Isued October 31, 1914 
V EVERHART ^MUSEUM? 
SCIEsTSCE, 
AND ART 
JjB H. WARREN, M.D. 
Director 
NATURAL HISTORY LEAFLET NO. 5 
R. N. DAVIS 
Curator 
The C 
ommon V—lTO'Wr (QqilYus Americanus) 
And It s Egg-hatmg Habit 
From The Times, Scranion, Pa., October 20 ih, 1914 
Farmers, poultry raisers and sports- 
men are asked to send their views on 
the crow to Dr. B. H. Warren who 
edits weekly the natural history column 
in the Times. 
From the time of Audubon and 
Wilson, both great naturalists, there 
has been more or less difference of 
opinion among ornithologists as to the 
true economic status of the common 
crow and the gaudy, garrulous blue jay. 
Both are plentiful throughout Pennsyl- 
vania, where they are found during all 
seasons. 
The crow and jay are omnivorous. 
They kill and devour noxious forms of 
animal life. Zoologists who are hostile 
to these birds are of the opinion that 
the penchant which they possess for 
eating the eggs and young of many 
species of beneficial wild birds is by all 
odds greater than benefits conferred by 
the devouring of harmful forms of in- 
sect life. Crows in addition to robbing 
nests of wild birds, steal eggs of 
domestic fowls and also devour their 
young. Crows likewise do damage in 
corn fields, but to offset such loss to 
the farmer, they also destroy many cut- 
worms, beetles and grasshoppers. 
Practical fi'eld ornithologists who are 
disposed to regard the crow and blue 
jay with favor, frankly admit that these 
birds rob nests of both eggs and 
young, and they also do not deny that 
crows (i. e. depraved individuals) will 
sometimes eat eggs of domestic fowls 
and likewise carry off for food young 
chickens, ducks and turkeys. Some 
eminent naturalists who defend crows 
and jays seem to believe that the dif- 
ferent forms of insect life they con- 
sume in the course of the year 
more than counterbalance the losses 
occasioned by the destruction of great 
numbers of wild birds of both game 
and nongame varieties by the black 
and blue-coated pilferers. 
Leading naturalists who give partic- 
ular attention to food habits of birds 
base their opinions mainly on the exam- 
inations of the crops and gizzards of 
adult birds, captured during all months 
of the year and also, when practicable, 
of the viscera of young, when under 
parental care. The careful examination 
of food substances taken from the 
alimentary tracts of feathered victims, 
if examined by experts, may in most 
cases, be regarded as quite conclusive. 
In the case of egg-eating birds, how- 
ever, the belief is entertained by many 
naturalists — Dr. B. PI. Warren of the 
Everhart Museum, being one who holds 
this view — that these examinations of 
stomachs as collected by the great ma- 
jority of field workers should not be 
taken as conclusive. This idea is ad- 
vanced because so far as can be learned 
few, if any, colectors who have gathered 
in large numbers the crops and gizzards 
of such typical egg-devouring birds as 
crows, ravens and jays have not been 
able to secure any considerable number 
of these birds in the act of eating eggs, 
OVER 
