Irish Ornithology. 407 



contained three eggs, but the others contained only two eggs 

 each. We left one of the latter, hoping to find a third egg 

 on a future occasion, but when we revisited it the next day 

 the two eggs were gone, and we found the broken shells lying 

 on the rock not far off, probably eaten by one of the smaller 

 species of Gulls, possibly in revenge for a similar act of 

 robbery. It is curious that the Great Black-backed Gull 

 should be so rare. It is the largest and the strongest 

 of the Gulls which breed in the British Islands. It 

 seems to have the pick of the breeding-places, and one 

 would suppose that it had no enemies that it need fear. It 

 seems to stand sullen and proud and solitary amongst the 

 smaller species. Perhaps the reason of its comparative 

 scarcity is to be found in its unsocial habits. It may not 

 yet have learnt the security that is to be found in numbers. 

 The Herring Gull (Larus argentatus) is a smaller bird, but 

 it is very gregarious. There were thousands of pairs scat- 

 tered over the island, some breeding on the level pasture, 

 others on the steep grassy slopes, whilst a few invaded the 

 colonies of Razorbills and made their nests amongst the rocks. 

 The Lesser Black-backed Gull (Larus fuscus) was much less 

 numerous, and was principally confined to one valley, which 

 sloped gently down to the top of the cliffs. Most nests of both 

 these species contained three eggs, but we found one nest of 

 the Herring Gull containing four eggs. We took one very 

 handsome clutch of the Lesser Black-backed Gull containing 

 three blue eggs, with scarcely a spot on them. These large 

 Gulls were very noisy whilst we were near their nests. 



There are several colonies of Cormorants (Phalacrocorax 

 carbo) on the island, one of them on a lofty pile of granite 

 rocks separated from the main island by a narrow channel. 

 Mr. Ussher swam across and climbed up to the colony. 

 Most of the nests contained young birds nearly as big as 

 their parents, and covered all over with sooty-black down. 

 Some of the young birds were very small, and their slaty- 

 black skins were absolutely naked. A dense crowd of Guille- 

 mots, each sitting upon its solitary egg, filled up the space 

 between the Cormorant's nests. The top of the rock and 



