Vol. XIV 
5807 Brea, Food of European Birds. 1I 
from dung, or consisted of scattered kernels picked up in stubble- 
fields, he still considers that it must all be counted against the 
birds, as it shows their taste for grain. Thisis not fair. Grain so 
obtained has no value to the farmer and should not be reckoned as 
a loss. As a matter of fact, Mr. Gilmour’s own tables show that 
the Rooks do not “‘ attack and prey freely upon the farmer’s grain 
whenever and wherever favourable opportunity is presented.” 
Many stomachs taken in harvest time show no grain, and a large 
proportion of them contained some insects. It cannot be claimed 
that any of them lacked opportunity to eat grain, for all were 
collected practically from the same locality. 
In comparing the results obtained by these investigators some 
important differences are noted, and it is seen that the two have 
drawn almost diametrically opposite conclusions The Rooks 
examined by Dr. Hollrung contained 17 mice, an article of food 
which Mr. Gilmour does not seem to have found in his. The 
insects, unlike those eaten by the Scottish Rooks, were mostly 
noxious species whose destruction was a decided benefit to the 
farmer. While grain was eaten to some extent by Dr. Hollrung’s 
Rooks, it does not appear to constitute an important article of 
their diet economically considered. 
Mr. Gilmour assumes that the Rooks taken in Fifeshire fairly 
represent those of the whole of the Lowlands of Scotland in their 
food habits, an assumption that may possibly be true, but Dr. 
Hollrung’s investigation shows that no such supposition will hold 
for extensive areas of country. Stomach examination as well as 
field observation shows more and more that the kind of food taken 
by birds is determined by availability as well as taste; conse- 
quently the food of any particular species will vary to a certain 
extent in different localities. 
The Common Crow (Corvus americanus) represents in this 
country, as nearly as may be, the economic position occupied by 
the Rook in Europe, and a few points of comparison in their food 
may not be without interest. The food of the Crow consists of 
about the same proportion of animal and vegetable matter as that 
of the Rook. 
In the first four items of Dr. Hollrung’s list the Crow and the 
Rook present a great Similarity of taste, the Zachnosterna of this 
