1886.) Crow Roosts and Roosting Crows. ` 691 
CROW ROOSTS AND ROOSTING CROWS. 
BY SAMUEL W. RHOADS, 
BY no means the least interesting topic in the life-history of 
Corvus americanus is that which relates to the roosting habits 
of this familiar and persecuted bird during six months of the 
year. 
Throughout the breeding and rearing period which, in the 
Middle States, is almost cotemporary with the spring and sum- 
mer months, the crow is not a gregarious bird, differing in this 
particular from its lesser kin, the blackbirds, which are eminently 
gregarious throughout the year; but as autumnal changes alter 
the face of nature and usher in new aspects of environment, the 
flocking habit becomes universal and the scattered families unite 
by common consent from the four quarters of their dispersion. 
The most casual observer cannot fail to remark the phenomenal 
increase in apparent number of crows in this latitude on the 
approach of winter. We may not account for this by referring 
it to the mere fact that flocking birds seem more numerous than 
they are in reality, nor is it possible that the immense assemblage 
of crows in the vicinity of Philadelphia during the winter season 
1S Composed solely of birds resident in the States of Pennsylva- 
nia and New Jersey. In the face of plain evidence to support 
such a conclusion, ornithologists generally ignore the fact of 
crow migration. ; 
Undoubtedly the increase of crows at this season is largely 
due to accessions from the New England and Western States 
which join the thousands assembled from the interior of our mid- 
dle districts. This migration, though “partial” and in some 
degree influenced by the comparative severity of winters, is none 
less a typical one, a necessary provision for their self-preser-_ 
' vation and a prime factor in the struggle of existence, even ina 
_ bird whose hardihood and tenacity of life have become almost 
~ Proverbial, > 
Careful observation and inquiry convinces me that during win- 
: ee a radial sweep of one hundred miles, described from the city 
~ Philadelphia and touching the cities of New York, Harris- _ 
_ *urg and Baltimore, will include in the day time, in its western 
_ SeMmicircle, fully two-thirds of the crows (C. americanus) inhabit- | 
ue North America, and aż night an equal proportion in its eastern 
