwell upon
the earth in our own time, or which occupied
it in ages not very remotely preceding the
present. Some of the most remarkable Orni-
tholites of the early Tertiary Period relate to

6 THE STORY OF THE BIRDS

such gigantic avine forms as Gastornis. Fossil
remains of this bird have been discovered in
the south of England (near Croydon), as well
as on the Continent. Specialists are by no
means agreed respecting its affinities, but its
large size is indisputable, bigger than an Ostrich,
and like that bird incapable of flight. Another
remarkable Ornitholite belonging to this era of
strange avine forms is the Odontopteryx toliapica
from the London Clay of Sheppey, represent-
ing the remains of a bird possessing curiously
serrated jaws. At this era appear the remains
of Halcyornis (also from the Sheppey beds),
considered by some to be allied to the Gulls ;
of Proherodius, showing affinities with the
Herons; and Lithornis, provisionally associated
by Owen with the Birds of Prey, but possibly
more nearly allied to the Cranes. Osteornis
from the shale of Plattenberg at Glarus may
belong to the present wide-ranging and domi-
nant order of the Passeres.

Passing on to the Ornitholites of the Upper
Eocene we have the remarkable series of avine
remains from the Paris Basin, with the identi-
fication and comparison of which the names of
Cuvier and Milne-Edwards are so inseparably
associated. Of the fourteen genera to which

ORIGIN AND CHARACTERISTICS 7

Milne-Edwards referred the various remains no
less than half are still existent, whilst the other
seven are more or less closely allied to others in
a similar state. Precisely the same remarks
apply to the Ornitholites of this period from
equivalent beds in other parts of Europe, in-
cluding our own islands, but the remains of
many additional species have been discovered,
most of them more or less distantly allied with
types that are living in our own era, although in
not a few cases not in the same geographical
areas as was then the case. The Ornitholites
of North America tell a very similar story ;
whilst a most interesting avine fossil of this
period from New Zealand, Palaeeudyptes antarc-
ticus, a giant Penguin standing seven feet high,
is specially worthy of mention.

The Ornitholites peculiar to the Miocene
Period, as might naturally be expected, still
continue to present, and in increasing abund-
ance, characters which indicate still closer
affinities with genera and species of birds that
are in existence now. Some of course of those
fossils represent types that have completely
disappeared from the earth, but in few cases
do we find such vast distinctions that characterise
the Ornitholites of earlier eras, an eloquent and

8 THE STORY OF THE BIRDS

most significant demonstration of the wonder-
ful progress of avine evolution. Two of the
most remarkable types of this era are Phoro-
rhacos and Brontornis. These avine giants are
from the Miocene deposits of South America.
These, together with several other genera (in all
we believe eight or nine are recognised), com-
prise what shortly after their discovery was
supposed to be an absolutely new order of birds
to which the name Stereornithes was applied,
but which subsequently was declared to possess
no such taxonomic importance. These very
wonderful bird remains, the existence of which
was only discovered a decade ago, appear to
indicate a rich avifauna in South America even
at that remote era, and form evidence of a most
significant kind relating to the dispersal of life
over the globe. The most remarkable feature
of these birds is the enormous size and massive
structure of the head, in comparison with the
limbs, although some of these are of gigantic
proportions. Probably we never shall have any
but the faintest idea of what these bird
monsters were actually like in life, but that
they must have presented a most impressive
appearance with their huge laterally compressed
and hooked beak, cannot be doubted. That

ORIGIN AND CHARACTERISTICS 9

they were unable to fly seems certain. Some
Ornitholites of this era found in Europe are
intermediate between the Storks and Ibises
(Ibidopodia), another a species allied to the
Flamingoes (Palaelodus). We must attribute
the comparative scarcity of Ornitholites in the
Pliocene deposits either to the prevailing con-
ditions at that time being unsuitable for their
effectual preservation or to our own want of
success in discovering them. The fragments of
the Pliocene avifauna so far as they have been
revealed by scientific investigation represent
the remains of birds differing little from types
existing to-day, whilst many of them were
undoubtedly generically and in some cases
possibly specifically the same. A significantly
still greater similarity characterises the avine
remains of the Post-Tertiary Period ; whilst
the geographical area occupied by these
Pleistocene birds is in most cases the same as
that of their surviving representatives or de-
scendants. In the majority of instances these
Post-Tertiary relics are, so far as we can judge,
of the same species that exist to-day. Some
of course have become extinct altogether, as for
instance the Crane (Grus primigenia) and the
Pelican, remains of which latter have been

io THE STORY OF THE BIRDS

discovered in the English Fens ; others have
disappeared from scenes which their remains
tell us they once occupied ; as for instance the
Snowy Owl and the Capercailzie from Devon-
shire, bones of which have been found in that
wonderful necropolis of our ancient fauna, Kent's
cavern, near Torquay.

Two other points seem specially worthy of a
brief notice before we leave this portion of the
subject. The first relates to the gigantic birds
of the early Tertiary Period. There can be no
doubt that some at least of these ponderous
avine types managed to survive in one or two
favourable spots until quite recent times and
long after their contemporaries had vanished
from the earth. The two most famous sanctu-
aries of these archaic birds are the long and
completely isolated areas of New Zealand and
Madagascar. Among these curious birds, re-
mains of which have been discovered in quite
recent deposits (notably near ancient camping
places of the aborigines, in caves, sand drifts
and swamps) in New Zealand, may be men-
tioned the Moas (Dinornis), the huge Raptorial
bird Harpagornis, and a monster Goose. All
these birds were flightless. It is round the
Moas that most interest gathers, not only

ORIGIN AND CHARACTERISTICS n

because their remains have been carefully
studied by Owen and others, but their previous
existence lingers in the traditions of the Maori
people themselves, a race now almost as extinct
as the huge birds with which it was contem-
poraneous. Taking into account the compara-
tively restricted area to which they were
confined, these birds must have been not only
numerous in species but in individuals ; whether
these giant birds attained such a development
in such narrow geographical limits is yet a
moot question. Moas were either destitute of
wings or possessed them in a rudimentary or
functionless condition only. This helplessness
unquestionably contributed to their rapid ex-
termination when savage man appeared upon
the scene. How long they lingered we have no
reliable means of ascertaining, although Hutton
considered that they became extinct between
300 and 500 years ago.

Of little less interest are the extinct ^Epyor-
nithes of Madagascar, perhaps chiefly because
they are generally believed to be the Rocs of
Arabian romance. If this be so it shows how
even the wildest fable may rest upon a more or
less complete foundation of fact. Even to this
day some of the inhabitants of that African

12 THE STORY OF THE BIRDS

island cherish the belief that these birds still
exist, and attribute to them (which of course is
fable pure and simple) the power of flight. The
first definite indication that such huge birds had
formerly lived in Madagascar was the discovery
of their colossal egg-shells, supplemented after-
wards by the finding of bones. These remains
have been referred to no less than five species,
some however of which belong to birds of much
smaller size. One of these large egg-shells is
now in the British Museum, and measures some
thirteen inches in length by nine and a half
inches in breadth ; whilst a still larger example
was formerly in the possession of the late Dawson
Rowley. The flightless and consequently help-
less condition of these stupendous birds must
soon have led to their complete extermination
after man appeared in the island.

The second point to which I specially want
to refer is the occurrence in the Miocene de-
posits of Europe of certain genera of birds that
in our time are strictly confined to the Tropics.
Among the most remarkable of these may be
mentioned the remains of Psittacus (a genus
of Parrots), a form of Swift (Collocalia) now
confined to the Tropics, a Secretary Bird
(Serpentarius), what appears to have been a

ORIGIN AND CHARACTERISTICS 13

Hornbill, a Plantain-eater (Necrornis), an Adju-
tant (Leptoptilus), certain forms of Cuckoo
(Centropus), and Trogons (Trogonidae). By
most zoologists the presence of such species in
Europe is taken as an indication that the climate
at that time was much warmer than it is now,
or even of a tropical character. This may or
may not have been the case ; but to suggest that
these birds (now only found in warm latitudes)
were driven south by the cooler climate of the
succeeding Pliocene era, or the intense cold that
characterised that of the Glacial Epoch, is not,
in my opinion, a correct interpretation of the
facts. I maintain that one of the laws of dis-
persal is that species never retreat from adverse
conditions of life. All such species that during
later Tertiary time had spread north and east
from southern and even equatorial bases, and
become sedentary in the warm equable climate
of Euro-Asia must have been completely ex-
terminated by the advent of adverse conditions
of life, primarily due to a change of climate.
Let it then be clearly understood that these
avine types now extinct in Europe did not
originate there during the long-continued warm
climatic conditions of the later Tertiary Period,
that they did not at the approach of a cooler

14 THE STORY OF THE BIRDS

climate retreat southwards towards the Tropics,
but that they originally extended their range
northwards from southern bases where the
generic roots of such forms exist to-day, not-
withstanding the fact that a glacial catastrophe
exterminated all these northern offshoots of
which a few scattered relics have been dis-
covered.

The lesson then briefly summarised that all
Ornitholites convey is that existing birds — birds
as we see and know them to-day, have descended
in a direct line from ancestors which differ more
and more widely from living types the farther
we trace them back into the remote past, until
we are confronted by those semi-reptilian forms
which appear to be the earliest progenitors of the
great and now highly specialised avine group.

Having thus briefly glanced at the origin of
birds let us pass on to a consideration of the
most salient points in the structure and char-
acteristics of existing forms. Commencing with
external features, a bird, as we have already
stated, is known by its feathers. What are
feathers, those wondrous things with which all
birds are clothed, the chief vehicle of their
matchless beauty, the bearer of those glorious
sheens and tints and hues that single out this

ORIGIN AND CHARACTERISTICS 15

class of creatures as the most attractive of
organic beings ? Feathers, with the skin in
which they grow, form the integument of a bird,
and are classed with hairs, bristles, metatarsal
scales, spurs, claws, and bill sheaths as epidermal
structures. Probably many readers may think
that feathers grow from all parts of a bird's skin,
but such is not the case (with almost the sole
exception of the Penguins, Screamers, and Ratite
birds such as Ostriches). The feathers of a bird
grow in various tracts or well-defined patches,
technically called pterylae, the spaces between
these tracts, whether covered with down or
absolutely naked, being known as apteria. These
feather tracts are known as the pterylosis or
pterylographie of a bird, and as they vary a
good deal in their pattern or direction in the
several groups, their study is of some importance
to the ornithologist in his efforts to form a
natural classification of birds. Feathers not only
grow upon the newly formed chick, but at
certain intervals of time upon the adult bird,
when they are renewed either to replace acci-
dental loss, or at the seasons of the moult when
the old plumes are shed or pushed out by an
entirely new set. We may define feathers then
as horny products of the epidermal cells of the

16 THE STORY OF THE BIRDS

skin which collectively form the covering of a
bird and enable it to fly. A feather, generally
speaking, consists of the following parts : A, the
barrel or quill, calamus ; B, the principal shaft,
rhachis ; C, the secondary or aftershaft, hypo-
rhachis ; D, the web composed of a regularly
arranged series of fibres or barbs, rami} attached
to which are a double series of barbules or radii,
which again in their turn give rise to barbicils
or cilia, which latter generally end in booklets,
hamuli. These latter it should be remarked are
of very great importance, because they serve to
interlock or join the barbules and barbs together,
and thus serve to render the surface of the flight
feathers almost impervious to air. Feathers may
be roughly divided into three classes ; viz. contour
feathers, down-plumes, and riloplumes. The first
are not only the largest but perhaps the most
important. They are those that appear nearest
the surface, and therefore form the outline or
contour of the bird's figure. They reach their
greatest development of course in the wings
(remiges) and tail (rectrices). In some of these
feathers the cilia, and consequently the hamuli
are wanting, thus forming the disconnected webs
and decomposed plumes which are displayed as
ornaments or decorative tufts in so many birds.

ORIGIN AND CHARACTERISTICS 17

In other of these contour feathers the barbs are
absent altogether, the rhachis being webless ; as
in the wing quills of the Cassowary, the rectrice
wires of certain Birds of Paradise, and in most
of the tail-feathers of the Lyre Bird ; whilst the
same remarks apply to the rictal or gape bristles
with which so many birds are furnished, and the
eyelashes of such birds that possess them, as the
Hornbills. In some species the tip of the rhachis,
as for instance in the neck hackles of certain
Galline birds, and in some of the wing and tail
feathers of the Waxwings, is expanded into
wax-like modifications or processes. The down-
plumes, as their name suggests, are softer in
texture than the contour feathers by which they
are hidden, are present in greater numbers,
but are smaller. In these feathers the hooklets
(hamuli) are wanting, and the rhachis or shaft is
often absent, the barbs sprouting from a stunted
calamus. In connection with this type of feather
mention should be made of those highly curious
down -plumes known technically as "powder-
downs." They derive their name from the fact
that the slender tuft-like barbs and barbules of
which they are composed are continually dis-
integrating or crumbling at the tips into fine
powder. Powder-downs in some birds grow

i8 THE STORY OF THE BIRDS

over almost the entire body, not only on the
bare places between the contour feather tracts
but amongst these feathers themselves. In other
birds they are confined to certain spots or are
developed in well-defined pterylae. These peculiar
feather growths are by no means common to all
birds, only appearing in certain groups. Some
of the most notable of these are the Herons and
Bitterns, the Parrots, the Tinamous, a few of the
Birds of Prey (Blue-winged Kite, Harriers), the
Frog-mouths (a group of Goatsuckers), and some
of the Rollers. The archaic character of these
powder-downs seems indicated by the fact that
only in a single genus (Artamus) of the extensive
and highly specialised group of Passeres are they
known to occur. Lastly we have to notice that
peculiar kind of feather which is known techni-
cally as a filoplume. A filoplume is composed of
a short barrel (calamus) terminating in a slender
hair-like shaft (rhachis), carrying few or no
barbs (rami), and forms what is popularly termed
an aftershaft, technically called an hyporhachis
(already alluded to in describing the various
parts of a feather). This filoplume starts from
the base of the quill and varies a good deal in the
degree of its development in the different avine
groups. It becomes specially small in the

ORIGIN AND CHARACTERISTICS 19

Passeres, almost absent in the Pigeons, Wood-
peckers, Owls and so on, but is as large as the
main rhachis in the Cassowary and the Emu.
The aftershaft is generally concealed by the
contour feathers, but in some cases it extends
beyond them in the form of long slender filaments
or hairs on the neck or back. The Blackbird
furnishes a familiar example of a species pos-
sessing these nuchal hairs, whilst some of the
Bulbuls in the genus Tricholestes may be cited
as notable instances of the latter. Some of
the Warblers and Finches also exhibit them ;
whilst the white thread-like filaments displayed
by Cormorants are apparently another form of
filoplume. It may be mentioned that the soft
downy covering of so many young birds re-
sembles the down-plumes of adults, although it
differs in certain respects, notably in the abortive
or even absent shaft, the absence of cilia, the
filamentous rami, and with one exception the
absence of an aftershaft. But these are details
of far too technical a character to be dealt with
in a work aiming above all things to be popular,
and must be left to the more advanced student of
birds.

Having thus briefly dealt with the distribution,
structure, and growth of feathers, it now becomes

20 THE STORY OF THE BIRDS

necessary briefly to glance at the colour with
which they are adorned. This too is a most
complicated subject, and one which we can only
deal with here in a cursory way. In the first
place, to what is the colour of a feather due ?
Colour is due either to pigment or to peculiarity
of structure, or to both these causes combined.
These three causes may be thus briefly sum-
marised. In the first place colour may be pro-
duced by pigment, either in a diffused solution
or in the form of pigmented corpuscles. Colours
produced in such a way are constant in the sense
of not varying in tint in whatever position the
light may fall upon them or the eye may view
them. These colour pigments are firstly black
(Zoomelanin), secondly red (Zoonerythrin), thirdly
yellow (Zooxanthin), and fourthly and fifthly
peculiar pigments, red (Turacin) and green
(Turacoverdin), only known to be present in the
plumage of the Plantain-Eaters (Musophagidce).
Brown, it may be remarked, is a combination
of black and red ; white is not due to pigment,
but the appearance of such a feather is due to
the countless spaces between its molecules which
diffract and reflect the light. The remarkable
gloss, irrespective of colour, on so many feathers
is due to their highly polished surface. In the

ORIGIN AND CHARACTERISTICS 21

second place we have colour arising from a pig-
ment in combination with the overlying colourless
structures in the form of irregular longitudinal
ridges or polygonal bodies, between the surface
of the barbs and barbules and the pigment.
When the polished surface of such feathers is
scratched or held up against the light only the
colour of the pigment is visible. This is the case
with many blue, yellow, orange, and green
feathers. In the third place we have those
wonderful prismatic or metallic colours, of which
the radiant Humming-Birds offer the most
striking example. In these feathers a black or
blackish-brown pigment rests below a transparent
colourless layer, the surface of which may be
either smooth and polished, covered with longi-
tudinal ridges or sprinkled with innumerable pits,
which serve as a series of prisms or facets, and
change the colour of the feathers according to
the direction from which the light falls upon
them. It is interesting to know that these
prismatic colours change their hue in the same
order as those in the rainbow. When the light
glides in a vertical direction over the surface of
all these metallic feathers, the luminous rays are
absorbed and they appear black. But, as Martin
observes, respecting the plumage of Humming-

22 THE STORY OF THE BIRDS

Birds, it is no longer the same when the light
is reflected from these feathers, each of which
performs the office of reflector. Then it is that
the aspect of the emerald, the ruby and so on,
varying with the utmost diversity under the
incidences of the rays which strike them, is
given out by the molecular arrangement of the
barbules. It is thus that the gorget of many
Humming-Birds takes all the hues of green, and
then the brightest and most uniformly golden
tints, down to intense velvet-black, or, on the
contrary, that of ruby, which darts forth pencils
of light, or passes from reddish orange to a
crimson-red black.

A few words on abnormal colouration must
conclude this portion of the subject. Possibly
the most familiar form of Heterochrosis is
Albinism. I dare say every reader can recall a
partial or complete instance of such a form of
abnormal colouration, say in the Blackbird or
the Pheasant, to quote the most familiar species.
This is due to the absence of black pigment.
Perhaps the next most familiar form of excep-
tional colouration is that which is technically
known as Melanism. This is exactly the reverse
of albinism, and is caused by an excess of black
pigment which renders the feathers abnormally

ORIGIN AND CHARACTERISTICS 23

dark in colour. Less familiar forms of Hetero-
chrosis are Xanthochroism and Erythrism, in
which an abnormal amount of yellow or red
pigment is present. In some cases at least
(especially of the latter form) this is the result of
exceptional food. Lastly, the arrangement and
pattern of colour upon feathers demands a few
words of explanation. These to a great extent
are due to age, sex, or season. In many species
spots and streaks are a sure indication of youth
or immaturity, just as transverse bars, on the
other hand, are characteristic of the adult stage
of existence. In some highly specialised groups
(as for instance the Crows) there is but little
difference in colour between the nestling and its
parent, but in other groups (as for instance the
Gulls) several years may elapse before the young
finally get rid of their characteristic dress of
youth and assume the very different tints of the
adult, during this period between youth and
maturity practically recapitulating the ancestral
changes the species has undergone, it may be
from a mottled or spotted form to unsullied grey
and white, as in the Gulls and Terns. In a great
many birds the male is the most brilliantly
coloured, and remarkable for those wonder-
ful modifications of plumage that are classed

24 THE STORY OF THE BIRDS

amongst secondary sexual characters. There
are, however, one or two exceptions to this rule,
the Phalaropes, the Dotterel, and certain Parrots
furnishing us with instances in which the female
is most brilliantly adorned. The colour of a
bird's plumage in a great many instances varies
considerably according to season, and in some
cases great difference is produced by a long
fringe of barbicels that conceal much of the
conspicuous tints on the rest of the plumage,
and which abrade and drop off as the breeding
season approaches, but these matters are perhaps
best dealt with when we come to consider the
moulting of birds. Incidentally we may remark
that the Snow-Bunting and the Brambling
present us with two capital instances of this
peculiarity. The correlation of colour with en-
vironment is another branch of this interesting
subject. Most readers may recall how birds of
white plumage usually live amongst snow-clad
localities, as for instance the Snowy Owl and the
Ptarmigan ; how others that dwell in deserts
and on sandy plains are clothed in plumage in
which brown or yellow predominates ; how so
many forest-haunting species such as Parrots,
Fruit Pigeons, Barbets, and so on, are of tints in
which green largely prevails. These are in most

ORIGIN AND CHARACTERISTICS 25

cases modifications of colour for purposes of
concealment, whilst yet another branch of this
fascinating subject of animal colouration deals
with the curious phenomena of Mimicry (in
birds the known instances are comparatively
few) and with recognitory and warning colours.
(Conf. Curiosities of Bird- Life, Chaps, vii. viii.)

We cannot well leave the interesting subject
of plumage without devoting a few lines to the
moulting of birds. Moulting is the changing
or renewal at stated periods of the old abraded
and worn feathers, these being shed and re-
placed by new ones. Every living bird is sub-
ject to this process at least once every year, a
complete change of dress usually taking place
shortly after the breeding season is over. In
addition there are many birds that undergo a
complete moult twice in the year, in spring
and autumn ; others which have a partial
moult in spring as well as the full moult in
autumn ; whilst others, yet again, may almost be
said to be in a chronic state of moult throughout
the year. Birds with a double or partial spring
moult undergo this just previous to the nuptial
season, then acquiring those various wed-
ding ornaments for which so many species are
famous. So far as concerns the smaller contour

26 THE STORY OF THE BIRDS

feathers moulting is a slow and gradual pro-
cess, and as far as is known with little or no
stated order of sequence, although I have re-
marked in not a few species that the feathers
of the head are the last to be changed. The
flight feathers of the wings, and those of the
tail, are shed and renewed in pairs, in most
cases, so that the bird shall not be incon-
venienced or incapacitated from flight during
the process. In some groups, however, especi-
ally in the Swans, Geese, and Ducks, the wing
quills are shed rapidly and all, practically, at
once, so that the birds cannot fly until the new
feathers have grown. The Grebes, some of the
Rails, and the Flamingo furnish others. During
this period of comparative helplessness the
birds skulk amongst dense cover, or repair
to the sea or other open expanses of water,
whilst the males of many species of Ducks dis-
card their showy plumage at this time, acquir-
ing a dress very similar in colour to the female,
which they wear for some weeks until able to
fly again. Incidentally we may remark that
one species, the Logger-headed Duck, Tachyeres
cinereus of Patagonia, never seems to regain
the power of flight after the first moult of its
wing quills. Young birds, generally speaking,

ORIGIN AND CHARACTERISTICS 27

are later in their moult than adults, and in a
great many cases the first set of quills are re-
tained during the first year of existence, although
in not a few Gallinaceous birds, which are able
to fly before fully grown, new sets of quills are
acquired as maturity is reached. Among birds
that moult very slowly, or that are in a chronic
state of plumal change, may be mentioned the
Swifts, the Birds of Prey, the Herons, and the
Ptarmigan. With the exception of the latter,
which by the way dons no less than three
distinct plumages in the year, all these birds
appear to be moulting their wing quills very
slowly throughout the year save perhaps in the
breeding season. Some of this change of colour,
due to season, is produced by an actual change
of pigment and not by a replacement of the
feather. (Conf. Stray Feathers, p. 154, for ad-
ditional details respecting the moulting of birds.)
Before leaving this portion of the subject we
may briefly allude to another periodical change
which takes place in the integument .of certain
birds. This relates to the peeling or shedding
of the claws in some of the Grouse during
spring, the elongation of the bill in the Redpoles
during summer (possibly due to a change of
food), the shedding of a horny projection from

28 THE STORY OF THE BIRDS

the ridge of the bill (assumed by both sexes
during the breeding season), by the American
White Pelican, this peculiar excrescence strewing
the breeding ground of these birds literally in
bushels; and lastly the curious annual moult
which the bills of some of the Auks undergo
as well as the acquisition and shedding of the
horny or fleshy growths above the eyes and
round the gape. Our own familiar Puffin
furnishes a most interesting instance of this
phenomenon. Some very interesting details of
this peculiar form of moulting amongst the
Alcidae are published by Dr. Stejneger in Bul-
letin No. 29 of the United States National
Museum.

We will now proceed to a brief consideration
of the most salient characteristics of the skeleton
and internal structure of birds. Of course in
a work of the present scope it is not only im-
possible but unnecessary to enter into any
great detail of avine anatomy. The student
must seek such information in special works,
one of the most useful being Professor Newton's
Dictionary of Birds, Dr. Gadow's contributions
to which upon this subject being singularly
full and original. To these contributions we
are largely indebted for the following particulars

ORIGIN AND CHARACTERISTICS 29

relating to the osteology and digestive system
of birds. The skeleton of a bird may very
naturally be divided into three principal parts,
comprising the head, the trunk, and the limbs.
The vertebral column not only contains and
serves as a protection to the spinal cord, but
supports the head and limbs. It is composed
of a very variable number of units or vertebrae,
which are divided according to the position they
occupy into the following classes, viz., cervical
relating to the neck, dorsal to the back, sacral
or pelvic to the loins, and caudal to the tail.
The first cervical vertebra is termed the Atlas,
because it bears the head, and which is articu-
lated with it by a single occipital condyle. The
second, termed the Axis, because it is the pivot
on which the atlas and head turn, is consider-
ably longer and larger than the succeeding
cervical vertebrae, remarkable for their paired
or single ventral processes and vertical knobs,
when in the former condition assisting to pro-
tect certain blood-vessels, and when in the latter
serving for the attachment of the powerful
muscles which work the flexible neck. Suc-
ceeding these come the dorsal vertebrae, which
not only in many cases coalesce with each
other, but always do so with the sacral or pelvic

30 THE STORY OF THE BIRDS

vertebrae, and nearly always with the terminal
portion of the caudal vertebrae which, fused to-
gether, form the Pygostyle or terminal triangular
plate in which the rectrices or tail-feathers are
carried. A typical avine vertebra consists of the
centrum, an arch, and two ribs. The arch as
already stated encloses and protects the spinal
cord. This type of vertebrae, with the facets or
articular surfaces saddle-shaped, is termed hetero-
ccelous, and is restricted to Birds. The ribs of
a bird are attached to the vertebrae firstly by a
capitulum or head, and secondly by a knob or
tuberculum. That portion next to the head
is termed the neck, and this is succeeded by
the shaft, composed of two pieces, the dorsal
and the ventral. To the posterior margin of the
dorsal section is generally attached a thin bony
blade termed the uncinate process. This pro-
cess is attached to the ribs (with the exception
of the last) of all birds (save the Screamer), and
is also present in some reptiles. When the
ventral section reaches and articulates with the
sternum, the rib is a " true " one ; but if the
sternum is not reached it becomes a "false"
rib. Ribs according to their position are
classified as follows : cervical, cervico-dorsal,
thoracic, and lumbar. The number in these

ORIGIN AND CHARACTERISTICS 31

various classes varies considerably, not only
amongst species but even in individuals — a
fact which renders them of no value from a
taxonomic point of view. We now come to a
consideration of that part of the skeleton
technically called the sternum, or in more
familiar language the breast-bone. This very
important part of the avine frame is joined to
the vertebral column, as we have already seen,
by the thoracic ribs, whilst its anterior margin
supports the coracoids, or strong bones con-
necting it with the scapulae or shoulder-blades
and the clavicles or collar-bones, the three
pairs of bones combined forming the Pectoral
Arch or shoulder girdle. The last-named are
generally united or fused at the ventral end,
into a V-shaped Furcula, much better known
as the " wish-bone " or " merry-thought." The
furcula is subject to considerable modification
in certain birds, notably in the Crane, the Swan,
and the Frigate Bird ; in other birds the clavicles
are degenerated, the dorsal portion alone being
retained, the ventral end being reduced to a
ligament. In some birds (the Parrots for in-
stance) the clavicles are absent. In many
instances the furcula is ossified with the anterior
portion of the keel of the sternum ; whilst in

32 THE STORY OF THE BIRDS

Ratite Birds, the Frigate Bird, and the now
extinct Dodo the coracoids and the shoulder-
blades are fused together. Two very distinct
types of sternum exist. Of these by far the
most generally prevailing is that in which the
ventral surface is provided with a ridge or keel
(carina). The other type of sternum is that in
which the keel is absent, more resembling a flat-
bottomed boat (ratis). This latter is found in a
few archaic types only, such as the Ostrich, Rhea,
Cassowary, Emu, and Kiwi. Birds with a keel
to the sternum are therefore termed Carinate
Birds, whilst those in which this ridge is absent
are called Ratita Birds, these groups forming
the two divisions into which all living birds are
separated by systematists. Before leaving the
sternum we have to allude to the various pro-
cesses on the sides behind the articulation of
the ribs. The most noticeable of these are
situated near the posterior portion, and consist
of outgrowths (although connected by mem-
branaceous tissue), giving the margin when
macerated a more or less deeply notched ap-
pearance, or when the extremities are joined
or enclosed by bone or cartilage they form
what are technically termed fenestrae. In some
birds two of these notches on each side of

ORIGIN AND CHARACTERISTICS 33

the posterior margin of the sternum occur, in
others but one. These peculiarities appear to
possess little taxonomic value, the configuration
of the anterior portion of the sternum being
more important in this respect. The next por-
tion of a bird's skeleton that we have to
consider is the pelvis, composed of a number
of fused vertebrae together with three bones
on either side, the largest and most dorsal of
which is called the Ilium, the ventral or middle
one termed the Ischium, and the anterior and
most slender of all known as the Os pubis,
and all meeting at the acetabulum or cup of
the pelvis in which the head of the femur or
thigh-bone articulates. These three paired bones
coalesce with each other at an early stage of
the bird's existence, whilst the notch between
the two first named of these bones becomes a
foramen in all known birds with the exception
of the archaic Ratitae and Crypturi. From the
trunk of the skeleton we now pass to a brief
notice of the bones of the limbs. We will
take those of the wings or anterior limbs first.
These consist of the Humerus or upper arm-
bone which articulates with the coracoid and
scapula, the Ulna and Radius which together
compose the forearm, and the Carpus or wrist,

34 THE STORY OF THE BIRDS

the Metacarpus or space between the wrist and
the digits, and the Digits or fingers, the three
sets together forming the hand. The first and
shortest of the three metacarpals (together
forming the metacarpus) bears the thumb or
Pollex (to the basal joint of which the bastard
wing is attached), consisting of one or two
joints (the terminal one frequently absent or
aborted) ; the second and strongest composed
of two or three joints is termed the Index ;
whilst the third, the weakest and most slender,
has one joint only. Some few Archaic birds
(Ratitae) possess the second metacarpal only ;
whilst in the Penguins it is fused with the first.
Claws at the tips of the metacarpals are rare
in existing birds, although as we have already
seen the extinct Archaeopteryx was provided
with them. In modern birds they apparently
mostly appear accidentally upon the thumb and
index, and probably in no case are functional.
We have seen a pollex claw upon the Common
Whitethroat, and such is found in various
Anserine birds, in the fowl, and in some
Raptorial birds. Conical spurs are not un-
common on the carpal and metacarpal bones,
and are often used as weapons.

The bones of the legs or posterior limbs, like

ORIGIN AND CHARACTERISTICS 35

those of the wings, are composed of three prin-
cipal portions. The first of these is the Femur
or thigh, which, as we have already mentioned,
articulates with the cup or acetabulum of
the pelvis, following which come the Tibia
and Fibula, often more or less coalescent and
together forming the shank or "drumstick,"
and lastly the bones of the Foot. Not a little
confusion exists, even amongst persons fairly
familiar with birds, respecting these three divi-
sions of a bird's leg. The actual thigh of a
bird is hidden by the plumage, and the shank
(Tibia and Fibula) is often mistaken for it, as
the metatarsus is for the shank. The metatarsus
is a compound structure formed by the fusion
of the second, third and fourth metatarsal bones,
which when maturity is reached do not lie in
the same plane (except in the Penguins and
some Parrots), the third having its upper end
thrust backward and its lower end pushed
forward during the course of growth. The
fifth metatarsal is only seen in the embryotic
stage, soon disappearing, whilst the first meta-
tarsal chiefly remains separate, lying in the
majority of birds behind the distal part of the
others. The metatarsus is covered with a series
of angular horny plates or scutellae, varying

36 THE STORY OF THE BIRDS

considerably in size in the different groups, in
some consisting of a series of fine reticulations,
in others of oblong plates, or of both combined,
whilst in others yet again the surface of the
metatarsal is smooth and " booted." Following
the metatarsals come the toes, which form that
part of the foot upon which a bird stands or
walks. Owing to the transitory character of the
fifth metatarsal a bird never shows any trace of
a fifth toe. The first toe in not a few cases is
aborted, in the Ostrich the second toe is want-
ing, whilst in two genera of Kingfishers the second
toe is aborted : the only instance known of an
aborted fourth toe is presented by the Timeliinae,
genus Cholornis. The hind toe (Hallux) has two
joints or phalanges only, the second toe or digit
possesses three, the third toe four, and the fourth
toe five joints. The Swifts, however, are excep-
tional, having only three phalanges in each of
the anterior toes, whilst in the typical Goatsuckers
and the Sand-Grouse the fourth digit possesses
only four. The toes of birds are modified in
an immense number of ways to bring them into
harmony with the conditions of life and the
various habits of their possessors. In numbers
of birds either the hallux or the fourth digit is
reversible at will, as in the Owls and to a lesser

ORIGIN AND CHARACTERISTICS 37

extent in the Plantain-Eaters and certain forms
of Rollers. In other groups this temporary con-
dition has become permanent, and we have what
is termed a " zygodactylous " foot, as presented
by the Woodpeckers, Cuckoos, and Parrots.
In the Mouse Birds (Colius) the hallux can be
brought forward whilst the fourth digit can be
turned backwards at will, whilst in some of the
Swifts and Goatsuckers all the digits constantly
turn forwards, this class of foot being techni-
cally called a " pamprodactylous " one. In
many water birds the anterior digits are joined
together by a membrane, thus forming what we
call a webbed foot, so admirably adapted for
swimming, whilst in the Pelicans the hallux is
also joined to the other digits by a web. The
hallux is by far the most variable of the digits,
and may either exist on the same plane as the
other digits, when it is usually large and of
service, or be raised above the others, and is
then smaller and without function. This is
especially the case in the Wading Birds, in
others it is reduced to a mere stump as in the
Petrels and certain three-toed Woodpeckers, and
in others it is entirely wanting, as in the Auks,
Bustards, Ostriches, and allied birds (Ratitae),
and one or two Waders (Sanderling, Grey

38 THE STORY OF THE BIRDS

Plover). The inner margin of the claw on the
third toe or digit of some birds is toothed,
serrated, or pectinated as in the ^Goatsucker, the
Herons, the Cormorants, the Coursers, Pratin-
coles and some of the Grouse.

From the trunk and limbs we pass to the
head or rather the skull, the last portion of
the avine skeleton we have now to consider.
The complicated nature of this part of the
skeleton and the large amount of space that
would be required to render its description at
all intelligible to the average reader, make a
detailed notice of the numerous parts here im-
possible. The student or interested reader may
therefore be referred to some standard work
on vertebrate anatomy (such as Owen's, or better
still the masterly contributions of Dr. Gadow
to Professor Newton's Dictionary of Birds),
where full particulars may be obtained. The
various bones of the head, it may be stated,
fall naturally into several groups, as, for instance,
those forming the Cranium, which includes all
the bony and cartilaginous parts of the skull
except the jaws and the palato-pterygo-quadrate
bones, those appertaining to the visceral arches
which give rise to the Hyoid Apparatus, the
palate and the jaws. The Bill lends itself to

ORIGIN AND CHARACTERISTICS 39

more popular treatment, and is so closely con-
nected with the habits and characteristics of
birds that some amount of detailed description
becomes absolutely necessary in a work of the
present scope. A Beak (rostrum) consists of
an upper jaw or Maxilla, and a lower jaw or
Mandible. The bill is divided into several parts
by anatomists, chief of which are the culmen or
dorsal ridge of the upper bill, the apex or tip,
the dertrum or swollen hook in which it often
terminates, the genys or ridge or angle of the
lower mandible, and the tomia or cutting edges
of the bill. The horny sheath or rhamphotheca
in which the bones of the bill are enclosed in
some cases consists of a number of pieces, but
in the majority of cases forms one coherent
sheath. In birds of the Duck tribe most of the
covering sheath is soft, only the tip or nail being
hard and horny ; whilst in Raptorial birds and
Parrots the distal end of the bill is hard and the
basal portion is soft and forms a cere, in which
the nostrils are generally situated. The nasal
portion of the bill in many birds is soft and
furnished with an operculum, as in the Pigeons ;
whilst in the Petrels this operculum is still more
developed and forms a tube. In some birds the
horny sheath is curiously modified and swollen

40 THE STORY OF THE BIRDS

into certain horns, knobs, and protuberances,
reaching its climax in the Hornbills and Toucans :
the Coots, Swans, and Scoters may be also
instanced. Reverting to the nostrils we find
certain very distinct classes ; those in which the
nasal cavities are separated by a septum are
termed "impervious," and those in which the
septum is incomplete, the nasal cavities com-
municating, are termed "pervious." Another
type of nostril is found in the Cormorants, for
instance, in which it is reduced to a mere slit,
and becomes still further emphasised in the
Gannets, in which the nasals are absolutely
closed, and the birds are reduced to exercising
the sense of smell through the mouth. The
edges of the mandibles in many birds are more
or less deeply indented, notched, or serrated,
thus enabling the bird better to seize and devour
its prey ; in the Ducks and allied birds these
serrations take the form of lamellae used for
sifting and securing food. Mention should here
be made of that small calcareous protuberance
at the tip of the upper bill which is developed
in 'the embryonic stage of all birds, and known
as the "egg tooth." This "tooth" is used as a
file by the chick in freeing itself from the egg-
shell, and is cast soon after its purpose has been

ORIGIN AND CHARACTERISTICS 41

fulfilled. It is interesting to remark that a similar
" egg tooth " is present in reptiles and used for
the same purpose. We might say with perfect
truth that the modifications in the form of the
bill are almost endless — adapted for every con-
ceivable method of obtaining food. A brief
glance at some of the most striking types must
however suffice. Passing over the ordinary type
of bill which is found in such a large number
of birds even belonging to the most diverse
families, we have as specially modified forms the
broad, depressed, lamellae-furnished bills of the
Duck tribe ; the powerful curved and hooked
bill of Raptorial birds ; the exceptionally strong
and rounded bill of the Parrots, so admirably
adapted for reducing to pulp the hard nuts and
fruits upon which these birds so largely subsist ;
the chisel or wedge-shaped bill of the Wood-
peckers, which enables those birds to reach their
prey or excavate their nest holes amongst timber.
Then we may instance the lance-shaped bills of
the Herons and Divers, adapted to seize fishes,
or the broad, flat spatulate bill of the Spoonbills.
Or, again, as quite another type, the singularly
weak bill of the Swallows, Goatsuckers, and
Swifts, almost functionless as a food seizer. The
amount of variability in the form of the bill in

42 THE STORY OF THE BIRDS

some otherwise homogenous groups of birds is
most remarkable, and significantly proves with
what ease this organ may become modified to
meet certain conditions of life. Two of the most
striking examples of this are furnished by the
Charadriidae or Wading Birds, and the Trochilidae
or Humming-Birds. In the former group we
have hard chisel-shaped beaks in the Oyster-
catchers, sharp and slender ones in the Phala-
ropes, Stilts, and Avocets (in the latter upturned),
long and sensitive in the Snipes, arched in the
Curlews, heart-shaped or spatulate at the end
in the Spoonbilled Sandpiper, and absolutely
turned towards the right in that singular form
the Wrybill. Little less variable is the modi-
fication in the bill of the Humming-Birds, and
which can only be described as astonishing. Its
abnormal maximum length is reached in the
genus Docimastes, in which it is longer than the
bird, including the head and tail ; whilst its
abnormal minimum length attains in the genus
Rhamphomicron, in the smallest species of which
it is only a quarter of an inch. We find in this
family every gradation, from a perfectly straight
bill to one so curved or arched as to describe
almost one third of a circle, appropriately termed
Sickle Bills ; whilst in other species it is strongly

ORIGIN AND CHARACTERISTICS 43

recurved like that of an Avocet ; another singu-
lar modification is presented in the much-com-
pressed bill of birds in the genera Heliothrix
and Schistes. In some species the bill is hooked
and the edge of the mandible serrated. Amongst
the more aberrant types of bill mention may be
made of that of the Whale-headed Stork and the
Boat-bill (Cancroma) and Shoe-bill (Balaeniceps),
in which the bill is shoe or boat shaped ; of the
very curious bill of the Whalebirds (Prion), in
which the jaws do not completely close ; of the
bill of the Skimmer (Rhynchops), which is
scissor-shaped, much compressed laterally, and
the lower mandible is considerably longer than
the upper one. Mention may also be made of
the curiously modified bill of the Flamingoes, in
which the upper mandible is not only highly
mobile, but is much smaller than the lower one,
which is almost immovable ; and lastly, of the
singular formation of the bill of the Crossbills,
which, as the name of the birds indicates, has the
two mandibles obliquely crossed.

