20 40 Proceedings of the Ro>/al Irish Academy. 



round the coasts of Donegal and Gonnaught this species has numerous 

 colonies on marine islands, some very large, the nesting-ground being 

 occasionally shifted. Warren found that in 1904 the nest:; had increased 

 to 800 or 1000 on the beach inside Bartragh on the Moy estuary. Arctic 

 Terns breed also on the great lakes of Mask, Carra, and Corrib, where 

 they probably outnumber the Common Terns, as they certainly do on 

 the coasts. 



Sterna minuta, Linn. Littlk Tern. — Foster and Ussher found two colonies 

 on gravelly reefs in Clew Bay, twenty-five nests on one ; on Inishkea 

 several pairs were breeding. Many nest on Bartragh, and there are 

 colonies on sandy shores in Donegal, Sligo, Connemara, and the Aran 

 Islands, but this species is more local and far less numerous than the 

 Common and Arctic Terns. 



Larus ridibundus, Linn. Black-headed Gull. — Arrives on Clare Island in 

 very small numbers in June and July after breeding, when it becomes 

 common on Clew Bay, Achill Sound, and generally on the coasts and 

 estuaries. The only breeding-place recorded on a marine island is on 

 Beginish, one of the Blaskets, now apparently abandoned (Praeger). 

 This Gull nests on islands of fresh-water lakes near the coast of Donegal 

 and near Killala Bay, and further inland is greatly increasing on lakes 

 and bogs. 



Larus canus, Linn. Common Gull.— Another increasing species, which 

 breeds on islets of lakes near the coasts of Donegal, Mayo, and Con- 

 nemara, on one island oft' Kerry, on Inishkea. and near Inishbiggle in 

 Achill Sound. After the breeding- time a few are. to be seen about 

 Clew Bay and the harbour of Clare Island. 



Larus argentatus. J. F. Ginelin. Hekkixg-Gull. — Common and- resident, 

 breeding in small colonies among the other sea-birds (for want of 

 separate space) along the cliff-face of Clare Island. About a dozen 

 pairs breed in company on The Bills, and on the cliffs of Achill there 

 are other colonies, where Patten saw a flock precipitate themselves 

 towards the sea for mere sport with closed wings, spreading them to 

 stop their course just before immersion, and then rapidly reascending 

 with spiral flight. They nest on Inishturk, Inishark, and probably on 

 every rocky coast and many an island round Ireland. 



Larus fuscus, Linn. Lksskk Black-backed Gill. — Occasionally seen on 

 Achill Sound and about Belmullet. "Wallace once saw there a flock of 

 twenty-one. Three were seen among crowds of Herring Gulls at Inishkea 

 whaling-station. Breeds on some marine islands off Donegal and Kerry, 



