Family XVI. AGELAINAE. MARSH BLACK-BIRDS. GENUS II. MOLOTHRUS, Swains. COW-BIRD. |
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Family |
THE COW-PEN-BIRD. [Brown-headed Cowbird.] |
Genus | MOLOTHRUS PECORIS, Gmel. [Molothrus ater.] |
The works of Nature are evidently perfect in all their parts. From the
manifestations of consummate skill everywhere displayed, we must infer that the
intellect which planned the grand scheme, is infinite in power; and even when we
observe parts or objects which to us seem unnecessary, superfluous, or useless,
it would be more consistent with the ideas which we ought to have of our own
feeble apprehension, to consider them as still perfect, to have been formed for
a purpose, and to execute their intended function than to view them as abortive
and futile attempts.
The seed is dropped on the ground. It imbibes moisture, swells, and its
latent principle of life receiving an impulse, slowly unfolds. Its radicle
shoots down into the earth, its plumule rises toward the sky. The first
leaflets appear, and as we watch its progress, we see it assuming size and
strength. Years pass on, and it still enlarges. It produces flowers and
fruits, and gives shelter to multitudes of animated beings. At length it stands
the glory of the forest, spreading abroad its huge arms, covering with its dense
foliage the wild animals that retreat to it for protection from the sun and the
rain. Centuries after its birth, the stately tree rears its green head to the
sky. At length symptoms of decay begin to manifest themselves. The branches
wither, the core dies and putrefies. Grey and shaggy lichens cover its trunk
and limbs. The Woodpecker resorts to it for the purpose of procuring the
insects which find shelter beneath its decayed bark. Blackness spreads over the
heavens, the muttering of the thunder is heard. Suddenly there comes on the ear
the rushing noise of the whirlwind, which scatters the twigs and the foliage
around, and meeting in its path the patriarch of the forest, lays him prostrate
on the ground. For years the massy trunk lies extended on the earth; but it is
seen gradually giving way. The summer's sun and the winter's frost crumble it
into dust, which goes to augment the soil. And thus has it finished its course.
Look again at the egg, dropped on its curious bed, the construction of
which has cost the parent bird many labours and anxieties. It also is a seed,
but it gives rise to a very different object. Fostered by the warmth imparted
by the anxious parent, the germ which it contains swells into life, and at
length bursting its fragile enclosure, comes tottering into existence. To
sustain the life and contribute to the development of this helpless being, the
mother issues in quest of food, which she carefully places in its open throat.
Day after day it acquires new development under the fostering care of its nurse,
until at length, invested with all the powers which Nature intended to bestow
upon it, it spreads its pinions to the breeze, and sallies forth to perform the
many offices for which it is destined.
How often have I watched over the little bird in its nest, and marked the
changes which day after day it exhibited: the unfolding of its first scanty
covering of down, the sprouting of its plumelets, the general enlargement of all
its parts! With what pleasure have I viewed the development of its colouring
and the early manifestations of its future habits!
Amid these wonderful operations of Nature, there is one which has
occasionally engaged my attention, and occupied my thoughts, ever since I first
became acquainted with the bird of which I now proceed to speak.
The Cow-bird, which in form and character is allied to the Crow Black-bird,
the Redwing, the Orchard Oriole, and other species, differs from these birds in
one important circumstance, which approximates it to the Cuckoo of Europe, a
bird entirely different in habits and appearance. Like that bird, it makes no
nest of its own, but deposits its eggs, one at a time, in the nests of other
birds, leaving them to the care of a foster-parent.
In the State of Louisiana, the Cow-pen-bird, or as it is also called, the
Cow Blackbird, or Cow Bunting, is seen only at long intervals. Some years pass
without the appearance of a single individual there. At other times immense
flocks are observed mixing with the Redwings, Crow Blackbirds and Robins,
searching about the farm-yards, the fields, and the meadows with great diligence
for food. At such times they are easily approached, and are shot in great
numbers, being considered more delicate and better flavoured than the species
with which they associate, excepting the Robin. Like the Redwings, they seek
the swamps and the margins of lakes and rivers, where they roost among the tall
sedges, flags, and other aquatic plants. When disturbed in these retreats, they
rise in a dense mass, perform various evolutions in the air, and alight again to
resume their repose. At daybreak, they return to the cultivated parts of the
country to search for food. In Georgia and South Carolina, they occur in great
abundance every winter. Some also spend the winter in Virginia and Maryland, as
well as in the States of Kentucky and Indiana, where I have observed them
lingering about farm-houses and cow-pens during severe weather. Great flocks,
however, retire much farther south. I have seen many of these birds passing
high in the air, at mid-day, in the month of October, pursuing their course
steadily, as if bent upon a long journey.