We now pass to a very brief sketch of some
of the internal organs of a bird. Here again the
various divisions of the internal structure are
each so complicated and important that anything
like an exhaustive description is impossible

44 THE STORY OF THE BIRDS

within the limits we have assigned to our treat-
ment of the subject. The Muscular, Nervous,
and Digestive Systems of a bird each require the
fullest treatment to render the study comprehen-
sive, and any attempt would be more or less
futile to condense it in the limited space
at our disposal or to bring it at all into pro-
portion with the purely introductory character
of the present little treatise. Suffice it then to
say, that the muscles of a bird constitute what
is popularly known as flesh, and consist of a
series of fibres, arranged with their long axes
in the direction of the muscles' action, each
being in connection with a nerve-cell, the ex-
citement of which causes contraction and the
drawing together of the parts to which the
whole muscle is attached. Muscles are of two
kinds. First, involuntary or unstriped muscles,
usually of slow and rhythmical action, belong-
ing to the viscera and the skin : second, volun-
tary or striped muscles; whilst the cardiac
muscles are to some extent intermediate between
the two. The Nervous System of a bird consists
of two portions, a Central portion made up of
the Spinal Marrow or Cord and the Brain, and
a Peripheral portion containing the Cranial and
Spinal Nerves with all that relates to the

ORIGIN AND CHARACTERISTICS 45

alimentary and genital organs and the circu-
lation. The Digestive System embraces the
Alimentary Canal and its various glandular ap-
pendages either embedded in its walls, or like
the Liver and Pancreas connected with it by
special passages. Its function is to prepare the
food, partly by mechanical and partly by chemi-
cal processes, and to absorb the nutritive fluid
(Chyle) by aid of the lymphatic vessels. The
first organ of digestion is the Tongue, which
is subject to an immense amount of modifica-
tion, often; similar in distantly related groups,
due to correlation with special modes of ob-
taining food. In birds the tongue can scarcely
be regarded as an organ of taste, although in
many species it is of the greatest use in securing
prey, and in most is subservient to deglutition.
A brief description of some of the principal
types of tongue may not be devoid of in-
terest. It certainly reaches its greatest de-
velopment in birds of the Duck tribe (as well
as in the Flamingoes), whilst in the other
extreme it becomes reduced to a mere
nodule in the Pelicans and Gannets, in some
of the Herons, Storks, Hornbills, Hoopoes,
Kingfishers, Goatsuckers, Petrels, and Ratitae
birds. In Raptorial birds the tongue is short,

46 THE STORY OF THE BIRDS

thick, soft, and spatulate ; in the Woodpeckers
it is exceptionally long, round, narrow, and
pointed at the extremity, in some species armed
with hooks directed backwards. The tongue
of some of the Parrots (Trichoglossidae) exhibits
a brush-like fringe, whilst that of the Toucans
(long and slender and non-protusible) is clothed
with numerous short bristles along the sides.
In the Humming-Birds and Sun-Birds especially
the tongue is subject to special modification,
and is wonderfully adapted to the mode of
feeding. It is extremely long, and in the Hum-
ming-Birds consists of a slightly flattened tube
towards the base, which divides before reaching
the forked part of the organ, and a flange or
thin lamella is developed along the outer edge.
This flange curls upward and inward and con-
verts the forked tip into two tubes, the anterior
half of the flange being more or less fringed.
Some of the latter fimbrication, however, appears
to be due to the constant use of the flange.
Following the tongue comes the (Esophagus or
gullet, which in many birds opens into the
ingluvies or crop, which is succeeded by the
glandular proventriculus or anterior portion of
the stomach, which leads to the muscular ven-
triculus or posterior portion, popularly termed

ORIGIN AND CHARACTERISTICS 47

the gizzard. This latter communicates with
the intestines (which vary considerably in
length in the various avine groups), which
towards their extremity at the beginning of the
rectum in many birds are provided with a
pair of blind-sacs or lateral dilatations techni-
cally called caeca. The presence or absence of
these sacs in a functional condition is chiefly
dependent upon the nature of the food ; and
they are most developed in herbivorous species,
least so in those that subsist on animal food,
and absent in species that subsist on fruit and
grain. This, however, is a broad generalisation,
there are many exceptions ; and in some cases
one of these sacs only is present, and that in a
rudimentary state. The process of digestion
may be thus briefly summarised : after the
tongue has played whatever part is assigned
to it, the food is swallowed and passes through
the gullet assisted by moisture from numerous
glands into the stomach. In birds which have
a crop, however, the food is subjected to the
action of certain secretions which, aided by the
heat of the body, exert a softening influence
and prepare it for its entry into the stomach.
Here again it comes under the influence of
secretions from the gastric glands, and is also

48 THE STORY OF THE BIRDS

subjected to the mechanical process of tritura-
tion or crushing (especially in birds that subsist
upon grain and consequently possess muscular
stomachs) in the gizzard, the action usually
being facilitated by the presence of stones, grit,
or sand swallowed by the bird to aid digestion.
When thus prepared the food then passes on
through the pylorus into the small intestine,
where in the first loop of which (the duodenum)
it is mixed with the secretions of the liver and
pancreas, the action of which converts the
soluble portions into peptones which are con-
veyed into the lymphatic system and so into
the blood. When present and functional the
caeca receive what remains of the food, where
still more nutrition is extracted. The remaining
waste substance then returns to the rectum, and
is finally ejected through the cloaca or vent in
the form of faeces or " droppings."

Passing over the organs of reproduction, we
come to those of respiration. Here, again,
space does not admit of much general descrip-
tion, although we must deal at some length with
the organs of voice, which are such a peculiarity
in birds. Leading to the organ of voice is the
Trachea or windpipe branching at the end into
the two Bronchi, each of which enters the lung

ORIGIN AND CHARACTERISTICS 49

on that particular side. The Trachea is a flexible
tube composed of a large series of rings, and
is the passage by means of which a bird not
only breathes but through which most of its
notes are uttered. The dilatation of a part of
the trachea, usually near the middle, is a feature
found in many groups of birds, whilst some of
the Anseres even present a second expansion,
either close to the larynx or more generally near
the lower end. Another remarkable tracheal
modification exists in the males of most Anseres,
some half-dozen or more of the lowest rings
being fused together, and forming what is tech-
nically known as the bulba ossea or "laby-
rinth." In some species of Swans and Cranes the
trachea penetrates into the keel of the sternum;
the excessive lengthening of the trachea causes
it in some birds to be looped. These various
modifications exert considerable influence on the
cries of certain species, but the song owes its
production to another modification at the lower
end of the trachea and the adjoining parts of
the bronchii. This modification is termed the
Syrinx, and is absolutely peculiar to birds. It
consists of a series of muscles attached to the
extremities of the bronchial semi-rings. These

voice muscles reach their highest development

D

50 THE STORY OF THE BIRDS

in what are known as the Oscines or Singing
Passeres. Most of these birds possess five or
seven pairs of syringeal muscles. The four or
five distal tracheal rings are fused solidly together
into a little box or chamber communicating with
the bronchial tubes, the first and second bronchial
semi-rings being closely attached to the trachea ;
and the spaces between the second and third,
and third and fourth semi-rings, being gene-
rally closed by outer tympaniform or drumlike
membranes, whilst the remaining semi -rings
are closed by an inner similar membrane. The
result of the manipulation of these muscles in
endless combinations of rotating and rocking
movements is the utterance through this tracheal
sounding pipe of those lovely songs for which
the true singing birds are so justly famed. Three
types of Syrinx are recognised by anatomists,
dependent upon the position of the sound-
producing membranes, and termed Tracheal,
Bronchia, and Tracheo-Bronchial respectively.
The first-named type includes birds that possess
a loud voice, and form the well-marked group of
Clamatore Passeres, confined to the Neotropical
Region. In the second type the trachea has no
sounding membranes, and includes various Goat-
suckers and Swifts, whilst there are certain forms

ORIGIN AND CHARACTERISTICS 51

of syrinx intermediate between this type and
the next peculiar to certain Cuckoos and Owls.
The third type is the normal one, including the
Singing Passeres, its principal features having
already been described. Here we may say that
the tongue in no way assists the voice in
birds ; with the possible exception of Parrots in
captivity.

Summarising Professor Furbringer's con-
clusions respecting the origin of birds, he
commences with the supposition that they com-
menced their descent as toothed forms of small
or moderate size, with long tails and four feet
similar to those of a lizard, their bodies clothed
with a primitive sort of down. These were
succeeded by creatures in which the down had
become feathers and the fore limbs had become
prehensile organs, the hinder limbs chiefly used
for progression ; these modifications being corre-
lated with a transformation of the legs and
pelvis and a fusion of the metatarsals, resulting
in a flightless feathered biped. The feathers not
only now began to increase in size and stiffness,
but various modifications of the skeleton and
the muscles eventually endowed these early
avine forms with the power of flight. The two
species of Archaeopteryx are all that remain to

52 THE STORY OF THE BIRDS

us of this special type, from which, by many
modifications, especially in the fore limbs and
the caudal region, birds as they exist to-day
have sprung.

In conclusion we ought to say that, accord-
ing to the state in which they are hatched, the
young of birds are divisible into two distinct
groups, one of which is further separable into
two sections. When birds are hatched with
their eyes open, and clothed in down, able to
run almost directly they break from the shell,
and with sufficient food-yolk still in the stomach
to provide for immediate wants, they are classed
as Praecoces or Nidifugae. This group includes
the Ratitae, the Tinamous, Game Birds, Sand
Grouse, Cranes, Rails, Gulls, Waders, Ducks,
Geese and Swans, and the Grebes, Divers, and
Auks. When birds are hatched (it may be with
their eyes open or closed, or covered with down
or naked), unable to leave the nest, and fed
by their parents, and with a very small store
of food-yolk in the stomach, they are classed
as Altrices, or Lower Nidicolae. This group
includes the Penguins, Pelicans, Cormorants,
Gannets, Darters, Frigate Birds, Petrels, Herons,
Storks, Ibises, and Spoonbills. When, however,
the species in the group of Altrices are hatched

ORIGIN AND CHARACTERISTICS 53

blind and helpless, generally naked, fed by their
parents for a long period, and with no reserve
of food-yolk in the stomach when they break
from the shell, they are classed as Higher
Nidicolae. This group includes the Pigeons,
Birds of Prey, Owls, Parrots, Cuckoos, all
Picarian birds and all the Passeres.

CHAPTER II

THE PRINCIPAL BIRD GROUPS

The two Primary Divisions — The Carinatae and Ratitae —
Moas and Rocs — Rheas, Cassowaries, and Emus — Kiwis
and Ostriches — The Crypturi or Tinamous — The Im-
pennes or Penguins — The Colymbiformes or Divers and
Grebes — The Procellariiformes or Petrels — The Pelargi-
formes or Herons, Storks, Spoonbills, and Ibises — The
Pelecaniformes or Tropic Birds, Gannets, Cormorants,
Pelicans, Darters, and Frigate Birds — The Anseriformes
or Swans, Geese, Ducks, and Mergansers — The Grui-
formes or Cranes and allied birds — The Ralliformes or
Rails and Finfoots — The Galliformes or Game Birds —
The Pediophili or Sand-Grouse — The Columbiformes or
Pigeons — The Charadriiformes or Bustards, Plovers,
Sandpipers, Jacanas, Sheath-bills, Crab Plover, and Seed
Snipes — The Lariformes or Gulls, Terns, Skuas, and
Skimmers — TheAlciformesorAuks — TheFalconiformes
or Birds of Prey — The Coraciiformes — The Psittaciformes
or Parrots — The Cuculiformes or Cuckoos and Plantain-
Eaters— The Passeriformes or " Perching Birds."

WITHOUT leading the student into the hopeless
labyrinth of avine classification, it will, I hope,
be quite possible to give a brief outline of the
various great natural groups into which the
kingdom of the Birds is divided by systematists.

54

THE PRINCIPAL BIRD GROUPS 55

Much difference of opinion exists not only
respecting the taxonomic value of various
anatomical characters, but as regards the affini-
ties and relationships of these groups, as well
as the position in the avine system of not a
few aberrant forms. But on the other hand
opinion is much less divided, if not in com-
plete accord, amongst systematists respecting
the composition of the several great groups
which we will shortly proceed to describe at
some length. Birds naturally separate them-
selves, as we have already seen, into two great
primary divisions — one the Carinatae, possessing
a keel to the sternum, the other Ratitae, in which
this keel is absent. This latter division is com-
posed entirely of birds in which the faculty of
flight is wanting ; and as Professor Fiirbringer
seems to have demonstrated, these birds are
the retrograde or degenerate descendants of
birds that possessed volant powers — the body
increasing in bulk as the muscular power of the
wings decreased. There can be no doubt that
the Ratitae comprise the most archaic of exist-
ing birds, so that we may appropriately com-
mence our survey of the principal avine groups
with a brief notice of them. Huxley divided the
Ratitae into five distinct groups, one of which

56 THE STORY OF THE BIRDS

contains no surviving representatives, and to
this number we can with equal propriety add
another, thus bringing the number of groups, or,
as we will call them, Orders, up to six. These
are the Immanes or Moas, and the ^Epyornithes
or Rocs, both of which are extinct (confer pre-
ceding chapter, p. 10) ; the Rheae or Rheas, the
Megistanes or Cassowaries and Emus, the
Apteryges or Kiwis, and the Struthiones or
Ostriches. It is difficult to say which of these
orders is the most highly specialised, for each
exhibits characters which might place it in that
position according to the value we may attach
to them. This, however, is a matter beyond
the province of the present chapter, and we
must pass on to a consideration of the chief
groups of Carinate birds.

First of these, and, as was suggested by
Huxley, a connecting link between the Ratitae
and the Carinatae, we have that small but very
distinct order the Crypturi or Tinamous. They
number just upon eighty species, and have their
home in the forests and on the open plains
of the Neotropical region. Tinamous are com-
paratively small birds, ranging from the size
of a Quail up to that of a domestic Fowl, and
somewhat closely resemble a Partridge in form

THE PRINCIPAL BIRD GROUPS 57

and general colouration. The wings are rounded
and short, suggestive of sedentary habits, whilst
the general actions somewhat resemble those
of the birds in the previous division. The eggs
of these birds are very remarkable, the surface
of the shell being so highly polished as to
resemble burnished metal or glass, and of
various striking colours, such as pale yellow,
green, blue, rich brown and orange. Another
interesting characteristic is that the male bird
performs the duty of incubation. But
little appears to be known respecting the
habits of these curious birds. Tinamous are
said by some observers to be somewhat stupid
birds, easily captured ; whilst their small brain
capacity seems to furnish another proof of
their comparatively low organisation.

Our next group consists of those exceedingly
curious birds the Penguins, which form the
very distinct natural order Impennes, the
Sphenisciformes of some authorities. Perhaps
the most remarkable character of the Penguins
is their peculiar wings, which are so small and
flapper-like as to render the birds absolutely
flightless. These abortive wings, however, are
of great service to the birds in water, and in
some cases are used to assist their owner

58 THE STORY OF THE BIRDS

in its progress over the land. The plumage
is exceptionally dense and compact, covering
the entire body. Penguins assume a ventro-
podal or erect attitude when on land, and
present a very comical appearance as they
stand in regiments at their breeding-places,
where it may be mentioned they are so absurdly
tame that their numbers, in not a few places,
have been terribly reduced by man's wanton
persecution. Fortunately, they do not frequent
the land much except during the breeding
season. The water is their natural element,
and here they dive and swim with great celerity,
aided by wings and feet, very often progressing
for long distances just below the surface, appear-
ing every now and then for a moment to
breathe. Their notes are harsh and barking.
Their food chiefly consists of crustaceans and
other marine animals, with fish and scraps of
vegetation. Penguins breed in large companies,
known as "rookeries," congregating on rocky
islands for the purpose, and making a rude
nest of grass and leaves, placed in holes, under
heaps of boulders, in caves, or amongst the
tussocks of vegetation. Their two eggs are very
pale bluish-green, coated thickly with a chalky
substance, and closely resembling those of

THE PRINCIPAL BIRD GROUPS 59

the better-known Cormorants. The incubation
of these is apparently undertaken by both sexes
(the birds standing over them like Auks), and the
young are fed for a considerable time. Regular
paths to the water's edge are frequently trodden
by the birds in going to and leaving their nests,
which in some cases are a mile or so from the
sea. The largest Penguin known stands about a
yard high, the smallest about half that. More than
a score species of Penguin are known to science.
Considered by some authorities to be some-
what closely allied to the preceding, we have
now to glance at the Colymbiformes, an order
which contains (as two sub-orders) the Divers
and the Grebes. These birds, whether so closely
related as some recent morphologists think, or
not, certainly form an archaic group, and at
the same time a very distinct one. The order
is one of the smallest in the avine kingdom,
the Divers numbering less than half-a-dozen
species, the Grebes not more than twenty-five
or so. Both Divers and Grebes are eminently
aquatic, the feet of the former being webbed,
those of the latter furnished with lobes. The
legs are situated very far back, whilst the
metatarsi are very much flattened — a peculi-
arity which offers least resistance to the water

60 THE STORY OF THE BIRDS

between each stroke. They swim and dive
with wonderful skill, and also possess the habit
of sinking themselves at will in the water until
perhaps only the tip of the beak is exposed.
Their plumage is dense and compact, whilst the
Grebes possess the peculiarity of having the
tail-feathers aborted. Both Divers and Grebes
stand upon the metatarsus, and the ventropodal
position has been claimed as their exclusive
attitude upon land, but the evidence does not
warrant this (Conf. Bird Life in a Southern
County, p. 251). The flight of the Divers is
rapid and strong, some of the species perform-
ing long migratory journeys ; the Grebes are
not such strong fliers, perhaps, but many of the
species are migratory. Some of the latter birds
are famous for the crests and tippets that they
assume just prior to the breeding season. The
Divers make slight nests upon the ground and
lay two spotted eggs ; the Grebes make a more
or less floating nest — a large mass of vegetation
with a cavity at the top in which the half-dozen
eggs are deposited. These are very elliptic in
form, white in colour and chalky in texture.
The Divers feed principally upon fish, the Grebes
upon aquatic insects, molluscs, crustaceans, small
fish, and various vegetable fragments. The notes

THE PRINCIPAL BIRD GROUPS 61

of the Divers are loud and unearthly screams,
mostly heard during the nesting season, but
those of the Grebes are more feeble and of a
croaking description.

Another archaic and fairly distinct order is the
Procellariiformes, which includes the Petrels,
the Fulmars, the Shearwaters and the Alba-
trosses. They are all pelagic birds, and remark-
able for their great power of wing. Their chief
external characteristic is the tubular nostril, a
feature that serves to identify them at a glance.
They vary in size from about that of a Sparrow
(the Storm Petrel, or " Mother Carey's Chicken,"
the smallest web-footed bird known) to that of
a big Goose (the Albatross Diomedea exulans,
one of the largest of volant birds, and with an ex-
panse of wing of upwards of twelve feet). All
the species have the anterior toes connected by
webs ; all swim well and buoyantly, and many
of the smaller species possess the habit of patter-
ing the surface of the waves with their feet,
running as it were over the water, hence the
name of Petrel derived from the Apostle Peter ;
but their most usual province is the air. They
are the feathered nomads of the wide ocean
wastes, and rarely visit the shore unless to breed,
or when driven to do so by exceptionally violent

62 THE STORY OF THE BIRDS

storms. None of the species is remarkable for
any brilliant coloured plumage, the prevailing
tints being blacks, browns, greys, and white.
In all known species the sexes are similar in
colour. Many of the species are of nocturnal
habits, especially the smaller forms of Petrels
and the Shearwaters, but the Albatrosses and
Fulmars are chiefly diurnal. Some of the most
remarkable forms in this order are the Diving
Petrels, which appear to be more terrestrial in
their choice of haunt, frequenting fiords and
inlets. These birds possess the habit of diving,
but little seems to be known respecting their
economy. The notes of these birds are harsh,
cackling, and grunting. The birds often become
very vociferous at night at their breeding-places.
Some of the species are remarkably silent, notably
the Fulmars. These birds breed on remote
ocean islets and lonely coasts, some burrowing
into the ground, others making their rude nests
upon the earth, or on cliffs or amongst boulders.
None of the species lays more than one egg for a
brood, and this egg is white and chalky, in some
cases sprinkled or dusted with a zone of reddish-
brown spots. They feed upon crustaceans,
cephalopods, jellyfish, and similar marine crea-
tures, varied in some cases with scraps of sorrel

THE PRINCIPAL BIRD GROUPS 63

and other vegetation. This order contains about
one hundred species.

Our next order, the Pelargiformes, is by no
means such a homogenous one as those that
precede it. It includes the Herons, the Storks,
the Spoonbills, and the Ibises, each of which
may be again divided into a sub-order or at
least a family, some of the latter yet separable
into various sub-families. These are all long-
legged birds, and most possess a sufficient family
likeness to render their identification with the
group fairly easy. Their long wings, long necks,
and long spear-shaped bill (except in the Spoon-
bills, in which it is spatulate, and in the Ibises,
in which it is arched and slender like that of
a Curlew) are also other characters which are
common to the order. It is impossible here,
with the very limited space at our disposal, to
enter into any detailed description of the
numerous sections into which the Herons may
be divided. All we can do is briefly to enume-
rate the most striking. First we have the Herons
proper, of which our own British species may
be taken as typical ; then come the smaller
Herons, the graceful Egrets, the Night Herons,
the Bitterns, and Little Bitterns, and lastly that
somewhat aberrant and highly curious form the

64 THE STORY OF THE BIRDS

Boat-bill (Cancroma). As a group the Herons
are semi-aquatic, and frequent lakes, rivers,
swamps, and morasses, and the flat sea-coasts.
They are birds of powerful if somewhat laboured
flight, and walk with ease and grace. Their
notes are harsh and guttural, and singularly
weird and booming in the Bitterns. They feed
on fish, small mammals, birds, reptiles, insects,
crustaceans, worms, and molluscs. Their usually
bulky nests, made of sticks, rushes, grass, leaves,
and roots, are either placed on trees or cliffs
or amongst the dense vegetation of the swamps
and marshes. The eggs are generally bluish-
green, but white in some cases and brown in
others. Many of these birds are exceptionally
graceful, being adorned either constantly or
during the nuptial season with mazy plumes
and long pendent crests and gorgets ; others
are of brilliant green or brown or black, in
some cases loricated with metallic sheen. The
Spoonbills and the Ibises are very similar in
their economy to the Herons, but the eggs are
of a different type, especially in the former.
The Storks again form a small group quite
apart from the rest of the order. The typical
Storks bear resemblance to the Herons in gene-
ral appearance. One of their most salient

THE PRINCIPAL BIRD GROUPS 65

anatomical characteristics is the absence of
syringeal muscles and their consequent want of
voice, the only sounds they make being those pro-
duced by clappering or striking the mandibles
together. Their habits and mode of reproduc-
tion are very similar to those of the Herons,
but their white eggs are very characteristic.
Some of the more aberrant forms are very
interesting, including the Adjutant (Leptoptilus)
with its enormous neck pouch ; the Jabiru
(Mycteria) standing five feet high, with its bare
head and neck ; and lastly the still more extra-
ordinary Open-bills (Anastomus), so termed
because of the wide gap between the two man-
dibles near the point. The curious Shoe-bill
(Balaeniceps), and the Hammer-head (Scopus)
are aberrant forms, which may possibly be
associated with the Storks, although opinion is
divided as to their kinship. Perhaps they are
deserving of at least family rank.

Another heterogeneous order is the Pelecani-
formes, the Steganopodes of Illiger and some
other authorities, included in the same order as
the foregoing by others. We include within it
the Tropic Birds and Gannets, the Cormorants,
Pelicans, and Darters, and the Frigate Birds.
They are all aquatic birds, and mostly marine

66 THE STORY OF THE BIRDS

in their habitat, the three last named being least
so. The birds in this order are characterised
by the peculiar structure of the feet, the interior
toes as well as the hallux or hind toe (which is
turned forwards) all being connected by a web.
The birds in the various groups (or perhaps
sub-orders) vary considerably in structure and
appearance. Thus in the Tropic Birds and
Frigate Birds the head is large and the neck is
comparatively short and stout. In the Cor-
morants and Darters the head is small, but the
neck is long, especially so in the last-named
birds. The Pelicans are furnished with a large
pouch between the angle of the lower jaw. The
bill is long, straight, and usually compressed,
cone-shaped and pointed in the Gannets and
Tropic Birds, terminating in a more or less stout
hooked nail in the Cormorants and Frigate
Birds ; in the Darters, long, slender, and pointed.
The legs are placed far back. The wings are
long and ample (least so in the Cormorants), as
might naturally be expected in such an assem-
blage of aerial species. In many species the face
and gular region are bare, the latter often furnished
with a sac. The tail varies considerably, from
the soft rectrices of the Pelicans to the rigid ones
of the Cormorants and Darters. In the Tropic

THE PRINCIPAL BIRD GROUPS 67

Birds the central feathers in the tail are much
prolonged ; in the Cormorants and Gannets it
is wedge-shaped ; in the Frigate Birds it is
acutely forked ; in the Darters it is broad and
fan-shaped. The wing bones of the last are
very specially modified, the furcula coalescing
with the coracoids, whilst the latter similarly
join with the proximal end of the scapula, result-
ing in a nearly rigid framework. This peculiarity
is believed to be closely connected with the
extraordinary soaring or sailing flight of these
birds. The neck of the Darters also presents us
with a feature believed to be unique amongst
birds, the eighth vertebra articulating with the
seventh nearly at a right angle, causing a " kink,"
whilst the muscles connected with this are also
specially modified, the whole forming a beautiful
apparatus by which the birds secure, with the
least possible exertion, the fish upon which they
subsist. We also find great diversity of plumage
in this order, from the pure white of the Gannet
or the Pelican (in the latter with a rosy blush)
to the bottle-green of the Cormorant, or the
loricated blackish-brown of the Frigate Bird.
In many species elaborate nuptial filoplumes
and other ornaments are assumed. In most
species the young are hatched naked, but soon

68 THE STORY OF THE BIRDS

assume a downy covering, whilst in the Tropic
Birds and Frigate Birds they are hatched with
a coat of down. Most of these birds are com-
paratively silent ; but the Gannets are perhaps
the noisiest at their breeding-places. The nests
are usually made upon the ground, or in trees
or on cliffs, the birds generally breeding in large
societies, but the Tropic Birds do not make any
provision for their eggs. The Tropic Birds,
Gannets, Pelicans, and Frigate Birds lay one egg
only for a sitting, which is mostly white and
chalky, but spotted with brown in the Tropic
Birds ; the Cormorants and Darters lay several
eggs for each sitting. Fish is the principal food
of the birds in this order.

As it is impossible to indicate or express
the relationships of the different groups one to
another in a linear series or arrangement, it
is quite immaterial in what sequence we deal
with the various orders, so we may now next
glance at the Anseriformes. This is one of the
most self-contained and natural of the avine
groups, becoming absolutely homogeneous if
we restrict it to the Swans, Geese, Ducks, and
Mergansers, but in it must also be included
the Screamers and Flamingoes. Both these
latter must be regarded as very aberrant forms,

THE PRINCIPAL BIRD GROUPS 69

and are certainly entitled to rank in separate
sub-orders. The Screamers (Palamedeae) can
scarcely be regarded as web-footed, for the
membranes between the long toes are rudi-
mentary. In this group the uncinate processes
to the ribs are wanting, a character not found
in any other existing birds. The bill is short
and stout, a horn or caruncle starts from the
forehead of one species, and the wings are
armed with two sharp spurs. Another curious
feature is the series of air cells between the
skin and the muscles, producing a crackling
sound when the body is pressed. These birds
swim well, and to some extent resemble the
Waterhens in their habits. The eggs are white,
and the young are clothed with down. The
Flamingoes (Phoenicopteri) are more Anserine
in their affinities, but some of these may be
due to analogy. They stand to some extent
midway between the Storks and the Geese.
Their most striking external features are the
long legs and long neck. We have already
dwelt upon the singular formation of the bill
in this group. The anterior toes are webbed.
These birds build conical nests of mud, and
lay but a single chalky-white egg for a sitting.
The young are hatched covered with down.

yo THE STORY OF THE BIRDS

The sub-order Anseres (the Swans, Geese, Ducks,
and Mergansers) contains birds that cannot
readily be confused with the members of any
other order or group. Their most characteristic
external features are their generally broad flat
bills, furnished with a nail at the tip of the
upper mandible, which are either serrated or
furnished with lamellae, and their webbed feet,
all the anterior toes being united by a mem-
brane. The bill varies a good deal in shape,
from the short sub-conical one characteristic
of the Geese to the broad spatulate one of the
Shovellers and the narrow elongated one of
the Mergansers, or furnished with a small hook
in the latter, and some others. The chin-lobe
in the genus Biziura is remarkable. The wings
in some species are armed with spurs. The
tail varies a good deal in shape, but is generally
short, rounded in some, cuneate in others, and
less frequently singularly spine-like and rigid.
The peculiar formation of the trachea in some
species in this order has already been alluded
to (conf. p. 49). A marked similarity of habit
runs through the birds of this sub-order — all,
or nearly all, the species are eminently aquatic,
marine or inland. Most are gregarious at some
time of the year or another. The peculiarities

THE PRINCIPAL BIRD GROUPS 71

of their moulting have been dwelt upon in
the previous chapter. The food is partly of a
vegetable and partly of an animal character.
The nest is placed on the ground, more or less
plentifully lined with down from the parent, in
holes of trees or cliffs, in burrows, and excep-
tionally in low bushes or trees. The eggs are
numerous, buff or green of various shades, or
white in colour, with considerable gloss. The
young are hatched covered with down. These
birds with few exceptions fly well, swim or dive,
and many are of migratory habits. Upwards of
two hundred species are included in this order,
all save nine belonging to the Anseres.

The next order we shall notice is a small
one, the Gruiformes or Cranes and allied birds.
Small as this order is, it is a most hetero-
geneous one, and is composed of the Cranes,
the Limpkins, the Kagu and the Trumpeters.
Each of these is worthy of at least family
rank, the Cranes (nineteen species) constituting
the Gruidse, the Limpkins (two species only)
the Aramidae, the Kagu (one species) Rhinoche-
tidae, and the Trumpeters (six species) Psophiidae.
Some authorities include the Sun Bittern (Eury-
pygidae) and the Seriemas (Cariamidae) in the
present order. Both represent swimming forms

72 THE STORY OF THE BIRDS

of some ancient type, and to assign them a
natural place in the avine classification is a well-
nigh hopeless task. The Cranes are a group of
large wading birds, long-necked and long-limbed.
The bill is stout, and about as long as the head,
the nostrils enclosed by a membrane, and the
nasal groove extends more than half the length
of the upper mandible. The peculiar modifi-
cation of the sternum and the trachea has
already been described (conf. pp. 31, 49). The
wings are long and ample, the inner secondaries
developing into drooping plumes which partially
conceal the short tail. The young are hatched
covered with down. Cranes live in swamps and
on vast open plains, and are remarkable for
their extended migrations. Their flight is power-
ful and sustained. Their notes are loud and
trumpet-like. They make their nests on the
ground in the swamps, and their two or three
eggs are handsomely marked. They feed on
grain, seeds, shoots and leaves, lizards, snakes,
and small mammals. The Limpkins present
features which ally them to the Cranes on one
hand and to the Rails on the other. They
frequent streams and marshes, make a nest on
the ground, and lay numerous white eggs spotted
with brown and purple. The Kagu is a most

THE PRINCIPAL BIRD GROUPS 73

extraordinary bird, about as big as a fowl, with
a long pendent crest, and the wings are beauti-
fully marked and spotted with white, buff, and
black. This bird during periods of sexual rivalry
or excitement indulges in a mad sort of reel,
spreading out its parti-coloured or spangled
wings, and then seizing the tip of its tail or that
of one wing in its bill, begins to whirl round
and round, producing a most novel effect. The
Trumpeters are also remarkable birds, somewhat
Fowl-like in size and appearance, with long legs
and long necks. They are gregarious and dwell
in swampy forests, rarely fly, but run with great
speed, and it is said swim when hard pressed.
Their cry is loud and far-sounding. The food
consists of fruit, grain, and insects. They make
a nest upon the ground and their eggs are
whitish.

Our next order is the Ralliformes, comprising
the Rails and Finfoots, with which we may
also perhaps include the single species of
Mesites. The Rails by themselves constitute a
pronounced homogeneous group, but the in-
clusion of the Finfoots and Mesites introduces
a heterogeneous element. By some ornitholo-
gists the Finfoots are relegated to a separate
order, and Mesites is referred to a sub-order

74 THE STORY OF THE BIRDS

of the Gruiformes, or even included in the Galli-
formes. The Finfoots here forming a separate
family only (Heliornithidae), although obviously
allied to the Rails, are probably a more archaic
and less specialised group. They number but
four species. The anterior toes have broad
scalloped webs. The young are reputed to be
hatched naked, but next to nothing is known of
the reproduction in this family. Their general
habits are Rail-like. The single curious form
constituting the family Mesitidae has the toes
without webs or scallops, and the presence of
powder-down patches (conf. p. 17) is a special
feature. The bill is long and slender, the wings
rounded, the lores and orbits are naked. But
little is known of this curious bird's habits.
The Rails are remarkable for their much com-
pressed body, comparatively short rounded
wings, long legs and toes, the latter sometimes
furnished with webs and scallops. Some of
the Rails are incapable of flight, and conse-
quently these in most instances are threatened
with extermination. The bill, in this order, is
subject to considerable variation; long and com-
paratively weak in the Rails, short and stout
in the Crakes, and strongest of all in the
Gallinules. In not a few cases the forehead is

THE PRINCIPAL BIRD GROUPS 75

furnished with a frontal shield, usually of some
conspicuous hue, or with large caruncles and
knobs. In some cases the wing is furnished
with a spur. The tail is small, and sometimes
almost concealed by the coverts. Most of the
Rails are frequenters of swamps and marshes
and the banks of pools and streams, but some
of them evince a partiality for drier districts.
They are somewhat graceful birds in their
carriage and progress upon the land ; their
flight is laboured, and usually undertaken with
reluctance, nevertheless many of the species
are migratory. They swim and dive with great
skill, and in some cases are somewhat addicted
to climbing and perching in trees. The notes,
generally speaking, are loud and startling, and
of a very distinctive character. Their food
consists of both animal and vegetable sub-
stances. As a rule the Rails are not very
social or gregarious. The nests are generally
made on the ground amongst aquatic vegetation,
or are anchored amongst reeds and rushes some
distance from land. They are made of various
kinds of vegetation. Some few are said to breed
in burrows, others to make spherical structures.
The eggs are mostly numerous and spotted. The
young are hatched covered with down.

76 THE STORY OF THE BIRDS

We will next pass to a consideration of the large
and important order called Galliformes, which
includes what are popularly known as "Game
Birds." Except for one or two trifling excep-
tions, they may be described as a homogeneous
group composed of perhaps half-a-dozen families.
The most aberrant forms associated with the
Galliformes, in the arrangement here adopted,
are the Megapodes (Megapodiidae), the Curas-
sows, Guans and allied forms (Cracidae), and
the Hoatzin (Opisthocomidae). These have been
accorded the rank of a sub-order by some syste-
matists, but family distinction only seems to
us sufficient. Morphologically the Megapodes
appear to be the lowest of the entire order,
confirmatory of which may possibly be their
very peculiar method of reproduction, the birds
burying their eggs in the ground or covering
them with a heap of mould and leaves, and
thus leaving them to be hatched by the sun's
rays or the warmth generated by the decaying
vegetation. The Curassows and Guans closely
resemble the Megapodes in structure, but their
habits are very different. They frequent arboreal
haunts, and make their nests in trees. It is said
that Guans interbreed with domestic Fowls. The
Hoatzin is certainly the most aberrant form of

THE PRINCIPAL BIRD GROUPS 77

all, but resembles the Gallinaceous type more
closely than any other. Various anatomical
modifications render this species unique among
birds, the most remarkable of which is that the
sternum is furnished with a keel only on the
posterior part, the anterior part being aborted ;
the double crop is also unusually capacious, and
rests upon the furcula or wish-bone and the fore
part of the sternum. Another most interesting
peculiarity is that the young birds (which are
able to run as soon as they are hatched) possess
two claws on the wings (on the index and pollex)
which they use to climb about the branches
with, hooking them over the twigs, and progres-
sing with the additional aid of bill and feet. The
most typical families contained in the order
Galliformes consist of the Pheasants, Partridges,
Quails and allied birds (Phasianidae) ; the Hemi-
podes (Turnicidae), raised to the dignity of a
sub-order by some ornithologists ; the Grouse
(Tetraonidae) ; the Guinea Fowls (Numididae) ;
and lastly, the Turkeys (Meleagridae). With the
limited space at our disposal it is impossible to
describe even the chief peculiarities of these
several families, but the following characteristics
are practically common to the entire order. The
sternum contains two very deep notches on the

78 THE STORY OF THE BIRDS

posterior margin ; the episternal process is per-
forated to receive the base of the coracoids,
except in the Hoatzin. The hind toe is always
present, but varying in size and position ; the
body feathers have a well-marked hyporhachis
or aftershaft. The bill is comparatively short
and stout, curved and wide at the base, the upper
mandible overhanging the lower one. The wings
are comparatively short and rounded ; the tail is
most variable, not only in shape but in number
of rectrices. The young are hatched covered
with down, and able to run as soon as hatched.
In no other order do we find greater diversity
of external characters. The great variety and
brilliancy of the wattles, combs, and excrescences
that decorate the head, the development of spur,
the magnificent colours and bewildering variety
in the plumage, and the wonderful modification
of the tail-feathers and coverts, would require
many pages of description to do them justice,
whilst a similar remark applies to the diversity
of habits. About 400 species and races are
known.

Following the Galliformes we have here to
notice another small and yet very characteristic
order, namely the Pediophili or Sand-Grouse.
The position of these birds in the avine system

THE PRINCIPAL BIRD GROUPS 79

seems yet to be an undecided point. By some
authorities they have been included in the same
order as the Pigeons ; by others they have found
a place among the Game Birds. A more recent
authority has referred them to a sub-order of the
Charadriiformes. Whatever their affinities, there
can be no doubt that the Sand-Grouse form a
very highly specialised group, and at the same
time possibly a very archaic one. Sand-Grouse
are birds about the size of a Partridge, with
a bill resembling that of the Game Birds, but
the wings are long and pointed, adapted for
prolonged and powerful flight, the outermost
primary in one species having the shaft pro-
longed into a filament ; the tail is wedge-shaped,
the central feathers much prolonged and slender.
The feet are more or less covered with dense
short plumes ; and in two species the hallux is
wanting, and the anterior toes are enclosed in a
kind of sheath or " podotheca," the whole form-
ing a padded foot, and a feature unique amongst
the class Aves. Sand-Grouse are dwellers on
deserts and rough scrub-covered plains ; some
of the species are migratory or nomadic. They
are more or less gregarious. Their food consists
of grains, seeds, and vegetable substances. They
make but a scanty nest upon the ground, and

8o THE STORY OF THE BIRDS

their three eggs are very oval in form and
spotted with surface and shell markings. The
young are hatched covered with down. Sixteen
species of Sand-Grouse are at present known to
science.

