GULLS 115 



but the gizzards contained the bones shown in 

 the third and fourth rows, which read respec- 

 tively : a whiting earlier in the day, and a 

 whiting and sea urchin the day before; the 

 second bird, two whiting and four sprats. That 

 this last bird had recently taken fish which it 

 had disgorged is proved by the two vertebrae, 

 which show complete processes. 



To arrive at an estimate of the fish that the 

 gulls were taking in Aldeburgh Bay on that 

 morning, I have argued as follows : Two con- 

 tained twelve fish, two disgorged; it is fair to 

 presume these latter had taken an equal number 

 of fish. From the otoliths and bony globules 

 found, we can be certain that the four had taken 

 twelve food fishes earlier in the day — that is, a 

 total of thirty-six whiting and sprats by noon. 

 The flock of gulls in Aldeburgh harbour follow- 

 ing up the sprats was certainly not less than 

 20,000 in number, which gives an estimate of 

 180,000 food fishes taken by noon. Gulls were 

 feeding in a similar manner all round the east 

 coast at this time. 



How easy it is to miss a fish taken by a gull 

 earlier, and subsequently followed by other food, 

 is shown on the lower half of the same plate, 



