ii4 ANIMAL LIFE UNDER WATER 



ing the real numbers of food fishes destroyed by 

 gulls. 



In December, 1913, my brother and I stayed 

 at Aldeburgh, and on one morning examined 

 four birds in the bay. The first was a kittiwake ; 

 in it there were nine recently taken sprats in 

 the gullet, and the gizzard contained the bones 

 shown in the first row on the plate opposite. 

 These are portions of two whiting otoliths, seven 

 bony globules, and the bodies of four vertebrae. 

 The margins of the otoliths were still indented, 

 so that we could be quite certain this kittiwake 

 had taken a small whiting and four sprats 

 earlier in the day in addition to those in the 

 gullet. 



The second kittiwake examined was an 

 immature bird, and had three sprats in the 

 gullet, and among the debris in the gizzard were 

 whiting otoliths and bones, as shown in the 

 second row, indicating that the bird had taken 

 these fish recently. 



The third and fourth birds, a kittiwake and 

 a common gull, when shot, hung their heads 

 under the water and continued to swim, a sure 

 sign that they were disgorging. The gullets of 

 both these birds were, in consequence, empty ; 



