over-methodical in presenting these reasons, but will mention them in
the order in which they occur to him. If we keep in mind the invariable
succession of the seasons, and that this annual rotation has continued
for ages, and if we also remember that all animals are dowered by their
Creator with as much intelligence as is necessary for their well-being,
much of the difficulty attaching to this subject will at once disappear.
Birds, like their human kinsmen, learn by experience and tutelage, and
are also gifted with a sure instinct that amounts in many cases almost
to reason. Take, for instance, this one fact. As the sun creeps
northward in the spring, it pours a more and more intense heat upon the
northern portions of the tropical and sub-tropical regions. The heat
would soon become intolerable to certain birds, which have doubtless
tried the experiment of spending the summer in equatorial countries; or
if individuals now living have not tried it, perhaps some of their more
or less remote ancestors have. That birds do make experiments is proved
by the fact that several pets of mine will carefully “sample” a new kind
of food offered them, and if they do not find it to their taste, will
let it severely alone; nor is it any the less evident that young birds
receive instruction from their elders. Thus the necessity of leaving the
torrid regions as summer approaches may have been impressed on the
migrating species from time immemorial.
Again, as spring advances, insect and vegetable life is revived in
regions farther north, and this certainly must act as a magnet upon the
birds, drawing them from point to point as the supply of food becomes
scarce in the more southern localities. Then, let us suppose for a
moment that all the birds did remain in the south through the summer;
there would sooner or later be a bird famine in the land, for the supply
of seeds and insects would soon be exhausted. Our feathered folk are
simply obliged, on account of the exigencies of food, to scatter
themselves over a larger extent of country. They solve the problem of
food supply and demand by these annual pilgrimages to the boreal lands
of plenty.
To go a little more to the root of the matter, we may easily imagine how
the migrating spirit got its first impulse and gradually became evolved
into a habit of something like scientific precision. If the first birds
lived in tropical climates, as was probably the case, some of them, as
the food supply became exhausted, would be crowded northward, or would
go of their own accord, and wherever they went they would find
well-filled natural larders. Having once discovered that spring
replenished the north with food, they would soon learn the desirability
of making periodical journeys to that part of the globe. With this
constant quest for food must also be coupled the instinctive desire of
most birds for seclusion during the season of reproduction,—an instinct
that would naturally drive them northward into the less thickly tenanted
districts. But it may be objected that many species make long aerial
voyages, passing over vast tracts of country to reach their chosen
summer habitats in various parts of the north; and it is well known that
the same individuals will return again and again, on the recurrence of
spring, to the same locality. How are these facts to be accounted for?
If we accept the glacial theory—a hypothesis pretty well established now
among scientific men—we may readily conceive that, as the sun melted the
ice at a greater distance in both directions from the equator, the
habitable area of the earth’s surface would gradually become enlarged.
For the sake of vividness let us fancy ourselves living at that period
of the world’s history. Let us select a point north of the equator where
a given pair of birds can live in summer. They find plenty of food
there, and are comparatively undisturbed by other birds, and they
therefore become attached to the place, most feathered folk having a
strong “homing instinct.” When winter comes, they and their progeny are
forced to retire to the south; but they do not forget their pleasant
summer haunt, their Mecca in the north, and therefore, at the approach
of the following spring, they obey the home impulse and hie by easy
stages to the beloved spot. Some of their number doubtless find it
possible from time to time to push farther northward, and thus other
breeding-haunts are selected. As the glacial accumulations melt away,
the whole temperate region and a large part of the frigid zone become
habitable. All this takes place by a very gradual process, requiring
thousands of years, thus giving ample time for heredity to infuse the
migratory habit into the nature of the birds. Every new generation would
learn the route and other needful details from their predecessors, and
thus the process would go on in an unending circuit year by year.
