13 
Summary. 
The results of this investigation so far as it has progressed from 
the consideration of 209 stomachs shows : — 
(i) That a large proportion of the food of the rook con- 
sists of grain, and that it is taken mainly in the 
autumn, winter, and early spring months. 
(ii) The total amount of animal food is not so large as grain, 
but reaches a high percentage during May, June, 
July, August, and September. 
(iii) There is some evidence to show that a grain diet may 
be preferred, but there is also evidence which shows 
that a great many insects (about half of which are 
injurious) are taken by the rook particularly in its 
nestling stage, and that it is therefore most important 
to have a good supply of birds during this phase in iis 
life-liistory. 
(iv) It is difficult from the evidence yet obtained by this 
inquiry to say whether the rook is on tlie wliole a 
beneficial or an injurious bird, as the material upon 
which the account is based is not sufficiently repre- 
sentative. 
(v) Tlie only satisfactory way to obtain a correct idea of the 
economic status of the rook is to have an even supply 
of birds each montli from the same and as many locali- 
ties as possible so that they can be examined when 
feeding under all kinds of conditions; it is most 
important to have reliable observational evidence, and 
careful consideration must be given to the available 
food supply and the many facts connected with migra- 
tion. It may in some cases be impossible to arrive at 
a perfectly definite conclusion as to the bird’s economic 
status, as the conditions under which the rook lives 
• are so complex and vary from time to time, but even 
if this were the case there would be a distinct 
advantage in knowing that the problem had been sub- 
jected to a properly organised scientific inquiry and 
was free from the prejudice which so often cliarac- 
terises the thoughts of persons interested only in one 
particular subject. • 
