112 BRITISH BIRDS. [vol. ix. 



an unoccupied nest \\'as situated near the blind : it had 

 probably been constructed by a pair A\hich liad eggs in a 

 nest about four yards further away. This was certainly 

 strongly suggested by the behaviour of one of the Gulls 

 belonging to this nest. Into this unoccupied nest I put 

 a clutch of three Gulls' eggs. As soon as quietness had 

 been estabhshed, one of the Gulls came from the near-by 

 nest to these eggs and touched them a\ ith. its beak with- 

 out doing them any harm. A Crow then flew down 

 towards these eggs, but was driven off by the Gull that 

 had come up to the nest, assisted by another which had 

 a nest in- the vicinity. The GVow, undiscouraged , tried 

 agam, but Avas driven ofP by the Gull that came first to 

 the nest, and A\'hich had e\ddently taken the eggs under 

 its protection. In a short space of time the CVow made 

 two more attempts to gain the nest, edging gradually 

 towards it, though apparently thinking of anytliing but 

 the nest, the sly thief. At the second attempt the Crow 

 with a quick thrust evidently pierced one of the eggs 

 before he was driven off and pursued several yards by the 

 Gull. The Gull on retummg philosophically devoured 

 the damaged egg itself ! 



Another C^ow haAoiig arrived (probably the mate of 

 the first), both made repeated attempts to reach the 

 nest, but the Gull (;hased them off : most of the time 

 it stood on guard about a yard from the nest, once 

 standing on it for a short time. 



Wlienever a Crow ventured near, the Gull chased it 

 off with upraised wings. However, whilst the (JuU was 

 chasing one Crow the other reached the nest and was 

 there some seconds, helping himself to an egg ; the Gull 

 on its return drove the Crow off and ate the remains of 

 the egg itself. For the rest of the afternoon the Gull 

 was successful in its end(^avours to guard the remaining 

 egg, though the CroAV made repeated atteuqits to rea.ch it. 



This shows clearly that the Gulls cannot ])r()te{t their 

 eggs by simply guarding thom. The first Crow to reach 

 the nest was only there an instant, but it pierced an egg. 