After the foregoing was written, my attention was called to the
following quotation from Dr. J. A. Allen’s valuable paper on the “Origin
of the Instinct of Migration in Birds.” The extract is taken from an
article by Frank M. Chapman, published in “The Auk” for January, 1894:
“Nothing is doubtless more thoroughly established than that a warm
temperate or sub-tropical climate prevailed down to the close of the
Tertiary epoch, nearly to the Northern Pole, and that climate was
previously everywhere so far equable that the necessity for migration
can hardly be supposed to have existed. With the later refrigeration of
the northern regions, bird life must have been crowded thence toward the
tropics, and the struggle for life thereby greatly intensified. The less
yielding forms may have become extinct; those less sensitive to climatic
change would seek to extend the boundaries of their range by a slight
removal northward during the milder intervals of summer, only, however,
to be forced back again by the recurrence of winter. Such migration must
have been at first ‘incipient and gradual,’ extending and strengthening
as the cold wave receded, and opened up a wider area within which
existence in summer became possible. What was at first a forced
migration would become habitual, and through the heredity of habit give
rise to that wonderful faculty which we term the instinct of migration.”
The reader’s attention is also directed to Mr. Chapman’s own article in
the number of “The Auk” indicated.
It may be asked why some species remain in torrid and temperate
climates, while others wing their way to the far north, even beyond the
boundary of the Arctic Circle. My answer is, There is some Power that
has wisely arranged all these matters, either by gradual development or
by an original creative fiat. Every species is made to fit with nice
precision into its peculiar niche in the creation. Perhaps Bryant
suggests the true explanation in his poem entitled “To a Waterfowl”:—
“There is a Power whose care
Teaches thy way along that pathless coast,
The desert and illimitable air,
Lone wandering, but not lost.”
This may seem like begging the question; yet, to my mind, it is
impossible to develop a philosophy of the universe without assuming an
original creative Intelligence. True, the laws of evolution will account
for many of the details, and birds, like men, are empowered in a large
measure to work out their own destiny; but somewhere there must be a
Power that has infused into Nature all these wonderful potentialities of
development. Involution must precede evolution.
But this is speculation. Account for them as we may, the facts are
evident. Within the circle of my own observation there is abundant proof
of this varied but wise adaptation in Nature. There, for example, is the
tiny golden-crested kinglet, which remains here all winter, no matter
how severe the weather, and seems to be the embodiment of good cheer;
whereas the brown thrasher, a bird many times as large, would be likely
to perish in the first snow-squall. Then, when spring arrives, Master
Kinglet hies to the north for the breeding-season, while Monsieur
Thrasher comes up from the south and becomes my all-summer intimate.
Another matter of intense interest concerning bird migration is that the
migrants which winter farthest north are, as a rule, the first to arrive
in the spring at their summer homes or vernal feeding-grounds. For
instance, in the latter part of March or the beginning of April, while
the thrashers, cat-birds, and others which winter in our Southern
States, are arriving in New England, New York, Pennsylvania, and Ohio,
the warbler army, which spends the winter in the West Indies, Yucatan,
and Central America, is just crossing over from those countries to the
southern borders of the United States.
When autumn comes, experience has taught the migrants that their only
safety lies in making their way to the south before cold weather sets
in; for many of them certainly do start on this voyage long before
winter drives them from their northern haunts. In my opinion, they are
gifted with sufficient reason—call it instinct, if you like—to do this,
and I do not think they are moved by an uncontrollable impulse which
acts upon them as if they were mere automata.
Portions of the migrating army often overlap. For example, the juncos
and tree-sparrows are winter residents in my neighborhood, but very
frequently they remain here a month or more after the earliest arrivals
from the south. Presently, however, they grow nervous, flit about
uneasily, trill little snatches of song, inure themselves to flight by
longer or shorter excursions about the country, and then join the
northward procession _en route_ for their breeding-haunts in British
America. With regret I bid them adieu, but find compensation in the
knowledge that their places will be supplied by a brilliant company of
summer residents.
