VOL. XIII.] THE BIRDS OF BARDSEY ISLAND. 193 



The ;Herring-Gull {Lams a. argentatus). 



' A summer resident in large numbers, and probably occurring 

 about the island in most months of the- year. The 'low cliff, 

 largely step like in character, beneath the steep grass slopes 

 and just above the tide-washed rocks on the north and east 

 sides of the mountain, form one huge Herring-Gull colony. 

 There are slight breaks here and there, caused by short areas 

 of precipitous rocks and caves, but the colony is practically 

 continuous the whole way round. Mr. Aplin suggests that 

 at the time of his visit a few pairs may have been breeding at 

 the southern point of the island, but there were none there 

 in 1913, nor could I find any elsewhere. 



The mortality amongst the young birds seems to be high. I 

 found several that had died from falling off the nesting shelf, 

 and any that wandered into the territory of another pair of 

 birds were unmercifully attacked, and if unable to reach shelter 

 eventually killed and eaten. Out of twenty-nine broods 

 ringed onl}^ eight consisted of the full number of young. 



There were always some thirty or forty Herring-Gulls about 

 the east bay, where they attended the arrival of the boats or 

 visited any of the fields where ploughing was going on. The 

 nesting birds were always in pairs ; so perhaps these were 

 birds that had lost their broods or had for other reasons given 

 up breeding operations. They were, with rare stray exceptions, 

 all fuUy adult. 



In September adults and immature birds were present in 

 large numbers, chiefly in the east bay, but a good many were 

 always round the coast, particularly at the south end. The 

 numbers present showed no fluctuation, but were considerably 

 less than the summer population. 



The British Lesser Black-backed Gull [Larus ftissus 

 affmis). 



Probably a regular double-passage migrant. 



Recorded by I\Ir. Coward, but not by Mr. Aplin . 



On June 23rd, 1913, a single bird was seen flying south 

 down the west coast. In September a single adult bird 

 appeared on the reef off the west bay on the nth. On the 

 next day there were two there in the morning and a dozen in 

 the afternoon, evidently a migratory party halting. On the 

 14th only one was left, and it had gone by the next day. 



[To he continued.) 



