MR. J. HAMMOND ON FOOD OF BIRDS. 
323 
migration. It is stated by Saunders 13 that the starling 
migrates to this country from Northern Europe in the 
autumn (our birds going further south and west) and returns 
again in the spring. One definite case was noted in the 
course of this investigation ; a bird was killed at Shropham 
(near Thetford) by Mr. F. Mann’s gamekeeper, which had 
been ringed a few days before in Viborg, Denmark, by 
C. Mortensen who is investigating migration. It is the 
autumn migrants from abroad which do the damage to seed 
corn; for example, 10 average stomachs in November would 
contain 72 grains of wheat beside much corn husk. At the 
same time it ought to be pointed out that they are eating 
considerable numbers of insects, etc. To abate this plague 
there seem to be two courses open (since the birds are very 
difficult to scare off tiie fields) either (1) to dress the seed 
corn wiih something which will render it distasteful to birds ; 
or (2) as an extreme measure if (1) fails, to kill off the 
migrants in large numbers. With reference to (1) — experi- 
ments by the German Imperial Institute 14 have shown that 
corn dressed with Prussian blue, creolin or powdered aloes 
was distasteful to rooks. Numerous tar preparations have 
been put forward, but they seem open to the objection that 
as a rule they retard germination. With regard to (2) — It is 
a matter of general belief, and has been recorded by several 
observers, that starlings have increased enormously in 
numbers of late years. It has been suggested that this is 
due to a series of mild winters, but it may possibly be a result 
of their preservation in those places from which they migrate. 
It is probable that this increase in numbers has been out of 
proportion to that of their insect food so that wheat has been 
taken in order to eke out the diet. It should then follow 
ihat if their numbers were reduced, insect food would be in 
sufficient abundance to form the entire diet without the 
13. Saunders, H. and Newton, A. Yarrell’s British Birds, London, 
1882. 
14. See Jour, of Bd. of Agric. and Fish., Dec., 1909. 