From the Sand-Grouse we may conveniently
pass to the Columbiformes or Pigeons, a re-
markably homogeneous and well-defined group,
composed of nearly 500 species (470 are re-
cognised in the British Museum Catalogue).
These birds are allied apparently to the Game
Birds, through the preceding order, and to the
Plovers. Some authorities divide this order into
two sub-orders, but as one of these (Didi) is
exclusively composed of extinct forms (the Dodo
and the Solitaire), we need not stay to consider
them. All living members of this order, ac-
cording to Count Salvadori, their most recent
monographer, are divisible into five families
(some of which are again made up of several
sub - families). These are the Treronidae or
Fruit Pigeons, Columbidae or Typical Pigeons,
Peristeridae or Ground Pigeons and Doves, the
Gouridae or Crowned Pigeons, and the Didun-
culidae or Tooth-billed Pigeons, of which but
one species is known, and that is threatened
with extermination. Pigeons vary considerably

THE PRINCIPAL BIRD GROUPS 81

in size, the largest being the Crowned Pigeons,
which are nearly as big as a Goose, and the
smallest are included in the Doves, and are
scarcely as large as a Skylark. The Pigeons
all bear such a " family resemblance " that none
of them can be readily confused with any other
birds. Perhaps their most striking external
feature is the somewhat Plover-like bill, enlarged
and hardened at the tip (which is modified into
a decided hook in the Tooth-billed Pigeon) and
covered at the base with soft skin, in which the
nostrils, partly concealed by an incumbent valve,
are situated. The metatarsus is more or less
feathered (except in some of the small Doves) ;
the anterior toes are moderate in length, but
the hallux is small. The plumage is dense and
compact, and the hyporhachis is absent from
the contour feathers or rudimentary only. It
is impossible here to give the many features of
the various families and genera. All that we
can say is that the predominant colour is grey
or brown, often loricated on the neck and
breast with metallic sheen, but in some genera
the birds are brilliantly arrayed in purple,
gold, green, and red. Pigeons as a group are
arboreal in their habits, but some species show
a partiality for rocky or even barren districts,

82 THE STORY OF THE BIRDS

Many of the species are gregarious at some time
or another ; some are migratory. The flight is
powerful and well sustained. Their cooing
notes seem common to the entire group. Their
food consists principally of grain, seeds, shoots
of vegetation, and fruits. The nests generally
are slight platforms of sticks, but some species
breed in holes of trees or rocks, others on the
ground. The eggs are normally two in number,
but in some forms three are said to be laid, in
others but one. These are always white, or
some pale shade of cream in colour. The
young are hatched blind, but with a clothing
of thin yellowish down, and are dependent upon
their parents for a long period. As a rule in-
cubation in this group is performed by both
sexes.

Our next order will be the Charadriiformes.
This may be taken to include the Bustards,
Plovers, Sandpipers, and Jacanas, together with
the aberrant and more generalised and archaic
forms known as the Sheath-bills, the Crab
Plover, and the Seed Snipes. Some or all of
these may possibly require to be included in
several sub-orders ; all of them at least deserve
family rank. The present order may be said
then to consist of nine fairly well denned

THE PRINCIPAL BIRD GROUPS 83

families, some of which are divisible again into
sub-families. These are the Otididae or Bustards,
the CEdicnemidae or Stone Curlews, the Cur-
soriidae or Coursers, the Glareolidae or Pra-
tincoles, the Charadriidae or Plovers, Sandpipers
and Snipes, the Parridae or Jacanas, the Dro-
madidae or Crab Plovers, the Chionididae or
Sheathbills, and the Thinocorythidae or Seed
Snipes. The number of species contained in
this order is nearly three hundred. In point
of size the Bustards are by far the largest,
some of these weighing between twenty and
thirty pounds or more, whilst the Stints may
be classed as the smallest, with a body less than
that of a Sparrow. There is great diversity in
the external characters of the birds composing
the present order, and in none more so than
the bill. In the Bustards (of which thirty
species are recognised) the bill is stout and
somewhat flattened, and without the swollen tip
characteristic of so many other forms in this
order, a peculiarity which is also marked in the
short and curved bills of the Seed Snipes,
Coursers, and Pratincoles. In the typical Plovers
the point of the bill is hard and swollen into
what is technically called a dertrum ; in some of
the Sandpipers it is hard at the tip (Totaninae) ;

84 THE STORY OF THE BIRDS

in others, although hard at the tip, it is provided
with a small number of nerves (Scolopacinae),
which in the typical Snipes become much more
abundant. We have already alluded to the form
of the bill in this group (conf. p. 42), so that
little more need be said here. Mention, how-
ever, might be made of the horny covering or
case at the base of the upper jaw of the Sheath-
bill, and the frontal plates and curious wattles
that adorn the head of certain Lapwings or
Jacanas. The birds in the present order are
terrestrial, with long legs and necks more or
less, and with, in most cases, ample wings. The
toes are subject to considerable variation, from
the short ones of the Bustards to the exceed-
ingly long and slender ones of the Jacanas (the
latter birds being enabled by them to run over
floating vegetation) ; in some cases (as in the
Avocets) the anterior toes are united with a
complete web, in others they are semi or par-
tially webbed at the base, or furnished with
lobes, as in the Phalaropes. In some forms a
few of the primaries are attenuated. The tail-
feathers also vary considerably in number and
shape. The birds in this order are more or
less gregarious, especially during winter. They
run and walk well, many swim, and not a few

THE PRINCIPAL BIRD GROUPS 85

are known to perch in trees. Their food is
partly animal and partly vegetable substances.
They usually nest upon the ground, making a
slight provision for the eggs, which are generally
four in number. These as a rule are handsomely
marked and pyriform in shape, but the Crab
Plover is said to lay a white egg and to breed
in a burrow. The young, almost without ex-
ception, are hatched clothed in down, and
able to run about soon after leaving the shell.
We may also mention that many species are
migratory.

Following the Charadriiformes, and certainly
closely related to them, come the Lariformes or
Gulls, Terns, Skuas, and Skimmers Here again
we have a remarkably homogeneous assemblage
of birds, possessing external characteristics
which prevent them from being confused with
any others. This order may be conveniently
subdivided into four well-marked sections, only
one of which, however, is worthy of more than
sub-family rank. These are the Gulls (Larinae),
the Terns (Sterninae), the Skuas (Stercorariinae)
and the Skimmers (Rhynchopinae). Possibly
the Skuas form a distinct family, as will be seen
below. The birds in this order have the an-
terior toes united by a web. The bill in the

86 THE STORY OF THE BIRDS

typical Gulls is strong and the upper mandible
is curved ; in the Terns it is nearly straight and
pointed, in the Skuas it terminates in a distinct
hook, and furnished with a naked cere at the
base, whilst in the Skimmers it is much com-
pressed, and the lower mandible is a great deal
longer than the upper one (conf. p. 43). In
the two first-named groups the metatarsus is
moderately long, but in the two latter groups
it is proportionately shorter. The claws are
weak in all groups except the Skuas, in which
they are curved and sharp. The wings are long
and pointed, especially so in the Terns and
Skimmers — birds that may be said almost to
live in the air. The tail varies considerably in
shape ; nearly square in most of the Gulls, more
or less acutely forked in many of the Terns, and
the two central feathers projecting beyond the
others (acute in some species, curiously twisted
in another) in the Skuas. These birds are all
aquatic in their habits, and most of them are
marine. Many frequent inland localities to
breed, others are partial to lakes and rivers.
They are more or less gregarious at all seasons,
and not a few are migratory. They fly well and
buoyantly, having great command over them-
selves in the air, swim equally well, but do not

THE PRINCIPAL BIRD GROUPS 87

dive. Some species (Terns) plunge like Gannets
to secure their prey. They feed largely on fish,
but may be described, as a group, as practically
omnivorous. Their notes are harsh and un-
musical. The Skuas obtain much of their food
by chasing and robbing other Gulls of their prey.
They breed on the ground or rocks, the Gulls
and the Skuas making more or less elaborate
nests, but the Terns provide little or no ac-
commodation for their eggs. These are mostly
three in number, sometimes two, and in excep-
tional instances four, and richly marked with
spots and blotches. In this order the sexes are
nearly alike in colour. The prevailing tints are
grey and white in the adult Gulls and Terns
(often with a black hood or crown), browns and
yellow in the adult Skuas. The immature birds
are mostly mottled brown of various shades,
whilst the young are hatched covered with
down. Some hundred and ten species are
known.

Another allied group is the Alciformes or
Auks, which, although it contains but a single
family (Alcidae), is composed of birds present-
ing considerable variation of structure and
plumage, especially of the head. The order
comprises the Auks (of which the recently

88 THE STORY OF THE BIRDS

extinct Great Auk or Gare Fowl was the largest
known representative, as big as a Goose, but
incapable of flight), Guillemots, and Puffins,
numbering some thirty species. Now that the
Great Auk is gone, the members of the present
order are all comparatively small birds, ranging
from about the size of a small Duck to that
of a Thrush. They are web-footed, the anterior
toes being united by a membrane ; the meta-
tarsus is short, and the legs are placed so far
backward as to render their gait clumsy. But
this is compensated by their exceptional
swimming and diving powers, all the members
of the order being as active in the water as
the fishes themselves. The wings are short
and narrow, nevertheless the birds fly well
and rapidly, sometimes for long distances ; the
tail is short, either rounded or graduated. In
some forms (the Puffins) the eyes are decorated
with horny growths, and rosettes of skin are
displayed about the mouth ; whilst nuptial
plumes, often of a most eccentric character,
ornament the head during the pairing season.
Small as this order is, the birds composing it
present an extraordinary amount of variation
in the form of the bill. First we have the
long pointed bill of the Guillemots, then the

THE PRINCIPAL BIRD GROUPS 89

deep laterally compressed coulter - shaped bill
of the typical Auks, and the short arched bill
of the Little Auk, and lastly the still more
laterally compressed and deeper bill of the
Puffins, with its wonderful series of horny
sheaths or appendages, assumed during the
breeding season and lost in autumn (conf.
p. 28). The Auks are all pelagic birds, and
as a rule only resort to the land to breed.
They are more or less gregarious at all seasons,
but especially so during the time of repro-
duction, when they congregate at certain time-
honoured spots to rear their young. They
are comparatively silent birds, their notes
being harsh and grunting. Their principal
food is fish and small marine animals. The
Guillemots and Auks make no nest, but lay
their one, or in exceptional cases two eggs
either on the rock ledges or in chinks and
fissures ; the Puffins usually burrow into the
soft ground or select a suitable crevice amongst
cliffs or even masonry, and form a rude nest
of dry grass, at the end of which they lay
one egg, exceptionally two. The eggs of the
Auks and Guillemots are almost without excep-
tion very handsomely marked, and present
such a variety of colour as to render detailed

90 THE STORY OF THE BIRDS

description here impossible ; the eggs of the
Puffins are mostly dull white, with but a few
faint rusty and grey spots and blotches : the
egg of the Little Auk is pale greenish-blue.
The prevailing colours of the Auks are black
or sooty-brown above, and white below. The
young are hatched covered with down, but
are tended by the parents for some consider-
able time.

This concludes our review of web-footed birds,
and we now pass again to quite a distinct type,
the Falconiformes or Birds of Prey. This is
another exceptionally homogeneous order, com-
posed of birds with special features that preclude
them from being confused with any others.
We may briefly diagnose them by the external
characters of the strong hooked or notched bill
with its basal cere, and the lateral position of
the eyes, to which may be added in the majority
of species the long, powerful, hooked and sharp
claws. The Birds of Prey are divisible into at
least two sub-orders, one of which contains the
American Vultures only (Cathartae), and the
other (Accipitres) is separable into four very
distinct families. These are the Secretary Birds
(Serpentariidae), composed of one species only ;
the Old World Vultures (Vulturidce) ; the Eagles,

THE PRINCIPAL BIRD GROUPS 91

Hawks, Falcons, Harriers, and allied birds (Fal-
conidae) ; and lastly the Ospreys (Pandionidae).
The American Vultures present various important
anatomical differences from their Old World re-
presentatives, among which may be mentioned
the perforated nostrils, the small elevated hallux,
and the absence of syringeal muscles. Included
in this sub-order is the remarkable Condor. Of
the Old World sub-order Accipitres, the most
aberrant form is the Secretary Bird, a long-legged
bird, more like a Crane than a Raptor in appear-
ance, standing more than a yard high, with a con-
spicuous nuchal crest, and the two central tail
feathers more than double the length of the
rest. Its partiality for snakes and other reptiles
ensures it protection from man. The Old World
Vultures are externally characterised by the
absence of feathers from the head, the frequent
presence of a ruff round the neck, blunt claws,
and the absence of a "tooth" or notch in the
hooked bill. They are for the most part eaters
of carrion, and though gifted with marvellous
powers of flight, are comparatively sluggish birds.
They build huge nests of sticks, &c., and their
eggs, one or two in number, are white or vari-
ously marked with reddish-brown and grey. The
next family is by far the most extensive, and

92 THE STORY OF THE BIRDS

contains such distinctive groups as the Eagles,
the Bearded Vultures, the Carrion Hawks, the
Hawks, Harriers, Buzzards, Kites, and typical
Falcons. Although in such a large assemblage
of birds we meet with much diversity of form and
plumage and habits, the general characteristics
are present which sharply define the group from
all others — the same short stout bill, curved and
hooked, the same powerful feet armed with
talons, the same powerful wings (if differing in
length and form). Great diversity of size is also
present, for we have only to compare the mighty
Sea Eagles with the diminutive Falconet no
bigger than a sparrow ! But little tendency to
gregariousness is exhibited, although in some
cases marked social habits are presented. They
frequent almost every description of scenery —
from the sea-coast to the mountain tops, from
the ice-clad regions to the steaming forests of
the Equator. Gifted with keen sight and smell,
they hunt their prey in a great variety of ways,
and their food is of an animal nature. Their
nests may be placed in almost every kind of
situation, from the ground to the tops of trees
and beetling precipices. Their eggs may be
either pale blue and spotless, or richly orna-
mented with blotches and spots of reddish-brown

THE PRINCIPAL BIRD GROUPS 93

and grey. The young are hatched covered
with down, but remain in the nest until fledged.
Not a few of the species are migratory, and
some must be classed amongst the most widely
ranging of birds. The Ospreys are speci-
ally remarkable for the structure of their feet.
The outer toe is reversible, and the soles of
the feet are thickly covered with spicules, whilst
the claws or talons are exceedingly curved
and sharp. These birds live on fishes, which
they catch by plunging upon them like a Gannet
or a Tern. In their reproduction they closely
resemble the typical forms. About 350 species
are included in this order.

The next order we shall notice is the Coracii-
formes, a most heterogeneous assemblage, which
is divisible into no less than seven sub-orders
and nineteen families, each of which constitutes
a fairly compact group. The first of these sub-
orders (Coraciae) includes the Coraciidae or
Rollers, the Momotidae or Motmots and Todies,
the Alcedinidae or Kingfishers, the Meropidae or
Bee-eaters, the Bucerotidae or Hornbills, and the
Upupidae or Hoopoes. The second (Striges)
includes the Strigidae or Owls. The third (Capri-
mulgi) includes the Caprimulgidae or Goat-
suckers, the Podargidae or Frogmouths, and the

94 THE STORY OF THE BIRDS

Steatornithidae or Oil Bird. The fourth (Cypseli)
includes the Cypselidae or Swifts, and the
Trochilidae or Humming- Birds. The fifth (Colii)
includes the Coliidae or Colies, an isolated little
group. The sixth (Trogones) includes the
Trogonidae or Trogons as its only representa-
tives. The seventh (Pici) includes the Galbulidse
or Jacamars, the Bucconidae or Puff Birds, the
Capitonidae or Barbets and Honey-guides, the
Rhamphastidae or Toucans, and the Picidae or
Woodpeckers and Wrynecks. It is absolutely
impossible even to give the leading characteristics
of such a number of diverse groups (containing
a grand total of nearly 1800 species) in the
space at our disposal. The affinity of the Owls
with the birds in this order and not with the Birds
of Prey is, however, specially worthy of mention ;
as is also the fact that among the species above
enumerated are to be found some with plumage
of the most gorgeous colours in the avine class.

Next in order of sequence come the Psittaci-
formes or Parrots. Here we have another of
those homogeneous groups containing birds that
cannot readily be confused with those in any
other order. Although displaying an infinite
variety of colour, and differing greatly in size
and general appearance, the Parrots may be

THE PRINCIPAL BIRD GROUPS 95

readily distinguished from all other avine forms
by their characteristic beak and zygodactylous
feet. The former is in most species short and
strong and arched, the upper mandible mobile
and loosely articulated to the skull, the lower
mandible truncated: the base of the bill is
furnished with a cere. The Parrots (numbering
about five hundred species) may be divided into
half-a-dozen fairly well defined families as
follows : the Stringopidae or Owl Parrots, of
which but a single species is known ; the Psitta-
cidae or Typical Parrots ; the Cacatuidae or
Cockatoos ; the Cyclopsittacidae ; the Loriidae or
Lories ; and the Nestoridae or Keas. The Owl
Parrot or Kakapo (Stringops habroptilus) is
apparently unable to fly, spending its time upon
the ground or climbing about the trees, balanc-
ing itself with its short rounded wings. Other-
wise the wings in this order are fairly long and
powerful ; the tail varies considerably in shape,
short and square, elongated, wedge-shaped, and
in some species the central feathers are bare of
barbs except at the tips, where they form
racquets. In this order the colours are often
gaudy, and displayed in the loudest of patterns.
Parrots are of gregarious habits. Their food
consists principally of nuts, fruits, buds, leaves,

96 THE STORY OF THE BIRDS

roots, grain, &c., and some species are more or
less insectivorous. As is well known, these birds
often hold their food with their feet. Many of
these birds are arboreal, but others frequent
herbage-covered plains and rocks. Their flight
is somewhat slow and laboured ; upon the
ground they walk with ease, and in the trees
climb about the branches, aided by their bill.
Their notes as a rule are harsh and discordant.
Parrots are monogamous, and nest in holes of
trees or rocks, or in the ground; but a few forms
are said to make globular nests amongst the
grass. They make little or no nest as a rule, and
the eggs vary from one to a dozen in the various
species, the larger forms laying the fewest and
the smaller forms the greatest number. The
young are hatched naked, and remain in the
nest holes until fledged.

Passing on from the Parrots we come to the
Cuculiformes or Cuckoos and Plantain-Eaters.
These may be divided into two very distinct
groups ; by some authorities raised to the dignity
of sub-orders, by others regarded as only of
family rank. The latter view will be taken
here. The Cuculiformes then will consist of
the Musophagidae or Plantain-Eaters, and the
Cuculidae or Cuckoos. The latter family may

THE PRINCIPAL BIRD GROUPS 97

be again separated into half-a-dozen sub-fami-
lies, which we will shortly specify. Taking the
Plantain-Eaters first, we find that they differ
from the Cuckoos in several important respects,
although obviously very closely allied to them.
The feet in this sub-order are only semi-zygo-
dactylous, the outer toe being reversible. The
bill is stout, the culmen being rounded or
compressed and serrated or denticulated along
the margin. In two species the base of the
bill is modified into a frontal shield. The
contour feathers are furnished with an after-
shaft ; the wings and tail are rounded, the latter
composed of ten rectrices. All the species but
one possess erectile fan-like crests. Plantain-
Eaters either live in companies or in scattered
pairs. They are arboreal species, shy and
restless, and feed on fruits, insects, worms and,
it is said, small birds. Their notes are loud
and discordant. Their flight is somewhat un-
even, yet on occasion well sustained. So far as
is known, the Plantain-Eaters construct rough
platform-like nests in the branches, and their
eggs are pale blue. The young are hatched
naked. A very remarkable peculiarity should
be mentioned respecting the plumage of these
birds. The crimson feathers yield a peculiar

98 THE STORY OF THE BIRDS

pigment, named by Professor Church " turacin,"
and containing copper, soluble in water. This
colour is not unfrequently washed out if the
birds get their plumage wet, although it is sub-
sequently regained.

The Cuckoos are distinguished by their com-
plete zygodactyle feet, and the absence of an
aftershaft to the contour feathers. The bill is
very variable in shape, nearly straight, curved,
arched, and in some few species exceptionally
large, or the upper mandible laterally com-
pressed into a mere plate. The wings are long
and pointed in the migratory species, more
rounded and concave in sedentary forms. The
tail, consisting of ten feathers (except in a single
sub-family, the Crotophaginae, where they are
only eight), is usually long, and either square,
fan-like or wedge-shaped. In some species the
upper tail coverts are half or quite as long as the
rectrices or tail-feathers. Some of the Cuckoos
are remarkable for their occipital crests, whilst
bifurcate feathers are frequent on the head and
neck. Some of the species are remarkably social,
others are as solitary in their habits. There are
arboreal and terrestrial species. Their food
consists of insects, larvae, reptiles, small animals
and birds, and in some cases seeds and berries

THE PRINCIPAL BIRD GROUPS 99

are said to be devoured. Their notes are loud,
distinctive and peculiar, some of their cries
being quite a feature in certain lands. There
is great variety in the nesting arrangements of
the Cuckoos ; some of the birds make nests and
hatch and care for their young in the usual way ;
but the majority are parasitic, dropping their
eggs into the nests of other birds and taking no
further interest in the welfare of their offspring.
The young are hatched naked. The various
sub-families into which the Cuculidae is divided
are as follows : First, the Cuculinae, of which our
own Common Cuckoo may be taken as typical.
Second, the Centropodinae or Coucals, long-
legged Cuckoos, mostly terrestrial in their habits,
and having the hind toe furnished with a long
straight spine-like claw ; they are non-parasitic,
and their eggs are white and of chalky texture.
Third, the Phcenicophainae or Couas, and Rain
Birds, partly arboreal and partly terrestrial ; the
former of heavy flight and good climbers, the
latter seldom perching : they are non-parasitic,
and their two or three eggs are white. Fourth,
the Neomorphinae, which includes the curious
Chaparral Cocks, terrestrial species, capable of
running with great speed, and rarely using their
short wings ; they are non-parasitic, and lay

ioo THE STORY OF THE BIRDS

three or four white eggs. Fifth, the Diplop-
terinae, a very small group, containing but three
species ; and Sixth, the Crotophaginae, containing
the Anis. These are sociable birds, and curiously
enough when breeding several females join and
share the same nest. About a couple of hundred
species of Cuckoo are recognised.

Our last order consists of the Passeriformes
or " Perching Birds." It is by far the largest of
the groups into which the birds of the world
have been divided, containing some 5500
species, or not quite half the number of existing
avine forms. The subdivision of this enormous
assemblage of species can scarcely be said to
have been satisfactorily accomplished, although
not a few systematists have essayed the task.
The present order contains the most highly
developed birds. Some authorities remove the
Broadbills (Eurylaemidae) and the Lyre Birds
(Menuridae) from the Passeriformes, and raise
each of them to the dignity of a separate
order ; other ornithologists refer them to dis-
tinct families in the order just named. The
separation of the Lyre Birds has the very signi-
ficant fact of the nestling being thickly clothed
in down to support it ; whilst the Broadbills
have certain anatomical peculiarities to warrant

THE PRINCIPAL BIRD GROUPS 101

their being kept apart. The remaining Passeres
may be conveniently divided into four lesser
groups, viz., the Oscines or Singing Passeres,
the Oligomyodae or Non-singing Passeres, the
Tracheophonae or South American Passeres, and
the Atrichornithes or Australian Scrub Birds.
The number of families into which each of these
sections or groups should be divided, is quite
impossible to say, scarcely two authorities agree-
ing in this respect. Some systematists admit
no fewer than thirty-seven in the Oscines, which
includes the Crows, Starlings, Orioles, Finch-like
birds, Larks, Creepers, Titmice, Shrikes, Wax-
wings, Thrushes, Wrens, Timeline Birds, Fly-
catchers, Swallows, and so on. This is by far
the most extensive group. The Oligomyodae is
made up of eight families, and includes such
forms as the Tyrant Birds, the Manakins, the
Cotingas (which includes the curious Umbrella
Bird and Bell Birds), the Plant-cutters, and the
Pittas. The Tracheophonae consists of three
families, the Wood Hewers (among which must
be numbered the Oven Bird), the Ant Thrushes,
and several genera of very aberrant birds classed
as the Pteroptochidae. The Atrichornithes com-
prise a single family of peculiarly modified birds,
having the clavicles or furcula rudimentary. It

102 THE STORY OF THE BIRDS

is quite impossible to enter into greater details
concerning this vast assemblage of birds, which
vary in size from the Raven, say, to the Goldcrest,
and although differing but little in structure
present an amount of variation in colour, in
form, in song, in general habits and economy,
that can only be described as amazing. The
Passeriformes represent the latest stage of avine
evolution ; they are unquestionably the most
highly specialised as they are the most abundant
and dominant of all avine life. The two most
important characters that distinguish these birds
from all others are the aegithognathous palate, in
which the vomer is truncated anteriorly and not
connected with the maxillo-palatines ; and the
anterior toes are connected with the flexor per-
forans digitorum, and the hallux by the flexor
longus hallucis. There are many birds that
superficially resemble the Passeriformes, so that
external characters are comparatively useless.

CHAPTER III

THEIR DISTRIBUTION IN SPACE

The geographical distribution of birds — Views of Sclater,
Huxley, and Wallace — Dr. Sclater's Zoological Regions
— The Palsearctic Region : its characteristic birds —
The Ethiopian Region : its characteristic birds — The
Indian or Oriental Region : its characteristic birds —
The Australian Region : its characteristic birds — The
Nearctic Region : its characteristic birds — The Neo-
tropical Region : its characteristic birds — Distribution
of the Moas and Rocs — Distribution of Ratitae birds —
Distribution of Carinatas birds — The Tinamous — The
Penguins— The Divers and Grebes — The Petrels — The
Herons, Storks, Spoonbills, and Ibises — The Tropic
Birds, Gannets, Cormorants, Pelicans, Darters, and
Frigate Birds — The Screamers, Flamingoes — Swans,
Geese, Ducks, and Mergansers — The Finfoots and
Rails — The Cranes, Trumpeters, Seriemas, and Sun
Bitterns— The Game Birds — The Sand-Grouse— The
Pigeons — The Plovers and Snipes, &c.— The Gulls,
Terns, Skuas— The Auks— The Birds of Prey— The
Coraciiformes — The Parrots — The Cuckoos and Plan-
tain-Eaters— The Passeriformes, or Perching Birds.

IN the two previous chapters we have dealt with
the Origin and Salient Characteristics of Birds,
and with the chief groups or orders into which
they are divided. Naturally we come next to

io4 THE STORY OF THE BIRDS

the Geographical Distribution of Birds, or the
way in which the various species that compose
those orders are dispersed over the earth's surface.
In the previous chapter we commenced by divid-
ing living birds into two great sub-classes, the
Rheas, Cassowaries, Emus, Kiwis, and Ostriches
forming one of these, called Ratitse, and all
remaining birds forming the other, called
Carinatae. Ratitae birds we have divided into
four orders with living representatives, whilst
Carinatae birds have been separated into twenty
orders. Let us now briefly consider how the
various species that form these twenty-four
orders of birds are distributed over the earth's
surface. The first really scientific effort to do
this was made by Dr. Sclater, who divided the
world longitudinally into six great avifaunal
regions. This was followed a few years later
by a scheme of which Huxley was the author,
in which he considered that the earth's surface
was better divided latitudinally, and that four
regions were preferable to Dr. Sclater's six.
Eight years later still, Dr. Wallace published his
great book on the geographical distribution of
animals, in which he adopted Dr. Sclater's views,
and these have been more or less generally
accepted ever since. Although many grave

DISTRIBUTION IN SPACE 105

objections can be urged against the longitudinal
regions sketched out by Dr. Sclater, and although
personally we consider that the whole subject
will require serious modification, and that some
scheme of latitudinal division will yet be proved
to be the correct one, we think that for the
purposes of the present little work these six, or
perhaps five (as we shall shortly learn), regions
may be recognised. Dr. Sclater's six regions
were named respectively . as follows : I. the
Palaearctic Region; II. the Ethiopian Region;
III. the Indian, or as it is frequently termed, the
Oriental Region ; IV. the Australian Region ;
V. the Nearctic Region ; and VI. the Neotropical
Region. There is now, however, a very widely
prevailing opinion amongst naturalists that
New Zealand should form a separate region,
and that the Palaearctic and Nearctic Regions
should be amalgamated, and called the Triarctic
or Holarctic Region. It is not possible here to
describe the many sub-regions and provinces into
which the half-dozen regions have been sub-
divided, although we may roughly define the
geographical limits of the latter and briefly
indicate their most characteristic avine features,
before sketching out the distribution of the
various orders.

io6 THE STORY OF THE BIRDS

The Palaearctic Region may be said to include
Europe from Iceland eastwards, Africa north of
the Sahara, with the island groups of the Canaries,
Madeira, and the Azores, and the whole of Asia,
including Japan, with the exception of South
Arabia, India, the Burmese countries, Malaysia,
and the southern half of China. Among the
most characteristic birds of this region may be
instanced the typical Warblers, the Accentors,
the Magpies, Nutcrackers, Bullfinches, typical
Buntings, and Pheasants, and all those northern
and arctic forms so many of which, however, are
common to the Nearctic region, and thus furnish
one of the strongest arguments for amalgamating
these two areas. The Ethiopian Region is one
of the most compact of these zoological realms,
and consists of the whole of Africa south of the
desert, but including the whole of Egypt and, of
course, the island of Madagascar. Its peculiar
bird types include the Vulture Crows, the Plantain-
Eaters, the Colics, the Oxpeckers, Guinea Fowls,
and Ostriches. The Indian or Oriental Region
includes South Arabia, India, and the remaining
portions of Asia lying south of the limits of the
Palaearctic portion of that continent. Among the
types peculiar to this region may be mentioned
the Laughing Thrushes, Tailor Birds, Barbets,

DISTRIBUTION IN SPACE 107

Hornbills, certain Cuckoos, and the Jungle
Fowls. The Australian Region may or may
not include New Zealand and the surrounding
islands, as we have already explained, but
otherwise is made up of Australia, New Guinea,
and all the other islands situated to the north of
that continent as far as Celebes, together with the
whole of Oceania (or the islands of the Pacific)
excepting the Galapagos. Amongst its vast and
varied avifauna mention may be specially made
of the Piping Crows, Birds of Paradise, Honey-
suckers, Lyre Birds, Frog-mouths, Cockatoos,
Mound Birds, Emus, and Cassowaries. The
Nearctic Region includes Greenland and the
whole of North America as far south as Mexico.
A special feature of its avifauna is the many points
of similarity between it and that of the Palaearctic
Region, but amongst its most characteristic forms
we may name the Wood Warblers, the Greenlets,
Blue Jays, Tyrant Birds, Hangnests, Mocking
Birds, Wild Turkeys, and Turkey Vultures. The
Neotropical Region comprises the remaining
portions of the American continent, from Mexico
southwards to Cape Horn and the few outlying
islands of the southern seas. This region is
perhaps the richest of all in birds, among some
of its special and most dominant groups being

io8 THE STORY OF THE BIRDS

the Tanagers, Ant Thrushes, Manakins, Humming-
Birds, Macaws, Puff Birds, Toucans, Motmots,
Curassows, Tinamous, Trumpeters, Sun Bitterns,
and Penguins.

We will now proceed to give a brief outline
of the geographical distribution of the various
orders already described in the previous chapters.
We may at once dismiss those extinct orders,
including the Moas, which were apparently
peculiar to New Zealand, and the Rocs which,
as we have already seen, were confined to
Madagascar, and pass on to the remaining four
orders of Ratitae birds. The first of these include
the Rheas, birds exclusively confined to the
Neotropical Region, to the pampas and dry
open plains. The second order includes the
Cassowaries and Emus. The former birds are
distributed over the islands of the Malay Archi-
pelago— Ceram, Aru, Jobi, New Guinea, New
Britain — and North Queensland in Australia.
The Emus are confined to the Australian Con-
tinent, though formerly inhabiting Tasmania and
some of the adjoining islands. The third order
includes the Kiwis, those curious flightless birds,
doomed possibly to early extinction, which are
confined to New Zealand. The fourth order
of Ratita3 birds comprises the Ostriches (whether

DISTRIBUTION IN SPACE 109

three species or one seems to be still a moot
point), the largest of existing avine forms, now
peculiar to the Ethiopian Region, from Arabia
southwards to the Cape Colony, although there
is evidence to show that their range once ex-
tended into the deserts of South-western Asia.
As might naturally be inferred these archaic birds
are all of comparatively restricted distribution —
last survivors as it were of once wide-spread
dominant groups, holding on to existence in a
few isolated spots, and sooner or later doomed
to pass completely away from the world, where
now they seem so quite out of place amongst
more highly organised Carinatae birds.

Taking the twenty orders of Carinatae birds
in the same sequence as in the preceding
chapter, we have first to glance at the dis-
tribution of the Tinamous. These birds are
peculiar to the Neotropical Region, where they
range from Mexico southwards to the extreme
limits of Patagonia. Following these comes
the order containing the Penguins. These
birds are confined to the Southern Hemisphere,
where they may be said to range from the
Galapagos Islands on the Equator southwards
into the Antarctic regions as far as man
has yet explored. They are birds of the

no THE STORY OF THE BIRDS

southern seas, having their breeding stations
on various lonely islands right round this
portion of the world, between the Cape of
Good Hope and Cape Horn. Our next order
is composed of the Divers and Grebes. Of
these two families the Divers are essentially
an arctic and sub-arctic group, confined to
the northern portions of the Nearctic and
Palaearctic regions, furnishing another instance
in support of the view held by some naturalists
that these two areas should be merged into
one. The Grebes, on the other hand, are
cosmopolitan in their dispersal, and more or
less generally distributed throughout the world
in all suitable places, almost from one pole
to the other. The next order, the Petrels, is
equally as cosmopolitan in its distribution, only
instead of land, these birds are dispersed far
and wide over every ocean on the globe.
Perhaps they are most numerous in the southern
seas, and although as a group so universally
distributed, many of the species appear to
be very local, at all events during the breeding
season, almost the only time when they
normally visit the land.

The Herons, Storks, Spoonbills, Ibises, and
one or two other aberrant species that compose

DISTRIBUTION IN SPACE in

the order Pelargiformes (the next in our
sequence) are, taken as a group, cosmopolitan
in distribution, but some of the families are
more or less localised. The Herons and
Spoonbills are thorough cosmopolites, although
the latter do not extend into high latitudes,
and are absent from most parts of Oceania.
The Storks form the next most wide-ranging
family, most abundantly dispersed over the
Old World, where they are represented in
every Region, and least so in the New World,
where, however, they occupy both the Nearctic
and the Neotropical Regions. The Ibises are
nearly cosmopolitan, but do not extend into
the colder zones. Both Storks and Ibises are
absent from the Pacific Islands. The remark-
able Shoe-bill (Balaeniceps rex) is restricted to
the central portions of the Ethiopian Region ;
whilst the equally aberrant Hammer - head
(Scopus umbretta) is found over most parts
of that region, including Madagascar. Passing
on to the Pelecaniformes, the order, taken
collectively, is a most thoroughly cosmopolitan
one, but many of the families which compose
it are of somewhat restricted distribution.
Taking the half-dozen families separately, we
have the following facts. The Tropic Birds

H2 THE STORY OF THE BIRDS

are oceanic in dispersal, and practically con-
fined to tropic and warm temperate parts of
the seas in both hemispheres. Of the three
species one roams over the greater part of
the Atlantic Ocean, the Indian Ocean, and
the Pacific Ocean ; another has a very similar
range, but is not known to occur in the
western portions of the Indian Ocean, whilst
the third is absent from the Atlantic Ocean,
but frequents the other two oceans. The
Gannets are another oceanic family chiefly
confined to the warmer portions of the great
oceans, although extending to Iceland in the
Atlantic and to the Cape and Australian seas
in the south. The Cormorants are nearly
cosmopolitan, but do not penetrate very far
into the Arctic Regions, and are apparently
absent from Oceania, although exceptionally
abundant in New Zealand, including the
Chatham Islands. The Pelicans are a widely
distributed group represented in the warm and
tropical parts of every zoological region. The
Darters are similarly scattered over the warmer
portions of these regions, although unlike the
Pelicans absent from Europe, and only just
entering the Palaearctic Region in Palestine.
The two species of Frigate JBirds are distributed

DISTRIBUTION IN SPACE 113

over the tropic seas right round the world, but
one of them is apparently much more local
than the other, confined to the Eastern seas.

The Anseriformes constitute collectively an-
other absolutely cosmopolitan order, but two
of the sub-orders have a distribution considerably
more restricted. These latter are the Screamers,
which are confined to the Neotropical Region,
and the Flamingoes occupy the tropical por-
tions of Asia (with South Europe), Africa, and
America, but are absent from Australia. The
birds composing the sub-order Anseres are the
great cosmopolites. The distribution of the
various sub-families into which the Anatidae is
divided is as follows. The Swans are some-
what remarkable in their dispersal, because their
area of distribution is a discontinuous one.
Swans are distributed over the arctic and tem-
perate portions of the Palaearctic and Nearctic
Regions and the more southern parts of the
Neotropical Region, whilst the Black Swan is
exclusively Australian. Geese, of which several
sub-families are recognised, are practically cos-
mopolitan. The more typical Geese are all
Northern Hemisphere species, some of which
are specially arctic in their distribution. Ducks
may be classed as absolutely cosmopolitan, but

H

H4 THE STORY OF THE BIRDS

many of the genera are significantly geographi-
cal. Thus Dendrocygna is a tropical genus, its
members being found right round the world ;
Chenalopex ranges over the Ethiopian and
Neotropical Regions ; Tadorna and Casarca
(Sheldrakes) are Old World forms; Chaulelas-
mus is confined to the Northern Hemisphere ;
Poecilonetta is common to South America and
the Ethiopian Region ; Elasmonetta is peculiar
to New Zealand ; Nesonetta (a flightless species)
is confined to the Auckland Islands ; Malecorhyn-
chus to Australia and Tasmania ; Heteronetta
to the southern portions of the Neotropical
Region. The cosmopolitan genera are Nettion
or Teals, Anas or Typical Ducks, and Spatula
or Shovelers ; whilst Querquedula (Garganey) is
found over the Northern Hemisphere and the
Neotropical Region ; and Dafila (Pintails) is
cosmopolitan, with the exception of Australia
and New Zealand. The sub-family containing
the Diving Ducks and Eiders is almost exclu-
sively a Northern Hemisphere one, with the
exception of the genus Nyroca (Pochards), which
is cosmopolitan ; Metopiana, which is Neotropi-
cal ; one of the five species of Fuligula which in-
habits New Zealand, the Auckland and Chatham
Islands ; and Tachyeres, confined to the Strait

DISTRIBUTION IN SPACE 115

of Magellan and the Falkland Islands. Many
of these Ducks are arctic or sub-arctic in their
distribution during summer. That containing
the Musk Duck (Erismaturinae) is distributed
over the Australian, Palaearctic, Ethiopian, Ne-
arctic, and Neotropical Regions ; that containing
among other forms the Swift Ducks of the Andes
(Merganettine) is confined to New Zealand,
Waigiu, and the Andes of the Neotropical
Region; whilst that containing the Mergansers
and Smews (Merginae) is partly Nearctic and
Palaearctic, and also distributed over a portion
of the Neotropical and Oriental Regions together
with the Auckland Islands. Few other homo-
geneous groups are more erratically dispersed,
although the significance of such a distribution
is as yet little realised by ornithologists.

The Gruiformes are another wide-ranging
order, although many of the species included
in it are considerably localised. The Typical
Cranes are represented in all the great zoo-
logical regions, with the exception of the Neo-
tropical Region, or at least only just entering
the extreme north of that area as winter migrants.
A considerable number of Cranes are found in
the Palaearctic Region, whilst others are found
in the Oriental and Ethiopian Regions ; the

n6 THE STORY OF THE BIRDS

Nearctic Region claims two species and the
Australian Region one. Of the more aberrant
forms composing this order we have the Trum-
peters, confined, to the tropical portions of
South America; the Limpkins, another special
avine feature of the Neotropical Region ; whilst
the still more aberrant Kagu is confined to New
Caledonia, a remote island of the Pacific. For
geographical purposes we may as well here
allude to the Seriemas and the Sun Bitterns,
which are both peculiar to the Neotropical
Region.

