4 
would render the work rather large and it is hardly necessary 
at the present time. A complete tabulated statement* of the food 
of the rook has been made and the notes will be incorported in a 
larger and fuller account which it is hoped will be published in 
the near future. In this table the various insects are classified 
as either beneficial, injurious, or neutral, and the same divisions 
are allowed for the other invertebrates ; g'rain, roots, and mis- 
rellaneous food are also classified. 
Natuee of Food. 
It has been stated on many occasions that the rook feeds largely 
upon insects in all stages. This appears to be true for certain 
periods of the year, but the rook is not very particular as to its 
diet, and if the supply of insects falls short (as it does during 
the winter months) a good deal of grain and other food is 
taken. The rook would, in fact, appear to be omnivorous. 
It is perfectly obvious that the nature of the rook’s food must 
not be judged from particulars obtained at any special period of 
the year and from certain localities, but should be based on 
information obtained from the examination of a large number' 
of specimens which have been killed over a large area ; more- 
over the supply of birds should be as even as possible each month 
and continued for a few years. If this plan could be carried 
out birds would be obtained which had been living under many 
different conditions. 
The problem is one of great complexity and, if reliable results 
are to be obtained, many factors must be taken into consideration. 
Not only does the food of the rook vary at different times of the 
year and according to the available supply, but it also varies in 
different phases of the bird’s life history. It is well known that 
during the breeding season birds take a much larger proportion 
of insects as food than at other times, so that it is important not 
only to examine as many birds as possible at this time of year, 
but the number should contain many nestlings. Very few 
nestlings have been received, but in the case of nine received in 
May from Wasperton Hill Farm, Warwickshire, and Treffgarne, 
Pembrokeshire, it was found that the principal food consisted of 
injurious insects. 
Unfortunately, very few birds have been received from these 
localities during the other months of the year,t so that it is 
impossible to say whether much damage is done by the rook during 
these months in the particular districts, and, if so, whether the 
injurious effect more than counterbalances the benefit conferred 
during the breeding season. 
It will be seen, by reference to Table No. II., that a very large 
proportion of the food taken by the 209 specimens during the 
months, September to May inclusive, was grain, and it might be 
said that as more grain than animal food was found in the gizzards 
* Copies of the detailed tabulation of the food may be seen either at the 
offices of the Board of Agriculture and Fisheries or at the University of 
Manchester, 
f See Table No. 1. 