The Cow-pen-bird, after passing the winter in the Southern States, or in
regions nearer the equator, makes its appearance in the Middle States about the
end of March or beginning of April, arriving in small parties. Their flight is
performed chiefly under night; and during the day they are seen resting on the
trees, or frequenting the banks of streams in quest of food. They continue to
be seen in small flocks until the beginning of June, when they disappear, the
various flocks having successively passed northward.
Its flight is similar to that of the Redwing, with which it frequently
associates in its rambles. During spring and summer it feeds on insects, larvae
and worms, frequenting the cornfields, meadows and open places.
The males and females arrive together; but contrary to the general practice
among the feathered tribes, these birds do not pair. The males seem to regard
the females with little interest. The numberless acts of endearment, the many
carrollings, joyous flights, and bursts of ecstatic feeling, which other birds
display at the commencement of the breeding season, are entirely dispensed with.
When a particular intimacy takes place between two individuals of different
sexes, it soon ceases, and the same individuals mate with others. The sexual
attachment intended for the benefit of the young brood does not take place,
because in this species the young are not to be reared by their parents, but to
be left to the care of birds of other kinds. The Cow-pen Buntings, in fact,
like some unnatural parents of our own race, send out their progeny to be
nursed.
When the female is about to deposit her eggs, she is observed to leave her
companions, and perch upon a tree or fence, assuming an appearance of
uneasiness. Her object is to observe other birds while engaged in constructing
their nests. Should she not from this position discover a nest, she moves off
and flies from tree to tree, until at length, having found a suitable repository
for her egg, she waits for a proper opportunity, drops it, flies off, and
returns in exultation to her companions.
The birds in whose nests the eggs of the Cow Bunting are thus deposited,
are all smaller than itself. That which is most frequently favoured with the
unwelcome gift is the Maryland Yellow-throat. The other species in which I have
found the egg of the Cow-bird are the Chipping Sparrow, the Blue-bird, the
Yellow-bird, several Fly-catchers, especially the Blue-grey and the White-eyed,
and the Golden-crowned Thrush. The nests of these birds are very different in
form, size and materials, as well as in position, some being placed high on
trees, others in low bushes, and that of the Thrush on the ground.
It is also a very remarkable circumstance, that although the Cow-bird is
larger than the species in the nests of which it deposits its eggs, the eggs
themselves are not much superior in size to those of their intended
foster-parents. This is equally the case with the European Cuckoo, which
selects, for the purpose of depositing its egg, the nest of the Titlark,
Hedge-Sparrow, or some other small bird. And here, as in so many other cases,
may we observe the adaptation of means to ends which nature has so admirably
made. The egg of the Cuckoo, in fact, is not so large as that of the Skylark, a
bird which, to the other, hardly bears the proportion of one to six. The
intention here has not been by a similarity in size and coloring, to deceive the
bird in whose nest the egg, is placed, for, on all occasions, the individuals on
which the gift have been bestowed, receive it unwillingly, and, in fact,
manifest great alarm and resentment. On the contrary, the object has been to
secure the development of the embryo, by adapting the size of the egg to the
capability of imparting heat to it.
Should the Cow-bird deposit its egg in a nest newly finished, and as yet
empty, the owners of the nest not unfrequently desert it; but, when they have
already deposited one or more eggs, they generally continue their attachment to
it. There is reason for believing, however, that, on all occasions, they are
aware of the intrusion that has been effected.
The Cow-bird never deposits more than one egg in a nest, although it is
probable it thus leaves several in different nests, especially when we consider
the vast numbers of the species that are to be seen on their return southward.
It does not make a forcible entrance, but watches its opportunity, and when it
finds the nest deserted by its guardians, slips to it like one bent on the
accomplishment of some discreditable project. When the female returns, and
finds in her nest an egg which she immediately perceives to be different from
her own, she leaves the nest, and perches on a branch near it, returns and
retires several times in succession, flies off, calling loudly for her mate, who
soon makes his appearance, manifesting great anxiety at the distress of his
spouse. They visit the nest together, retire from it, and continue chattering
for a considerable time. Nevertheless, the obnoxious egg retains its position,
the bird continues to deposit its eggs, and incubation takes place as usual.
The egg of the Cow-bird is of a regular oval form, pale greyish-blue, sprinkled
with umber-brown dots and short streaks, which are more numerous at the larger
end.