One of the strangest features of migration is the fact that a bird will
sometimes make the voyage from north to south, and _vice versa_—or a
part of the voyage—alone, at least as far as companionship with
individuals of its own kind is concerned. Whether this is done
advertently or inadvertently I am unable to say, but the fact cannot be
disputed. In the spring of 1892, as noted in another chapter, a hooded
warbler was flitting about a gravel bank in a wooded hollow, and
although I scoured the country for miles around day after day, I never
met another bird of this species. The little Apollo in feathers was so
gentle and familiar that surely his mates would not have escaped my
notice had there been any in the neighborhood. Why he preferred to
travel alone, or in company with other species rather than his own kin,
might be an interesting problem in avian psychology. A little farther
down the glen a single mourning warbler was also seen at almost the same
date. His companions had probably wished him _bon voyage_, and left him
to strike out in an independent course through the trackless ocean of
air.
That the army of migrants travel mostly by night is a well-known fact
that can be verified by any one who will stand out-of-doors and listen
to their chirping overhead. They seem to move in loose flocks, for there
are intervals of complete silence, followed by a promiscuous chirping
from many throats. Nor are these nocturnal calls all uttered by a single
species, but usually a number of species seem to be travelling in
company. One might say, therefore, that the feathered army moves in
squads. As they travel in the dark, very little can be said about their
flight; but every student has found species of birds in an early morning
ramble which he could not find anywhere on the previous day, proving
that they must have arrived in the night. Here is a single excerpt—many
might be given—from my note-book: “On the third of March, 1894, I took a
long stroll into the country, remaining in the fields until dusk; not a
single meadow-lark was to be seen or heard. At daybreak next morning,
however, the shrill whistle of I know not how many larks rose like
musical incense from the fields and commons in the rear of my house.
Depend upon it, had these lavish minstrels been in the neighborhood
during the previous afternoon, they would not have escaped my attention,
for they could not have kept their music in their larynxes, not they!
There is a cog in Nature’s machinery lost if the meadow-larks are silent
for a half day in the spring.”
In 1885 Mr. William Brewster, the well-known ornithologist, made some
intensely interesting discoveries on the nocturnal flight of migrants,
at Point Lepreaux Lighthouse, New Brunswick. The principal lantern,
which was in the top of the tower, cast a light that could be seen
fifteen miles away in clear weather. Even on dark and foggy nights this
lantern would throw out a strong light to such a distance that a bird
coming into the lighted area could readily be seen. On stormy nights the
lighthouse seemed to possess a fatal attraction for the lost and
rain-beaten birds, which would fly toward it and often dash against the
glass, the roof, and other portions of the tower with such force that
they fell dead or disabled. Mr. Brewster could see them approaching in
the prism of light, some dashing themselves with fatal effect against
the tower, but more, fortunately, turning aside or gliding upward over
the roof, and then pressing on toward the west with incessant chirping.
During rainy weather a larger proportion would strike the brilliant
obstruction.
It is interesting to notice that different species composed the
companies that passed the lighthouse. For instance, on the night of
September first, seven different species of warblers and one red-eyed
vireo were killed or disabled, and one Traill’s flycatcher entered the
mouth of the ventilator, and came down through it into the lantern. A
few evenings later, about forty per cent of the specimens identified
were Maryland yellow-throats, forty per cent more red-eyed vireos, and
the remaining twenty per cent were made up of two kinds of thrushes and
six kinds of warblers. These figures are given to show the heterogeneous
composition of the migrant army.
Mr. Brewster also found that no birds came about the lantern except on
densely cloudy or foggy nights, and that they came in the greatest
numbers when the first hour or two of the evening had been clear and was
succeeded by fog or storm. These data would seem to prove that the birds
began their nocturnal journey with the expectation of having pleasant
weather, and when the fog or storm rose later in the evening, they flew
lower and got bewildered by the glare of the lighthouse.