The Ralliformes are another cosmopolitan
order confined to no particular area, and uni-
versally distributed, with the exception of the
Polar Regions, whilst some of the species con-
tained therein are remarkable for their exceed-
ingly extensive distribution. In this group we
have many species confined to islands, some of
them having entirely lost the power of flight.
It is also a most significant fact that some of
the genera or families are indigenous to the
tropic zone right round the world — a pheno-
menon of distribution that is utterly opposed to
any theory of Polar dispersal and also to all the
accepted canons of Distribution. The two out-
lying and aberrant families are the Finfoots and

DISTRIBUTION IN SPACE 117

Mesites. Both these are of somewhat local distri-
bution, although in the former their geographi-
cal area can only be described as enormous,
extending from the Neotropical Regions across
the Ethiopian Region to parts of the Oriental
Region (Burma, Assam, Malacca) ; whilst the
latter, consisting of two species only, is confined
to Madagascar. As a group the Rails are practi-
cally cosmopolitan, although many of the sub-
families and genera are confined to restricted
areas. The Typical Rails, the Crakes, Typical
Gallinules, and the Coots are distributed over
most parts of the earth ; the Purple Gallinules
are most numerous perhaps in the Oriental and
Australian Regions, although represented in the
Neotropical and Ethiopian Regions, as well as in
South Europe ; the Weka Rails are an avine
feature of New Zealand ; the curious Ypecaha
Rails are exclusively Neotropical : other genera
are distributed over various islands in the Pacific.
One of the most widely ranging of Ralline birds
is the familiar Corncrake of our own English
meadows.

Yet another wide-ranging cosmopolitan group
has now to be considered, the Galliformes, or
Game Birds, and various allied forms. Perhaps
no other order of birds is more cosmopolitan in

n8 THE STORY OF THE BIRDS

its geographical distribution. Its representatives
are found almost as high in the Arctic Regions as
land is known, in every temperate zone, and
throughout the tropics and equatorial regions.
Many of the families and genera, however, are
limited in distribution, and some of the more
specialised or aberrant forms are extremely
local. These it may be as well to deal with
first. One of the most compact and geo-
graphically self-contained of these sub-groups
is the Curassows and Guans, which are distri-
buted over the Neotropical Region from Mexico
southwards. Their dispersal is largely depen-
dent upon forests, in which they love to dwell,
and their limits are practically confined between
the two tropics. Returning to the Old World
we have that other aberrant family, the Mega-
podes, which forms such a distinctive avine
feature of the Australian Region. Mound Birds
are distributed over most parts of Australia, but
do not inhabit New Zealand. Northwards the
family is well represented among the various
islands from New Guinea to the Philippines and
westwards to the Nicobars, the species inhabiting
the latter islands being, however, so isolated from
the others of the family and yet so closely allied to
some of them, that doubts have been expressed

DISTRIBUTION IN SPACE 119

as to whether it is strictly indigenous to that
locality. Last of the aberrant Galliformes comes
the Hoactzin, a species confined to the tropical
portions of South America. There are many
points of interest about the distribution of the
Typical Game Birds. Many of the families are
strictly geographical. Thus the Grouse are
confined to the Nearctic and Palaearctic Regions
— to the Northern Hemisphere in fact — another
fact in support of the contention that these two
regions should be merged into one. Then there
are two distinct groups, each composed of Par-
tridges and Quails, having representatives in the
New World and the Old World respectively.
Then again the Pheasants are almost exclusively
confined to Asia, whilst the Turkeys are just as
completely a feature of America. The Guinea
Fowls entirely belong to the Ethiopian Region,
and the Hemipodes are restricted to the Old
World. Many of the sub-families and genera
again are confined within comparatively narrow
geographical limits, as, for instance, the Peacocks
to the Oriental Region, the Jungle Fowls (from
which the various breeds of domestic Fowls have
been derived) to India and Malaysia, the beautiful
Polypectrons to India, China, and Malaysia, and
so on,

120 THE STORY OF THE BIRDS

The Pediophili, or Sand-Grouse, are a small
order, entirely restricted to certain portions of
the Eastern Hemisphere. It is most abundantly
represented in the arid desert districts of the
Ethiopian Region, and in similar localities in
the central portions of the Palaearctic Region.
Sand-Grouse occur sparingly in the Oriental
Region, and still more so in the extreme south-
west of the Palaearctic Region. The next order,
the Columbiformes, or Pigeons, may be said to
be almost cosmopolitan in their distribution,
although they are very unequally divided amongst
the various zoological regions. In the first place
they are by far the least abundant in cold or
northern latitudes, so that the Palaearctic and
Nearctic Regions are the poorest in species. The
Ethiopian Region also is not very abundantly
represented ; the Neotropical Region is much
richer, as is also the Oriental Region ; whilst the
Australian Region is remarkable for the abund-
ance and variety of this order of birds. This
latter region is undoubtedly eminently favour-
able to the development of the Columbiformes.
It abounds in islands, and thus affords those
facilities for isolation so favourable to the estab-
lishment of new species, and is singularly free
from the many predaceous animals — especially

DISTRIBUTION IN SPACE 121

monkeys — that in other parts of the world
have unquestionably checked the increase and
development of birds in this order. As a proof
of the richness of this region in these birds we
may state that the number of known species of
Pigeons contained in it is nearly equal to that
in all other parts of the world combined. Many
of the genera are very local, confined to a single
island or group of islands. The most widely
ranging groups are the Typical Pigeons (Columba)
and the Turtle Doves (Turtur), the former of
these being nearly cosmopolitan with the excep-
tion of the Australian Region, the latter is not
represented in the New World, and is absent
from nearly the whole of the Australian Region.
Roughly speaking, the distribution of the five
families is as follows. The Fruit Pigeons (Trero-
nidae) are all natives of the Old World, common
to the Oriental and Ethiopian Regions. The
Typical Pigeons (Columbidae) are cosmopolitan
within the limits already indicated, as are also
the Ground Pigeons and Doves (Peristeridae).
The Crowned Pigeons (Gouridae) are very local,
confined to New Guinea and a few of the neigh-
bouring islands ; whilst the Tooth-billed Pigeon,
the sole member of its family (Didunculidae),
is the most local of all, and restricted to the

122 THE STORY OF THE BIRDS

Samoa Islands, one of the Australian sub-
regions.

The Charadriiformes are another great cosmo-
politan order, included in which are some of the
most widely distributed of all avine forms. It
is, as we have already seen (conf. p. 82), a very
composite order, made up of no less than nine
more or less distinct families, the geographical
distribution of which may be thus outlined.
First we have the Bustards (Otididae), confined
exclusively to the Old World, birds of a decidedly
Ethiopian type. The Typical Bustards are found
in three out of the four zoological regions of the
Eastern Hemisphere, being only absent from the
Australian Region ; whilst the Ruffed Bustards
penetrate into every Old World region. Follow-
ing the Bustards come the Stone Curlews (OEdic-
nemidae), a small family, yet with a comparatively
wide area of dispersal, which includes the temper-
ate and tropical portions of the Old World and
the Neotropical Region in the New World. The
third family consists of the Coursers (Cursoriidae),
distributed over the Ethiopian and Oriental
Regions and the southern portions of the Palae-
arctic Region. The fourth family, the Pratincoles
(Glareolidae), has a very similar distribution, but
also includes Australia. The fifth family, which

DISTRIBUTION IN SPACE 123

includes the Plovers, Sandpipers, and Snipes
(Charadriidae), is the most cosmopolitan one of all,
divisible into at least eight sub-families, details
of the distribution of which are as follows. The
Oyster-catchers (Haematopodinae) are practically
cosmopolitan in their distribution ; the Typical
Plovers (Charadriinae) are the same, ranging over
the entire earth almost from pole to pole. Many
of the genera, however, are confined to certain
areas, and the distribution of many species is
considerably more restricted during the breeding
season than in winter. The Stilts and Avocets
(Himantopodinae), a small assemblage of species,
are almost cosmopolitan, the only exception being
high northern and high southern latitudes. The
Turnstones (Strepsilinae), numbering but a couple
of species, one almost cosmopolitan, the other
confined to the New World. The Phalaropes
(Phalaropinae) are restricted to the Northern
Hemisphere, chiefly to the arctic and sub-arctic
portions. The Wattled Lapwings (Lobivanellinae)
are distributed over the Oriental, Ethiopian, and
Australian Regions, including New Zealand ab-
normally, but not Oceania. The Semi-web-footed
Sandpipers (Totaninae) are another widely dis-
persed group, but most abundantly distributed
over the arctic and sub-arctic portions of the

124 THE STORY OF THE BIRDS

Northern Hemisphere, especially during summer.
The Cleft-footed Sandpipers and Snipes (Scolo-
pacinae) are nearly cosmopolitan, but most domi-
nant during summer in the Arctic Regions.
Returning now to the families, the sixth of these,
the Jacanas (Parridae), are found in the Tropics
right round the world ; the seventh, the Crab
Plovers (Dromadidae), contains but a single
species, which is distributed round the coasts
of the Indian Ocean. The eighth contains those
aberrant birds the Sheath-bills (Chionididae),
which are restricted to various islands in the
southern seas, such as the Falklands, South
Georgia, Kerguelen, and the Crozets. The ninth
and last family contains the Seed Snipes (Thino-
corythidae) ; these birds are distributed over the
southern or temperate portions of the Neotropical
Region.

Our next order, the Lariformes, is also a
most cosmopolitan one, distributed over the
seas and coasts of the entire earth almost
from pole to pole. The three families, com-
prising the Gulls, Terns, and Skuas respectively
which are included in this order, are each
cosmopolitan in distribution, but some of the
genera are very locally dispersed, some being
confined to high arctic latitudes, others to

DISTRIBUTION IN SPACE 125

the temperate or temperate and tropic zones,
others yet again being restricted more or less
to the equatorial littoral. On the other hand
the succeeding order, the Alciformes, is limited
to the temperate and arctic portions of the
Northern Hemisphere. The Auks (in which
we include the Guillemots and Puffins) are
a special feature of the wild rock-bound coasts
of the northern seas, just as the Penguins
(although but remotely related) occupy similar
localities in high southern latitudes. Specially
remarkable in the distribution of these birds
is the exceptional abundance of species of
Puffins in the North Pacific, so many of them
being famous for their nuptial crests and other
ornaments.

Following these we have now to consider
the distribution of the Falconiformes. Here
again we have a group of perfectly cosmo-
politan birds, penetrating far into the Arctic
Regions, and well represented in every con-
tinent, and in almost every island of any
importance suited to their needs. Of the two
sub-orders into which the present order may
be naturally divided, the American Vultures
(Cathartae) are exclusively confined to the New
World. The remaining sub-order, the Accipitres,

126 THE STORY OF THE BIRDS

containing all other known forms of Raptorial
Birds, is divisible into four families, the
geographical distribution of which may now
be briefly sketched. First of these the Secretary
Birds (Serpentariidae), of which but one species
is known, is confined to the Ethiopian Region.
Next we have the Old World Vultures (Vul-
turidae), which are distributed over the warm
parts of the Palaearctic Region, the whole of
the Ethiopian Region, and a great part of the
Oriental Region. Rather noteworthy is the
fact that these birds are absent from Mada-
gascar and Ceylon, from the tropical islands
of the Malay Archipelago, and from the entire
Australian Region. Following these we have
the Typical Raptores, including the Eagles,
Hawks, Falcons, Harriers, and so on (Falconidae).
Of the various groups or sub -families into
which this may be divided, we have the Carrion
Hawks (Polyborinae), mostly confined to the
Neotropical Region, but extending into the
Nearctic Region as far north as California ;
the Bearded Vultures (Gypaetinae), an Old World
group confined to the mountain ranges in the
south of the Palaearctic Region, from Spain to
North China, and to various parts of the
Ethiopian Region ; the Buzzards and Kites

DISTRIBUTION IN SPACE 127

(Buteoninae) may be classed as cosmopolitan,
with the exception of Oceania, where they are
very poorly represented (New Caledonia) ; the
Eagles (Aquilinae) are also practically cosmo-
politan, especially in the great continents ; the
Hawks, Harriers, and allied species (Accipitrinae)
are even more generally dispersed, except in
very high latitudes ; lastly, the Falcons (Fal-
coninae) are of almost universal distribution,
but they are scarcely represented in Oceania.
Not a few of the genera in this as in other
sub-families of Raptorial birds are somewhat
local, and occupy well-defined geographical
limits. Last of all come the Ospreys (Pan-
dionidae), a small family of two or three species,
yet wide-ranging and distributed over most
parts of the world, except the south temperate
portions of the Neotropical Region.

Next in our order of sequence comes the
Coraciiformes, comprising no fewer than seven
sub-orders and nineteen families. As an order
it is absolutely cosmopolitan, but taking the
families separately, we shall find that the majority
of species are confined to the tropical or sub-
tropical regions of the earth. The distribution
of these families is as follows. The Rollers
(Coraciidae) are chiefly characteristic of the

128 THE STORY OF THE BIRDS

Oriental and Ethiopian Regions (one very
abnormal species constituting the sub -family
Leptosomatinae being restricted to Madagascar),
but extend into the temperate parts of the
Palaearctic Region, and are also found in the
Australian Region. One species is curiously
isolated on the island of Celebes. The Motmots
and Todies (Momotidae) are a small group of
American birds, the range of the former extend-
ing from Mexico and the Antilles to Paraguay,
that of the latter restricted to the greater Antilles.
The Kingfishers (Alcedinidae), although as a
family very universally distributed, are not only
localised but unevenly dispersed. The present
headquarters of the Kingfisher family are in
the eastern portions of the Malay Archipelago,
an area specially remarkable for the number of
peculiar forms of these birds that occupy it. It is
also a remarkable and interesting fact that but one
genus of Kingfisher is represented in the New
World, and that by a single species, although
this vast region is apparently so well adapted
to the requirements of these birds. In the Old
World the Palaearctic Region is the poorest in
species, as the Australian Region is the richest,
although the family is well represented in the
Ethiopian and Oriental Regions. The genera,

DISTRIBUTION IN SPACE 129

of which the English Kingfisher and the Pied
Kingfisher of Europe are members (Alcedo and
Ceryle), are the most widely dispersed, as some
of the genera of the Australian Region (such
as Cittiura, Caridonax) are the most local and
restricted. The Bee- Eaters (Meropidae) form
another purely Old World group, which, like the
Rollers, are most characteristic of the Ethiopian
and Oriental Regions ; but their range is not
quite so extensive as that of those birds in the
Eastern Palaearctic and the Australian Regions.
The Hornbills (Bucerotidae) are a special avine
feature of the Ethiopian and Oriental Regions,
entering the Australian Region as far as the Solo-
mon Islands. The curious Hoopoes (Upupidae)
are another dominant Ethiopian type, extending
into the Palaearctic Region in the west as far as
South Europe, in the east as far as North China
and Mongolia ; whilst they are also found
throughout the continental portions of the
Oriental Region and in Ceylon.

The second sub-order contains the Owls
(Striges), long included with the Birds of Prey,
but with affinities more nearly approaching the
Goatsuckers. They are absolutely cosmopolitan
in their distribution, extending not only to the
Arctic Regions, but to many isolated oceanic

130 THE STORY OF THE BIRDS

islands. Some few of the species in this order
occupy enormous geographical areas, among the
most remarkable being the Barn Owl and the
Short-eared Owl. Many of the genera are
common to the Old and New Worlds ; a lesser
number are limited to the Eastern Hemisphere,
whilst a few are similarly restricted to the
Western Hemisphere. The Snowy Owl is a fea-
ture of the Arctic Regions as the Burrowing Owl
is of the American prairies ; whilst the Hawk
Owl is most typical of the northern woods.

Following the Owls we come to the apparently
nearly allied Goatsuckers, forming the sub-order
Caprimulgi, under which term are included three
families. This sub -order may be classed as
almost a cosmopolitan one, except that it is not
represented in New Zealand or in some of the
most isolated of the islands in the Pacific, nor
does it penetrate into the Arctic Regions. The
general distribution of the three families is as
follows. The Typical Goatsuckers (Caprimulgidae)
are divisible into two sub-families. Of these the
Caprimulginae is by far the most cosmopolitan,
having practically the range of the family, re-
presented in every zoological region excepting
New Zealand and the Eastern Pacific islands.
The Nyctibiinae is, however, restricted to the

DISTRIBUTION IN SPACE 131

Neotropical Region, where the species occupy
only the tropical portions of that division. The
Frogmouths (Podargidae), a small family of Goat-
suckers remarkable for their very large mouth,
are an avine feature of the Australian Region,
but some of the species are found over a con-
siderable portion of the Oriental Region. The
curious Oil Bird is the solitary member of the
last of the three families (Steatornithidae), and
is confined to the northern portions of the
Neotropical Region (from Peru to Guiana and
Venezuela). The fourth sub-order is composed
of the two very distinct families containing the
Swifts and the Humming-Birds respectively.
This sub -order is practically cosmopolitan,
although one of the families is entirely confined
to the New World, and the other is not repre-
sented in New Zealand. The Swifts (Cypselidae)
may justly rank as a cosmopolitan family,
although they are not found in New Zealand.
Three sub-families may be recognised. The
first contains the Typical Swifts (Cypselinae),
which have nearly the same range as the family,
except that they are not represented in the
Pacific. The second contains the Spine-tailed
Swifts (Chaeturinae), and is also a wide-ranging
group, represented in each of the great zoological

132 THE STORY OF THE BIRDS

regions, but absent from the western portions of
the Palaearctic Region, from the extreme northern
portions of the Nearctic Region, and the extreme
southern portions of the Neotropical Region.
Included in this sub-family are those Swifts, the
nests of which furnish the famous bird-nest soup
of the Celestial Empire. These birds form the
genus Collocalia, and range from Madagascar
across the Eastern Tropics to New Guinea and
the Marquesas Islands. The third sub-family
contains the Tree Swifts (Macropterygina3), which
are distributed over various parts of the Oriental
Region, and in many of the Malay islands be-
longing to the Australian Region as far east as
the Solomon group. The Humming-Birds
(Trochilidae) are confined to the New World,
where, however, their range is an enormous one.
These feathered gems — the loveliest of all avine
forms — are certainly the most wonderful and
remarkable feature of the bird-life of the New
World; birds with no very close surviving re-
lations, with absolutely no representatives or
analogues in any other parts of the world, they
stand alone and unique in the avine kingdom.
But few species penetrate to the more extreme
northern and southern limits of the group's area
of dispersal, and even these -are migratory, and

DISTRIBUTION IN SPACE 133

retire Equator-wards to winter. The great head-
quarters of the Trochilidae are in the northern
portions of the Neotropical Region, especially
in Ecuador, in the mountainous areas of the
Andes for about ten degrees north and south
of the Equator. The lowlands are comparatively
poor in species, and present the least metallic
colouring. The Humming-Birds decrease in
numbers farther south as we approach Chile
and the Argentine, although the family is re-
presented even as low as Cape Horn itself ;
whilst northwards, with the exception of the
West Indies and Central America, where these
birds are certainly plentiful, we find a rapid
falling off in numbers, and but a single species
penetrates as far as Alaska.

Our fifth sub-order is a remarkably small one,
the Colii, composed of a single family, the Colics
(Coliidae). These peculiar little birds, bearing a
superficial resemblance to a small Finch, with a
very long tail and a conspicuous crest, are con-
fined to the Ethiopian Region, but do not extend
to Madagascar. There are some eight or nine
species only. The sixth sub-order, the Trogones,
is also a small one, and composed of a single
family. The Trogons are a group of curious
and bright-coloured birds confined to the

134 THE STORY OF THE BIRDS

tropical forests of the Neotropical, Ethiopian, and
Oriental Regions. One of the most remarkable of
these birds is the Quezal (Pharomacrus mocinno)
of Guatemala, in which the wings are overhung
by lanceolate scapulars, and the tail more or
less concealed by flowing rump plumes between
three and four feet in length. The seventh sub-
order, the Pici, is a composite and heterogeneous
one, and includes no less than five families,
each very distinct, and mostly of tropical or
sub-tropical distribution. Taking these in the
sequence given in the previous chapter (conf.
p. 94), we have first the Jacamars (Galbulidae).
They are a small family of mostly metallic-
plumaged birds confined to the Neotropical
Region. Even here their range is comparatively
a limited one, extending from Mexico in the
north to Brazil in the south. None of the
species appear to be found west of the Andes.
The Puff Birds (Bucconidae) come next, another
small group of about fifty species, which, like
the Jacamars, are confined to the Neotropical
Region, ranging therein from Guatemala in the
north to Argentina in the south, but most
abundant in the great virgin forests near the
Equator. Puff Birds occur west of the Andes,
but are absent from the West Indies. The

DISTRIBUTION IN SPACE 135

Barbets and Honey Guides (Capitonidae) follow,
forming another tropical group, but of much
more extended distribution, being found in the
forest zone of the Equator round the world,
with the exception of Australia. The Barbets
are found in the Neotropical, Ethiopian, and
Oriental Regions. They are divisible into two
sub-families, viz., the Barbets (Capitoninae), rang-
ing through tropical America, Africa, and Asia, and
the Honey Guides (Indicatorinae), confined to the
tropics of Africa and Asia only. The distribu-
tion of these birds is specially interesting. They
are found in all parts of the Ethiopian Region,
with the exception of Madagascar; whilst in
Asia although found in the Himalayas they are
otherwise absent from India, yet appearing again
farther south and east on the mountains of the
Malay Archipelago and Borneo. The next family
consists of the Toucans (Rhamphastidae), another
most characteristic group of birds confined
to the Neotropical Region. All the species are
arboreal, and therefore confined to the forests,
not only of the lowlands but up to an elevation
of ten thousand feet. Their range extends as
far northwards as Mexico (but does not include
the West Indies, although one species reaches
Trinidad) and as far southwards as Argentina.

136 THE STORY OF THE BIRDS

Their headquarters are in the Amazonian and
Guianan forests. The last family of the present
sub-order contains the Woodpeckers and Wry-
necks (Picidae), subdivisible into two marked
sub-families. The Woodpeckers (Picinae) are a
very widely distributed group, but curiously
enough are absent from Madagascar and Egypt
and the Australian Region. They are most
abundant in the Neotropical and Oriental Region,
although ranging over the entire Palaearctic and
Nearctic Regions as far north as the limits of
forest growth, and being fairly well represented
in the Ethiopian Region. The Wrynecks (lyn-
ginae) are exclusively an Old World group. Of
the four or five species our Common Wryneck
(lynx torquilla) has by far the most extensive
range. Its summer range extends over the
greater part of the Palaearctic Region, whilst in
winter it includes most of the Oriental Region
and the northern portion of the Ethiopian
Region. The remaining species all belong to
the latter region.

The Psittaciformes are essentially a tropical
and sub-tropical order, Parrots only exceptionally
being found in the temperate zones. They may
be divided into six families. Parrots are most un-
equally distributed over their area of occupation.

DISTRIBUTION IN SPACE 137

The Palaearctic Region contains no representa-
tive of this group, whilst the Nearctic Region
can only claim one, and that now confined to its
more southern limits. The Neotropical Region
is fairly well stocked with Parrots, one species
penetrating as far south as the Strait of Magellan ;
but the Ethiopian and Oriental Regions are com-
paratively poor in species. The Australian Region
is the metropolis of the Parrots, that portion of
it extending from Celebes to the Solomon Islands
being exceptionally rich in genera and species.
It is in this region that the Parrots reach their
most southerly known limits, the Macquarie
Islands, in lat. 54° S. ; whilst their northern
range is most restricted in the Ethiopian Region,
not reaching the Tropic of Cancer. The first
family (Stringopidae) contains but a single species,
the curious Owl Parrot, confined to New Zealand.
The second family (Psittacidae) may be said
almost to range over the distribution of the order,
being represented in each zoological region.
The third family, the Cocakatoos (Cacatuidae),
are a special feature of the Australian Region,
although they do not extend into the Pacific
beyond the Solomon group, and are not repre-
sented in New Zealand. The fourth family
(Cyclopsittacidae) are restricted to a small

138 THE STORY OF THE BIRDS

portion of the Australian Region (from Timor to
North-east Australia, and New Guinea). The
fifth family, the Lories (Loriidae), are essentially
a group peculiar to the Australian Region. The
sixth family, the Mountain Parrots (Nestoridse),
are confined to New Zealand.

The Cuculiformes are composed of two
families, the Plantain-Eaters and the Cuckoos,
the former of which is of restricted distribution,
whilst the latter may be, broadly speaking, almost
classed as cosmopolitan. The Plantain-Eaters
(Musophagidae) are confined to the Ethiopian
Region, but they do not extend to Madagascar.
The Cuckoos (Cuculidae) are divisible into half-
a-dozen sub-families, which are distributed as
follows. The Typical Cuckoos (Cuculinae) are
almost exclusively an Old World group, where
they are represented in all of the great zoological
regions ; a few species are found in the New
World, where they range over the Nearctic and
Neotropical Regions. The Coucals (Centro-
podinae) are exclusively an Old World group,
distributed over the Ethiopian Region, the
Oriental and Australian Regions. The Couas
and Rain Birds (Phcenicophainae) have a some-
what peculiar distribution, being found in
Madagascar, in the Indian Region, and in

DISTRIBUTION IN SPACE 139

various parts of the Neotropical Region. The
Chaparral Cocks and allied birds (Neomorphinae)
are found in Sub-tropical North America, and
in Borneo and Sumatra. The American Cuckoos
forming the fifth sub-family (Diplopterinae) range
between Mexico, Ecuador, and Brazil. The Anis
(Crotophaginae) are also peculiar to the New
World, ranging from the Southern United
States over most parts of the Neotropical Region.
Cuckoos are most abundant in the Oriental or
Indian Region ; whilst the complete isolation of
the American species is significantly reflected
in the exceptional number of peculiar genera.

With a brief glance at the distribution of the
Passeriformes, we shall bring our review of
avine dispersal to a close. As an order we may
safely describe it as absolutely cosmopolitan. Its
representatives are found in every clime from
the ice-bound Arctic Regions to the torrid zone ;
there is scarcely an island that does not boast a
Passere of some kind. As a group these birds
dominate the earth ; in the grand scheme of
evolution the present era is particularly theirs.
If, however, the present order is cosmopolitan,
the various families that compose it are by no
means so widely dispersed. Among the most
cosmopolitan families may be mentioned the

i4o THE STORY OF THE BIRDS

Crows (Corvidae), the Wagtails and Pipits
(Motacillidae), the Finches (Fringillidae) ; but the
latter have no Australian Region representatives ;
the Swallows (Hirundinidae) and the Thrushes
(Turdidae). There are few parts of the world
where these groups are not represented. Among
the families of less general dispersal, yet repre-
sented in both the New and Old Worlds, we may
instance the Dippers (Cinclidae), the Wrens
(Troglodytidae), the Creepers (Certhiidae), the
Nuthatches (Sittidae), the Titmice (Paridae), the
Shrikes (Laniidae), the Waxwings (Ampelidae)
and the Larks (Alaudidae), but the latter are
very poorly represented in America. Among
the Passerine families entirely confined to the
Old World we may mention the heterogeneous
assemblage of small birds, chiefly remarkable for
their short rounded wings, of which the most
typical are the Babbling Thrushes (Timeliidae),
the Hill Tits (Liotrichidae), the Green Bulbuls
(Phyllornithidae), the Bulbuls (Pycnonotidae), the
Orioles (Oriolidae), the Cuckoo Shrikes (Campe-
phagidae), the Drongo Shrikes (Dicruridae), the
Flycatchers (Muscicapidae), the Birds of Paradise
(Paradiseidae), the Honey-suckers (Meliphagidae),
the Sun-Birds (Nectariniidae), the Flower-peckers
(Dicaeidae), the Weaver Finches (Ploceidae), the

DISTRIBUTION IN SPACE 141

Starlings (Sturnidae), the Swallow Shrikes (Arta-
midae,) the Broadbills (Eurylaemidae) (conf. p.
100), and the Pittas (Pittidae). Most of these
are tropical or south temperate families, the
Bulbuls, Orioles, Flycatchers, Sun-Birds, Flower-
peckers and Pittas alone encroaching upon
the Palaearctic Region (which cannot claim a
single peculiar family), and most of these do so
to the very slightest degree, with the exception
of the Flycatchers. Among the Passerine
families entirely confined to the New World we
may mention the Sugar Birds (Ccerebidae), the
Wood Warblers (Minotiltidae), the Viereos or
Greenlets (Vireonidae), the Hang-nests (Icteridae),
the Tanagers (Tanagridae), the Tyrant Birds
(Tyrannidae), the Manakins (Pipridae), the
Chatterers (Cotingidae), the Wood Hewers
(Dendrocolaptidae), the Ant Thrushes (Formi-
cariidae), and the South American Wrens (Pter-
optochidae). We find precisely analogous
phenomena of distribution in the New World
as we found in the Old World. Not a single Pas-
serine family is peculiar to the Nearctic Region ;
whilst such important groups as the Sugar
Birds, Tanagers, Tyrant Shrikes, Manakins, Chat-
terers, Wood Hewers, Hang-nests, and Bush
Shrikes are comparatively poorly represented

142 THE STORY OF THE BIRDS

in that region, and mostly in the southern
portions. These peculiarities of distribution em-
phasise the exceptional richness of the Neotropi-
cal Region in Passerine birds, for about a third
of the whole number of species in the order
are typically South American ones.

Of the most localised Passerine families we
may instance the Hill Tits, confined to the
Himalayan system ; the Birds of Paradise, con-
fined to New Guinea and the neighbouring islands
and the north and east of Australia ; the Honey-
suckers, confined to the Australian Region ; the
Mamo (Drepanididae) to the Sandwich Islands
(conf. Lost and Vanishing Birds, p. 211); the
Plant-cutters to temperate South America ; the
Lyre Birds to South and East Australia ; the
Scrub Birds (Atrichiidae) to East and West
Australia ; and, lastly, the aberrant Pitta-like
birds, of two species, forming the family Paic-
tidae or Philepittidae, confined to Madagascar.

CHAPTER IV

THEIR MEANS OF DISPERSAL AND MIGRATIONS

The dispersal of birds — Fortuitous dispersal — Ancient land-
surfaces — Polar dispersal — Equatorial dispersal — The
law of dispersal — Obstacles to dispersal — Discon-
tinuous areas of dispersal — Influence of climate upon
species — Species increasing their range during present
time — The migration of birds — Misconceptions con-
cerning migration — Transmutation and hibernation —
Migration and instinct — Migration not universal in
certain species — The Cause of migration — Migration
due to range expansion or colonisation — Cause of
migration in autumn — Length of journey variable —
The philosophy of migration — The wings of migrants
— Moulting of migrants — Course of autumn migration
— How birds find their way on migration — Migration
across seas — General aspects of migration — Duration
of migration — The speed of migration flight — The
height at which migrating birds fly — The perils of
migration — Lost birds at lighthouses — Various kinds
of migration — Vertical migration — Local movements
of birds — Nomadic migration — Irruptic movements.

THE two preceding chapters having dealt with
the principal groups into which birds are
divided by systematic ornithologists, and the
various parts of the globe over which they

are distributed, it becomes necessary now to

143

144 THE STORY OF THE BIRDS

devote a chapter not only to the various in-
fluences which may be said to govern this dis-
persal of avine life over the globe as fixed and
sedentary colonists, but as transitory visitors
to certain areas, which are reached by what
we term migration. The laws governing the
Dispersal and Migration of birds are as yet
but very little understood, and so long as
naturalists believe that these facts are chiefly
due to fortuitous agency, and are controlled
by accidental circumstances, our knowledge is
likely to remain very small, and our concep-
tion of the phenomena to be quite erroneous.
It must also be understood that the Dispersal
of birds and the Migration of birds are two
very intimately related subjects ; we cannot
discuss or study one without the other ; for as
we have already repeatedly insisted, they are
really correlative parts of the same phenomenon,
the Dispersal of birds being the key by means
of which we are enabled to solve not a few of
the mysteries of Migration.

We will first then devote a few pages to the
Dispersal of birds. How many readers might
reasonably conclude that Birds, of all living
things, would be the least likely to be confined
to certain areas, and especially to restricted

DISPERSAL AND MIGRATIONS 145

ones. Birds are gifted with very exceptional
means of locomotion ; most species can fly ;
many can swim ; so that the barriers that might
confine or check terrestrial animals would, not
a few readers may think, be utterly futile in
arresting the colonising movements of such
volant creatures. The facts, however, disclosed
in the preceding chapter all tend to demon-
strate that this is very far from being the case,
and to suggest that many more or less per-
ceptible influences are at work controlling the
dispersal of birds over the globe. In the first
place, if we admit that birds have sprung from
a reptilian stock, as the details relating to their
origin given in our first chapter appear incon-
testably to prove, and that the twelve thousand
(in round numbers) known species now in ex-
istence were not each created in the places
they at present occupy, then we must com-
mence with the fact that all species in each
genus (to go no farther back, this being suffi-
cient to illustrate our contention, but the same
principles apply to every family and order) have
descended from a common ancestor which must
at one time have been confined to a continuous
area, from which its descendants have spread
into other districts, where specific change has

146 THE STORY OF THE BIRDS

arisen, aided by isolation and changed condi-
tions of life. Now most naturalists believe that
this subsequent dispersal has been entirely for-
tuitous, that species have spread this way and
that over continuous land-surfaces or narrow
seas (in the case of land birds) ; or, in the case
of aquatic species, in whichever direction food
may have been procurable. Many of those
ancient land - surfaces, over which so many
species are believed to have emigrated, have
long since been replaced by water; as, for in-
stance, between Asia and America, and between
West Europe and Africa, or even between our
own islands and Europe. Another great factor
in the dispersal of birds over the globe is gene-
rally believed to be glacial epochs, which have
driven numberless species from high latitudes
into countries farther south. Hence the very
generally prevailing belief in what is termed
Polar Dispersal. In fact some authorities go so
far as to say that Life originated first at the Poles
and gradually spread towards the Equator. But
there are many grave difficulties in the way
of accepting such views, and we believe the
evidence points to a diametrically opposite
interpretation of the facts of dispersal, or in
other words, that birds were originally evolved

DISPERSAL AND MIGRATIONS 147

in the equatorial region, whence they have
spread in two grand streams north and south
towards the Poles. This evidence is too com-
plicated to be discussed in a popular little
volume like the present, but the reader may
consult the work on the migration of birds1
by the present writer, where his theories of
avine dispersal are fully elaborated. To our
mind innumerable facts of dispersal suggest
that species never emigrate or extend their
area in the Northern Hemisphere in a southerly
direction, nor do they so extend their range
in the Southern Hemisphere in a northerly direc-
tion. Farther, there is no evidence to suggest
that a species retires from adverse conditions
(as the retreat from a glacial epoch), or that
such have any influence whatever in expanding
its geographical area of occupation. We believe
that breeding conditions are the sole determin-
ing factor in such range expansion, and that a
species extends its area as a natural result of
increase. The soundness of these views is
confirmed by many facts of geographical dis-
tribution and migration. Not only do we find
many species absent from certain areas pre-
senting few or no barriers to emigration save

1 The Migration of Birds. Amended Edition, 1897.

148 THE STORY OF THE BIRDS

the significant fact that to enter such areas a
movement in a direction opposed to this sug-
gested law of dispersal would have to be made ;
but we also find that, however remote the
breeding grounds of a migratory species may
be from the original centre of dispersal of that
species (or one certain portion of it), it returns
unerringly to that base, notwithstanding the fact
that winter quarters are available by travelling
in some cases less than one-third the distance.
The distribution of our own Nightingale in
England is an admirable example of the first-
named fact, the absence of that bird from the
south-west peninsula of England being, we
believe, entirely due to that Law which forbids
emigration or range expansion in the Northern
Hemisphere to take a southern course ; whilst
such a species as the Arctic Willow Wren (Phyl-
loscopus borealis), that actually breeds as far
west as Finmark, but is not known to winter
any nearer that country than Burma (the range
base of the species), may be instanced as an
equally admirable example of the second fact.
It might be thought that such volant creatures
as birds would not be deterred in their colo-
nising or range-expanding movements by such
obstacles as narrow seas — in not a few cases

DISPERSAL AND MIGRATIONS 149

dividing countries where the coast-lines of each
are visible from either shore (as in parts of the
English Channel, for instance), but such is not
the case. Land birds everywhere evince a
rooted objection to extend their area by cross-
ing expanses of water, and a great many
instances could be given where narrow seas
which might be crossed in half-an-hour's easy
flight have effectually arrested dispersal. But,
on the other hand, we know that in not a few
cases the range of a species is divided by such
waterways. We have, for instance, the narrow
seas that divide our islands from the continent
of Europe and from each other, the Mediter-
ranean, the Japan Sea, many parts of the China
Sea, Behring Strait, Bass Strait, and so forth.
Now, as we have already stated, land birds
do not apparently ever increase their area over
waterways — seas and straits — so that the natural
inference in such cases of sea-divided areas of
dispersal is that the birds must have entered
those countries when no seas were barring the
way. In not a few cases we know that at
some comparatively recent geological epoch dry
land actually did take the place of what is now
shallow seas. This fact is further confirmed in
another way. Wherever two countries are

150 THE STORY OF THE BIRDS

divided by narrow shallow seas the avifauna
of each is very similar in character — we find
either the same species or others very closely
allied to them in both. But in the case of seas
of great antiquity — usually very deep — even
though in not a few cases comparatively narrow,
we often find that they separate avifaunae of
very different aspects. As examples of what we
mean we may instance Madagascar, an island
in which many families of birds commonly dis-
tributed over the African continent are entirely
absent, and on the other hand, out of a number
of less than 250 avine species more than 130
are peculiar to the island, many of which have
no near African allies. The reader will also
recall that in many cases mentioned in the
previous chapter Madagascar is excepted from
the Ethiopian range. Then we have New Zea-
land— another group of islands surrounded by
ancient and deep seas — presenting us with a
very similar series of facts. Or still more won-
derful and suggestive, we may instance the case
of two islands in the Malay Archipelago, Bali
and Lombok, which are separated by a very
narrow yet very deep and ancient sea. This
strait is but fifteen miles across in its narrowest
part, yet so effectual a barrier has it proved to

DISPERSAL AND MIGRATIONS 151

bird colonists that the avifauna of the two
islands differs more than does that of Japan
from Great Britain. As Wallace writes: "The
birds of the one are extremely unlike those of
the other, the difference being such as to strike
even the most ordinary observer. Bali has red
and green Woodpeckers, Barbets, Weaver- birds,
and black-and-white Magpie-Robins, none of
which are found in Lombok, where, however,
we find screaming Cockatoos and Friar Birds,
and the strange mound-building Megapodes,
which are all equally unknown in Bali. Many
of the Kingfishers, Crow-shrikes, and other birds,
though of the same general form, are of very
distinct species ; and though a considerable
number of birds are the same in both islands
the difference is none the less remarkable, as
proving that mere distance is one of the least
important of the causes which have determined
the likeness or unlikeness in the animals of
different countries." The world contains many
other similar contrasts.