Incubation has been continued for nearly a fortnight, and the young
Cow-bird bursts the shell. Another remarkable occurrence now takes place. The
eggs of the foster-bird are yet unhatched, and soon after disappear. In every
case the Cow-bird's egg is the first hatched, and herein also is manifested the
wisdom of Nature; for the parent-birds finding a helpless object, for whose
subsistence it behoves them to provide, fly off to procure food for it. The
other eggs are thus neglected, and the chicks which they contain necessarily
perish. Birds have probably the means of knowing an addle egg, for, when any
such remain after the hatching of the others, they always remove them from the
nest; and, in the present case, the remaining eggs are soon removed, and may
sometimes be seen strewn about in the vicinity of the nest. In the case of the
Cuckoo matters are differently managed, for the young bird of that species very
ungratefully jostles out of the nest all his foster-brothers and sisters, that
he may have room enough for himself. If we are fond of admiring the wisdom of
Nature, we ought to mingle reason with our admiration; and here we might be
tempted to suspect her not so wise as we had imagined, for why should the poor
Yellow-throat have been put to the trouble of laying all these eggs, if they
are, after all, to produce nothing? This is a mystery to me; nevertheless, my
belief in the wisdom of Nature is not staggered by it.
As the young Cow-bird grows up, its foster-parents provide for it with
great assiduity, and manifest all the concern and uneasiness at the intrusion of
a stranger, that they would do were their own offspring under their charge.
When fully fledged, the young bird is of a sooty-brown colour. Long after it
has left the nest, it continues to be fed by its affectionate guardians, until
it is at length able to provide for itself.
Towards the end of September, the old and young Cow-birds congregate in
vast numbers, and are seen wending their way southward, sometimes by themselves,
more frequently intermingled with other species, such as the Purple Grakles and
the Redwings, which they join in their plundering expeditions. They are to be
seen in the Middle States until near the end of October, although unusually
severe weather sometimes forces them southward at an earlier period.
This species derives its name from the circumstance of its frequenting
cow-pens. In this respect it greatly resembles the European Starling. Like
that bird it follows the cattle in the fields, often alights on their backs, and
may be seen diligently searching for worms and larvae among their dung. In
spring, the cattle in many parts of the United States are much infested with
intestinal worms, which they pass in great quantities, and on these the Cow-bird
frequently makes a delicious repast.
It has no song properly so called, but utters a low muttering sort of
chuckle, in performing which, it is seen to swell out its throat, and move the
feathers there in succession, in a manner very much resembling that of the
European Starling.
The young bird from which I made the present figure was sent to me by my
friend THOMAS NUTTALL, Esq., through Dr. TRUDEAU. It is the same as that
described by the former gentleman under the name of "Ambiguous Sparrow,
Fringilla ambigua," at p. 485 of his Manual of the Ornithology of the United
States and of Canada. On inspecting it, however, I at once felt convinced that
it was nothing else than a young Cow-pen-bird, scarcely fledged, it having been
found "in the early part of the summer of 1830." With the view, therefore, of
preventing further mistakes I thought it well to figure it.
It is in the habit of retiring to rest and spending the night on the reeds
bordering ponds in unfrequented places, as are the rest of our "Blackbirds."
One of their roosting-places is alluded to by my young friend Dr. THOMAS M.
BREWER, Of Boston, in a letter, as follows:--"The four Cow Blackbirds which I
obtained the last day you were with us, were shot in the marshes of Fresh Pond,
by Mr. CHARLES E. WARE. I went to the pond a day or two after, but was unable
to procure any, as it was so late in the afternoon that they were all gone to
roost in the reeds, and I could see them in thousands, nay, tens of thousands.
The rustling noise they made was truly deafening."
"You can hardly expect," continues Dr. BREWER, "that I should add any thing
to the detailed account which I have already given you of this bird, and yet I
cannot but think that much remains to be told respecting its habits. Many
circumstances relative to its history still solicit the attention of the
inquisitive naturalist, but of these I am not at present qualified to speak.
There is one subject, however, on which I may offer a few remarks, namely, its
laying in the nest of Fringilla tristis. WILSON first asserted that it burdens
that species with the charge of its egg; but Mr. NUTTALL denies the possibility
of such an occurrence, on the ground that the Cow Blackbirds are not present at
the time when the Goldfinch is breeding. For this, however, Mr. ORD takes him
to task, and states that he has himself seen a Cow Bunting's egg in the nest of
the bird in question. Now, it appears to me, that when we consider how
extremely incorrect WILSON'S description of the nest and eggs of Fringilla
tristis is, very little reliance can be placed upon his assertion in this case.
