HIGH MORTALITY AMONG YOUNG COMMON TERNS 273 



drought had come to an end before her visit on 

 27th July. 



(6) As regards the food-supply, this, in the case of the 



young Common Tern, seems to consist almost ex- 

 clusively of sand-eels. These may be found partly 

 swallowed by the young, or lying in the nests where 

 the parents have dropped them on being frightened 

 off. On one occasion I found a very small plaice in 

 the latter situation. A sand-eel which I took from 

 a bird only a day or two old, measured just 4 ins. 

 in length : it had been swallowed whole, and the 

 head was already partly digested, while the tail 

 protruded from the sides of the bird's beak. Mr 

 Ramsay has drawn our attention to the interesting 

 fact that the parents continue to feed the young on 

 the shore long after the latter can fly, in fact up to 

 the time of their departure from our coasts in mid- 

 September. 



(7) As an argument against scarcity of food being the sole 



cause of high mortality, I may quote Mr Ramsay's 

 note to the effect that " Among the Black-headed 

 Gulls which nest on Forvie Sands, an increased infant 

 mortality was also evident in 1910; but it was less 

 easy to estimate, owing to the fact that the gulls are 

 more scattered for nesting purposes than formerly, 

 and are much less numerous than the Terns." The 

 gulls have a much wider choice of food than the 

 Terns, and would not be affected by the same con- 

 ditions : a variety of insect food has been found in 

 dead young gulls of this colony. 



(8) Finally, Mr Ramsay believes that most of the birds of 



this and other local colonies left for the south 

 during the first half of August. Certainly only 

 occasional small parties were to be seen about the 

 coast after the 21st of that month. In normal years, 

 old and young are abundant in the first half of 

 September. A. L. T. 



36 2 M 



