8 NATURAL HISTORY SOCIETY OF DUBLIN. 



land," does not venture further in his record of any species than " Of 

 occasional occurrence," and, indeed, the amount of information at his 

 disposal did not warrant him further. One of our most ohservant na- 

 turalists, whose loss we must all regret, Dr. Charles Farran, read before 

 you a valuable paper on the genus Skua.*' This has reference entirely 

 to the identification of species, and more especially to two specimens 

 of Skuas, captured in Dublin Bay. He does not touch on the sub- 

 ject of migration at all. 



Four species of Skua (Lestris) occur in Ireland. The first and only 

 species, as I conceive, we can justly claim as a regular visitor, being a 

 summer and autumn migrant here, is the {par excellence) Skua (X. catar- 

 rhactes). Although, as Thompson states truly enough, rarely obtained 

 on our coasts, its visits are not rare, and every year, in favoured locali- 

 ties, this bird may be seen here. In Dublin Bay, in autumn and the 

 latter end of summer, this dark-coloured rover of the sea may be an- 

 nually seen ; sometimes they, or stragglers from further north, occur 

 late into the winter. This very day (December 2, 1862) I have been 

 watching an immature Skua, which, from its size and colour, can be 

 nothing else but this bird, hovering over the bay near Sandycove. It 

 is also remarkable in another way. It does not occur in the United 

 States, nor is it recorded in the "Fauna Boreali Americani;'' but, on 

 the other hand, it is met as far south as the Falkland Isles, as low 

 down as 50° and 54° south latitude. I can testify personally to having 

 seen a species very like it nearly all the way across the South Atlantic, 

 and in the South Pacific Oceans. It breeds in the Scotch islands, and 

 possibly some Irish breeding place will yet turn up. This species has 

 been always, though indirectly, quoted as a regular migrant. 



The other three species, on the other hand, are all northern, and 

 their migration in this country, with the exception of one species, has 

 never been hinted at. 



The first of these is Richardson's Skua. This, according to authors, 

 breeds regularly in the Northern British Islands, and has bred at least 

 once in Ireland {vide Thompson). Thompson has recorded but few 

 instances of its occurrence here ; but Mr. Warren has shown that nearly 

 every year, in October, the birds migrate along the western shores 

 southward. All these appear to be on their passage, as they neither 

 feed nor iemain, as far as at present known, on the coast. Stragglers 

 occasionally do so, and these probably supply the specimens met in 

 Irish museums. 



The next in order of frequency of occurrence is certainly the Long- 

 tailed or Button's Skua. Of this species Lieutenant Crane was fortu- 

 nate to witness the migration northerly in the summer of 1860, so that 

 we may conclude a southern migration also occurs in the summer. The 

 migration this gentleman witnessed established a curious fact, as these 



* " Proc. Nat. Hist. Soc. Dub.," vol. i., p. 8 : Dr. C. Farran " On the genus Skua 

 (Lestridae)." 