But seas are not the only barriers to the
colonising movements or dispersal of birds.
Mountain ranges in not a few parts of the world
have proved effectual obstacles to the range ex-
pansion of birds. In a similar manner deserts

152 THE STORY OF THE BIRDS

have checked avine colonisation in certain direc-
tions. It must always be borne in mind that
normal dispersal or extension of area is a result
of numerical increase ; as the individuals of any
species multiply they seek out new quarters and
occupy new districts. But the country that this
surplus population invades must be suited to
the requirements of the species that is gradually
invading it. If a supply of food cannot be
obtained, especially during the breeding season,
if suitable nesting-places are absent, then the
colonising movement cannot proceed in that
direction. The special requirements of each
species determine the general line of its emi-
gration. Forest birds could not, and would not,
attempt to increase their area across treeless
plains ; aquatic birds would only seek to do so
in directions (always, however, conforming to
the suggested law of dispersal already described)
where suitable haunts presented; whilst birds
that dwelt upon steppes and open country
would follow such country only and colonise
it. Then, again, mountain species would keep
closely to the mountains in entering new areas
of dispersal ; coast birds could only follow the
trend of the shore. Then in countless instances
as a sedentary species has gradually spread from

DISPERSAL AND MIGRATIONS 153

a more or less equatorial base, all the early pro-
genitors of that species may have from a variety
of causes absolutely disappeared, and left their
descendants as colonists in new countries far
remote from their primal origin, without a trace
being left to indicate the line of their dispersal.
In some cases we can form a pretty accurate
idea of the general route by the various allied
and representative species which have estab-
lished themselves nearer to the point of dis-
persal. With many migratory birds, however,
the ancient centre of dispersal, or the range
base from which the species commenced its
colonising movement, is still returned to and
used as a winter home. Here we may also state
that the geographical area of nearly every species
is continuous. Broken areas almost invariably
lead to specific differences. There are one or
two instances of apparently discontinued area
(Asio capensis for example), the species remain-
ing the same in each locality. But this may
be due to a recent interruption, and eventually
result in specific segregation should it remain
permanent. Many species may possibly have
originated on various islands as some large land
mass became split up into an archipelago by
volcanic or other action. As a rule, the more

154 THE STORY OF THE BIRDS

remote the connection of an island with the
adjoining continent the more diverse is the
avifauna found upon it. Another fact of special
interest to the student of geographical distribu-
tion is the enormous area occupied by some
species, and the remarkably restricted one of
others. The Barn Owl, for instance, is found
nearly all over the world, whilst many other
species of Owls are confined to a single island.

Finally, a few words concerning the influence
of climate upon species. We may aptly repeat,
almost word for word, what we wrote many
years ago upon this matter : The importance of
climate in zoological geography is considerable,
although the subject has been much neglected
by the student when seeking to solve perplexing
questions of distribution. For instance, the
Palaearctic Region presents some of the greatest
contrasts of climate to be found in the world,
and each particular kind of climate is stamped
indelibly upon the plumage of the birds within
its influence. The extreme west, including the
British Islands and Scandinavia, is moist, favour-
able to the development of brown ; the north
and central districts, including Russia, Siberia,
and Kamtschatka, are cold and dry, and here
the colours are bleached and, produce the arctic

DISPERSAL AND MIGRATIONS 155

forms, becoming the most pronounced in the
latter country. In Japan the humidity returns,
and much the same conditions prevail as in the
extreme west ; whilst in the dry, sandy districts
of the south, pale desert forms are found ; and
in the extreme south the climate is suitable to
the production of semi-tropical forms, where
the colours reach their greatest intensity. The
rainfall of a district is also stamped upon the
plumage of birds, as is remarkably apparent,
for instance, in examples of the same species
from the wet or the dry districts of India
respectively. This peculiarity may even be
observed on a small scale in the British Islands,
birds from the wettest districts generally being
perceptibly darker in tint than those from
localities where the rainfall is not so excessive.
Birds from tropical regions where the maxi-
mum of humidity and warmth prevails have
the greatest intensity of colour, browns and
greys being perhaps the most susceptible. Olive
browns are characteristic of a medium rainfall;
rufous browns unfailingly reflect an excess of
moisture. Dry, cold climates bleach ; hot and
dry climates have a tendency to produce pale-
ness, becoming most pronounced in deserts.
We may also remark that some species are

156 THE STORY OF THE BIRDS

known to be increasing their area of dispersal at
the present time, or within the historic period.
As a rule, and possibly because of the great
stability or quiescence at the present time of
those conditions that influence colonisation, but
little expansion of area is now in progress.
Among birds that are certainly adding to their
area of occupation, or have recently done so, we
may mention the Starling, the Rook, the House
Sparrow, and the Partridge.

We will now pass on to a brief notice of the
Migration of Birds. The coming and the going
of these birds of passage appear from the very
earliest periods of which we have any record to
have made a great impression upon mankind.
Jeremiah of old had evidently well studied the
migration of birds, telling us that the Stork
knows her appointed times, and how the Turtle
Dove, the Crane, and the Swallow observe the
time of their coming. The Prophet could not
have selected better examples to illustrate his
allusion, for the whole four species are migrants of
the most pronounced type. Even savage man has
not failed to remark the phenomenon, and to draw
up his mental calendar punctuated by the dates of
arrival and departure of the migrant birds.

There is certainly no other avine habit which

DISPERSAL AND MIGRATIONS 157

has been so much misunderstood or round
which so much mystery, superstition, and wild
theory has gathered as the migration of birds.
Much of this has lingered almost to the present
time, and even now there is not a little connected
with avine season flight that still requires
elucidation. We, have, however, divested the
subject of some of its most incredible theories
and speculations. No one now, for instance,
believes that migratory birds seek a refuge in the
moon during their absence from northern lands
in winter ; and yet this was almost regarded as
a scientific fact a hundred and fifty years ago.
There are still, however, some country people
who will stoutly maintain that the Cuckoo
undergoes transmutation in autumn, turning into
a Hawk for the colder months. We have known
one or two otherwise most intelligent game-
keepers who thoroughly believed in this dual
existence of the Cuckoo. Like many another
legend it rests somewhat on fact, because our
adult Cuckoo very closely resembles a Sparrow-
Hawk, whilst the young one in its brown-barred
plumage might very easily be mistaken for a
Kestrel. Then there was the yet more widely
prevailing belief that migrant birds — especi-
ally Swallows and Swifts — became dormant

158 THE STORY OF THE BIRDS

at the approach of winter, and passed that sea-
son snugly hidden away in nooks and crannies,
or buried in the mud at the bottom of pools
of water. As most readers may know, Gilbert
White believed in this hibernation habit, and
not a few scientific men of distinction supported
the theory. Possibly opinion nowadays may
have gone too far in the opposite direction, and
the general ridicule with which suggested hiber-
nation among birds is received conceals the
actual facts. We must remember that seasonal
torpidity is a common practice among many
animals and insects ; that it is not a physical
impossibility in birds, although there can be
little doubt that if birds ever do sink into
lethargic slumber the isolated instances must
be exceedingly exceptional. There is some
evidence to suggest that birds have been known
to pass into this state. The testimony seems to
be absolute and reliable. On the other hand the
reader may rest assured that in no known species
does hibernation generally take the place of
migration. We have already dwelt at some
length upon this question of avine hibernation
in our book on the migration of birds, to which
the reader may be referred.1 Another equally

1 The Migration of Birds, chap, ii., pj>. 50-69.

DISPERSAL AND MIGRATIONS 159

absurd belief attributed to migratory birds was
their presumed power to find their way from
one country to another without experience or
guidance. Young birds were believed to be
hatched with an instinctive knowledge, not only
of when to migrate, but how, quite irrespective
of their more experienced parents. It is some-
what remarkable that even at the present day
there are naturalists who believe in this mys-
terious faculty, and stubbornly assert in proof of
it that the young birds migrate before their
parents in many cases. This would certainly
be very remarkable if it were true, but it is not,
as we shall learn later on. Many erroneous
opinions also still prevail concerning the speed
at which birds migrate, the infallibility of the
faculty of migration in birds, and the cause of
the habit ; but these are questions that we may
more aptly discuss in later pages.

In the first place, we may begin by saying that
the habit of migration is by no means a universal
one amongst all the individuals of many migra-
tory species. The Robin, for instance, is practi-
cally a resident species in England, but those
individuals that breed in Sweden and other
northern lands are migratory, and travel even as
far as Africa to winter. The Goldcrest is also a

i6o THE STORY OF THE BIRDS

resident in our Islands, but, as every ornithologist
knows, vast numbers of migrant Goldcrests ap-
pear in them in autumn. The Hooded Crow is
a resident in Scotland, but in many parts of the
Continent it is a migrant, crossing the North Sea
in vast hordes every autumn to winter with us.
Similarly in the south we find certain migratory
species, some individuals of which appear to be
sedentary, such, for instance, as the Sedge
Warbler, the Chiffchaff, and the Corncrake.
Not only, however, is the habit of migration
irregular, but the distance traversed is very vari-
able among the individuals of a species, some
journeying more than double the distance that
others do. The breeding range of the Wheatear,
for instance, extends from North Africa to Jan
Mayen, whilst the winter or range base of this
species extends to the Equator.

A few words now as to the Cause of migration.
Perhaps the most popular opinion respecting this
is, that the habit is due to failure of food. Migra-
tory birds leave their winter quarters or base as
summer comes on, and the requisite food begins
to fail ; whilst they quit their northern haunts as
winter approaches, for a similar reason. Many
naturalists of eminence are content to find
the cause of migration in these suppositions.

DISPERSAL AND MIGRATIONS 161

Another, if less generally attributed cause, is the
rise or fall of temperature. Other ornithologists
believe that it had its origin in the accidental
wanderings of birds, or even the aimless roam-
ing of young birds in quest of food ; whilst a
very ingenious hypothesis attributes it not to
want of food, but to want of light, during the
several months of polar night in the Arctic
Regions, ages ago, when those latitudes enjoyed
a much warmer climate in winter than they do
now. It will be noted that all these hypotheses
on the cause of migration really mean a retreat
from adverse conditions of life. Failure of food
supply can scarcely be a tenable hypothesis, be-
cause, unfortunately, birds begin their migrations
in numberless cases before food shows any sign
of becoming scarce ; neither can migration arise
from accidental roaming, because birds, of all
creatures, are closely attached to certain spots,
and exhibit no propensity for straying beyond
their normal limits, which are determined by
other and perfectly well-known causes. After a
long and close study of the facts, I am disposed
to attribute the spring migration of birds to the
range expansion or colonisation of a species
gradually increasing the distance from its winter
base. As we have already seen, the general trend

i62 THE STORY OF THE BIRDS

of this expansion is mostly polewards, but some-
times nearly due east or west. I attribute the
autumn migration of birds to an overpowering
impulse to return to the winter or range base, in
which each individual and its descendants has
some special spot, to which it is drawn by a
variety of local causes. There are thus two
points to which a migratory bird is attracted : its
non-breeding centre, often an area associated
with its gregarious instincts ; and its nesting-
place, with the equal attraction of a mate. Most
of us know how unerringly birds return season
by season to their old breeding-places ; it may
not be so widely known, still it is as much a fact,
that birds return with as much certainty to cer-
tain spots in which they pass the winter. The
breeding impulse may be said to be the primal
factor in spring; the social instinct, or an equally
strong nostalgic impulse, a chief factor in autumn.
The habit of returning in autumn, as soon as re-
production is accomplished and the moult safely
over, to certain areas, appears to be as deeply
rooted as the desire to return to other localities
to breed in spring. The Impulse to return may
be, and possibly is, inherited. But inheritance can
go no further than this impulse ; the successful
accomplishment of the journey depends upon

DISPERSAL AND MIGRATIONS 163

other factors. Young birds are not hatched
with this hereditary knowledge, only with the
inherited impulse to undertake the habit, as the
many blunders committed by migrant birds in
undertaking their annual journeys conclusively
prove, which we shall learn later on. The won-
derful amount of variation in the length of the
migration journey, between the breeding-places
on the one hand and the winter or home centres
on the other, seems to me conclusively to prove
that the habit of migration is purely and simply
an acquired habit — one, in fact, that is subject to
almost individual variation and exigencies. The
migration journey when first initiated must have
been insignificantly short, and only reached its
present amazing length in many species gradually
with the expansion, or even entire change, of the
breeding area. As instances of birds with very
short migration flights, we may name the Grey
Phalarope and the various Eider Ducks ; greater
flights are presented by such birds as the Wood-
cock and the Rufous Warbler, with a length of
from 1000 to 2000 miles ; moderate flights by the
Crane and the Lapwing, say from 3000 to 5000
miles ; long flights by the Cuckoo and the Corn-
crake, say from 6000 to 7000 miles ; whilst the
most extended are presented by such species as

164 THE STORY OF THE BIRDS

Swallows and Hudsonian Godwits, with a journey
of from 7000 to 10,000 miles. These extreme
limits, however, only represent the length of the
migration of the species, not of the individual, for
in many cases we have two sets of individuals of
the same species, one set moving north, the other
set moving south, from the equatorial centre of
dispersal.

A few words now on what we may term the
philosophy of migration. We have briefly dealt
with what we believe to be the Cause of migra-
tion ; now let us try and ascertain how and
under what conditions the wondrous journey
is accomplished. In a preceding chapter where
we had the various bird groups under review,
attention was repeatedly drawn to the fact that
many families were remarkable for their long
pointed wings. It is in such groups as these
that we find the birds most remarkable for their
migrations. Generally speaking, a bird must
have wings adapted to quick and sustained
flight to be able to migrate successfully ; hence
the rule is for birds of passage to be long
winged and capable fliers. These long, power-
ful wings have been developed by successive
generations of regular migration flight : the
birds that fly most have the highest developed

DISPERSAL AND MIGRATIONS 165

apparatus for aerial movement ; those that fly
least the weakest ; and in some cases, as we
have already seen, disuse of the wings has
eventually ended in loss of flight altogether.
It is not a necessary corollary, however, that
all long -winged birds are migrants. Many
sedentary birds have long wings, but this is the
result of having constantly to depend upon
them to secure food : the Humming-Birds and
many Birds of Prey are cases in point. It is
most significant that the groups with the most
rounded and concave wings are generally dwel-
lers in warm regions, leading a sedentary life ;
in cold and temperate regions it is the excep-
tion to find a short weak-winged bird, the rule
for them to have long and strong ones. Again,
in order that migratory birds may be best able
to undertake their periodical journeys, we find
that they generally moult their plumage before
they start. Once this tedious and dangerous
process is over, migrating birds, which during
its progress were sickly and skulking, brighten
up, and each day only seems to increase the
impulse to commence their annual passage.
But migrants, as most observers know, do not
all start off together ; the ones that complete
their moult earliest seem in many cases to be

166 THE STORY OF THE BIRDS

the first to go, then late broods may delay others.
So far as I have been able to ascertain, the
general Order of migration is as follows. The
first individuals of a species to migrate are birds
that have lost their eggs or young, or from
some cause have been prevented from breed-
ing during the previous season. Following
these are many young birds and their parents,
the males in many species preponderating ;
then comes a rush of migrants, in which females
may be the most abundant ; whilst the rear is
brought up by laggards kept behind from a
variety of causes, such as damaged wings. The
normal course of autumn migration, then, is for
young birds to predominate in the earlier stages
of the movement, adult birds towards the close.
In spring this order is to some extent reversed.
Then the adult males generally take absolute
precedence, the old females travel next ; the
young of the previous season, the more or less
immature individuals follow (in some cases
these latter apparently spending the summer
south of the breeding area), whilst, last of all,
come the weakly and crippled.

The question now may naturally arise : How
do birds find their way on migration across so
many miles of land and sea ?. Here the greatest

DISPERSAL AND MIGRATIONS 167

mystery of Migration might be thought to come
in. This portion of the subject at all events is
surrounded by much unnecessary mystery, and
agencies have been invoked, even by scientific
naturalists, to account for this seeming wonder-
ful power of birds to pass from place to place
apparently unguided. Birds have been said to
possess a mysterious sense of direction, an in-
herited but unconscious experience. Other
naturalists have come to the conclusion that
birds possess an inner magnetic sense, by which
they are not only guided but able to ascertain
their position in relation to the magnetic poles.
The performance of the Homing or Carrier
Pigeon has been brought forward to prove that
birds possess an inherited sense of direction.
But the facts of the case, instead of supporting
the assertion, directly refute it. These Pigeons
have to undergo a careful course of training
before they are able to fly from one distant
place to another ; that is to say, they have to
be taught the way in a series of stages until
they have learnt the topography of the route.
If this be obscured by fog the birds will not
attempt the task, or doing so soon lose their
way. They fly by sight, aided by a very reten-
tive memory for certain landmarks. Another

i68 THE STORY OF THE BIRDS

naturalist suggested that birds found their way
across seas by noticing the peculiar roll of
the waves ; but these are constantly varying in
direction, especially in narrow land-locked seas
which are crossed by migrants, according to
the influence of ever - changing winds. The
reader may perfectly well rest assured that all
this theorising is profound nonsense. The
theory of instinct may be very pretty and very
attractive, but it is not supported by logic or
by facts. Birds migrate purely and simply by
an exercise of those extremely acute powers of
observation and keen aptitude for recognising
landmarks, the result of an intensely receptive
memory, the result of experience, and coupled
with a great knowledge of locality. But these
powers, great as they undoubtedly are, would
be useless along a strange road, so that birds
individually keep close to certain routes, these
latter having been gradually formed as the
range has spread out from the original centre
of dispersal. Little by little during the history
of the species has the journey become longer
as the breeding-places became more and more
distant from the winter range base. The road
is so familiar even to those individuals that
breed the farthest from the winter base that

DISPERSAL AND MIGRATIONS 169

they are able, given favourable meteorological
conditions, to perform the journey with the
utmost confidence, and even in a single, more
or less uninterrupted, flight. The habit of mi-
grating across seas was acquired when those
areas were dry land. There are few (we doubt
if there are any) or no instances of migration
across deep and ancient waterways ; the sea
has gradually replaced the land as the habit
of migrating across the area was formed. Not
only so ; at the great altitude at which birds
migrate there are few if any waterways that
cannot be spanned by the eye of a bird migrat-
ing over them, one coast-line coming into view
as soon as, or even before, the other is lost.
We may here state that some writers have
asserted that certain birds reach their breeding-
grounds by one route and return to their winter
quarters by another, but there is not a shred
of reliable evidence to support the contention.
If such were the case migration would then
reach to a degree of mystery that even the
wildest theory has yet failed to carry it.

The general aspects of Migration are full of
absorbing interest. Some birds appear to travel
exclusively by day, others as habitually by night,
others yet again both by day and night. The

170 THE STORY OF THE BIRDS

great majority of birds appear, however, to
prefer the latter time. Then the punctuality of
their arrival in certain spots season after season
is most remarkable. Almost to the day, nay
almost to the hour, we may confidently look
for certain migratory birds to arrive, and sel-
dom are we disappointed. The Swifts leave my
Devonshire home each year almost to the day ;
they arrive with almost the same punctuality.
Some sea-birds visit their breeding-places with
equal punctuality. The sociability or the reverse
of migrant birds is also interesting. Some birds
migrate in a solitary way, eschewing the com-
pany of their kindred, so far as we can see ;
others always congregate for the annual journey.
Generally speaking, however, gregarious tenden-
cies are a characteristic feature of migration both
in spring and autumn, but more especially so
at the latter season. Social tendencies are also
common during migration, and it is no un-
common thing to see a large flock of travelling
birds composed of several species. Again, an
odd bird or so of one species will not unfre-
quently attach itself to a flock of migrants, per-
haps of very distantly allied birds, and journey
in their company. Then there are not a few
life-paired species in which the spring journey

DISPERSAL AND MIGRATIONS 171

especially is undertaken by the sexes in company,
male and female arriving together.

The duration of the migration of each species
is from one to two months at each season, having
regular phases of intensity. In some few species
the flight continues over a much longer time.
First the migration of a species is marked by
the arrival or departure of a few stragglers, the
most restless individuals ; then the migration of
that species becomes more pronounced, until its
period of greatest strength is reached, possibly
marked by one or two great "rushes," or extra-
ordinary numbers of individuals ; after which it
gradually dies away similarly as it commenced.
These phases of intensity are more characteristic
of some species than others. The whole period
that a migration of any one species lasts, how-
ever, is not occupied by absolute flight. The
time is taken up in gradually draining the
summer or winter area, and is of course shorter
in the species with a small distribution than it
is in those occupying a vast tract of country.
In some cases the breeding area of a species occu-
pies more than three thousand miles of latitude,
with a consequently great variation of climate
and date of season ; then it will be prolonged
over several months at least, the individuals

172 THE STORY OF THE BIRDS

breeding in the most northern portions leaving
them, it may be, six or eight weeks before the
individuals breeding in the southern portions
(and necessarily much nearer to the winter base)
do so. We may thus lay it down as a rule, that
where the breeding or winter area is narrow,
the migration is short, and vice versa. When
absolutely migrating, birds do not appear to
travel direct from the point of departure to their
destination ; rather do they travel by stages, and
in a more or less leisurely way, feeding and rest-
ing here and there en route. This is especially
the case in autumn ; spring migration always
appears to be more rapid. The quickest part
of the whole journey may possibly be that over
the sea ; but in many cases migrant birds have
no sea to cross at all. The actual speed at
which birds fly when migrating is very difficult
to ascertain. Some perfectly astounding state-
ments have been made concerning this matter,
but the reader is cautioned against accepting
them. That some birds can fly very fast we
know is unquestionable ; but that they habitually
do so when migrating is not supported by facts.
It has been said that certain species pass from
Africa to Central Europe at the astonishing
speed of four miles per minute for the whole

DISPERSAL AND MIGRATIONS 173

of the way without a pause or rest ! What we
do know respecting the flight of birds, and espe-
cially a long-sustained flight, is quite contrary to
these wonderful estimates. The Homing Pigeon
record for several successive hours is, we believe,
under sixty miles per hour ; but, aided by a gale,
a speed of 2150 yards per minute has been
reached. When we come to the relative speed
of migration, however, we are on much surer
ground. The Baltimore Oriole, by a very care-
ful series of observations, has been found to
travel at the rate of twenty-seven miles per day ;
the record of fifty-eight species gave an average
of twenty-three miles per day. The records also
tend to show that the smaller land birds do not
perform long journeys over land at one time.
King Birds have been estimated to do forty miles
in a single night, but, exceptionally, as many as
100 or even 200 miles in the same period of time.
At present, however, there is absolutely no reli-
able data upon which to speculate. The height
at which migrating birds fly is also very interest-
ing. Without ascending to a considerable altitude
the migrations of many birds would be simply
impossible. Most birds appear to fly high during
migration. Birds have been often observed on
passage flying at a height of from one to two

174 THE STORY OF THE BIRDS

miles ; Cranes have been detected passing across
the sun's disc at an estimated altitude of five and
three-quarter miles ! These latter birds, we may
mention, have been observed crossing the vast
Central Asian mountains at great elevations
above them. The most important benefit de-
rived from such a lofty course is the increased
range of vision that it ensures. The higher a
bird flies the farther it can see, the more ex-
tended becomes the visible segment of the earth's
sphere below it. From such lofty courses the
earth and sea spread out like a vast panorama
below the migrating bird, charged with a full
knowledge of the topography of its accustomed
route ; all the old familiar landmarks are recog-
nised as the wondrous journey is performed.

But all this is the brighter aspect of the
migration flight. Very often fogs and rain mists
obscure the land, and storms overtake these
feathered pilgrims, bringing disaster and death.
At such times during spring and autumn (the
latter season more especially, because then the
migrants are more numerous) scenes of rare
wonder are often witnessed at the lighthouses
and light-vessels on coasts frequented by migrant
birds. The poor lost little pilgrims are attracted
to the lanterns very often in tens of thousands,

DISPERSAL AND MIGRATIONS 175

where they flutter to and fro, or drift by in an
aimless manner utterly bewildered, or strike
against the glass with such force as to kill them-
selves. Large numbers are known to perish in
this manner every season. It is only on over-
cast nights, however, that such scenes are
witnessed, and even then as soon as the heavens
become clear the migrants disappear like magic,
passing on their way again. Many birds also
lose their way when on migration, especially in
autumn. A very large percentage of these lost
birds are young ones. This fact in itself should
at once do away with any theory of instinct, for
instinct must be held to be infallible. The
various cries uttered by birds when on migration
are also very interesting. These cries are uttered
most probably to keep the members of the flock
together as they fly across the night sky, and
often sound singularly weird and imposing from
the darkened air. It is also somewhat remark-
able that the noisy birds are those that chiefly
migrate by night : birds that travel by day
generally do so in silence.

In conclusion, we ought also to allude to the
various kinds of migration that birds undertake.
The best known type of migration is that of
which the Swallow, for instance, is a good

176 THE STORY OF THE BIRDS

example. This means a journey from some
southern land to a northern one for the summer,
and a return to the winter home in autumn.
Then we have what is termed Vertical Migration,
in which certain birds leave the lowlands and
plains in spring, and seek summer quarters high
up the mountains, it may be (and mostly is)
without leaving a country or crossing the sea
at all. This kind of migration is very prevalent
in warm countries. Indeed some few British
species — birds that visit us in summer — are verti-
cal migrants in more southerly localities, finding
suitable summer quarters by elevation rather
than by latitude. Then we may briefly allude
to the various local movements of birds, usually
undertaken during the non-breeding season.
These can scarcely be classed with regular
migration, because they are without any ap-
parent system or method, prompted solely by
a desire for food, and in all cases take place
within the normal area of dispersal of the species
engaging in them. The most pronounced kind
of local movement may be classed as Nomadic
Migration, usually prevailing among birds that
live in cold regions, and which are wander-
ing about almost all the year except when en-
gaged in rearing their young. Within certain

DISPERSAL AND MIGRATIONS 177

well-defined limits these birds appear to have
no settled home. Lastly, we may allude to the
Irruptic Movements of birds. These cannot be
classed either with normal migration or nomadic
migration. They are entirely abnormal move-
ments, only occurring at irregular intervals, and
caused by an exceptional excess of individuals
breaking forth from congested districts, spreading
far and wide, yet never succeeding in colonising
new areas. One of the most remarkable instances
of this irruptic movement is furnished by that
curious bird known as Pallas's Sand-Grouse.
Readers may recall its visits to Western Europe
and the British Islands a decade ago — an irruptic
wave of birds that spread from Central Asia.
Similar irruptic waves of Jays and Goldcrests
have also been remarked.

M

CHAPTER V

THE GENERAL HABITS AND FUNCTIONS OF BIRDS

The flight of birds— Flightless birds— The fitness of birds
for an aerial existence — Various modes of flight — Gliding
flight : how performed — Flight by active strokes of the
wings: how performed — The movement of the wings —
Soaring or sailing flight : how performed — Terrestrial
and aquatic motion of birds — Birds unable to progress
upon the ground — Running, walking, and hopping
movements — Progress in water — The food of birds —
Modifications of the bill — Common to various distantly
related groups — Social, gregarious, or solitary instincts
of birds — Mimicry in birds — Protective colours and
resemblances of birds — Forest birds — Desert birds —
Marsh and swamp birds — Moorland and mountain
birds — Arctic birds — Variation in birds — Of external
structure and colour — Dimorphism in birds — Sexual
dimorphism — Dimorphism independent of sex —
Structural dimorphism.

WE have now reached that stage in the story of
the Birds where it becomes necessary to devote
a chapter to their general Habits and Functions.
We have traced their history from their early
origin down to the present era, and briefly
sketched their general characteristics, anatomical
and otherwise ; we have grouped all living birds

GENERAL HABITS 179

into fairly natural orders ; traced the distribution
of birds over the world, and then discussed the
laws of their dispersal and migration. The most
characteristic habits and functions of Birds may
now fittingly help their story onwards.

Of course it would be quite impossible to give
even the barest resume of the habits, infinite in
variety, of nearly twelve thousand species of
birds. On the other hand we may, at least, be
successful in describing some of the more charac-
teristic habits possessed by most birds in common,
together with a few of the more remarkable pecu-
liarities of the class. These naturally group
themselves into various classes of phenomena,
among which we may mention Flight, Terrestrial
and Aquatic Motion, Social, Gregarious, or Soli-
tary Instincts, Food and the many methods of
procuring it, Mimicry, Protective Colours and
Resemblances, and, lastly, the very difficult
problems of Variation and Dimorphism.

We will first devote a short space to that func-
tion of the wings termed Flight, together with
certain aerial habits of birds. Flight may be said
to be nearly universal among birds ; it is one of
their most remarkable characteristics, their name
being almost synonymous with an aerial exist-
ence. There are, comparatively speaking, very few

i8o THE STORY OF THE BIRDS

birds indeed that cannot fly, and in all cases to the
contrary the wings have reached their present de-
graded and functionless state through disuse. It is
almost a demonstrable fact that the earliest bird
forms could fly, and that all flightless birds, no
matter how archaic their type (such as the Ratitae),
have been brought to that condition by the neglect
of their ancestors to make proper use of their
wings. Birds, then, are the only vertebrate animals
that can fly, with the sole exception of bats, and in
their case the analogy is scarcely a perfect one.

It requires but a very elementary knowledge of
the anatomy of birds to convince us that these
creatures are in every way fitted for an aerial
existence. Not only is the general shape of the
body one best adapted for easy cleavage of the
air, but the bones being hollow, are exceptionally
light, whilst the extraordinary lightness of their
dermal covering has passed into a proverb, " As
light as a feather." Then again, as we have
already seen, the anterior limbs of a bird are
attached to the highest part of the body, whilst
all the least weighty organs are similarly situated.
The heavy pectoral muscles and the stomach
being in the lowest part of the body renders the
centre of gravity as advantageous as possible be-
neath the suspension centre of the wings. Then,

GENERAL HABITS 181

many birds of exceptional flight endurance are
rendered even more buoyant by the presence of
curiously modified pneumatic skin, as well as vari-
ous air sacs. Vultures, Gannets, and Screamers
may be instanced, although it is only fair to state
that some anatomists suggest that the principal
function of these air sacs is to ventilate the lungs,
which in birds are only capable of comparatively
limited movement. Even in this case, however,
their correlation with flight is obvious. Professor
Roy (who contributes a most interesting article
on Flight to Professor Newton's Dictionary of
Birds, to which we are indebted for many of the
following particulars) divides avine Flight into
three distinct classes. According to this autho-
rity, then, Flight may be performed, firstly, by
gliding or skimming ; secondly, by active strokes
of the wings ; and, thirdly, by sailing or soaring.
In the first place, we must remember that the
relation of the wing area to the weight of the
bird varies considerably, and that the greater the
former relatively is the more powerful the flight
will be. An, equally large amount of variation
exists in the strength of the wing muscles, this
corresponding with their weight. Then, as we
have already seen, the shape of the wing is
equally subject to much variation, and is largely

i82 THE STORY OF THE BIRDS

correlated with the general habits of the bird.
Gliding Flight is classed by Professor Roy as the
simplest. An example of this in its commonest
form is presented when a bird, having reached a
certain velocity by rapid wing-beats, extends them
and expands its tail, and skims forward for some
distance. Sometimes the necessary speed for the
performance of this kind of flight is attained by
descending from some eminence. This move-
ment cannot last very long, because it is made
either at a loss of vertical height, or continued
forward movement. The direction, however, may
be upwards or downwards, in the former illus-
trated by the swoop of a Falcon with closed
wings to the ground, the momentum thus gained
being sufficient to send the bird gliding upwards
again on extended wings. Most observers must
often have been impressed by the consummate
ease with which a gliding bird can guide its
motion, but how this is done is not at all gene-
rally known. Any increase of velocity tends to
push upwards the anterior part of a gliding bird's
wing, and cause the bird to rise higher in the air.
But this a bird can prevent in various ways,
either by changing the position of its centre of
gravity forwards by extending its neck (in a
long-necked bird like a Crane or a Heron), or

GENERAL HABITS 183

backwards, by retracting it, or (in a short-necked
bird) by moving forwards or backwards the ex-
tended wings, or opening or closing the tail.
Change of direction upwards or downwards can
thus be obtained by moving backwards or for-
wards the centre of gravity, and this without
changing the angle of the under surface of the
wings and tail with the general direction of the
flight. All this involves but little muscular exer-
tion, and a similarly small amount of energy. A
turn to the right or left is made by changing the
centre of gravity to one or the other side of its
centre of suspension by the expanded wings,
either by a turn of the head, the course following
the same direction, by partly bending one wing,
or raising one side of the expanded tail, which
also causes a turn in the same direction.

Flight by active strokes of the wings is the
most ordinary method adopted by birds in pass-
ing from place to place. As Professor Roy
points out, it is much easier for a bird to sustain
itself in the air by active flight, if it have a certain
initial relative velocity, than when it begins to fly
from a point of relative rest. Most large birds,
especially, therefore seek to rise from the ground
with their heads to wind. In the absence of wind
(and in some species this condition is immaterial)

1 84 THE STORY OF THE BIRDS

these birds gain an initial velocity by running for
some distance, or, in the case of aquatic birds, by
striking the water with the tips of their wings for
the first few strokes. Smaller birds gain an ini-
tial velocity by a spring, and this fact explains
why so many short-legged birds rise with diffi-
culty from a flat surface, or, in some cases, are
unable to do so at all. That kind of active flight
known as "hovering" (of which the Kestrel is
such an excellent and familiar example) can only
be indulged in by birds of very powerful flight,
great exertion being apparent in the frequency
with which the wing strokes succeed each other.
As a rule, the wings are moved quickest as the
flight commences, the angle through which the
pinions move being a large one, in some cases
the wings striking each other above the back at
the end of the up-stroke, and the tips nearly
meeting at the end of the down-stroke. This
may often be remarked in the Ring-Dove, the
noise made by the wings striking each other
being considerable. As the flight becomes
quicker the wing-beats become slower, and the
angle made by the wings is much smaller. We
are indebted to instantaneous photography for a
clear demonstration of how the wings of a bird
are moved during flight. The wings, or rather

GENERAL HABITS 185

we should say the upper arm-bone or humerus,
moves in an elliptical direction during the down-
stroke (which takes a longer time to make than
the up-stroke), which describes the front half of
the ellipse, the wings moving forward as well as
downward. Having made this stroke, the wing
moves backwards and upwards, describing the
posterior half of the ellipse, and the plane of the
wing is altered, so that it looks down and for-
ward. During somewhat rapid flight the up-
stroke is chiefly a passive movement, the bird
continuing to rest on the wings, the velocity of
the body slightly, decreasing, but recovering
speed again with the next down-stroke. Just
as flight commences, however, the up-stroke is
an active one, and the long quills in the wing
separate from each other, thus reducing the air
resistance to the back of the wing as it travels
upwards.

Soaring or sailing flight is much the rarest
form of aerial motion indulged in by birds. It
primarily differs from gliding flight, in the fact
that the bird practising it does not of necessity
lose vertical position or velocity as a result of
atmospheric resistance. The birds in which
soaring or sailing flight is most typical are
Vultures, Falcons (notably Eagles), Frigate

i86 THE STORY OF THE BIRDS

Birds, Gannets, and so forth. These aerial
soarers are mostly big birds, with an extensive
wing or sail area in proportion to their total
weight. More or less wind appears to be abso-
lutely essential to this mode of flight, and one
of its most marked characteristics is the curved
or circular course which it describes. Various
theories have been propounded to explain how
these soaring flights are performed, but as yet
their explanation is by no means complete or
satisfactory. They have been attributed to up-
ward currents of air, as well as to the varying
velocity of the wind at different heights above
the earth. By whatever means they are per-
formed they are wonderful exhibitions of volant
force ; and the observer may well be profoundly
impressed as he watches the soaring flight of
Vulture or Eagle high up in the blue sky, con-
ducted, as it were, with no visible effort.

From the aerial progress of birds we will now
turn to a brief notice of their terrestrial and
aquatic motion. There is probably a greater
amount of variation in the latter methods of
progress than there is in aerial locomotion.
There are, for instance, far more birds unable
to walk than there are unable to fly. It is,
as we know, very exceptional to find birds

GENERAL HABITS 187

incapable of flight, for functional wings are very
essential to the existence of most species. On
the other hand, there are large groups of highly
specialised birds that are unable to progress
along the ground with their legs and feet. We
may instance the Humming-Birds and the
Swifts, numbering together many hundreds of
species, also the Swallows, although the latter
birds are perhaps not quite so helpless in this
respect. Humming-Birds and Swifts never nor-
mally visit the ground ; Swallows often do so,
however, but they rarely attempt to make any
progress there, and never unless aided by their
wings. As we know, these birds find an abund-
ant compensation for their loss of terrestrial
motion in their remarkable volant powers. They
may be said to pass most of their existence in
the air, where legs would be a superfluity. Their
anterior limbs have developed at the expense
of their posterior ones. Then again we find
many species of birds that walk with difficulty
or with a ludicrous amount of awkwardness.
Among these we may mention such species as
Divers, Auks, Grebes, Penguins, Frigate Birds,
Pigeons, and Ducks. Some of these possess
great powers of wing (Frigate Birds), but the
majority, although very capable fliers, find their

i88 THE STORY OF THE BIRDS

legs of the greatest service as aids to swimming
and diving. These are placed so far back as
to render walking by no means easy or elegant
in the purely aquatic species ; but their adaptive-
ness to an aquatic existence is beyond criticism.
Their legs and feet are used as oars, modified
in various ways so that they may combine the
greatest power of propulsion in the backward
movement or stroke with the least degree of
resistance in the forward one. Many of these
birds (Divers for instance) are said to assume
a ventropodal position when on land, never
standing in an upright attitude ; but that this
is not invariably the case my own and others
observations prove beyond doubt.

The usual modes of progress on land by birds
is either by running, walking, or hopping. We
cannot say that either mode of progression is
peculiar to certain groups, or in many cases to
certain species, but generally speaking these
various methods of moving about are character-
istic of the following birds respectively. All the
Ratitae birds both walk and run, when the latter,
usually balancing themselves with their short
wings. Amongst Carinatae birds the typical
walkers, as they certainly are the most stately,
are Cranes, Herons, Storks, Flamingoes, Bustards,

GENERAL HABITS 189

and so forth. The Rails, too, are very ele-
gant in their carriage ; so, too, are the Gulls ;
but the Terns, owing to their comparatively
short metatarsi, are but indifferent walkers.
Game birds both walk and run, as also do
many of the Plovers and Snipes ; but running
is an especial feature in the progress of the
Charadriiforme birds on land. Incidentally we
may remark that we once saw a Ringed Plover,
when standing upon one leg on the sands, hop
for several yards rather than put the other leg
to the ground. Pigeons are but poor walkers
or runners, owing to the short metatarsi ; so,
too, are Sand-Grouse ; and even more especi-
ally Goatsuckers, and many of the Cuckoos.
Amongst the swiftest bird runners we may
include some of the Rails. The long-legged
Geese are fair walkers, but the shorter-legged
Ducks are awkward and waddling in their gait.
Parrots, again, are clumsy walkers, although
they are agile enough in trees, where they climb
about the branches assisted by both bill and
feet. Many of the Kingfishers are practically
incapable of terrestrial progress. Amongst Pas-
serine birds we have examples of each mode
of progression ; in fact some species employ all,
as fancy or circumstances may decide. Crows,

THE STORY OF THE BIRDS

for instance, both walk and hop ; Thrushes not
only walk and hop, but occasionally run as well.
We often find considerable difference in the gait
of very closely allied birds. A Chaffinch not
only runs, walks and hops, but a Sparrow in-
variably progresses by the latter means alone.
The most expert runners amongst the Passeres
are the Wagtails, Pipits, and Larks. A hopping
gait is certainly the most prevalent amongst
small Passerine birds. Woodpeckers, when they
do visit the ground, which in some species at
all events is much more frequently than is
generally supposed, progress in long hops ; but
on the trunks of trees they run and walk only,
supported by the stiff tail. The Passerine
Creepers progress in a similar way. We may
conclude this portion of the subject by a brief
allusion to the various actions of aquatic birds.
We pass over the plunging of Gannets and
Terns and other species, for that scarcely
comes within the scope of the present subject,
being connected with flight. Aquatic birds,
then, may either swim or dive. The birds that
dive of course can swim equally well, but there
are many birds that swim yet never dive. Even
amongst the Ducks we have two special groups ;
one distinguished for diving, the other for

GENERAL HABITS 191

swimming only. This aquatic progress is
usually associated with webbed or lobbed feet,
but some species are equally expert at swim-
ming and diving with no such appliances. The
Water-Hens furnish us with a capital instance
of this. Another very curious habit of certain
aquatic birds (notably Divers and Grebes) is
that of gradually sinking the body into the
water until all but the beak or the head is sub-
merged. Lastly, we may mention the peculiar
motions of certain Petrels, these birds frequently
running, as it were, over the smooth surface of
the ocean waves, pattering the water with their
webbed feet.

