52 
Report on the Food Found in 
Miscellaneous Vegetable Matter. — Vegetable matter, which could not 
be identified, occurred in 27 cases. 
Miscellaneous Food. 
In 15 instances meat and carrion occurred, and kitchen refuse was 
found in 9 gizzards ; this included small pieces of bread 3 times, potato 
twice, portions of bone 3 times, and tea leaves once ; unrecognisable 
miscellaneous food occurred once. 
Summary of Results. 
Summarising the contents of the 209 rooks containing food, 
grain was in greatest abundance, it having been found in 73 per 
cent, of the gizzards, and in 57 cases in which it occurred it 
formed 70 to 80 per cent, of the food contents. Roots of value 
to the farmer ( i.e ., potatoes, mangolds, etc.) were found in 20 per 
cent, of the birds. Injurious insects occurred in 36 per cent, of 
the gizzards, the percentage for “ leather- jackets ” ( Tipulidce ) 
being 15, and 9 for “ wireworms ” or their imagos (E later idee) . 
At least 2 instances in this enquiry show in a very pronounced 
manner the large number of injurious insects which may be 
taken by a single rook in the course of a short time. Thus in 1 
gizzard from Cumberland 95 whole Tipulid larvae (“ leather- 
jackets ”) were found, and as many as 103 Elater larvae (“ wire- 
worms ”) were present in another ; it is, therefore, obvious that 
these birds were rendering valuable service to the farmer. 
This investigation has shown that the percentage of animal 
food taken from April to September is large and also that it is 
made up mainly of injurious insects ; so that for six months 
rooks appear to take a large quantity of injurious insects as 
food. On the other hand, we have to record a large quantity 
of grain in the rooks’ diet ; for 9 months of the year (from 
September to May inclusive) the percentage of grain is very 
high, and only falls to a really low level in June, July and 
August. 
It would, however, be most unwise to rely entirely upon 
statistics obtained from stomach dissections and to say that, 
because the figures show a large percentage of grain, the rook 
is doing a great amount of damage to the crops. It has been 
frequently observed that rooks, when feeding upon grain in 
September and Oc tober, are not doing any damage to the 
crops but are merely taking the grain which has been dropped 
during harvesting operations. Reliable observational evidence 
in addition to dissections is, therefore, of much importance in 
an investigation of this nature. The rook appears to feed 
largely upon insects in all stages during certain periods of the 
year, but it is not very particular as to its diet, and, if the 