Many theories of bird migration have been proposed and argued at length,
but, on the whole, I incline to Mr. Brewster’s theory that the old
birds, having learned the advantage of these semi-annual expeditions,
and having also determined the route by means of certain landmarks, act
as aerial pilots to the army of young birds to whom the way is still
unknown. Mountain ranges, river valleys, coast lines, and sheets of
landlocked water doubtless serve the purpose of guide-posts to these
airy travellers. Much as has been written on the subject, however, there
still remains a large field for original research.
VII.
PLUMAGE OF YOUNG BIRDS.
It is surprising what odd and variegated costumes are sometimes worn by
the juvenile members of the bird community. Frequently their attire is
so different from that of their elders that even the expert
ornithologist may be sorely puzzled to determine the category to which
they belong; yet there are usually some characteristic markings, however
obscure, by which their places in the avian system may be fixed. As a
rule, the plumage of young birds is more striped and mottled than that
of mature specimens, Nature playing some odd pranks of color-mixing in
tiding a bird over from callow infancy to full-fledged life. Fashion
plates in the world of bantlings would be of little account, as no fixed
patterns are followed.
Some parts of the growing bird’s plumage change to the normal color
sooner than others. I remember a young male indigo bird that I saw in
October, whose garb, just after fledging, must have been a warm brown
almost like that of the adult female; but now he had cast off a part of
his infantile robes, and put on in their stead the cerulean of his male
parent; his tail, rump, and the base of his wings were blue, while the
rest of his plumage was brown. He made a unique and pretty picture as he
sat atilt on a blackberry stem, asking me with loud _Tsips_ to admire
his quaint toilet. Early in the spring I have seen indigo birds in whose
plumage the tints were quite differently blended and arranged.
What a party-colored suit the young bluebird wears! His breast, instead
of being plain brick-red as in the case of the adult bird, is profusely
striped with dark brown on a background of soiled white; and his upper
parts, in lieu of the warm azure of riper years, are a lustrous brown
curiously mottled with tear-shaped blocks of white; while his wings and
tail have already assumed the normal blue of this species. In the days
of his youth the chipping-sparrow also dons a striped vest, so that, if
it were not for his smaller size, it would be difficult to distinguish
him from his relative, the grass-finch.
My admiration was especially stirred, one midsummer day, by the dainty
appearance of a small coterie of bush-sparrows flitting about on a
railroad which I was pursuing on foot; a large patch on their wings was
of a dark, glossy brown tint, extremely pretty, and looking precisely as
if it had been painted by the deft hand of an artist. Their under parts
were variously streaked with white and dusk. At first I scarcely
recognized my familiar little sylvan friends; but their intimacy with
several adult specimens, as well as several well-known diagnostic
markings, settled the question of their identity beyond a doubt.
Not every person is aware that the common redheaded woodpecker is no
red-head at all during the first summer of his buoyant young life, but a
black-head instead, or, rather, his head and neck are very dark gray.
However, one day in September I was delighted and amused to find an
adolescent woodpecker whose head and neck were beginning to turn quite
reddish, flecked everywhere with white, giving him a decidedly
picturesque appearance as he scuddled up an oblique fence-stake. Of
course the red-head is always _sui generis_, but in this case he seemed
to be more so than usual. Nearly all the woodpeckers—the downy, the
hairy, and the golden-winged—are devoid of the red spots on their heads,
while young, to prevent them, I suppose, from becoming vain.
Sometimes an entirely foreign tint is introduced into the plumage of the
young bird during his transition state. One day I was surprised to
observe a decidedly bluish cast on the striped breast of a young towhee
bunting, which was all the more curious because there is no blue
whatever in the plumage of either the adult male or female. But the most
curious freak of Nature’s dyeing I have ever seen in the bird world was
in the case of a young scarlet tanager, whose body, including the wings,
was completely girded with a band of white, the border of which was
quite irregular. As every observer knows, the only colors visible in the
adult male’s plumage are black and scarlet; still, when the scarlet
feathers are pushed aside, they show white underneath, and that may
account for the albino quality of this specimen.