Now a few words concerning the Food of
Birds and the various methods of obtaining it.
Our study of the structure of birds has already
suggested the great variation in the food which
must prevail among the many thousands of
species. The diverse way of obtaining it, the
immense amount of modification in the struc-
ture of the bill and feet, to say nothing of
the internal organs of digestion, are none the
less interesting. Generally speaking, the bill of
a bird is a sure indication of the general food
of a species, whilst the feet and wings suggest
to some extent the method of securing it. The

192 THE STORY OF THE BIRDS

long pointed wings, the weak feet, and the
wide gape of the Swallow all indicate an insect
diet secured whilst the bird is coursing about
the air. The equally long wings, in combi-
nation with the powerful feet with their sharp
claws, and the strong hooked and toothed bill
of the Falcon, tell us as plainly as spoken
words could do that this bird is a hunter of
living creatures — that it preys upon flesh. The
chisel-shaped bill of the Woodpecker, with the
curiously modified tongue, the zygodactyle feet,
and the stiff- pointed tail, betray the bird's
partiality for insect food and the peculiar
methods of obtaining it.

The modification of the bill in some groups
is very much more extensive than in others.
A diverse amount of modification in the bill
seems correlated with a high degree of organi-
sation, and its consequent variety of habit
and food. Thus we should expect to find,
and really do find, the greatest amount of
variation in the bill amongst the most highly-
organised group of birds, the Passeriformes.
Here we cannot say that any shape of bill is
typical, no more than we can assert that any
one kind of food is common to the group of
the insectivorous Passeres — such as Warblers,

GENERAL HABITS 193

Thrushes, Wrens, Vireos, and Bulbuls — we find
bills adapted not only for picking up insects,
but for seizing worms, grubs, and so forth ;
then as we come to the more specially insec-
tivorous forms we find a widening of the bill
and a greater development of rictal bristles, as
in the Flycatchers ; whilst in the exclusively
insectivorous feeders the bill itself becomes
small and weak and the gape exceptionally
wide, as in the Swallows. Another change of
food is unerringly indicated as we reach the
Titmice and Nuthatches, the bill now being
perceptibly and relatively stouter, and adapted
for digging into wood and other hard sub-
stances in quest of grubs, nuts, and so on ;
whilst still greater strength and a perceptible
hook and notch characterise the bill of the
Shrikes, which seize large case-protected insects,
small birds and mammals. Then we revert
to the finer-shaped bills again as we reach
the insectivorous Wagtails, for instance, whilst
a more slender and longer bill again is pre-
sented by the Sun-Birds, many of which have
this organ specially modified in shape and
length to reach insects, and possibly nectar,
in certain flowers. Another change of food
introduces us to yet another type of bill. With

N

194 THE STORY OF THE BIRDS

the Larks we come to the graminivorous section
of the Passeriformes, and the stouter bill plainly
indicates that hard seeds as well as insects are
sought. As we approach a more exclusive
seed diet the bill as surely becomes modified
to cope with it. The Buntings have the palate
furnished with a hard, bony knob, and the
bill modified to fit it, which enables these
birds to crush and shell hard seeds with the
greatest precision. The Finches also have a
hard bill more or less similarly modified for
the purpose of cracking seeds ; whilst the hard,
strong conical beak of the Crows is well
adapted to the almost omnivorous diet of those
birds. One of the most remarkable modifica-
tions of the bill in this group is presented by
a New Zealand species, the Huia, scientifically
called Heteralocha acutirostris. In the male of
this species the bill is short, stout pointed,
and nearly straight, whilst in the female it is
long and curved almost like a sickle. Now
the favourite food of this bird is the grub of
a certain timber-boring beetle. To obtain this
the bill of both sexes is brought into use. The
male with his short strong bill digs away as
much of the wood as possible that conceals
the grub, then the female with her long slender

GENERAL HABITS 195

bill comes and drags it out. When not feed-
ing in company the male digs his prey out
of the decayed wood, whilst the female probes
the nooks and crevices for hers. This pecu-
liarity is an example of what is called sexual
dimorphism, a phenomenon of which we shall
say more presently.

It is a somewhat remarkable fact that very
similar modifications of the bill are found in
distantly related groups of birds where the
same kind of food is sought. There is, for
instance, a very strong resemblance between
the bills of the Divers, Grebes, Herons, and
Storks — all possessing beaks more or less spear-
shaped, and adapted most beautifully to seizing
slippery fish. But, on the other hand, we also
find extraordinary divergence in the shape of
the beak in some members of the same order.
What, for instance, could be more unlike than
the sharp spear-like bill of the Heron and the
flat spoon-shaped beak of the Spoonbill ? Dif-
ferent food, or different methods of securing
it, explain the curious variation ; for one bird
stands by the water-side and transfixes the fish
as they swim unsuspectingly by, whilst the
other sifts the mud and water, moving the flat
bill from side to side in a half circle. The

196 THE STORY OF THE BIRDS

bill in the Charadriiformes also presents con-
siderable diversity in harmony with special
kinds of food and peculiar methods of obtain-
ing it ; in the Lariformes, however, there is
much greater uniformity, because these birds
all feed upon fish and similar prey. The Terns,
however, have the bill modified to seize their
prey by a plunge, whilst the type of bill is
most emphasised in the Skuas, which are, as
we have already seen, notorious robbers of
the food from the Gulls. Another group in
which the food is very uniform in character
is the Parrots, and as a consequence we do
not find much radical modification in the bill,
that organ being adapted to crush nuts, fruits,
and so on.

We may now pass on to a brief notice of the
social, gregarious, or solitary instincts of Birds.
Even the most casual observer of birds cannot
fail to remark that these creatures vary a good
deal in their social instincts, either throughout
the year or more particularly at certain seasons.
As we find examples of each of these instincts in
almost every great group, no general rule can
well be laid down respecting them. Perhaps
the most widely prevailing of these instincts is
the social one. This may be partial ; that is to

GENERAL HABITS 197

say, it may only be displayed at certain times
or seasons, or it may be permanent in its pre-
valence. When the social or gregarious instinct
is only a partial one it is generally displayed
after the breeding season is over, when the
broods and their parents join others and form
into flocks which pass the autumn and winter
in company. Less generally, however, we find
these conditions absolutely reversed, certain
birds becoming gregarious at the approach of
the nesting season ; yet when the young are
reared the gatherings disperse, and more or less
solitary instincts prevail until the return of
another breeding time. On the other hand,
there are many species that remain gregarious
throughout the year, always breeding in socie-
ties, and continuing in company when sexual
duties are over. Many birds individually mani-
fest a social instinct, not always a desire for
the company of their own kind, but an incli-
nation to mix with a flock of some other
species. It may be that these socially inclined
birds have no opportunity for the time being
to join gatherings of their own species, and
gratify a gregarious yearning in the only manner
available. Lastly, we have the recluses, birds
that remain in a more or less solitary state

198 THE STORY OF THE BIRDS

always, save in the season of reproduction.
Some of the most solitary of these are the
Eagles and other Raptorial Birds. It is also
worthy of remark in connection with this pecu-
liar instinct, that some birds allow their broods
to keep in company with them almost up to
the time of the next breeding season ; but
others invariably disperse their family as soon
as the nestlings are able to forage for them-
selves. In a great many cases the brood and
parents migrate in company; in fact, grega-
rious and social tendencies are exceptionally
characteristic of migratory species. A plausible
explanation of these social and gregarious in-
stincts in birds may be that a greater amount
of safety is ensured by flocking together ; and
this seems confirmed by the fact that the most
solitary birds are either of large size or preda-
ceous habits — birds well able to take care of
themselves.

We will now pass on to a brief considera-
tion of Mimicry, Protective Colours, and Re-
semblances amongst Birds. These are subjects
which an entire volume would not be sufficient
to exhaust ; all that we can do is to give a few
of the most interesting facts. Take the subject
of Mimicry first, a fascinating study truly, and

GENERAL HABITS 199

one concerning which but comparatively little
is known. For our present purpose we cannot
do better than give the general substance of
what we have already written in a volume to
which the present may aptly serve as a supple-
ment.1 Of all forms of protective modification
of plumage that of Mimicry — a weak and de-
fenceless bird imitating the colour of a stronger
and more favoured one — is certainly the most
curious and remarkable. Two facts, however,
must be kept in mind ; the first, that this re-
semblance between distantly related species is
apparently unconscious on the part of the
species practising it ; the second, that all in-
stances of similarity of colour in different species
are not necessarily cases of Mimicry. These
must fulfil certain conditions, admirably laid
down by Dr. Wallace, as follows. The imitative
species must inhabit precisely the same locali-
ties, the imitators must be the more defence-
less or labour under some other disadvantage,
be least numerous individually, and present
marked differences from the majority of their
allies. In every true case of mimicry the points
of imitation are external and visible only. Some
of the most interesting instances of avine

1 Curiosities of Bird Life, pp. 235-241.

200 THE STORY OF THE BIRDS

mimicry are presented by the Cuckoos. Not only
do certain species of these birds very closely
resemble Hawks, but others bear a remark-
able likeness to certain Game Birds. Our own
Cuckoo resembles the Sparrow-hawk so closely
that even small birds are apparently deceived, as
seems confirmed by their chasing it, just as they
often mob the rapacious bird. Then the young
Cuckoo in its turn bears a very remarkable
likeness to the Kestrel ; and this may pos-
sibly be an advantage to it, for the small foster-
parents of the Cuckoo do not fear the Kestrel ;
whereas if it resembled the Sparrow-hawk at
this age, they might easily become alarmed at
its Hawk-like appearance, and desert it long
before it was able to take care of itself. The
resemblance to the Kestrel must doubtless be
a further advantage to the young Cuckoo by
often saving it from the attacks of predatory
birds and beasts. Then other species of Cuckoo
that resemble Game Birds derive an advantage
from the fact that the latter are strong, pugna-
cious species, living in companies, and usually
accompanied by bellicose males ready to attack
and beat off marauding birds and animals.
Other Cuckoos again resemble certain pugna-
cious Drongo Shrikes, inhabiting the same

GENERAL HABITS 201

districts. Other and even more interesting cases
of avine mimicry have been recorded by Wallace,1
who writes as follows : " More perfect cases
of mimicry occur between some of the dull-
coloured Orioles in the Malay Archipelago and
a genus of large Honey-suckers — the Tropi-
dorhynchi or ' Friar Birds.' These latter are
powerful and noisy birds, which go in small
flocks. They have long, curved, and sharp
beaks, and powerful grasping claws ; and they
are quite able to defend themselves, often driv-
ing away Crows and Hawks which venture to
approach them too nearly. The Orioles, on
the other hand, are weak and timid birds, and
trust chiefly to concealment and to their retir-
ing habits to escape persecution. In each of
the great islands of the Austro-Malayan region
there is a distinct species of Tropidorhynchus,
and there is always along with it an Oriole that
exactly mimics it. All the Tropidorhynchi have
a patch of bare black skin round the eyes and
a ruff of curious pale recurved feathers on the
nape, whence their name of Frinr Birds, the
ruff being supposed to resemble the cowl of a
friar. These peculiarities are imitated in the
Orioles by patches of feathers of corresponding

1 Darwinism, pp. 263, 264.

202 THE STORY OF THE BIRDS

colours; while the different tints of the two
species in each island are exactly the same.
Thus in Bouru both are earthy brown ; in
Ceram they are both washed with yellow ochre ;
in Timor the under surface is pale and the
throat nearly white." Very remarkable is the
fact that even a protuberance on the bill of the
Honey-sucker is imitated by a similar peculia-
rity on that of the Oriole. Incidentally we may
remark that Dr. Wallace, finding a peculiar
form of Oriole on the island of Gilolo, was
able to predict that a Friar Bird similar in
appearance would some day be found there ;
and this it actually was ! In Brazil we have
a case of a fierce bird-eating Hawk imitating
another Hawk perfectly harmless and feeding
upon insects. But the most marvellous part
about this is that in localities where the harm-
less bird is absent the rapacious species never
adopts the disguise. Another interesting in-
stance is furnished by a Bulbul of Madagascar
imitating a Shrike found in the same country.
Although the latter bird is dimorphic the Bulbul
closely resembles or mimics feather for feather
the two types of colouration.

The various Protective Colours and Resem-
blances of birds are little less wonderful. No

GENERAL HABITS 203

one can make a very exhaustive study of Birds
without soon coming to the conclusion that
colour plays a very important part, nay, many
parts, in their economy. No matter what de-
scription of haunt we select, we are pretty sure
to find within it birds of some kind presenting
in various ways protective modifications of
colour, not only for purposes of concealment
from enemies, but in some cases to enable
them better to steal upon their own prey. This
protective colouration often runs almost uni-
versally through entire groups of birds. In
the tropics, for instance, we have birds with the
prevailing tints of their plumage yellow or
green in many different families ; and we can
well understand of what vast service such hues
are amongst the evergreen foliage. In more
northern latitudes many of these gaudy-coloured
birds would be conspicuous enough, but here
in the virgin forests of the Equator their brilliant
hues and violently contrasted tints harmonise
completely with the vegetation.

But the protective colours of forest birds do
not appeal so forcibly to the casual observer
as some of the hues that deck species living in
more open situations. Take desert birds, for
example. These birds are almost invariably

204 THE STORY OF THE BIRDS

clothed in plumage so exactly resembling in
tint the ground upon which they live, that their
discovery is next to impossible. We may liter-
ally walk up to these birds crouching upon the
bare ground, and not one shall we see until it
rises absolutely from under our feet. The
Larks, the Buntings, the Finches, the Chats,
the Bustards, the Coursers, and the Sand-
Grouse are all clad in khaki hues. Our
soldiers have but followed the birds in render-
ing themselves inconspicuous on the open veldt
or the stony hillsides ; and one would have
thought that they had profited earlier by the
example set them by dame Nature. We find
the same great law prevailing upon the sandy
coasts and mud flats where Plover and Sand-
piper are decked in tints that harmonise closely
with the colours around them. These protective
hues of course are chiefly confined to the upper
parts of the body. Nearly all these latter birds
are white below — the most conspicuous hue in
nature — and we also find that many desert
species carry all their showy colours on the
under surface of the body. These protective
colours are the common heritage of all species
dwelling in such regions, peculiar to no special
group, although it is a significant fact that in

GENERAL HABITS 205

certain families where some of the species dwell
in more wooded districts and others in deserts,
it is only the latter that are modified in this
special way. We can better illustrate our mean-
ing by giving an instance. The Buntings, as
a group, are bright-coloured birds, yet the
Common Bunting is soberly arrayed in brown,
which harmonises closely with the brown earth
and the grey fallows upon which it loves to
rest ; whilst more significant still, we have the
sand - coloured Saharan Bunting, which lives
upon the North African deserts. Or yet again,
the Sparrows are a bright-coloured conspicuous
group, but when we reach the Sahara we meet
with a beautiful cream-coloured species — the
Passer simplex of ornithologists — which has dis-
carded the typical Sparrow garb and clothed
itself in the universal khaki instead.

Leaving the coasts and the deserts behind us
and entering the marshes and swamps, we find
other types of protective colouration. Here we
have such birds as Snipes with their peculiar
striated or lined colours blending beautifully with
the ribbon-like leaves of grass or sedge ; or yet
again, the Bitterns, in their garb of brown and
yellow absolutely losing their identity amongst
the tall brown stems and yellow leaves of the

206 THE STORY OF THE BIRDS

marsh vegetation. In the latter case the Bitterns
are aberrant in their general colouration, for the
Herons as a group are showy and conspicuous
birds — a deviation from the general prevailing
colour of the family in obedience to that law
of colour which insists upon harmony between
bird and haunt. Out on the open moors and
heaths a different kind of protective colouration
again confronts us in the marvellous tints of
the Red Grouse ; whilst higher up the mountain
sides the Ptarmigan in its pencilled dress assimi-
lates most closely with the stones and lichens,
and in winter (when its plumage is white) with
the all-pervading snows. This latter modifica-
tion, seasonal with the Ptarmigan, becomes con-
stant in such birds as the Snowy Owl, the large
Arctic Falcons, the Ivory Gull, and the Snowy
Petrel, which all live permanently within the
regions of almost perpetual snow. We must
also call attention to the fact that all these birds
which are protectively arrayed are endowed
with the faculty of rendering their concealment
as effective as possible, either by always alight-
ing on spots where their tints harmonise the
best with surrounding objects, or by crouching
low to the ground, the tree trunk, the sand,
and so forth, and there remaining absolutely

GENERAL HABITS 207

motionless until the threatened danger has
passed. In these situations they often so closely
resemble a stone, a clod of earth, an excrescence
on the bark, a heap of leaves, or the stalk and
leaves of surrounding plants, that discovery is
next to impossible.

We will bring the present chapter to a close
with a few 'remarks on the somewhat compli-
cated and at present but little understood sub-
jects of Variation and Dimorphism. Possibly
few readers even remotely suspect to what an
extent variation occurs among birds. The fact
can only be realised by the actual examination
of large series of individuals of the same species.
Variation, as most persons know, is a very com-
mon phenomenon amongst domesticated birds
and animals ; it may never be so pronounced
in wild birds, because of the strong tendency
of natural selection to prevent it, but it is
present in all to a degree that is not positively
harmful to the species. When, however, it may
reach an exceptionally pronounced type, such
as in the case of an albino bird, it is invariably
stamped out owing to its want of harmony with
its environment. It is therefore no exaggera-
tion to say that no two birds are exactly alike ;
the more minute the examination, the greater

208 THE STORY OF THE BIRDS

the amount of variation becomes apparent. The
larger the number of individuals we examine,
the more shall we be impressed with the differ-
ences they present. Confining ourselves to
external structure we shall find that the bill,
the legs and feet, the wings and the tail, are
all subject to individual variation, amounting
in the two extremes to an astonishing degree
of divergence. Colour is no less variable than
structure. As we may view each individual of
a large series of birds little or no difference
in tint might be detected, but by placing the
series — say of fifty or a hundred skins — side by
side the important variation in tint at once
becomes apparent. To a very considerable ex-
tent colour variation is correlated with geo-
graphical distribution, which in many cases
means that differences of tint are due to climatic
influences, as we have already seen. Then
again, structural variation is often correlated
with insulation, and often induced by it ; for we
often find the island representatives of a seden-
tary widely ranging continental species percep-
tibly larger or smaller than the others. It may
also be due to geographical distribution, as in
the case of the Crossbill, for instance. The dif-
ference in the size of the bill of the Common

GENERAL HABITS 209

Crossbill (Loxia curvirostra) and the Parrot
Crossbill (Loxia pityopsittacus) is believed to be
entirely due to the latter bird feeding on much
harder food in the Scandinavian fir forests,
whilst the former attacks smaller seeds and fruits.
The researches of Messrs. Allen and Wallace
have very clearly proved that the amount of
variation usually reaches ten or twenty, or even
twenty-five per cent, of the average size of the
varying part, whilst from five to ten per cent,
of the specimens examined present nearly as
large an amount of variation. It is by means
of this ever-present variation in every part of
a bird (internal as well as external) that natural
selection is able to work, and thus to harmonise
it with its constantly changing conditions of
existence in the struggle for life.

Among birds there are two very distinct kinds
of Dimorphism. By this latter term is meant
that in certain species constant and well-defined
differences, either in form or colour, are found
between individuals of the same species. First,
then, we have that dimorphism which is entirely
dependent upon secondary sexual characters ;
and, second, the dimorphism which may occur
in either sex without any distinction. Cases of
sexual dimorphism are so frequent amongst

2io THE STORY OF THE BIRDS

birds that we might almost describe them as of
universal prevalence. It may be seen in many
different forms, but its most frequent type is
that of general colouration. Innumerable in-
stances may be called to mind by every reader
at all familiar with birds in which the male is
more showily dressed than the female, as, for
example, in the Blackbird. More striking in-
stances are furnished by species in which the
male bird is adorned with crests or plumes, or
other nuptial ornaments, or is armed with spurs,
or decorated with tubercles, wattles, combs, and
so forth. Sexual dimorphism also extends to
the organs of voice, and such peculiarities as
pouches and sacs. We have already noticed
sexual dimorphism in the bill of the New Zea-
land Huia (conf. p. 194). In not a few cases it
is manifest in size. In great numbers of birds
the female is considerably bigger than the male,
especially in the Birds of Prey ; in other cases
she is smaller, notably among the Galliformes
and Ratitae Birds.

Of dimorphism independent of sex the in-
stances are much rarer ; indeed, but few cases
are known among birds. One of the most
remarkable of these is furnished by several
species of Skuas, which have two very distinct

GENERAL HABITS 211

phases of plumage, broadly described as a light
one and a dark one. This peculiarity is not
in any way a sexual one, and very often a male
and female of each type of plumage may be
noticed paired. Whether the Hooded Crow
and the Carrion Crow are two types of a
single dimorphic species seems not to be quite
so well determined, ornithologists differing in
opinion, some asserting that the birds are spe-
cifically distinct, although interbreeding. The
peculiar variety of the Ringed or Bridled Guil-
lemot may also be another instance of colour
dimorphism. Of structural dimorphism inde-
pendent of sex we may mention the large and
small billed form of the Dunlin, and lastly the
large and small race of the Wheatear.

CHAPTER VI

THE LOVE DISPLAYS OF BIRDS

Bird music — Vocal music of birds — Variety in song — Capri-
ciousness of song — The origin and purpose of avine
song — Individual variation in the song of birds — Imita-
tion— Do birds sing by instinct or imitation? — Vocal
sounds of birds— The instrumental music of birds —
Made by ordinary appliances — Made by special modi-
fications of the plumage — The drumming of the Snipe
— Modifications in the wings of the Humming-Birds —
In other species — Wing modification in the Manakins
— Sounds made by air sacs or pouches — The love dis-
plays of birds — Aerial displays of Humming-Birds — Of
Tyrant Birds — Love displays of the Birds of Paradise —
Of Bustards — The love-posturing of the Argus Pheasant
—The Bower Birds — Their curious "bowers" — The
dances of certain Rails — Of the South American Jacana
— Of the Spur-winged Plover — Of certain Ducks —
Parades of plumage — The meaning and purpose of
this display — Sexual selection — The vitality, excitability,
and pugnacity of birds.

WE will now proceed to the consideration of
another class of phenomena peculiar to birds,
and absolutely unique so far as all the rest of
the animal kingdom is concerned. This more
especially relates to the music or song of birds,

THE LOVE DISPLAYS OF BIRDS 213

as well as their various love cries and sounds,
together with those wonderful displays which are
intimately connected with their courtship and
their love. Bird music very naturally divides
itself into two distinct classes ; that is, it may
either be vocal music, produced by the organs
of voice, or it may be instrumental music, pro-
duced by certain purely mechanical means.
The vocal music of birds is unquestionably the
sweetest of all natural sounds, and one which, no
matter how great the variety in which we may
hear it, or how widely contrasted each song
may be within the most limited area, is never
out of harmony. Who ever heard a trace of
discord in the avine chorus of the woods and
fields ? Now, this is a consummation to which
even the human voice, and human music too,
can make no pretension, with the possible ex-
ception, shall we say, of such gifted ears for
melody as that famous Highland piper who,
during the narration of his fighting and piping
experiences to a few boon companions, is re-
ported to have said : " It was ae grand nicht
in Mrs. Glasse's wee back parlour in the Coo-
gate — nineteen pipers besides her nain sel, a'
playin' at the same time, an' a' playin' deeferent
maisik, when I jist thocht I was floatin' tae

2i4 THE STORY OF THE BIRDS

heeven on the hairmony " ! From a popular
point of view, song is very loosely associated
with birds in general. All the smaller birds
are very generally believed to sing in some
way. The capacity for song, however, is com-
paratively a local one, practically confined to
the Passeriformes, which, as we have already
seen, are provided with a special apparatus for
producing it (conf. p. 49). But even amongst
the Passeres song is by no means a general
accomplishment, and is practically confined not
only to the smaller species of the group, but
most developed in the duller-plumaged species.
The music of birds, there can be little doubt,
is one of the many forms in which natural
beauty is expressed. But Nature is by no
means lavish of her gifts, for few birds com-
bine any marked vocal powers with brilliancy
of plumage. These birds display their beauty
in another way, by exhibiting it upon their
painted wings, or plumes, or crests, and so
fprth. Another striking feature of bird music
is its almost endless variety. If, however, we
class music as a secondary sexual character, we
need not feel surprised at its diversity, for of
all characters, secondary sexual characters are
the most variable, and modified in almost

THE LOVE DISPLAYS OF BIRDS 215

endless ways. Another almost equally remark-
able feature about avine song is what we may
term the capriciousness of its possession. Few
species form their songs out of the same com-
bination of notes, and in many instances very
closely allied birds differ remarkably in the
quality of their voice. As a familiar instance
we have the Willow Wren and the ChiffchafT,
both very common little spring visitors to Eng-
land, and so much alike that it requires some
considerable knowledge of birds to distinguish
them. But the Willow Wren possesses a charm-
ing and plaintive song, a little run of beautiful
notes that form one of the sweetest bird-sounds
in spring, whilst the Chiffchaff's attempt at
music only amounts to a monotonous double
note, not easily mistaken for that of any other
British species. The high degree of organisa-
tion of the Passeriformes, and the fact that the
special vocal organs for producing true song
are peculiar to them, seem to indicate that the
group is comparatively a recent one. The
logical inference from this is that Song is but
a recent acquirement among birds, and that the
earth during the earlier eras of avine evolution
was absolutely wanting in avine melody.

Much diversity of opinion prevails concerning

216 THE STORY OF THE BIRDS

the origin and purpose of avine song. A very
popular idea is that song, or the instinct of song,
is but the outward expression of exuberant in-
ternal joy. The evidence, however, appears to
be overwhelming that song originated in sexual
rivalry, and has been developed and perfected,
fostered and increased, by that stronger and more
assertive vitality which is, without exception, so
characteristic of birds with any pretensions to
musical skill. Singing birds appeal to the female
through their sweet and joyful cries ; they sing
their best and loudest, and warble one against
the other in the heat of their passion, striving
their hardest to outsing all rivals within hearing.
Song also seems to be the agent of joy expres-
sion, and may also be indulged in as a pastime
or diversion, many species singing more or less
constantly throughout the year, and even when
sexual rivalry is dormant. But it is a rule, with-
out any exception whatever, that all song-birds
sing their best when inspired by love, and that
in no case does this music show the faintest
decline in power at a season when pairing
instincts are predominant. Song and sexual
rivalry are resumed together each season, and
the music dies away with the decline of that
sexual stimulus. Song, we may remark, declines

THE LOVE DISPLAYS OF BIRDS 217

perceptibly in brilliancy and persistency after
the laying period is over, and the more acute
stages of sexual strife are passed. That won-
drous, if soberly arrayed, songster the Nightingale
loses his sweet music as the young are hatched,
and his entrancing voice becomes a disagreeable
croak until passion inspires it anew the following
season. The singing period of all song-birds is
a season of irritation and war. Rival males sing
at each other, chase each other from tree to tree,
fight fiercely, and sometimes seem so lost in
their ecstatic rage as to become oblivious to their
own personal safety. Birds have been known
actually to die under the violent exertions of
song that a rival has inspired.

The very perceptible amount of individual
variation in the song of birds must be men-
tioned. This is a very difficult study, for it
requires a sensitive musical ear and some train-
ing to pursue it ; and yet it forms a most pro-
mising and pleasing field of inquiry. Another
puzzling question relating to song is the imita-
tion of other birds' notes practised by various
species. The standard of perfection in song is
also by no means a constant or uniform one.
We find a considerable range of variation in
this as in all other things. This is especially

2i8 THE STORY OF THE BIRDS

remarkable at the period when a species re-
sumes its voice after months of silence, and in
the maiden efforts of young individuals. All
young birds are generally indifferent songsters,
the art having to be learnt with considerable
effort or practice ; whilst some fully adult indi-
viduals, of probably every singing species, are
much finer musicians than others, the song
evidently improving with the age of the bird
up to a certain period. Song, we should say,
is almost entirely confined to the male sex ; in
some cases female birds have been known to
sing, but their performance is generally confined
to the utterance of a few twittering notes, and
which probably represent what was once the
best performance of the male at an earlier
period in the history of the species — the crude
beginning of a song which he has eventually
developed into music of entrancing sweetness.

Now comes the question, whether birds sing
by Instinct or by Imitation ? The belief is a
wide one, that young song-birds are hatched
with an inherited ability to sing like their parents ;
able without tuition or experience to warble
off the song characteristic of their species when
the proper season arrives. This is an utterly
erroneous assumption, with not a single scrap

THE LOVE DISPLAYS OF BIRDS 219

of direct evidence to support it. Every bird-
fancier knows full well how readily young birds
acquire a song totally unlike that of their species.
Many facts might be brought forward to prove
that the songs of birds are acquired by Imitation,
and that if young birds never have an oppor-
tunity of hearing the song peculiar to their species
they are totally unable to produce it. A bird's
song, then, is just as much an acquired faculty
as the acquisition of a language by a child.

As we previously remarked, one of the most
noteworthy characteristics of avine song is its
extraordinary variability, not as applicable to the
music itself (although the songs of some birds
are infinitely varied), but with regard to the
extent or degree of perfection which it has
reached in the various species. We find every
gradation of song, from the few harsh grating
notes of some of the Buntings, or the simple
trills of various Tits, for instance, to the finished
and gloriously beautiful performances of certain
of the Thrushes and Warblers. Amongst these
singing Passeres then there are birds of which
their vocal utterances are of the highest order —
producers of that wonderful melody of voice
that appeals with equal force and favour, if
only coincidentally, to the most cultivated and

220 THE STORY OF THE BIRDS

aesthetic human tastes as well as to their own
pleasurable or passionate gratification. It is
not within the scope of the present volume to
describe in detail the songs of the various species,
but before leaving the subject we ought perhaps
to call attention to the fact that the action of
birds during the utterance of their music varies
considerably. Some species invariably sing
whilst standing at rest, others when skipping
to and fro in frantic joy, others when soaring
or flying, others yet again accompanying their
melody by a more or less display of plumage,
or muscular action of the wings and tail.

We now pass to a consideration of certain
vocal sounds, none of which reach the human
standard of a song, appealing to no human
taste as the exquisite melody of song uni-
versally does ; many of them to our ears being
most discordant, impressive, curious, or startling,
though possibly appreciated by the sex to which
in a great many cases they seem specially to be
addressed. Sometimes they sound the signal of
defiance, or the invitation to the fray. In a
scientific sense these strange sounds, when uttered
under the influence of love or passion, must all
be classed as music or song. The familiar note
of the Cuckoo, for instance, is confined to the

THE LOVE DISPLAYS OF BIRDS 221

male, and uttered during the season of courtship
and love only. Many of these strange sounds
are an accompaniment to the various dances,
displays, marches, evolutions, and antics that
we shall shortly describe. Others, of course,
are in no way connected with love or war, but
serve as alarm notes, or to indicate the where-
abouts of companions. In certain species the
vocal organs differ very considerably in the two
sexes, being then instances of audible sexual
dimorphism. The boom of the Bittern, for in-
stance, is one of the most extraordinary sounds
in nature, and seems to be entirely a sexual
production. Such a wild unearthly night-cry
has very naturally become surrounded by super-
stition ; the bird was thought to produce it by
inserting its bill into a reed, or burying it deep
in the mud. This boom consists of two perfectly
distinct sounds, and is said to be produced
as the bird inhales and exhales its breath. Then
we have the piercing cries emitted by the Divers,
well likened to the screams of tortured chil-
dren ; or the awe-inspiring notes of the Owls —
all love cries, and claiming to be classed as avine
music. Then the notes of the Goatsuckers are
equally curious, and have in many cases been
syllabled into such phrases as " Willy-come-go,"

222 THE STORY OF THE BIRDS

"Whip-poor- Will/' "Who-are-you?" andso forth.
Again, some of the American Wood Hewers
(Dendrocolaptidas) assemble and indulge in a
chorus of piercing cries, sounding like shrieks of
insane laughter. Another extraordinary cry is
that of the Bell-Bird of South America, the
solemn tolling note of which, uttered at measured
intervals, may be heard at a distance of several
miles through the forests. During this perform-
ance the bird erects the peculiar appendage on
the forehead. This consists of a spiral tube,
nearly three inches long, jet black in colour,
dotted with minute white feathers, and which by
communication with the palate can be inflated
with air and raised, but when empty it becomes
pendulous. Another species, the Friar Bird of
Australia, utters a cry which the colonists render
as " More pork," or " Four o'clock." The Bustards,
too, emit some strange vocal sounds during
courtship ; whilst the love notes of certain Grouse
are curious, if not actually impressive. Then
we have the call of another Australian species
so like the cracking of a whip, that the pro-
ducer of it has been named the "Coach-whip
bird." Lastly, we may mention the musical
trills — usually modulations of the call -note —
peculiar to certain Sandpipers and Plovers,

THE LOVE DISPLAYS OF BIRDS 223

heard only during the season of courtship and
love.

We have now to deal with that varied assort-
ment of sounds produced by mechanical means,
and forming the second of the two classes into
which we have divided avine music. This we
have termed Instrumental Music, because the
organs of voice take no part in its produc-
tion. These sounds are produced in a variety
of ways ; not only by the bill, but by certain
modifications of the feathers ; whilst in some
cases the ordinary plumage is so manipulated
as to obtain the required effect. We may first
draw attention to a few instances in which these
sounds are produced by ordinary appliances.
Many species of Woodpeckers have a habit of
tapping with the bill the trunks or branches of
trees ; and if these chance to be hollow a noise
is produced which can be heard for a consider-
able distance ; whilst the bird's head is moved so
rapidly that our eye can scarcely follow it. So
loud is this noise, under certain favourable cir-
cumstances, that it seems as though the trees
were actually being split asunder. These noises
are for the most part peculiar to the nesting
season, and most naturalists are agreed that they
are signals between the sexes. Some birds are

224 THE STORY OF THE BIRDS

vocally mute, as we have already seen, the organs
of voice being absent or in a rudimentary con-
dition only. These species succeed in making
much sound by smartly snapping the two man-
dibles together. The Storks furnish us with a
capital example of these bird mutes. What is
technically known as the "klappering" of the
Storks is a very remarkable performance, gone
through not only as the birds stand upon the
ground, but as they fly, often at vast heights.
In producing this singular sound the bill is
laid against the stomach or the back, and then
the two mandibles are struck together so rapidly
as to form a kind of trill, curiously modulated
both in speed and tone. During the love season
certain Game Birds produce various humming
or rattling sounds with their wings at the time
of courtship ; whilst some of the Nightjars make
a booming noise with their wings. The common
Nightjar of our English woodlands produces what
is apparently a wing sound, as male and female
chase each other in the evening gloom.

We will now proceed to glance at a few of the
most curious and characteristic modifications of
plumage which are utilised in the production of
various sounds. Many of these special modifi-
cations are dimorphic and peculiar to the male

THE LOVE DISPLAYS OF BIRDS 225

birds alone ; in other species they are common
to both sexes, but in these cases the males are
generally the most specialised. As one of the
most familiar instances of feather modification
for the purpose of producing sound, we may
mention the tail of the Common Snipe. In this
species the outermost rectrices have a stiff sabre-
shaped shaft ; but it seems extremely doubtful
whether the drumming sound that this Snipe
makes in spring is produced entirely by this
modification. It appears to be caused by the
combined action of the wings and tail. During
the love season the male Snipe, as if to parade
his inordinate vanity, soars far up into the air,
then suddenly descends on vibrating wings and
outspread tail, making the peculiar bleating
noise which seems to be produced by the air
waves being driven by the powerful wing-beats
through the expanded and rigid tail feathers.
There are other species of Snipe in which the
tail feathers are modified in a much more
remarkable manner, as, for instance, in the Pin-
tail Snipe (Scolopax stenura) of East Asia.
This bird has no fewer than twenty-six rec-
trices, the outermost being little more than
threads. The sound produced by this modifica-
tion appears not to have been described by

226 THE STORY OF THE BIRDS

naturalists, but it is doubtless a very extra-
ordinary one.

Although we find a considerable amount of
modification in the tails of birds, and especially
in the Humming-Bird group, there can be little
doubt that they are more for decorative pur-
poses than for musical ones. Amongst the
Humming-Birds the rectrices vary considerably
in shape ; but the modification of the wing is
more important from a musical point of view.
These feathers are moved rapidly, and can be
manipulated better than the tail for the pro-
duction of special sounds. We ought also to
state that the wings of Humming-Birds are
remarkably free from decorative colours, but on
the other hand the tail is famous for the many
glorious tints it displays, rivalling the rain-
bow in splendour. In this group the remiges
are modified to an astonishing degree. In the
genus Selasphorus the first primary is sharply
pointed or abruptly excised at the tip ; in
Lafresnaya and Aglaeactis it is very narrow,
and sometimes curved inwards, upwards, or
outwards, whilst in other genera the quills or
shafts of the primaries are exceptionally thick
or abnormally swollen, as in Campylopterus and
Sphenoproctus. Most of these modifications are

THE LOVE DISPLAYS OF BIRDS 227

peculiar to the adult males ; and in one species
at least (Selasphorus) we know that the flight
during the mating season is accompanied by
a shrill screeching noise said to resemble the
sound made by a wood splinter touching a cir-
cular saw in rapid motion ; the bird rising to
some height and then descending like a flash,
making the singular sound which does duty for
a love note or song. This attenuated first pri-
mary is found in various birds very remotely
related. It occurs in the American Woodcock,
in the South American Guans, the Indian Lesser
Florican, and Pallas' s Sand-Grouse. The male
of one species of Guan (Penelope nigra) is
known to make a crashing noise like that of
a falling tree, as he flies downwards : the Flori-
can produces a deep-toned humming sound.
The various modifications of the secondary
quills are no less remarkable. Perhaps the most
curious instances are furnished by the Manakins.
Many of these species have the shafts of the
secondaries abnormally thickened and the webs
of various shapes. Even the bones of the wing
are exceptionally strong and thick. These mo-
difications are also dimorphic, confined to the
male, the corresponding feathers in the wing of
the female being of the normal shape. Most

228 THE STORY OF THE BIRDS

peculiar sounds are produced by the aid of these
feathers, for the birds are otherwise songless,
the vocal muscles being absent in this group.
One species makes a sharp sound like the crack
of a whip, followed by a rasping sound similar
to the call of the Corn-crake ; another succeeds
in making a sharp and whirring sound like that
made by a small wooden rattle, followed by
several sharp snaps. We ought also to mention
in connection with the present subject that the
males of some other birds are provided with
air sacs or pouches, which they inflate during
the period of courtship, just like bagpipes, and
by the aid of which various booming or drum-
ming sounds are produced.