I can add my testimony to the authority of Mr. NUTTALL as to the absence of the
Cow-bird from this State while the Goldfinch is breeding here. The former
leaves Massachusetts before the first of July, sometimes earlier, indeed by the
middle of June, and never lays on its return late in September. I have never
found the nest of the Goldfinch before the 7th of August, although Mr. NUTTALL
states that it breeds in July. But then Mr. ORD says that he has himself
witnessed the occurrence. I would be the last person to doubt that gentleman's
veracity, nor have I the slightest idea that he would wilfully make a
mistatement; yet I cannot help thinking that in this matter he has been
deceived. Perhaps he is correct: but, in that case, he must either have in his
part of the country a distinct species of Goldfinch, or its habits and those of
the Cow-bird must be very different there from what they are here. At all
events, it is utterly impossible that such an occurrence could ever have taken
place in Massachusetts. I think, therefore, that the Goldfinch should be struck
from the list of those species in the nests of which the Cow-bird lays. On the
other hand, Sylvia Blackburniae and S. vermivora are to be added to it. The
Cow-bird is very common at Boston, having its eggs in the nests of the
White-eyed Vireo, the Red-eyed, and any other that it chances to encounter, and
departing in autumn for the south.
COW BUNTING, Emberiza pecoris, Wils. Amer. Orn., vol. ii. p. 145.
ICTERUS PECORIS, Bonap. Syn., p. 53.
MOLOTHRUSS PECORIS, Cow-pen or Cuckoo Bunt, Swains. and Rich. F. Bor. Amer., vol. ii. p. 277.
COW TROOPIAL, or Cow Blackbird, Icterus pecoris, Nutt. Man., vol. i.p. 178.
COW-PEN-BIRD, Icterus pecoris, Aud. Orn. Biog., vol. i. p. 493; vol. v.p. 233, 490.
Male with the head and neck sooty-brown, the body black, glossed with
green, the fore part of the back with blue. Female considerably smaller,
greyish-brown, the lower parts lighter. Young with the upper parts
greyish-brown, the quills and tail darker; wing-coverts and secondary quills
narrowly edged with light brown, primaries with whitish; lower parts dull
yellowish-white, the sides marked with a series of dark brown pointed spots.
Male, 7, 11 1/2.
Dispersed from Texas northward to lat. 68 degrees, and throughout the
United States. Great numbers winter in the Southern States.
An adult male of this species preserved in spirits presents the following
characters. The roof of the mouth has three longitudinal ridges anteriorly, the
middle ridge terminated by a soft prominence, similar to that of the Buntings,
behind which the palate descends in the same manner as in them. The posterior
aperture of the nares is oblong, with an anterior slit. The tongue is 7
twelfths long, fleshy, tapering, flat above, horny towards the end, and pointed.
The oesophagus, which is 3 1/4 inches long, passes along the right side of the
neck, accompanied by the trachea; its diameter at the commencement is 4
twelfths, but it immediately dilates into a crop, which extends to the length of
1 1/2 inches, its greatest width being 1/2 inch; it then contracts to 1/4 inch,
and enters the thorax. The proventriculus measures 4 1/2 twelfths broad. The
stomach is a strong muscular gizzard, 9 twelfths long, 7 1/2 twelfths broad, a
little compressed; the lateral muscles large and distinct; the epithelium tough,
longitudinally rugous, and of a reddish-brown colour. The contents of the
stomach are grains of wheat. The intestine is rather short, and of moderate
diameter, being 9 1/2 inches long, and varying from 2 twelfths to 1 1/2 twelfths
in breadth; the diameter of the rectum 2 1/2 twelfths, being the same as that of
the gut immediately before it; and there is scarcely any distinct cloaca, the
width of that part being not more than 4 twelfths. The coeca, 1 inch distant
from the extremity, are 3 twelfths long, 1/2 twelfth in diameter.
The trachea is 2 inches 2 twelfths long, rather wide in proportion to the
size of the bird, although not more than 11 twelfths in diameter. The rings are
58; the bronchial half rings about 15. The lateral muscles are moderate; the
sterno-tracheal extremely slender. There are four pairs of inferior laryngeal
muscles, as in all the singing-birds, whether thick-billed or not.
The digestive organs of this bird are in all respects precisely similar to
those of the Finches, Grosbeaks, Buntings, and other allied genera.
The oesophagus, [a b c d], is considerably dilated on the neck; the
stomach, [e], is a strong muscular gizzard, having the lateral muscles large and
distinct, the lower prominent, the epithelium longitudinally rugous. The
intestine, of which the commencement only is here represented, [f g], is rather
short and of moderate width. The coeca are an inch distant from the extremity,
and about a quarter of an inch in length; and the rectum forms only a slight
dilatation in place of a cloaca.
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