When he is first fledged, the pattern of the young cardinal grossbeak’s
plumage very much resembles that of his mother; but soon the bright red
of his full dress begins to peep here and there through the
grayish-olive of his kilts and trousers, so to speak, making him look as
if he had been meddling with a keg of red paint and had splashed himself
liberally with it. By and by there is a very odd blending of tints in
his suit. Scarcely less curious is the garb of the young white-crowned
sparrow; his whole head is black or blackish-brown, except a tiny speck
of white in the centre of the crown, gleaming like a diamond in its dark
setting. In the adult bird the whole crown is a glistening white,
bordered on each side by a black band, which circles about on the
forehead and separates the crown-piece from the white superciliary line.
Some of the warblers are scarcely recognizable in their juvenile attire.
For example, the young black-poll, bay-breasted, and chestnut-sided
warblers bear little, if any, resemblance to their parents, whose
diversified nuptial robes make our woodlands radiant in the spring. The
young are quite tame in their soiled olive plumes, and look so much
alike that the ornithologist is often at his wits’ end to tell them
apart. Were it not for the yellow rumps of the magnolia and myrtle
warblers when young, one would scarcely know them from a dozen other
species as they pursue their journey southward in the autumn. The
Maryland yellow-throat does not deign to wear his black mask until he is
about eight months old, and the boy redstart contents himself with his
mamma’s style of dress until he returns in the spring from his sojourn
in the south, and does not seem to be ashamed to be tied to her
apron-string. And there is that natty little dandy, the ruby-crowned
kinglet—it is said, on good authority, that he must be two years old
before he is entitled to wear the ruby gem in his forehead; which must
be a sore deprivation for this little aristocrat in feathers. Perhaps in
kingletdom a bird does not become of age until he is two years old.
Thus it will be seen that the study of ornithology is made more
difficult, and at the same time more interesting, by this change of
toilet among the birds,—more difficult, because the observer must learn
to identify the birds in their youthful as well as in their adult
plumage; and more interesting, because of the greater variety thus given
to this branch of scientific inquiry.
VIII.
NEST-HUNTING.
Nothing in Nature is more pregnant with suggestion than the nest of a
bird. The story of one of these deftly woven dwellings in the woods, if
fully written, might prove almost as weird and romantic as the history
of a castle on the Rhine. What madrigals, what pæans, have been sung,
and what victories celebrated, from the time the first fibres were
braided until the chirping nestlings were able to shift for themselves!
And, alas, how many fond hopes have perished as well! No doubt the ruses
and subterfuges employed to elude cunning foes or ward off their
murderous attacks, would fill a volume of valuable information on
military tactics. One might write comedies or tragedies about the
nest-life of the birds that would be no less interesting than realistic.
More than that, the study of these wonderful fabrics would virtually be
a study of the psychology of the feathered artisans, each nest being an
index of a special type of mind and a measure of the bird’s mental
resources. As William Hamilton Gibson has well said: “To know the
nidification and nest-life of a bird is to get the cream of its
history;” than which nothing could be truer or more aptly expressed.
No wonder the poets have so often been thrown into lyrical moods over
the homesteads of the birds! Mrs. Margaret E. Sangster’s poem on “The
Building of the Nest” is perhaps not unfamiliar to most readers; but one
stanza is so graceful and rhythmical that it begs for quotation at this
point:—
“They’ll come again to the apple-tree—
Robin and all the rest—
When the orchard branches are fair to see
In the snow of blossoms dressed,
And the prettiest thing in the world will be
The building of the nest.”
In one of my rambles I found an abandoned towhee bunting’s nest
containing three eggs, and could not help speculating as to the cause of
its desertion. Might there have been a quarrel between husband and wife,
making a separation necessary? I am loath to believe it, although, if
certain acute observers are correct, divorce is not wholly unknown in
the bird community. But in this case I am inclined to think that some
enemy had destroyed the female, for a male flitted about in the bushes,
calling a good deal and singing at intervals, and there seemed to be a
plaintive note in his song, as if he might be chanting an elegy. At all
events, the pair that built the nest had had their tragedy.