ECONOMIC RELATIONS OF OUR BIRDS. 
547 
a moth; one, a dragon-fly; one, wheat; three, oats; and one, grass seeds. The 
stomachs of two specimens contained insects, none of which were identified. 
Grubs, caterpillars, may-flies and other insects, green com, wheat, barley and 
wild oats (Wilson). Crickets, grasshoppers, beetles, spiders and seeds of various 
kinds (De Kay). Crickets, grasshoppers, beetles, spiders and various grass-seeds 
(Samuels). Cotton-worm (Brewer). Canker-worm (Maynard). Hymenoptera, 
caterpillars, leaf-chafers, curculios and seeds of weeds (Forbes). 
112. Molothrus ater (Bodd.), Gray. COWBIRD. Group III. Class b. 
This species reaches us eaidy in the spring, and, like the Bobolink, disappears 
in August. I have never seen it later than the 9th of this month. “A strange 
point in the history of this species is its unexplained disappearance, generally 
in July, from many or most localities in which it breeds. Where it goes and 
for what purpose are unknown.” In the spring they are often about stock-yards 
in quest of corn and seeds. Later they frequent pastures, keeping close to the 
cattle and horses, apparently for the purpose of obtaining the insects that are 
startled by the grazing herd. They are said also to feed upon the parasites that 
infest cattle. 
Whatever speculations may be indulged as to the origin of the strange para¬ 
sitism of the Cowbird, we must always regret that so pernicious a trait should 
have been engrafted upon bird-nature. Why the Cowbird should not incubate 
her own eggs does not appear in her structure; but that she generally deposits 
them where the foundlings will receive unstinted care is attested by the obser¬ 
vations of many. Did not the adventitious fledglings result sooner or later in 
the destruction of the rightful young, we might deal more leniently with this 
species. As it is, on grounds of economy, and in view of the scant abundance 
of insectivorous birds in agricultural districts, the Cowbird merits no protection. 
Nearly every species which rears the young of this parasite is as useful as itself, 
but in most instances, if not all, a single Bunting supplants a brood of from 
three to five individuals. Where a pair of Vireos, for instance, might have 
reared four or five young birds of their kind, their energies have been devoted to 
a single Bunting. 
The following are some of the birds that are known to act as foster parents to 
this species: Turdus mustelinus, T. fuscescens, Minniotilta varia, Polioptil 
ccerulia, Helminthophaga ruficapilla, Dendroeca cestiva, D. virens, D. Black- 
hurnioe, D. discolor, D. Pennsylvanica, Geothlypis trichas, Smrus auroca- 
pillus, SetopJiaga ruticilla, Passerina cyanea, Vireo olivaceus, V. solitarius, V. 
gilvus, V. noveboracensis, V. flavifrons, Sayiornis fuscus, Empidonax minimus, 
Contopus virens, Sturnella magna, Harporhynchus rufus, Spizella domestieus 
and Pipilo erythrophthalmus. It has been stated on a previous page that seven out 
of fourteen Pewees’ fS. fuscusJ nests visited at Ithaca, N. Y., in the spring of 
1878, contained either the eggs or the young of the Cowbird. From this fact 
it appears that instead of twenty-eight or thirty-five Pewees which might have 
been reared in the seven nests, only seven Cowbirds could have taken their 
place as insect destroyers. Such is the check which this bird imposes upon the 
Pewee at Ithaca. If, as is generally believed, each existing Bunting represents 
a brood of young birds whose birth has been prevented, it is doubtless within 
the bounds of truth to assert that the number of Cowbirds existing at any time 
represents a deficiency in the bird population of the country of three times their 
number; and as the nests in which tliis parasite usually deposits her eggs are 
those of the most exclusively insectivorous species we have, it is evident that 
