138 THE ESSEX NATURALIST. 
Commenting on the above observation, Mr. E. W. H. Blagg 
suggests that the wood pigeon probably casts pellets only at 
certain seasons of the year, when it has been feeding upon certain 
kinds of food. He adds: ‘‘ A few days ago (May r4th), I found 
several ‘ castings ’ of this bird, composed chiefly of the husks of 
oats.’’92 
A pellet of this bird in the Essex Museum, picked up from 
beneath a roosting tree, in March 1910, is made up entirely of 
seeds of Holly. 
CURLEW. 
Mr. R. Elmhirst, in 1915, described how he found, on a 
favourite roosting-place of Curlews, numerous pellets, composed. 
chiefly of fragments of quartz and shells, which he reasonably 
assumed to be castings of this bird. He describes them a; “‘ about 
one inch long by half an inch broad, and consisting of 30 to 40 
small bits of quartz, and weighing about four grains : some of 
them contain a few bits of shell, and one consists almost entirely 
of shell.’’93 
Mr. J. E. Harting records that he extracted cockles of large 
size, with the shells unbroken, from the stomach of a Curlew, 
and he wondered how they could possibly have been swallowed 
whole.9+ Specimens of entire shells of Cardium taken by Mr. 
Harting from a Curlew’s stomach are in the Essex Museum, 
the size of the largest being 22 mm. by 20 mm., and another 
measuring 20 mm. by 18 mm. 
TERNS. 
Mr. H. W. Robinson states : “I have studied very carefully 
the food of Terns, and handled over two thousand young ones, 
the majority of which regurgitated the contents of their crops. 
The chief food of the common Tern consists of young herrings, 
with a fair number of whiting, and also a few young codling, 
lumpsuckers, and long rough dabs.”’ (In Yorkshire Post, quoted 
in NATURALIST, July I, 1920, p. 208). Mr. Robinson does not 
say, however, if this regurgitated food takes the form of pellets. 
BLACK-HEADED GULL. 
Pellets of this species are of common occurrence on the 
feeding-spots. Useful testimony to the beneficial character of 
92 Ibid. p. 236. | 
93 Zoologist, 1915, p. 7I. 
94 Zoologist, 1884, p. 68. 