We have now to consider that portion of the
subject which deals with Display rather than
with vocal or other sound ; with those curious
flights, posturings, love antics, and dances which
may justly rank as some of the most remark-
able phenomena in nature. This special kind
of display, broadly speaking, may be divided
into two distinct types : that indulged in by
aerial species, and that peculiar to terrestrial
species. In studying the subject we shall find
it impossible to draw any arbitrary line between
the various aerial movements of certain species,

THE LOVE DISPLAYS OF BIRDS 229

often accompanied by the display of some special
ornate development, and the terrestrial move-
ments of others, likewise attended with the
parade of certain decorations. Of the aerial
performances we may here select a couple from
the Humming-Birds. Stolzmann tells us how
he watched entranced the aerial ballet of that
marvellous racket-tailed Humming-Bird, the
Loddigesia mirabilis. It is one of the rarest
species, and down to 1880 (when Stolzmann
practically rediscovered it) but a single skin
was known in any scientific collection. He
found that these Humming-Birds were in the
habit of assembling at certain spots on the bare
plateau to indulge in aerial movements. Two
birds would first of all hover in the air opposite
to one another with their bodies in a vertical
position, then with expanded tail they flew first
to one side then the other uttering a clicking
note. Sometimes several males took part in
this performance. At other times one bird
would hang below a slender branch as another
bird went through the mazy dance, when sud-
denly the position of the two performers would
be exactly reversed, one taking the position and
performing the actions of the other. Meantime
the wonderful racket-shaped tail is moved in a

23o THE STORY OF THE BIRDS

variety of ways, the spatulate ends sometimes
being bent forwards almost to the crown of
the head. This Humming-Bird is not a very
brightly coloured one, the tail being apparently
the principal decoration, and therefore manipu-
lated accordingly. Belt observed two males of
another Humming-Bird, the Florisuga mellivora,
displaying their charms in a sort of friendly
rivalry before a single female of the same species.
First one would dart upwards, suddenly ex-
panding the snow-white tail, which, like an in-
verted parachute, covered more space than the
rest of the bird, and then gradually descend,
turning slowly round, displaying both back and
front ; then the other would soar as its com-
panion came down, going through precisely the
same actions. Some of the Tyrant Birds are
also remarkable for aerial display. One of these,
Cnipolegus hudsoni, is black with a white bar
on the wings. It is in the habit of sitting on
a dead twig at the top of a bush, at intervals
leaving this perch and beginning literally to
waltz round and round in the air so rapidly
that the wings, looking like a mixture of black,
white and grey mist, make a loud humming
sound. Just as suddenly this wild fantastic
dance ceases, and the bird resumes its perch to

THE LOVE DISPLAYS OF BIRDS 231

sit quite still until the performance is repeated.
Many other instances might have been given
of these aerial ballets, but we will now visit the
tree-tops for an example of a stately minuet,
which is danced among them by some of those
gorgeous creatures the Birds of Paradise. The
males of the Great Bird of Paradise assume their
full wedding plumage in May, and during that
month companies of them assemble at certain
spots each morning to go through a kind' of
dance and display. These dancing parties are
held in the tree-tops, a tree being selected with
an extensive head of spreading branches, clothed
with large scattered leaves, in which there is
plenty of room to move about. Here perhaps
a score of these gorgeous birds collect, raise
their wings, and elevate their exquisite plumes,
which are kept continually vibrated. Between
whiles the birds fly across from branch to branch
in great excitement, so that, as Wallace aptly
says, the whole tree is filled with waving plumes
in every variety of attitude and motion. During
this performance the long plumes completely
overshadow the bird, which is hidden in the
golden glory waving above. The various dis-
plays of other species of these birds are equally
interesting.

232 THE STORY OF THE BIRDS

In some cases these displays take the form of
posturing and deliberate movement. One of
the biggest of these performers is the Great
Bustard. The male throws himself into indis-
cribably odd attitudes during the recurring
periods of courtship. Another Bustard, an
Indian species (Otis bengalensis), puffs out his
plumage in a very similar way, turning his tail
right over his back, until he seems to be nothing
but a shapeless mass of feathers, when he begins
to strut about, bursting with pride, and as if
entreating the female birds to come and admire
his vain display. A still more remarkable
instance of posturing is furnished by that very
beautiful bird, the male Argus Pheasant. In
this species the secondary quills are enormously
developed, and each of them is ornamented with
a row of circular spots on the outer web, besides
being elegantly striped and marked with rows
of smaller spots. These large spots are wonder-
fully shaded, and stand out like balls, resting
loosely within cups or sockets. When about to
display, he elevates his curiously elongated tail
feathers, and throws out his bespangled wings
into an almost circular shield, behind which the
body is almost entirely hidden, the neck and
head being held on one side, and he sometimes

THE LOVE DISPLAYS OF BIRDS 233

peeps between two of the feathers. These
males are not apparently very pugnacious,
neither do they live in close companionship
with the hens, but clear an open space in the
forest which they keep very clean and tidy,
removing all dead leaves and twigs for a space
about eight yards square. Here, in this sort of
drawing-room, they spend much of their time
in solitary state, uttering notes of invitation to,
and awaiting visits from, the hens, when they
perform a dance, and give a display of their
charms for the benefit of the latter. Very curious
dances or displays are indulged in by the Cock
of the Rock and the Ruff. Again, many of the
Game Birds are notorious for their gatherings
during the love season for a similar purpose.
These displays often terminate in combats be-
tween rival males.

In many cases these dances and displays take
place in certain recognised meeting-places, the
birds of both sexes resorting to a common
rendezvous. But even more extraordinary are
those birds that actually build an elaborate and
often highly decorated structure in which to
conduct the antics or posturings incidental to
their courtship. These are the famous Bower
Birds. Incredible as the fact may be, it really

234 THE STORY OF THE BIRDS

seems as though these gifted, if plain-looking
birds sought by absolutely artificial means to
add to their attractiveness. Certainly they
exhibit an aesthetic taste for the beautiful im-
measurably greater and more refined than that
of the Australian aborigines themselves, and an
appreciation of beauty for its own sake which
can only find its parallel amongst the most
highly civilised races of mankind. These bowers,
avenues, or runs vary a good deal in shape and
material amongst the several species, but they are
all constructed for a similar purpose, and have
nothing whatever to do with the nest. Some
of these bowers are made of twigs, and are
decorated with feathers, shells, bones, and leaves ;
and in the collection of these materials the birds
must expend a very great amount of labour.
In the bower of the Spotted Bower Bird the
decorations are very profuse, and little paths
strewn with stones diverge from the mouth of
the bower. The most wonderful bower of
all is that made by the Gardener Bower Bird.
This species builds an elaborate circular hut-
like structure at the foot of some large tree,
and about two feet high and three feet in
diameter. It is formed of the stems of orchids,
which radiate and slope to the ground from a

THE LOVE DISPLAYS OF BIRDS 235

central support, crowned with a mass of moss,
and sheltering a gallery round it. One side of
this hut is left open, and in front of it is what
has been aptly termed "the garden." It consists
of a bed of green moss, decorated and bedecked
with the most brilliantly-coloured berries and
flowers, and is some six or eight feet in expanse.
Marvellous as it may seem, the bird removes the
garden ornaments as they wither, and casts them
into a heap at the back of the premises, gather-
ing a fresh supply ! Through and about these
bowers the male birds strut and pace and race
after the hens that resort to them, becoming
excited almost to frenzy in the mad strange
dance and curious antic.

It would seem that the displays of some birds,
like the songs of others, are indulged in for the
sole sake of pleasurable excitement. Science is
indebted to Mr. Hudson for a record of some
of these curious performances, of which he was
actually an eye-witness. Some of the Rails join in
these festive dances, which we can only liken to
balls. In South America there is a species known
as the Ypecaha Rail, which is in the habit of as-
sembling at some chosen spot, usually a small
patch of smooth level ground close to the water,
and surrounded by tall dense reeds. First one of

236 THE STORY OF THE BIRDS

the birds utters a thrice-repeated cry, apparently
a note of invitation, responded to by birds on all
sides, which hurriedly repair to the recognised
trysting-place. Perhaps a score birds so con-
gregate, bursting through the reeds and running
on to the open space, when the singular per-
formance commences. Mr. Hudson describes
this as a " tremendous screaming concert,"
screams, shrieks, and moans being uttered in
quick succession, and all the time the birds rush
from side to side as if gone mad, the wings
extended and vibrating, and the long beak
opened wide and raised vertically. The whole
performance lasts but a few minutes, after which
the birds disperse to their own particular haunts.
Still more curious is the festive dance of a
species of South American Jacana, a performance
which Mr. Hudson tells us seems specially de-
signed to bring out the concealed beauty of
the silky greenish-golden wing feathers. These
birds live in pairs, and sometimes a dozen may
be seen feeding on marshy ground within sight
of each other. In response to a note of invi-
tation from one of the birds, the others cease
feeding, and fly to a certain spot, where, forming
a close cluster and uttering excited notes, they
display their wings like flags grouped closely

THE LOVE DISPLAYS OF BIRDS 237

together, or wave them up and down with slow,
measured beats. In both these displays males
as well as females appear to take part.

But even yet more curious than all is said to
be the dance of the Spur-winged Plover of the
same region. This unique display is called by
the natives its dance, or square dance, and three
birds are required for its due performance ; and
it is said that the birds are so fond of it that
they indulge in it all the year round, not only
during the day but on moonlight nights as well.
These Lapwings live in pairs, and suddenly the
male of a neighbouring pair will leave his mate
and fly up to this pair, by whom he is received
with notes of apparent pleasure. Then the three
form a procession, the visitor walking in front
and followed by his hosts, all keeping step and
marching rapidly to the utterance of a resonant
drumming note to which they keep time with
their movements. The notes of the pair behind
are uttered like a drum-roll, but the leader gives
forth loud single notes at intervals. Presently
the march stops, the visitor elevates his wings
and stands motionless, whilst the other two,
exactly abreast, sink their voice to a murmur,
and stoop forward and downward as though
making their bow, and in this attitude remain

238 THE STORY OF THE BIRDS

for some time. This concludes the performance,
when the visitor returns to his own quarters and
to his mate, to receive in turn a single visitor
themselves later on.

Something very similar to the strange antics
recorded above may be noticed amongst the
various species of Ducks during the nuptial
period. These birds may not unfrequently be
watched quietly swimming, when suddenly, and
for no apparent cause, the male and female will
commence a sort of aquatic hide - and - seek,
accompanied by no small amount of uproar.
Just as suddenly will this strange frolic cease,
and the birds, facing each other, will exchange
bows with great regularity, either together or
precisely in turn.

Incidentally we may mention that occasion-
ally birds that usually display by vocal effort
resort to a parade of plumage. The Robin is
an example of this. On the evening of the 24th
February of the present year, we witnessed on
our lawn a most interesting display by three
male Robins. Each bird in turn raised its head
until the bill pointed nearly perpendicularly to
the sky, and slowly swayed the orange breast
from side to side as if in defiance ; the other
birds, evidently greatly excited by the exhibition

THE LOVE DISPLAYS OF BIRDS 239

(which to us seemed to be a kind of challenge),
eventually hopping up and buffeting the one
thus showing off. There could be no possible
doubt that these male Robins were seeking to
display the colour of their breasts to best ad-
vantage. No females were in sight, and each
bird all the time kept its tail elevated almost
over its back, and was evidently full of excite-
ment. No song accompanied this display, which
is all the more remarkable, because the Robin
is one of the most pugnacious and pertinacious
singers in the entire order. The vernal soaring
flights of the Chaffinch are also very beautiful.
These take place when two rival males meet,
and are never, so far as we can determine, ac-
companied by song or note of any kind. The
two birds rise perpendicularly in the air, some-
times for thirty feet or more, buffeting each
other all the time, then coming down in much
the same way. Time after time will these quar-
relsome flights take place, the effect of the
particoloured wings being extremely pretty.

In concluding this brief survey of avine song
and display, a few words seem necessary con-
cerning their meaning and purpose. Darwin
sought to weave all this display of song and
dance and antic into his masterly conception

240 THE STORY OF THE BIRDS

of Sexual Selection, and from a cursory review
of the facts this seems to be a very plausible and
possible explanation of the phenomenon. The
subject, however, has been much more minutely
investigated since Darwin worked and wrote,
and a vast array of facts has been collected
which not only tend to weaken his brilliant
hypothesis, but alsolutely to refute it. The
keystone of Darwin's arch was the taste or
choice of the female bird for certain charac-
teristics either ornate, musical, or terpsichorean,
in the male. But Taste or Choice is one of the
least constant things in this world. Darwin's
theory demands the practically impossible co-
incidence of choice throughout entire species
and groups of species, which, we venture to
assert, is demanding far too much from the
female members of them. All the evidence
tends to show that this song and display are
prompted by impulses of pleasure or rage, and
that spontaneous vitality which is invariably
attendant upon robust health. The impulse to
pair becomes strongest when life is in the full
tide of its vigour, seasonably after maturity ;
and these are the periods when ornaments are
brightest, when songs are gladdest, and when
display of all kinds is most vigorous. Male

THE LOVE DISPLAYS OF BIRDS 241

birds find an outlet for their excessive vitality
and superabundant energy in the development
of showy plume, sweet song, and wild display.
Another fact about much of this song and dis-
play, which seems absolutely fatal to any hypo-
thesis of sexual selection, is that in innumerable
instances the male birds indulge in them at
times when it is perfectly obvious no female
choice could be exerted. We may repeat here
what we have already expressed in a former
volume as our deliberate opinion upon this
question. The various species that are excep-
tionally adorned are also remarkable for the
extraordinary vitality, excitability, and pugnacity
of the males ; and these qualities are more or
less frequently being invoked for the display
of such ornament, or in combat with rivals or
intruders. The meeting of a rival, the sexual
excitement provoked by the presence of the
female, or even the intrusion of some stranger
species into the sacred precincts of a favourite
haunt, is almost invariably the signal for the
erection of a crest or plume, the display of a
spangled wing or tail, the inflation of a pouch
or sac, or the assumption of an attitude in which
the special decoration of the species is displayed
to its utmost advantage, a declaration of defiance

242 THE STORY OF THE BIRDS

or an outward manifestation of conjugal pas-
sion. There can be little doubt that the display
of so much excessive or supplementary vitality,
in the form of dimorphic secondary sexual char-
acters, has an overpowering effect upon the
female, quite irrespective of any conscious choice
or selection on her part ; and that, so overcome,
she yields to the embrace of the strongest and
most energetic male that, in spite of rival claims,
can take and keep her.

CHAPTER VII

THEIR REPRODUCTION (NESTS)

The unique character of birds' nests — The architecture of
Ratitae Birds— The nests of the Kingfishers— The Horn-
bills— The Swifts — Edible nests — The nests of the
Humming-Birds — Nests of the Passeriformes — Great
variety in the nests of the Passeres — Variation of nest-
type in the same species — Uniformity in the nests of
species — The architecture of the Wrens — Of the Swal-
lows—Of the Finches— Of the Starlings, Shrikes, Wax-
wings, Orioles, and Goldcrests — Nests of the Tropical
Oscines — In the Timeliidae — The Tailor Bird — Nests
of the Bulbuls, Cuckoo Shrikes, Drongos, and Green-
lets— Of the Birds of Paradise— Of the Sun-Birds— Of
the Flower-peckers and Sugar Birds — Of the Wood
Warblers and Tanagers— Of the Weaver Birds— Of the
Ox Birds and Hang-nests— Of the Broadbills— Of the
Pittas— Of the Tyrant Birds — Of the Cotingas and
Plant-cutters — The nest of the Oven Birds — The archi-
tecture in the Wood Hewer family — Of the Ant Thrushes
—Of the Lyre Birds— Nest of the Hammer-Head—
Nests of the Mound Birds— Of the Brush Turkeys—
Of certain Coursers— Of the Rails, Ducks, and Geese
— Of the Flamingoes — The utility of nests — The nest
in relation to the colour of the plumage — Instinct or
imitation in nest-building.

THE beautiful songs, the curious cries and sounds,
the varied posturings, antics, gestures, and aerial

gambols of birds, described in the previous chapter,

243

244 THE STORY OF THE BIRDS

are in most cases the preliminaries to the func-
tion of Reproduction — the prelude, as it were, to
the making of Nests and the laying of Eggs. As
in so many other ways, we find birds practically
unique in the wonderful and elaborate prepara-
tion they make for the reproduction of their kind.
Birds' nests are at once the most beautiful and
the most curious cradles throughout the animal
kingdom. Their production not only requires
a great amount of skill, but reflects intelligence
of no mean order. We shall find, however, that
the nest-building capabilities of birds are subject
to a very wide range of variation, and in not a
few species are entirely absent. It is not all
birds that make nests ; and we find an almost
perfect gradation from nestless species through
the crudest provision becoming more and more
elaborate, until we reach those wonderful struc-
tures that excite universal admiration. There are
birds, for instance, such as the Guillemot, that
lay their eggs on the bare rocks, or on the open
ground, like the Goatsucker and the Lapwing ;
there are others, like the Ostrich, that make no
nest, but bury their eggs in the sand; whilst
many species that breed in holes deposit their
eggs upon the powdered wood at the bottom,
making no provision in the form of a bed. Then

THEIR REPRODUCTION (NESTS) 245

we reach the crude ground -built nests of the
Waders, and kindred forms — the simplest pro-
vision, consisting merely of a slight hollow with
a few bents and grasses carelessly arranged
therein. Reaching higher types of nests still,
we have, for example, the crude heaps of vege-
tation formed by the Grebes and Rails, the slight
structures made by the Pigeons, and so forth.
Then there are other species that appear to re-
quire a nest, but object to make one for them-
selves, and so annex the deserted home of some
other bird. Some species form a bed for the
eggs out of the refuse of their food ; others
secrete a salivary fluid, which soon hardens when
exposed to the air, and forms a nest layer by
layer. It is amongst the Passeriformes that we
find the most remarkable avine architects, pre-
senting an almost bewildering variety in the
form and structure of their nests. Of course it
would be utterly impossible to compress into
a single chapter sufficient material for a portly
volume. All that we can do is briefly to glance
at the most characteristic types and at a few of
the more remarkable structures.

As might naturally be expected, we find a very
low type of architecture, or even an entire absence
of nest, amongst Ratitae Birds. The Ostriches

246 THE STORY OF THE BIRDS

and Rheas lay their eggs on the bare ground ;
the Cassowaries and Emus scrape out a small
hollow, placing a few bits of grass or various
plant-stems round the margin ; whilst the Kiwis,
more elaborate in their provision, excavate a short
tunnel in a chamber, at the end of which they make
a rude nest of dry fern fronds and other herbage.
We have already briefly indicated the usual
type of nest in each of the great avine groups,
so that it will be unnecessary to repeat it here.
To this, however, there were two exceptions, the
orders being too heterogeneous to admit of any
generalisation with regard to the nesting arrange-
ments. These were the Coraciiformes and the
Passeriformes; the former containing certain
species remarkable for their mode of architec-
ture, the latter a group in which nest-building
may, generally speaking, be said to reach its
highest degree of perfection. It is in these
groups, therefore, that a more detailed account
of the various types of nest seems to be most
necessary. The Kingfishers, for instance, are
very interesting in their method of nesting.
Many of the species tunnel into banks of rivers
and pools, forming a gallery several feet in
length, the end of which is enlarged into a
kind of chamber. Here a heap of fish-bones is

THEIR REPRODUCTION (NESTS) 247

gradually accumulated (the birds frequenting the
spot all the year round), the indigestible parts
of the food that are cast, and upon this bed
the eggs are deposited. The Hornbills are also
remarkable for their very singular methods of
nidification. They breed in holes in trees, a
circumstance about which there is nothing very
remarkable in the present order ; but as soon
as the eggs are laid, the female either builds
herself in the hole, or the male does so for her,
plastering up the entrance until but sufficient
space is left for the cock bird to pass food to
her. Here a voluntary prisoner she remains
until her task is done, emerging emaciated and
with worn and draggled plumage when the eggs
are hatched. It is worthy of remark that in
the Hoopoes the females evince a similar dis-
inclination to leave the nest hole, the males
feeding them during the whole period of incuba-
tion. Then in the nidification of the Swifts there
is much of exceptional interest, for to this family
belong the species which make the famous edible
nests, so highly prized in the Far East as articles
of food. These birds, belonging to the genus
Collocalia, breed in caves. The best quality of
these nests resembling isinglass, and formed from
a gelatinous secretion from the salivary glands,

248 THE STORY OF THE BIRDS

are worth their weight in silver, and are found
in caves in limestone and volcanic rocks ; those
from caves in a sandstone formation being of
inferior value. There are usually three crops
of these nests gathered in a season, the second
being the best. Their value depends upon their
purity or freedom from foreign substances, such
as dirt and feathers. The best quality nests are
white, the second quality is yellow, whilst the
third is discoloured and impure. The nests of
some other of the Swifts are very interesting.
A Guatemalan species is said to attach its tubular
nest to a rock with saliva, the nest itself being
made of seeds, each seed cemented together with
a similar secretion.

The last family in this order famous for the
nest-building capacities of its members is the
Trochilidae. It is somewhat remarkable that
the Humming-Birds should not only excel as
nest-builders, but should depart so widely from
the general rule prevailing in the order as to
make elaborate structures in the open. As we
have already seen, the majority of the Coracii-
forms breed in holes, and make but slight nests,
or even dispense with nests altogether, laying
their eggs upon the powdered wood only. Some
of the most exquisite nests that are known are

THEIR REPRODUCTION (NESTS) 249

made by the Humming- Birds — tiny structures
not a few of them, little bigger than a good-
sized thimble, yet perfectly finished and a model
of neatness. All the species, so far as is known,
build on one general model — an open cup-
shaped structure — although the manner in which
they are attached to the various objects that sup-
port them differs considerably. The materials
are such that admit of easy and effectual felt-
ing together — lichens, vegetable downs, small
feathers, wool, hair, moss, and spiders' webs.
In most cases this nest is attached to the upper
surface of a branch ; in other cases the nest is
horn-shaped, and fastened to the surface or
point of some ribbon-like leaf, or placed in the
centre of a bunch of leaves. More rarely the
purse-shaped nest is attached to a cliff. Gould,
who made this family an object of very careful
study and published a magnificent monograph
of the species, asserted that in some cases the
pensile nests were weighted with a little stone
or piece of earth should one side of the structure
be heavier than the other, in order to ensure
equilibrium. One very striking feature in Hum-
ming-Birds' nests is the manner in which they
are made to assimilate with surrounding objects,
by a garniture of lichens, spiders' webs, and so

250 THE STORY OF THE BIRDS

forth, just as our own Long-tailed Tit and
Chaffinch are in the habit of doing. The Hum-
ming-Birds seem very much attached to certain
nesting-places, often returning to them each
season, and they have been known to make a
new nest on the remains of the old ones for
several years in succession.

We now come to a consideration of the various
types of nests peculiar to the Passeriformes.
This order 4 is divisible into a very large number
of families, but the nests in each are by no
means confined to certain types, and the vari-
ation in their structure is by no means correlated
with affinity. Indeed, it is by no means unusual
to find several very distinct types of nest in a
single family or even in the same genus, whilst
in other cases a certain type of nest will run
through more or less distantly related groups.
The variety in the nests of the Passeres can only
be described as amazing, and must be taken as an
indication of the high degree of specialisation to
which the order has attained, of their wonderful
intelligence and power of adapting themselves
to a multitude of conditions and circumstances.
We have many remarkable instances of this
variation of nest-type even amongst familiar
British species. Take the Corvidae or Crows

THEIR REPRODUCTION (NESTS) 251

as our first example. Even among the few
British species we find a variety and an adapt-
ability that is little less than astonishing. The
Rook, the Jay, and the Crow make their large
nests in trees ; the Raven not only builds in trees
but on cliffs, as also does the Hooded Crow;
the Jackdaw and the Chough seek a hole in a
tree, cliff, or building ; whilst the Magpie adopts
a style of architecture peculiar to itself, and
makes a huge nest which is securely roofed in
by an almost impenetrable mass of sticks. Then
amongst the Titmice we have the cup-shaped
structure of moss, wool, feathers, and the like,
snugly hidden in a hole of a wall or a tree, and
the beautiful globular home of the Long-tailed
Tit (made of moss, wool, grass, hair, and feathers),
garnished externally with lichens and spiders'
webs, built in bushes and small trees. In this
latter group we have an instance of a dual type
of nest even in the same species ; for the Great
Titmouse when nesting in a hole of a tree makes
a cup-shaped structure, and when doing so in
the deserted home of a Crow or Magpie it con-
structs a perfectly globular nest of moss and
feathers. Then in our two species of Flycatcher
we find that the Spotted species makes a cup-
shaped nest of grass, twigs, moss, wool, and

252 THE STORY OF THE BIRDS

feathers, &c., which it places on a branch near
the stem, or even on trellis-work or masonry,
whilst the Pied species selects a hole in a tree
in which to hide its nest, made of similar
materials. Similar diversity of nest-building is
presented by the Warblers, some of these birds
making flimsy net-like nests of bents and hair,
which are attached to twigs or reeds or con-
cealed amongst vegetation, whilst others (as the
Willow Wrens) make globular structures lined
with feathers, which they place amongst the
herbage. On the other hand the architecture
of some species is remarkably uniform. The
Dippers, for instance, occupying a vast geo-
graphical area, build but one type of nest,
a domed structure of moss, grass and leaves.
This uniformity may be due either to the great
similarity of conditions of life to which all the
members of the family are exposed, or to their
somewhat ancient origin ; for we generally find
the least diversity of architecture in the older
groups. In the Larks the type of nest — an
open cup-shaped structure made of grass, bents,
and dead leaves, lined with hair — is remarkably
uniform, and generally made on the ground
amongst herbage ; but some of the species
(Mirafra) build domed structures. The Wagtails

THEIR REPRODUCTION (NESTS) 253

are another family of fairly uniform nest-
building habits, usually placing their substantial
cradles (made of dry grass, bents, roots, and
moss, lined with wool, hair, and feathers) in
well-sheltered spots — holes in walls or under
stones and turfs ; the Pipits place their nests,
not so elaborate as the Wagtails, amongst her-
bage in the open, although one or two species
love to hide them under stones and rocks. In
the Thrush family (Turdidae) we again meet
with considerable diversity of nest. All the
Thrushes, of which our Song Thrush may be
taken as typical, and all the Ouzels, of which
the Blackbird is an excellent example, build
open cup-shaped nests of grass, moss, leaves,
and twigs, cemented with mud (and in some
cases lined with decayed wood), and finally
lined with dry grass ; placing them in bushes,
trees, or on the ground in banks, amongst ivy,
and so forth. The Rock Thrushes and Wheat-
ears make nests of dry grass lined with hair
and feathers in the latter group, and cunningly
conceal them in holes of rocks, or under
stones, and in burrows. The Redstarts use
similar materials, hiding their nests in holes of
trees and rocks and walls. The Stonechats
and Whinchats make nests of dry grass, hair,

254 THE STORY OF THE BIRDS

and feathers, placing them in open sites amongst
herbage and at the foot of dense bushes.

Passing on to the Wrens (Troglodytidae) we
find a domed nest as the most typical, made of
moss, dry fronds and leaves, bents, rootlets, and
twigs, lined with hair and feathers, and placed in
bushes, under banks, amongst trailing or creep-
ing plants, in crevices of rocks, and so forth ; but
in some few genera the style of nest is open ;
and in another we have a purse-like structure
entered by a long passage of woven materials.
Then again the Swallows (Hirundinidae) present
us with an exceptional amount of diversity in the
plan of their nests. We find species like the
Sand Martin tunnelling into banks, and forming
a rude nest of dry grass and feathers ; others,
like the Swallow, building a saucer-shaped home
composed externally of mud and lined with
straws, grass, and feathers, placed in outhouses,
caves, &c. ; others, like the House Martin, globu-
lar, with an entrance near the top, and cemented
to rocks or masonry, or retort-shaped with a
long tube for entrance at the side, in similar
situations ; whilst some species utilise the nests
of other birds, and make their own abodes in that
of their host. The Finches (Fringillidae) are
remarkably uniform in their type of nest. This

THEIR REPRODUCTION (NESTS) 255

is generally an open cup-shaped structure of
varying degrees of depth, containing abundance
of material and warmly lined. The usual mate-
rials are twigs, straws, dry grass, moss, wool,
vegetable down, hair, and feathers ; whilst some
species garnish their nests with lichens, cobwebs,
bits of paper, and so forth. In some nests some
of the above-mentioned materials predominate,
and vice versa. Some of the Finches are rather
untidy builders, others are marvellously neat.
What, for instance, could be more slovenly than
the nest of the House Sparrow, especially when
made in a covered site ; whilst what could pos-
sibly be neater than the lovely little nest of the
Goldfinch or the Chaffinch ? Incidentally we
should mention that the House Sparrow builds a
double type of nest, domed when in trees, more
or less open when in holes. The situation of
the nest varies considerably, some species build-
ing in bushes, trees, hedges, buildings, or even
cliffs (as for instance the House Sparrow), others
seeking sites on the ground or amongst tall
plants or even in crevices of rocks, as in the
Buntings. The shallowest types of nest are
those made by the Hawfinches and Bullfinches ;
the deepest by such forms as Sparrows, Chaf-
finches, and Redpoles. The typical Finches are

256 THE STORY OF THE BIRDS

the neatest builders ; the Buntings the least so,
their nests seldom being very elaborate and
rarely lined with warm materials. In the Star-
lings (Sturnidae) the more typical species build
slovenly nests of straws, grass, wool, feathers,
&c., in holes of trees, walls, or even under heaps
of stones, and in burrows ; but some of the more
aberrant forms construct nests in the open, in
trees or bushes, and in these cases a globular
structure is made. The Shrikes always appear
to make open cup-shaped nests, of twigs, dry
grass, plant stems, moss, wool, hair, and feathers,
placing them in trees and bushes. The Wax-
wings also build open nests, very similar in
general form, and placed in trees. The nests
of the Orioles (Oriolidae) introduce us to another
type of avine architecture, these being slung
between forking branches, the rim of the nest
being worked or woven over the supporting
twigs ; the materials are chiefly the leaves and
stems of grasses, various fibres and bark strips,
and occasionally bits of paper. The nests of
the Goldcrests (Regulidae) are made on a very
similar plan, only suspended from the ends of
fir branches, and made largely of moss, lichens,
and spiders' webs, lined with feathers.

We now come to the more tropical ranging

THEIR REPRODUCTION (NESTS) 257

members of the Passeriformes contained in the
group Oscines (conf. p. 101). Here also we find a
very similar diversity of structure in the nests,
not only in the various families but in the differ-
ent genera. In the Timeliidae, for instance, there
is almost every type of nest to be found, but
domed or otherwise concealed nests are very
prevalent. Warm linings, however, are not so
general, grass, dead leaves, fibres, moss, and
twigs being the usual materials. The Tailor
Bird (Orthotomus longicauda) makes a wonderful
nest ; selecting a broad leaf, and drawing the
edges together with fibres (which are actually
knotted), lining the cone thus formed with fine
grass and vegetable down. Some of the Aus-
tralian forms (as in Pomatorhinus) fabricate huge
domed nests of twigs lined with feathers, adding
to them a spout-like entrance, and placing them
at the extremities of branches. The Bulbuls
(Pycnonotidae) chiefly build somewhat flimsy
open nests, placing them in trees and bushes,
but in one genus (lole) they are suspended like
the Orioles. The Cuckoo Shrikes (Campepha-
gidae) and the Drongos (Dicruridae) also make
open cup-shaped nests, placing them in bushes
and trees ; so also do the Greenlets (Vireonidae),
in many cases, however, slinging them like that

258 THE STORY OF THE BIRDS

of the Goldcrest between forking branches. The
Birds of Paradise (Paradiseidae), so far as is
known, make open cup-shaped nests of sticks,
twigs, dead leaves, moss, fibres, and grass,
placing them in bushes and trees. The Honey-
eaters (Meliphagidae) and the White-eyes
(Zosteropidae) have a habit of slinging their
cup-shaped nests between forks, weaving the rim
round them, and are somewhat exceptional in
providing a lining of vegetable down or feathers.
The nests of the beautiful Sun-Birds (Nectarin-
iidae) are of a very interesting type, domed and
pear-shaped in form, often with a porched
entrance, and suspended from slender branches
or the under surfaces of big leaves. They are
very neatly made of grasses, moss, fibres, and
roots, and lined with hair, feathers, and vegetable
down, being partly attached to the supporting
stem or leaf by spiders' webs. Lichens, cocoons,
scraps of bark, or even bits of paper are often
added by way of garniture and to render them
in harmony with surrounding objects, the better
to conceal them. Some of the Flower-peckers
(Dicaeidae) make very similar structures. The
Sugar Birds (Ccerebidae) build domed nests of
dry grass, roots, fibres, feathers, and the like,
some of them also having a projecting porch.

THEIR REPRODUCTION (NESTS) 259

The Wood Warblers (Mniotiltidae) build cup-
shaped open nests in trees and bushes, fabricating
them of dry grass, leaves, moss, twigs, roots, and
lichens, and lining them with hair and feathers.
Those of the Tanagers (Tanagridae) are very
similar, but not so deep or so warmly lined. The
Weaver Birds (Ploceidae) are also wonderful
little architects, their nests usually being retort-
shaped or globular, with a long neck for entrance,
which may either curve downwards or be almost
horizontal. In the nests of some species there is
little or no neck, and the purse-shaped structure
is suspended from a branch with a cunningly-
woven string. The materials are dry grasses,
twigs, roots, and leaves externally, lined with
feathers, vegetable down, or even wool. Many
of these birds build in societies, each pair of
birds contributing in making a huge umbrella-
like structure in a tree, the under surface being
nearly flat and full of holes, in which the eggs
are deposited. Some of these extraordinary
co-operative nests contain a cartload or more of
grass, and at a distance look like native huts.
They are used by the Weaver Birds year after
year, and added to and repaired as may be
required. The Ox Birds (Textor) form very
similar structures. Across the entrance of some

260 THE STORY OF THE BIRDS

of these pensile nests a guard is woven to prevent
the contents from falling out during high winds.
Sometimes great numbers may be seen hanging
from -a single tree ; whilst in Burma there are
few thatched houses without many of these
hanging nests dangling from the eaves. The
American Hang-nests (Icteridae) build very
similar pensile nests, varying in form from
nearly globular to almost every variety of retort
or bottle shape, some being as much as a yard
or even more in length. In some species the
nests are slung like hammocks, in others, especially
in the South American Cassiques, they hang like
long-necked flagons from the trees. These nests
are made of various wiry grasses, fibres, moss,
and hair. In some cases the outside of the nest
is attached to some convenient twig, the better
to steady it and prevent the contents from being
spilled. It has probably occurred to the reader
ere this that these penduline nests suspended
from tapering branches and drooping leaves are
a very frequent type in tropical countries, and
are made by many remotely related species.
They unquestionably serve the common purpose
of protecting their contents from the attacks of
snakes and monkeys and other predatory crea-
tures, so that their singular beauty is purely a
utilitarian one.

THEIR REPRODUCTION (NESTS) 261

In the other groups of the Passeriformes we
have the Broadbills (Eurylaemidae), in which the
nest is oval, the entrance being on the side near
the top, sometimes protected with a sort of porch,
or at other times prolonged into a tapering struc-
ture below. They are made of twigs, roots, grass,
moss, and leaves, and lined with green foliage,
which is frequently replenished when withered
as is also the case, by the way, with some of the
Birds of Prey (the Eagles and Buzzards, &c.),
and placed suspended from drooping branches,
often over water. The Pittas (Pittidae) are mostly
ground builders, and make globular nests, with a
side entrance of twigs, roots, grass, moss, and
fibres, in some cases cemented with mud. There
are several types of nest amongst the Tyrant
Birds (Tyrannida). These are made of twigs,
grass, moss, wool, and hair (sometimes such ab-
normal materials as rags, paper), felted in some
species with lichens and cobwebs, and are either
cup-shaped and open or domed. They are
usually placed in trees or bushes. There is no-
thing specially remarkable about the nests of the
Manakins (Pipridaa), but in the Cotingas (Cotin-
gidae) there are several types of exceptional
interest. The Cock of the Rock (Rupicola)
makes a nest of mud and twigs, lined with moss,

262 THE STORY OF THE BIRDS

and attaches it to the rocky sides of some dark
cave. Some other species build hanging nests
of leaves, stalks and wool, with a lateral entrance;
others form cup-like structures of lichens and
moss, placing them in forks of trees. The Plant-
cutters (Phytotomidae) have nothing uncommon
in their methods of nest-building, but in the
Wood Hewers (Dendrocolaptidae) we are again
introduced to a great variety of avine architec-
ture. Perhaps in no other family of birds do we
find so great a diversity in the nests. To this
family belong the famous Oven Birds (Funarius).
The Red Oven Bird is said by competent ob-
servers to begin nest-building in autumn, and to
continue the task right through the ensuing
winter. The wonderful structure is frequently
placed in the most conspicuous positions, on the
top of fences or boulders of rock, on some giant
cactus, or amongst the trellis-work on houses,
and sometimes several of these curious ovens
are made close together. This oven is nearly
globular in form, and is made of clay mixed with
bits of straw, horse-hair, and fibres. In the front
there is an upright opening, the wall on one
side of this curving inwards, forming a partition
nearly to the back (something like a univalve
shell), and leaving there a narrow passage, which

THEIR REPRODUCTION (NESTS) 263

leads into a second chamber, where the nest is
completed with a bed of soft dry grass. The
whole concern measures about a foot in dia-
meter, and may weigh as much as ten pounds.
As pointed out by Mr. Hudson, who has had
exceptional facilities for studying many species
of Wood Hewers, some other species excavate in
the earth, making long cylindrical burrows four
or five feet in length, terminating in a round
nest chamber; others that are of arboreal habits
nest in holes in wood. The marsh-frequenting
species attach spherical or oval domed nests to
the reeds, in some cases woven grass and clay
being so cleverly combined that the structure is
impervious to wet, practically indestructible, and
light as a basket. Another type is a large struc-
ture made of sticks, placed in bushes and trees,
to make and keep in repair which the owners
work more or less constantly all the year round.
These stick nests vary greatly in size and shape.
Some have a spiral passage leading from the
entrance to the cavity where the eggs are de-
posited, this being in many cases only just big
enough to hold the owner. In another species,
however (Homorus gutturalis), this nest cavity is
so large that " if the upper half of the nest or
dome were removed, a Condor could comfortably

264 THE STORY OF THE BIRDS

hatch her eggs and rear her young in it." An-
other species in the same genus (H. lophotis)
builds a similarly large nest, outwardly resem-
bling a gigantic powder-flask, placed horizontally
on the lower branches of a spreading tree. An-
other species (Pracellodomus sibilatrix), about
the size of a House Sparrow, makes so huge a
nest, at the extremity of a horizontal branch, ten
or fifteen feet from the ground, that its weight
when completed bends the branch down to within
a few feet of the earth. Some of the species in
the genus Synallaxis also make very curious
homes. One of these (S. phryganophila) makes
a stick nest about twelve inches deep, from the
top to the bottom of which runs a tubular passage
of finely interlaced twigs, "like a rain-pipe on
the wall of a house," and then, passing outside,
slopes upward, and finally terminates some two
or three feet from the actual nest. Another
species (the S. erythrothorax, of Yucatan) makes
so large a nest of sticks, that the natives believe
the builders are assisted by all the birds in the
forest. In some parts of South America these
nests are very abundant, upwards of two hun-
dred of them having been counted, varying in
size from a small pumpkin to a barrel, in thorn
trees within an area of twenty rods, some of the

THEIR REPRODUCTION (NESTS) 265

trees containing half-a-dozen. Another species
weaves a small straight tube out of grass, open
at both ends, and the aperture only large enough
to admit the finger, the parent bird having to
pass right through without turning round ! Yet
another species scoops out a round hollow in the
ground, and builds over it a dome of finely-
woven grass. As the nests of only some fifteen
species are known, out of a total of sixty-five
composing the entire family, we may reasonably
conclude that the architectural variety of the
Wood Hewers is by no means yet completely
known.

There is nothing specially remarkable about
the nidification of the so-called Ant Thrushes
(Formicariidae), these birds mostly building
shallow open nests in trees or bushes of straws,
grasses, fibres, moss, roots, wool, and hair.
Neither do we find much worthy of special
comment in the next family (Pteroptochidae),
although there are several apparent types of
architecture, some species nesting in burrows,
others making domed nests of grass, others open
ones of sticks. Lastly, we may mention that
the Lyre Birds (Menuridae) build domed and
oval nests, made of sticks, grass, fibres, leaves,
fern fronds, moss, lined with roots and feathers.

