70 BULLETIN" 621 TJ. S. DEPARTMENT OF AGRICULTURE. 
ous Rhus seeds (poison ivy and poison sumac) for each pellet. Along 
with these were seeds of nonpoisonous sumac, grapes, dogwood, 
hackberry, wild bean (Strophostyles) , and buckthorn (Bumelia). A 
mass of material gathered at a roost near Baltimore contained 156 
seeds of poisonous Rhus, estimated to be 25 per cent of the bulk of 
the pellets. These also contained 11 seeds of nonpoisonous sumac, 6 
of greenbrier, 4 of juniper, and 1 of hackberry. W. L. McAtee, of 
the Biological Survey, has informed the writer that at the roost 
formerly located at Woodridge, near Langdon, D. C, he recorded the 
following species of plants in such abundance as to justify the belief 
that they had sprouted from seeds brought there by crows: Poison 
ivy, poison sumac, flowering dogwood, sour gum, arrowwood, and 
frost grape. He also stated that in 1 square yard there were 51 plants 
of poison ivy. 
The seeds deposited at winter roosts form only a portion of the 
material of this character cast up by these birds (PL II, fig. 2). 
These pellets are dropped here and there over the birds' daily feed- 
ing range, and under such circumstances probably a much greater 
proportion of the seeds sprout. Conditions in the average roost are 
not advantageous to the germination of a large part of the deposited 
seeds, especially in the dense pine woods so frequently chosen. 
When the seeds thus distributed are of valuable trees and shrubs 
or even of harmless plants, the crow no doubt is performing a distinct 
service, but the dispersal of seeds of poison ivy and poison sumac 
must be considered undesirable. Examination of 1,340 stomachs of 
adult crows showed that seeds of these poisonous weeds constitute 
1.49 per cent of the yearly food. Most of them are eaten during fall 
and winter, January being the month of greatest consumption (5.02 
per cent). When it is remembered that practically all these seeds 
would develop into weeds of the most noxious character should they 
be deposited in a favorable environment, it is not surprising that the 
crow has been the subject of considerable criticism on this score. 
While it must be admitted that no agency aiding in the reproduc- 
tion of poisonous plants should receive encouragement, it will be well 
before being unduly severe on the crow to notice other factors work- 
ing toward the same end. Records of birds' stomachs examined by 
the Biological Survey show that no less than 65 species of birds feed 
on the seeds of poisonous Rhus. Many of these birds possess the 
same objectionable habit of regurgitating the seeds, and in several 
cases the percentage of such food eaten exceeds that of the crow; 
but none of them leaves so large a part of the seeds of poison ivy 
and poison oak in places where they will never germinate as does the 
crow. The latter, then, is in a way conferring a benefit in feeding 
on these seeds, as by so doing it reduces the supply which otherwise 