266 THE STORY OF THE BIRDS

We will conclude this necessarily brief sur-
vey of avine architecture by a detailed notice
of a few somewhat aberrant forms of nidifica-
tion. There is, for instance, the very curious
nest of the Hammer Head (Scopus umbretta).
This bird is about the size of a Raven, and yet
it builds a huge nest of sticks six feet in
diameter, which it either places in the fork of
a tree or on a ledge of rock. The external
model resembles that of the Wren, to select a
familiar example, but the internal arrangements
are very different. This globular stick-made
nest is said to contain three divisions, each
with so small an entrance that the bird gets
through it with apparent difficulty. Of these
chambers the top storey is the receptacle for
the eggs, the middle one is a kind of play-room
for the young birds when full grown, whilst
the basement is used for lookout purposes by
the old birds. Then we have the most extra-
ordinary methods of nidification prevailing
amongst the Mound Birds (Megapodiidae).
These birds, as we have already briefly stated,
bury their eggs in sand or amongst fermenting
vegetable matter, the heat from which eventu-
ally hatches them. Dr. Wallace, writing of this
peculiar habit, informs us in his delightful

THEIR REPRODUCTION (NESTS) 267

book on the Malay Archipelago that the Mound
Bird inhabiting the Moluccas forms an immense
mound of vegetable rubbish as much as eight
feet high and thirty feet in diameter. This
the birds throw up with apparent ease, grasping
the material in their large feet and throwing
it backwards. In the centre of the mound, at
a depth of several feet, the eggs are laid, and
eventually hatched by the heat generated by
fermentation. After the eggs are once deposited
in this curious incubator the parent birds appear
to evince no further thought for them, and the
newly-hatched chicks work their way up through
the rotten rubbish and at once run off into the
adjoining forests. The species that burrow in
the sand appear to tunnel obliquely for about
three feet, and then the eggs are laid at the end
of the gallery. The entrance is then closed
and the eggs left to hatch in due course.
Another species peculiar to the Nicobars was
found to make a mound eight feet high and
sixty feet in circumference. Sometimes lizards
lay their eggs in these mounds. The Australian
Brush Turkeys (of various genera in the same
family) have very similar habits, collecting
enormous heaps of vegetation, sometimes con-
sisting of many cartloads, and laying their eggs

268 THE STORY OF THE BIRDS

in circles about a yard from the apex, where
the generating heat hatches them. It is
rather remarkable that one of the Coursers —
the Cursorius aegyptius of ornithologists — re-
sorts to similar methods of nidification, burying
its eggs in the sandy banks of the Nile, where
they are at least partially hatched by the sun.
Incidentally we may also mention that not a
few other and more familiar birds partially
invoke similar aid ; for many of the shore birds
— such as Gulls, Terns, and Plovers — rarely sit
upon their eggs during the hottest hours of
the day; whilst the Grebes and some of the
Rails derive considerable assistance in the task
of incubation from the fermentation of the
aquatic vegetation with which they construct
their often floating raft-like nests. It is possible
that the dense bed of down which the Ducks
and Geese, &c., provide for their eggs may
materially assist in preventing loss of heat,
especially in high latitudes, but that it also
serves to conceal them during the parent's
temporary absence seems to us unquestionable.
Were it not for this precaution the very con-
spicuous eggs would soon fall a prey to maraud-
ing birds and animals. Another exceptionally
curious type of nest is made by the Flamingoes.

THEIR REPRODUCTION (NESTS) 269

These long-legged birds, as we have already
seen, frequent marshes and lagoons. They
build a most extraordinary nest, a tall conical
pillar of mud, with a shallow cavity at the apex
for the eggs. This structure is most beautifully
adapted to the conditions of nidification, being
either built in shallow water or so near to the
margin and in swamps subject to more or less
sudden inundation.

The thoughtful reader may well ask the
meaning of all this wonderful architecture, the
motive for such varying means for ensuring
the safe maturity of the eggs. It is not, how-
ever, the protection of the eggs that is the sole
consideration, the safety of the incubating parent
is of no less importance — safety, be it remem-
bered, at a time when the usual means for secur-
ing it are not so readily available, and various
exceptional dangers have to be guarded against.
To a very great extent (even to a degree that
amounts practically to a Law) the colour of the
parent's plumage is correlated with the manner
of nidification. To understand the facts it will
be necessary to divide birds into various classes
quite irrespective of their taxonomic affinities,
but according to the relation between the colours
of their plumage and the methods of their
nidification.

270 THE STORY OF THE BIRDS

Before the reader of this volume has reached
the present chapter he will be aware that in
a great many species there is a most marked
difference in the colour of the sexes, the females
in such instances being very much less brilliantly
coloured than the males, in not a few cases
this difference being so marked that one sex
is totally different from the other in general
appearance. Now this dull colour in so many
female birds is intimately connected with the
special means of nidification, and we find in
a vast number of species such inconspicuous
tints are correlated with an open nest. This
is ^admirably illustrated by such a species as a
Pheasant or a Black Grouse. In both these
species the males are very brilliantly coloured,
their plumage being exceptionally beautiful and
conspicuous, whilst the females are utterly
different and dressed in tints of mottled browns
and yellows. These birds nest on the ground,
but they are careful to lay their eggs amongst
vegetation where their own plumage harmonises
so closely with surrounding tints that they are
very difficult to see as they brood over their
treasures. We find the same rule prevailing
amongst hosts of other species which we have
not space to describe in detail here*

THEIR REPRODUCTION (NESTS) 271

But then, on the other hand, we have certain
species in which there is not such a marked
contrast in colour between the sexes, both being
adorned with showy, conspicuous, or even bril-
liant coloured plumage, and which notwith-
standing build open nests. This at first sight
seems a fatal objection to any law ; but we
must remember that some of these colours are
rendered inconspicuous by the special method
of nidification, and that in other cases the nests
are so hidden amongst foliage that the sitting
parent is well concealed from view. Then,
again, many of the species that come into this
division do not need to derive their safety
whilst incubating from an inconspicuous dress,
because they are pugnacious or powerful and
well able to defend themselves and their charge
from attack. Among such birds we may name
the gaudy Jays, the conspicuous Herons, Gulls,
Crows, and so forth. Other and less comba-
tive species sit very lightly, and leave their nests
the moment danger is detected. Then, again,
we have to consider another small group in
which the male is less showy than the female,
yet still hatch their eggs in open nests. We
have already alluded to this phenomenon, but
not, however, from the present point of view.

272 THE STORY OF THE BIRDS

Here we find that the males invariably perform
the duties of incubation, and in some instances
at least are known to display the greater solici-
tude for the eggs and young. The Dotterel
and the Phalaropes are two of the most familiar
instances.

We now come to consider the special mode
of nidification in species where both sexes are
of bright and conspicuous colours. Here, again,
the reader will have many instances in mind.
By far the greater number of species coming
into this group are tropical forms, a very large
number being included in the order Coracii-
formes. The rule in this group is that bright
plumage is correlated with a covered nest. The
sitting bird either hides itself in a hole of
a tree or rock, or in the ground, or builds a
domed nest in which it can conceal itself.
This will explain why we have found so many
remotely allied species adopt the same methods
of nidification. Some of these nests, however,
are placed in very exposed situations where
they would seem to invite attack. But as we
have already shown in not a few instances, these
nests are hung quite out of reach of enemies,
over water and at the extremities of long slen-
der branches. Then we must remember how

THEIR REPRODUCTION (NESTS) 273

cunningly so many nests are concealed by har-
monising their materials with surrounding tints.
In this group, again, we have what appears to
be a fatal exception, for there are not a few
species in which both sexes are not only dull
in colour, but build covered nests or place
them in sites well concealed from the outer
air. But in these cases we must assume some
special advantage in other ways, such as greater
warmth and shelter or protection from the sun
or certain enemies. Many of the species are
exceptionally weak and defenceless, such as the
Swifts, Sand-Martins, Wrens, Willow Warblers,
and so forth ; whilst the pugnacious Owls seek
seclusion because they are mostly nocturnal
and dislike the light. What more natural than
that they should rear their young in their day
retreats ? Lastly, we have a group in which
the females are decidedly less showy than the
males, and yet rear their young in covered or
concealed nests. The Redstarts, some of the
Flycatchers, the Chats, and Robin Chats, may
be instanced. In some cases, however, the male
assists the female in the duties of incubation ;
in others some special advantage or protection
is doubtless secured.

We may fittingly conclude the present chapter

s

274 THE STORY OF THE BIRDS

with a few remarks upon the mental powers
of birds that are called into play for nest-build-
ing. Birds' nests have long been regarded as
one of the most convincing proofs of blind
instinct. Birds are popularly believed not only
to be hatched with the power of singing the
song peculiar to their species, but with an in-
herited knowledge of how to build their special
type of nest, without tuition or experience.
But such an assumption is not supported by
one iota of fact or proof. On the other hand,
all the evidence at present available tends to
show that birds are not hatched with any in-
stinctive power to make a nest, but that they
have to acquire the art by imitating the work
of others — the nest in which they were reared.
To credit birds with this infallible nest-building
instinct is to endow them with powers that
man himself does not possess. Man with his
marvellous development of reasoning power is
as little able to build a dwelling typical of his
race or tribe without instruction or experience
as a bird is its nest. Neither is one creature
more gifted than the other in the matter of
language or song, for both have in each case
to be learnt. Instinct, again, if it is anything
it is unchangeable, and therefore if it controls

THEIR REPRODUCTION (NESTS) 275

nest-building these structures should never show
any variation from a certain type. But we
know that this is not so, for birds not only
change their materials but their mode and situ-
ation of nest-building. Many birds have done
so within the measure of historical record.
Swallows have changed their mode of nidifica-
cation, and deserted rocks or caves in certain
civilised countries for buildings ; the House
Sparrow and the Starling have done the same.
Then we have instances of birds changing their
mode of nesting to escape some threatened
danger, as for instance the Moorhen building in
trees, in spots liable to sudden floods, or certain
Penguins forsaking exposed open sites for their
nests and selecting covered situations to guard
them against the depredations of pigs. Many
other examples might be quoted to show, be-
yond all reasonable doubt, that birds are ever
ready to take advantage of any favourable cir-
cumstances, and to alter their habits accord-
ingly. The materials of nests are also constantly
being changed, and instances are on record
where the most unsuitable articles have been
fabricated into receptacles for their eggs. It
would be most unfair then to attribute to birds
such a poor substitute for reason as blind

276 THE STORY OF THE BIRDS

instinct. Rather should we endow them with
limited reasoning powers, with intelligence and
forethought, in the construction of their beau-
tiful if utilitarian homes. It is almost safe to
say that if birds had not been so endowed with
some amount of reasoning faculties, enabling
them to change their habits and economy in
sympathy with a changing universe, they would
all have become extinct long ago. One of the
most remarkable proofs in favour of reason
and absolutely fatal to instinct was brought
before our notice years ago. Some young
Chaffinches were taken out to New Zealand,
and these in due course attempted to make a
nest. The structure was so utterly different
from the typical nest of this species as to be
quite unrecognisable, and was possibly a crude
imitation of the nest of some New Zealand
bird. Particulars of this instance were fully
recorded by us in Nature at the time, and again
in our work entitled Jottings about Birds. It is
somewhat difficult, however, to grasp the com-
plete philosophy of this entrancing subject of
nidification without taking into consideration
the Eggs of birds, and to these we intend to
devote the following chapter.

CHAPTER VIII

THEIR REPRODUCTION (EGGS)

Eggs — The development of the shell — The deposition of the
colour pigments — The shape of the markings — How
formed — The two types of markings — Their distribution
— General resemblances amongst eggs of the same
species — Exceptions — Composition of the colour pig-
ments— The incubation of the egg — Incubation periods
in the various avine orders — The incubating sex — The
texture or grain of the egg-shell — The colour of the
interior of the shell — The form of eggs — The size of
eggs — The number of eggs produced by species in the
various groups — The colours of eggs — Generic types of
eggs — Variation in the colour of eggs in the same
species — Of the Guillemot — Of the Cuckoo — Uniformity
of colour in other groups — The colours of eggs heredi-
tary— Eggs of hybrids — The ancestral colour of eggs —
The utility of colour — White eggs in covered nests — In
open nests — Spotted eggs in open nests — In covered
nests — The protective colouration of newly hatched
birds.

FOR centuries the Eggs of birds have attracted
the attention of the scientific naturalist ; and
there can be little doubt that they have been the
coveted spoil of the less learned perhaps from
an even earlier period still. To most people

their central attraction is their great beauty and

277

278 THE STORY OF THE BIRDS

wonderful variety. But here we must look
behind this beauty and variety, and seek their
motive and utility — the part they play in the
Story of the Birds. The study of nests and
eggs is one of the most important branches of
ornithology, for in the proper pursuit of it the
observer cannot fail to become familiar with
much of that detail which forms the all neces-
sary supplement to those portions of the science
which are covered by our earlier chapters.

We may pass over the strictly embryological
portion of the study of Eggs, and commence
our description at that point in their history
when they receive their shell in the uterine
chamber of the parent. Here, according to Dr.
Gadow and other anatomists, the egg remains
for twelve to twenty hours, receiving during that
time its shell, which is formed by calcareous
excretions of the glandular walls of the uterus.
The external layer of the shell is most variable,
and may be smooth and shiny, as in that of a
Woodpecker, due to the small amount of calcine
salts, or rough and chalky, as in that of a
Cormorant, owing to an excessive amount of
these. Then comes the deposition of the colour
pigments, in such eggs that are spotted, this
apparently always taking place shortly before

THEIR REPRODUCTION (EGGS) 279

exclusion. As pointed out by Professor Newton,
these markings are generally and normally de-
posited in a circular form — as spots of varying
size — but in the passage of the egg through the
oviduct many of them become blurred, pro-
tracted, and smeared in endless series of com-
binations, and then the egg is blotched, or
receives that appearance with which every egg
collector is so familiar. Many of these blotches
or patches of colour are protracted in some par-
ticular direction, as the egg apparently passes on
with a rotatory motion towards the vent. This
explains the marked spiral deposition of the
markings on many eggs. But the eggs of all
birds, with the sole exception of those of the
Game Birds, as we discovered long ago when
working with the late Henry Seebohm, have two
very distinct types of markings. If we examine
an egg of a Guillemot, for instance, we shall
find that amongst the richer spots and blotches
there are others (varying in amount to a great
extent on individual eggs) much paler in colour,
due to a thin coating of shell material lying over
them. These paler markings must be deposited
at the earlier stage of the colouring process, and
may be either circular or protracted into blotches
and irregular stains. This may be proved by

280 THE STORY OF THE BIRDS

taking an egg ot a Guillemot, say, and gently
scraping the surface over one of these indis-
tinct underlying markings, when it will gradually
assume the same intensity of hue as the super-
imposed blotches or spots. The varying degree
of intensity of these underlying spots depends,
of course, upon the amount of shell deposit
over them. In some eggs they are just below
the surface ; in others they are faint and indis-
tinct, with a thick coating above them ; whilst
in not a few eggs we may find them both pale
and distinct. In some eggs these markings pre-
dominate, but the rule seems to be for the
surface spots to be most numerous. The cir-
cular spots must therefore, on the above
supposition, be deposited when the egg is at
rest ; whilst the pigment must dry very rapidly,
or we should not see that delicate tracery that
is so characteristic of the eggs of Buntings and
various other species. Generally speaking, the
markings are most abundant on and towards
the blunt pole, or larger end of the egg, which,
we should say, is always protruded first. This
position, however, is sometimes accidentally
reversed, as seems proved by the fact that
occasionally the colouring matter is almost
entirely collected upon the smaller end of the

THEIR REPRODUCTION (EGGS) 281

egg. In some groups this is much more fre-
quent than in others, as, for instance, amongst
the Birds of Prey and Terns and Gulls. The
ground-colour in the eggs of such species that
display it appears to be deposited soon after the
first set of spots are distributed ; in Game Birds
the deposition of spots and ground-colour may
be almost simultaneous. The amount of colour-
ing matter deposited is remarkably uniform in
the various species, generally speaking, especially
as regards the ground tint. Its arrangement,
however, is so diverse that probably no two
eggs are exactly alike, although they present
certain characteristics that render identification
a fairly easy task. As a rule, the eggs in a
clutch resemble each other ; and in many cases
we know that this resemblance keeps constant
through successive clutches laid by the same
parent; possibly the similarity may exist per-
manently during the life of the producer. Most
collectors have had experience of this fact,
obtaining certain peculiarly marked eggs from
certain spots for several seasons in succession.
This extends not only to eggs of the normal
colour, but to others displaying certain peculi-
arities of markings, or even the want of them.
In some species it is almost an invariable rule

282 THE STORY OF THE BIRDS

to find one egg in the clutch differing con-
siderably from the rest. In some of the Birds
of Prey this peculiarity is very striking, and in
no species more so perhaps than in certain
Eagles and Vultures. In the Golden Eagle,
for instance, one of the two eggs is generally
much more heavily spotted than the other.
This is often attributed by collectors to the
fact that the colour pigments were all exhausted
in decorating one egg only ; but it has been
proved many times that the first egg has been
the one in which markings were wanting. It
may be that the colour-producing glands
had not sufficiently recovered their functions
peculiar to the laying season before the first
egg was deposited. We have sometimes re-
marked a similar peculiarity in the eggs of
various Passeres, the first egg laid being much
less handsomely marked than those that suc-
ceeded it.

For the exact composition of the colour pig-
ments on eggs we are indebted to the re-
searches of Dr. Sorby, who ascertained by
the aid of spectrum-analysis that no less than
seven substances were found in them. These
were named Oorhodeine, Oocyan, Banded
Oocyan, Yellow Ooxanthine, Rufous Ooxanthine,

THEIR REPRODUCTION (EGGS) 283

Lichenoxanthine, and lastly, an as yet unnamed
substance yielding narrow absorption-bands in
the red. These colours appear to be closely asso-
ciated with bile-pigments, although not actually
agreeing with them. Oorhodeine is present in
most eggs, its absence being exceptional, and
is brownish-red in colour ; Oocyan and Banded
Oocyan are, as their names suggest, blue ;
Yellow Ooxanthine and Rufous Ooxanthine fur-
nish yellow or reddish-yellow, the former when
mixed with Oocyan producing a beautiful dark
green ; Lichenoxanthine is believed by Dr.
Sorby to be a constituent of the shell of eggs
of a brick-red colour. The undetermined sub-
stance is believed in combination with others
to produce an exceptionally brown tint. Oo-
rhodeine is believed to be closely related to
Cruentine, and possibly derived from the red
colouring pigments of the blood, and further,
that the two Oocyans have some chemical re-
lation with the bile. The reader anxious to
go deeper into this interesting question may
be referred to Dr. Sorby's paper on the sub-
ject published in the Proceedings of the Zoo-
logical Society of London, 1875 (pp. 351-365).
Whether Dr. Sorby's very interesting lecture
upon the subject of the colouring matter of

284 THE STORY OF THE BIRDS

birds' eggs, and which we had the pleasure
of hearing in Sheffield a quarter of a century
ago, is published we are unable to say.

When the egg-shell is completed, and in the
case of spotted or coloured eggs the pigments
have been deposited, the egg makes its way
from the cloaca out through the vent. It now
awaits incubation, or the development of the
contained embryo, in a nest or not as the case
may be, after which process the perfect chick
is duly hatched. The time occupied in this
process varies considerably in the different
groups. It has been observed that the length
of this incubation period depends not only
upon the state of perfection in which the
chick leaves the egg, but upon the size of
the parent (the larger species taking a greater
number of days than the smaller ones1) and
the prevailing temperature of the area or country
in which it takes place. It has been ascer-
tained that a reduction of temperature will
temporarily arrest the development of the
embryo in its earliest stages, whilst a higher
temperature than the normal one will not

1 Size alone is not a determining factor. We must also take
into consideration the order or family to which the species belongs
as well as the relative size.

THEIR REPRODUCTION (EGGS) 285

lessen the period of incubation, but often
prove detrimental to the life of the embryo.
According to the observations of Mr. Evans
(Ibis, 1891, pp. 52-93), and the many facts relat-
ing to incubation collected by him, the smaller
Passeres hatch their eggs in from twelve to
fifteen days, the larger species, including the
Raven, in nineteen or twenty days. The Crow
family are apparently the longest incubators
in the order, as of course they are the largest
species. In the Coraciiformes the period may
be slightly longer, but some of the Humming-
Birds are said to hatch their eggs in ten or
twelve days, whilst the Rollers, Kingfishers, and
Woodpeckers take from eighteen to twenty.
In the Owls the period of incubation is a long
one, ranging from twenty-six days in the Long-
eared Owl to thirty-three in the Eagle and
Snowy Owls. The Birds of Prey in some
cases are known to occupy from four (in the
Kestrel) to five weeks (in the Eagle). The
Condor is said, however, to take fifty-four
days. The Gannet takes nearly six weeks ; the
Cormorant about a month. The Herons vary
from about seventeen days in the smallest
species to twenty-five days in the larger, whilst
the Stork is said to occupy thirty days. Among

286 THE STORY OF THE BIRDS

the Ducks we have a range of from about
twenty days in the smaller species to thirty
days in the Geese, and from thirty-five to
forty days in the Swans. The Typical Pigeons
range from about fifteen to seventeen days,
the largest species in the order a month. The
Sand-Grouse incubate in a little over three
weeks to a month. In the Galliformes the
smaller species like the Quail take about three
weeks, the larger species a month. This is
also about the limit in the Charadriiformes
and the Lariformes. The Petrels are longer,
the smaller species taking about five weeks ;
the larger, such as the Albatrosses, eight or
nine weeks. The Auks take more than a month
(thirty to thirty-five days) ; some of the Im-
pennes are said to occupy six weeks, whilst
the Emu requires a couple of months, the
Rhea two weeks less, and the Ostrich takes
from seven to eight weeks, or even more. In
some species incubation commences as soon
as the first egg is laid ; in the majority of
cases, however, the process does not begin
until the last egg of the clutch or sitting is
deposited. As we have already seen the female
in most cases is the principal incubator ; in
some instances both sexes incubate in turn ;

THEIR REPRODUCTION (EGGS) 287

whilst in a very small number the cock bird
alone performs the duty. We may also state
that amongst the wading birds the chicks re-
main in the shell for some little time after it
is cracked for their egress.

But to return more particularly to the con-
sideration of the egg-shell. The texture, grain,
or surface of this requires a short notice.
This varies a good deal, and to some con-
siderable extent the peculiarities of its surface
are characteristic of certain groups. In a great
many species the grain of the shell is so
minute that the surface of the egg is more
or less highly polished, as in the case of the
Woodpeckers, reaching its greatest smoothness
in the curious eggs of the Tinamous. In the
majority of species the shell is comparatively
smooth, although in many a very minute grain
is visible even to the naked eye. In others it
is dull, somewhat rough and lustreless, as in the
Guillemot or the Sparrow-hawk, for instance.
In others yet again the surface is covered with
minute pits or pores, or grooves like shagreen,
reaching their highest development in such
Ratitae birds as the Ostrich and the Emu.
Then the egg-shell of various aquatic birds,
especially the Ducks, is peculiarly wax-like or

288 THE STORY OF THE BIRDS

oleaginous, whilst in the opposite direction we
have the rough-textured eggs of the Grebes
and the Cormorants, Gannets, and so forth,
the shell of which is coated with chalk, often
so thickly as entirely to obliterate the delicate
pea-green of the ground colour. The colour
of the interior of the shell when held up to
the light also presents some diversity, even in
obviously very closely allied species. In the
Guillemot, for instance, the interior of the shell
always appears yellowish-white if held up to
the light and viewed through the hole from
which the contents have been removed. In
the Razorbill, however, the interior of the shell
when examined in the same manner is a deli-
cate pea-green. This fact always serves to dis-
tinguish between the eggs of the two species,
even when they closely resemble each other
in colour.

Eggs vary in form almost as much as they
do in colour. We do not intend this remark
to apply in a strictly individual sense, although
considerable variation is apparent in the same
species, but chiefly to the various great orders
and families. Broadly speaking we can divide
their form into three fairly distinct classes or
groups, but almost every intermediate shape

THEIR REPRODUCTION (EGGS) 289

connects the extreme type. These are Round,
Oval, and Pyriform. Round-shaped eggs are a
special feature in such groups as the Falcons,
Owls, Woodpeckers, Rollers, Kingfishers, Bee-
Eaters, and so forth. Oval eggs are specially
typical of the Sand-Grouse, Pigeons, Nightjars,
and Cormorants, but various modifications of
this form are common to the majority of birds,
from the biconical shape characteristic of the
Grebes to the more familiar form of those of
the Song Thrush and most Passerine species, as
well as in the Game Birds, Petrels, and many
others. Pyriform eggs are chiefly confined to
the Charadriiformes, such as the Plovers, Snipes,
and Sandpipers, but also occur in the Auks and
one or two other families. We are as yet unable
to say definitely why the eggs of birds assume
these various shapes, but certain hypotheses have
been put forward to account for them. One of
the most ingenious and attractive of these is that
of Dr. Nicolsky. This naturalist asserts that the
normal shape of an egg is spherical, and that
it becomes more or less elongated by pressure
from the walls of the ovary before the shell
is deposited. He makes the suggestion that
birds laying spherical eggs usually maintain an
upright position, in which the weight of the egg

290 THE STORY OF THE BIRDS

counteracts the pressure of the ovary ; whilst
birds which lay oval eggs maintain a horizontal
attitude, the weight of the egg then assisting the
pressure of the ovary ; and lastly, birds which
lay pyriform eggs frequently change their posi-
tion from a vertical one when standing to a hori-
zontal one when flying or swimming. Seebohm,
on the other hand, has suggested a possible cor-
relation between the state in which the young
are hatched with the shape of the egg, the long-
legged praecoces laying pyriform eggs and the
short-legged altrices laying round eggs, whilst
the long-legged altrices and the short-legged
praecoces produce oval eggs. The subject re-
quires much more elaborate investigation than it
has hitherto received before any conclusion can
be drawn.

Now a few words concerning the size of eggs.
Here again we do not mean the variation in this
respect amongst the eggs of a single species or
individual (although this is much greater than is
generally suspected), but more the proportion-
ate size in relation to the parent in the several
orders and families. A big bird by no means
always lays a big egg, neither does a small bird
always lay a small one. In some species this dis-
proportion between the egg and its parent is very

THEIR REPRODUCTION (EGGS) 291

remarkable. A Jack Snipe, for instance, a bird
not much bigger than a Sparrow, lays an egg
considerably larger than that of a Magpie, and
not much inferior to that of a Crow. A Guille-
mot's egg is as large as that of the Golden
Eagle, the average actual measurements of the
former being 3.3 inches by 2.0 inches, whilst
those of the latter are 2.9 inches by 2.3 inches.
Whether the number of eggs to be covered by
the parent during incubation determines the size,
or whether the state of the young when hatched
(the largest eggs relative to the size of the
mother producing the most precocious chicks)
be the influencing factor, we are as yet unable
to say. Possibly both facts may exert some in-
fluence. The connection between relative size,
shape, and number appears certainly to be an
intimate one. There is considerable diversity
in the number of eggs produced for a clutch
or sitting. Species, for instance, like the Gannet,
the Guillemot, the Petrels, the Puffin, and the
Tropic Bird lay one egg only for a sitting ;
Pigeons, Eagles, Vultures, Goatsuckers, Hum-
ming-Birds as regularly produce two for the
same purpose ; Gulls and Sand-Grouse three ;
whilst the Sandpipers, Snipes, and many Plovers
as regularly lay four. Most of the Passeriformes

292 THE STORY OF THE BIRDS

lay on an average five or six ; some of the Coracii-
formes, such as the Kingfisher, and some Wood-
peckers, lay six or eight ; whilst amongst the
most numerous egg-producers we must include
the Game Birds, some of the Rails and the
Ducks, their clutches varying, roughly speaking,
from ten to twenty or even more. The number
of eggs that a bird may lay is no indication of
its relative abundance. The Fulmar was com-
puted by Darwin to be the most numerous bird
in the world, and yet it lays but a single egg.
The Gannet, the Guillemot, and the Puffin exist
in countless hordes in northern latitudes, yet
all of them lay one egg only. On the other
hand, species that produce an exceptional
number of eggs are not proportionately nume-
rous. A possible explanation of the phenome-
non may be that the species producing the
fewest eggs are least exposed to decimating
influences, whilst those that lay an exceptionally
large number may be more liable to the attacks
of certain enemies.

The colours of eggs are to a certain extent
characteristic of the various orders, families, and
even genera, which, on the theory of evolution,
is only what we might expect to find. As a rule
the more closely allied the species the greater will

THEIR REPRODUCTION (EGGS) 293

be the similarity of the eggs. But that this is not
always the case is proved by such great diver-
gencies as are presented in the eggs of the Song
Thrush and the Redwing, the Swallow and the
Martin, the Goshawk and the Sparrow-hawk,
the Little Bittern and the Common Bittern, and
so forth. On the other hand the peculiar char-
acteristics of the eggs in such groups as the
Crows, the Sandpipers and Snipes, the Birds of
Prey, the Pigeons, the Owls, the Petrels, and
Tinamous, are so sufficiently pronounced that
any experienced collector can readily distinguish
them at a glance. The eggs in the various
genera of Warblers are most significantly char-
acteristic and readily assignable. In the Willow
Warblers we have white eggs spotted with red ;
in the Tree Warblers the eggs are salmon
coloured, spotted with brown ; in the Grass-
hopper Warblers the finely powdered markings
of brown, and their general pinky appearance,
readily serve to distinguish them; in the Reed
Warblers greens and olive browns are the pre-
dominant colours.

We have, however, much variation in some
cases even in the same species. What, for in-
stance, could be more astonishing in this direc-
tion than the extraordinary variety in the eggs

294 THE STORY OF THE BIRDS

of the Common Guillemot. A judiciously se-
lected collection of these eggs justly forms one
of the most wonderful attractions of the oolo-
gical cabinet. In no other known species does
the egg vary so widely. The ground colours
are dark green, yellowish green, reddish brown,
cream yellow, white, and pale blue, with every
intermediate shade ; the markings are browns,
and greys and pinks of every possible tint, and
take the form of spots, splashes, blotches, streaks,
zones, and intricate netted tracery. Then we
have certain species in which the individuals
produce distinct types ; as in the Grass Warbler
(Cisticola cursitaus), the eggs being either white
or blue spotted with rufous, and sometimes un-
spotted blue or white. The Common Cuckoo
is also known to produce several very distinct
types of eggs, one being unspotted blue. The
uniformity of colour in other groups is just as
remarkable. The Herons are always some shade
of blue or green ; the Game Birds, although dif-
fering considerably in general colouration, may
always be distinguished by the entire absence of
underlying markings ; the Pigeons are always
white or the palest of cream colour ; the Parrots
are white ; the Birds of Prey are marked with
reddish brown only ; most of the species in the

THEIR REPRODUCTION (EGGS) 295

order Coraciiformes are white. Taken as a group
the Passeriformes present us with the greatest
diversity of egg colouration, possibly owing to
their high degree of specialisation and the vast
variety of conditions under which they live. As
a general rule their eggs are more or less spotted,
white or blue eggs being exceptional, although
characteristic of such families as the Sturnidae,
the Dicaeidae, and the Cinclidae. How far the
colours of an egg are hereditary we are as yet
unable to say. We do know, however, that
certain individuals produce certain varieties, and
appear to continue to produce them as long as
fecundity may last. To what degree the parent
transmits certain peculiarities in its own eggs to
those produced by its offspring is, however, un-
known, although there is some slight evidence
to suggest a hereditary tendency. Of course,
broadly speaking, in this, as in so many other
things in nature, "like produces like," and we
know that the eggs of birds continue to exhibit
certain general characteristics from generation
to generation. Another branch of this subject
relates to hybridisation. It has jbeen alleged
that the egg containing an hybrid is not exactly
similar to that produced by the female, but re-
sembles to a greater or lesser extent the eggs of

296 THE STORY OF THE BIRDS

the species to which the male may belong.
Here again, however, we are in the dark, and
the subject is one fraught with interest, and its
study is likely to yield results of great value.

We have now to consider the more philoso-
phical portion of the subject of eggs. Here, as
we found to be the case with nests, the won-
drous beauty of these shells is purely a utilita-
rian one, and it behoves us then to inquire what
part these varied tints play in avine economy.
As we found that to a very great extent the
colour of the parent's plumage is correlated
with the manner of nidification and the style of
architecture, so in like manner shall we find a
similar relationship between the colour of the
eggs and the manner in which they are brought
to maturity. Here again, in order to under-
stand the facts, it will be necessary to divide
eggs into groups quite irrespective of the taxo-
nomic affinities of the species that produce them,
but according to whether they are adorned with
colour pigments or not.

Taking into consideration the important fact
that Birds and Reptiles have descended from
some common ancestral type, we are probably
correct in the assumption that the eggs of the
earliest avine forms were devoid of any of those

THEIR REPRODUCTION (EGGS) 297

colour pigments that adorn those of so many
species at the present time. Colour appears to
be an after development, purely for protective
purposes, and in cases where it is not necessary
we do not find it present, or it may be in such
cases where we do so it is due to affinity or to
hereditary causes. Or it may be the inability
to develop it confines many species to certain
methods of nidification. Now in a great many
instances — in fact so numerous are these that
we may lay it down as a rule — where the eggs
are hidden from view in holes in the ground or
trees, or in domed or covered nests, they are
generally white or pale blue and without mark-
ings. Among such species we have the Wood-
peckers, Kingfishers, Parrots, most of the Owls,
the Rollers, Bee-Eaters, Dippers, Wrens, Titmice,
and so forth. In all these cases the white
eggs (or in some instances very sparsely spotted
ones) would not only be very conspicuous if
they were laid in open cup-shaped nests, but in
not a few species the sitting bird itself would be
rendered equally conspicuous by its brilliant or
showy plumage. But then it may be urged that
there are, on the other hand, a very considerable
number of species which actually do lay white
eggs in open and exposed nests. These apparent

298 THE STORY OF THE BIRDS

exceptions, however, only tend to prove the
truth of the rule. We have Ducks, for instance,
also certain Game Birds, Grebes, Rails, some
Owls, Pigeons, Nightjars, Herons, Cormorants,
and Storks, in all of which the eggs are very
conspicuous, and yet they are laid in open nests.
Now as regards the Ducks, certain Game Birds,
Grebes, and some Rails, we find that not only is
the parent's plumage very protective in coloura-
tion, thus shielding the conspicuous eggs from
view, but when the nest is left the hen bird is
very careful to cover the eggs with leaves and
other materials that effectually hide their showy
tints from view. That this seems certain is
proved in the case of the Ducks. Those species
with down of neutral and dull shades of colour
use it to conceal their eggs during absence from
the nest, but other species in which the down is
very light coloured — as for instance the Golden-
Eye, the Goosander and the Smew — resort to
holes in trees in which both the conspicuous
down and the conspicuous eggs are hidden from
sight. Then again, the hen Partridge and the
hen Pheasant, for example, lay their unmarked
eggs in open nests, but when they are sitting
upon them their own plumage is a most effec-
tual protection, whilst when they leave their

THEIR REPRODUCTION (EGGS) 299

charge for a brief interval they are careful to
strew leaves and withered herbage over them.
So also does the Little Grebe, for example, the
rapidity with which it can cover up its eggs when
leaving them in a hurry being simply marvel-
lous ! The Short-eared Owl lays her white eggs
on the open fens and marshes, but she carefully
shields them from view by her own inconspicu-
ous brown dress, and is a most persistent sitter,
only leaving her charge when absolutely com-
pelled. The Pigeons again all lay white eggs,
and the majority of species incubate them in flat
open nests. Here again, these nests are not only
very inconspicuous, but generally placed amongst
dense foliage — ivy in particular — and the birds
themselves are excessively wary during the period
of incubation. Then we must remember that
Pigeons are not only an abundant but very
widely dispersed group, especially in islands,
where enemies are few or absent, and these facts
surely indicate an immunity from danger or
special means of eluding it. The larger birds,
such as the Herons, Cormorants, and Storks,
which lay unspotted eggs in big flat open nests,
are equally safe from all ordinary enemies, for
they are quite strong enough to protect their
eggs from danger, and often breed in societies,

300 THE STORY OF THE BIRDS

where the entire community will join in repel-
ling any attack made by predaceous bird or
beast upon their eggs.

We now come to that division which in-
cludes the marked or spotted eggs, which, as a
similar rule, are generally deposited in open
nests or upon the bare ground with no auxiliary
protection whatever. In this group we begin
to realise the true significance of colour. The
colour of the egg, in a very large number of in-
stances, so closely resembles the ground on
which it rests that its discovery is only effected
by the most careful scrutiny. Every egg collec-
tor must have experienced the difficulty of find-
ing such eggs as those of the Lapwing, the Ringed
Plover, or the Lesser Tern, to quote but three
instances out of quite as many hundreds. The
one bird lays its eggs, often bare and nestless,
upon the rough fallows and waste ground of
the uplands, where their yellow ground colour
and brownish - black markings most effectually
hide them from detection. The others, Ringed
Plover and Lesser Tern, deposit their eggs on
the sea -shore, also providing no nest. The
former species, however, always selects a strip
of fine sand, where the minutely speckled eggs
closely resemble it ; whilst the latter bird as

THEIR REPRODUCTION (EGGS) 301

surely chooses a patch of rougher shingle, where
its more heavily-marked eggs so closely harmo-
nise with surrounding objects that we may tramp
to and fro across its breeding-place in vain quest
of objects we know are there. And so we might
go on giving instance after instance of richly-
marked eggs deriving their sole safety from
enemies from the resemblance between them
and surrounding objects. Then again, we also
find that birds building open nests amongst
foliage lay eggs more or less green in tint, as
in the Crows, Thrushes, Warblers, and so on.
Many of the smaller birds, as we have already
seen in the previous chapter, take great pains
to conceal their nests by building them exter-
nally of materials very similar in colour to
objects surrounding them ; in the majority of
cases the eggs themselves are also of quiet
colours, or in those species where they are
more conspicuous, the dark thickets and shrubs
are selected, where they are seen with difficulty.
Here again, the objection may be similarly
urged, that as we found white or unspotted
eggs in open nests, so also conversely do we
find many instances of spotted eggs deposited
in covered nests. We have, for instance, the
Jackdaw laying its spotted eggs in nests well

302 THE STORY OF THE BIRDS

shielded from the light of day, the Chough
hiding them in holes of rocks, the Grass
Warbler concealing its highly-spotted eggs in
a singular purse-like nest, the Nuthatches and
some of the Tits laying in holes in trees, and
so forth. The most plausible explanation of
these anomalies is that in some cases the mode
of nesting has undergone a change within com-
paratively recent time ; and certainly this is
borne out by the fact that, in such instances,
the eggs are very perceptibly paler and less
heavily marked than those of congeneric species
breeding in open and exposed nests. Oologists
know that the eggs of the Jackdaw and the
Chough are very much less marked than those
of the Crow or the Jay. We know that it is a
pretty constant rule in nature, that when once
any special development ceases to be functional
it has a very strong tendency to disappear. In
the case of domed nests we may almost safely
assume that this particular style of architecture
is a recent adoption, and the spotted eggs have
not yet lost their character. Then again, we
must remember that the colours of eggs are to
a great extent common to groups, orders, or
genera, as the case may be ; and then we can
understand why we might find a spotted egg in

THEIR REPRODUCTION (EGGS) 303

a covered nest, the parent having for a variety
of reasons changed its mode of nesting from
that usually adopted by the group to which it
belongs. In not a few of these cases it is by
no means unusual to find an egg quite devoid
of pigments — as in the Grass Warbler, for ex-
ample— and we can thus understand how in the
course of time such a type might come to pre-
vail, the tendency of the colour-producing glands
to become functionless through want of use or
demand. We must also bear in mind another
common fact in nature, namely, that many con-
trivances are retained long after their direct use
has ceased, because they may be in no way
injurious to the species. But these are questions
quite outside the scope of the present volume,
fascinating enough, but demanding more scien-
tific treatment than is here possible or desirable.
We ought, however, in bringing the present
section of our subject relating to the Reproduc-
tion of Birds to a close, to devote a few lines
to the protective colouration of many newly-
hatched chicks. In a great many cases the
chick that has been brought to maturity within
a shell decked with protective hues, walks into
the world clothed in a dress of similarly pro-
tective design, and, what is more remarkable,

304 THE STORY OF THE BIRDS

with a marvellously rapid developed aptitude
for deriving the fullest advantage from it. The
young of all birds hatched in a condition which
enables them to run, are clothed in down of
such colours that harmonise closely with the
special localities in which they live during in-
fancy. Then these chicks soon acquire the habit
of squatting close to the ground when threatened
by danger, and thus ensure the efficacy of their
protective dress. Caliology, the study of nests,
and Oology, the study of eggs, although as yet
but little-worked branches of ornithology, must,
however, always be classed as not the least inter-
esting portion of the Story of the Birds.

THE END

Printed by BALLANTYNE, HANSON & Co.
Edinburgh & London