SKUA. NATATORES. CATARACTES. 521 



IN its young state, as the Black-toed Gull (Larus crepi- Periodical 

 datus) of authors, this species is not of unfrequent occur- 

 rence, during the autumnal months, upon the northern coast 

 of England ; to which it is attracted by the Gulls that fol- 

 low the shoals of herring on their approach to the shallows, 

 for the purpose of depositing their spawn. Like the other 

 Skuas, it obtains the greater part of its subsistence by con- 

 tinual warfare on the above-mentioned birds ; vigorously Food, 

 pursuing and harassing them till they are compelled to dis- 

 gorge the food previously swallowed. In this occupation its 

 dark plumage and rapid flight are certain to attract the at- 

 tention of the spectator ; and there are few probably who 

 have visited the coasts of Scotland, and the northern districts 

 of England, who have not witnessed and admired the aerial 

 evolutions of the Teazer, and the distress of its unfortunate 

 object of attack. It is but very rarely met with beyond the 

 precincts of the Shetland and Orkney Isles in its adult state, 

 and only one instance has occurred within my own observa- 

 tion, viz. on an excursion to the Fern Islands in the month 

 of May, when two of these birds flew ahead ofrthe boat in a 

 northerly direction; and which were perfectly distinguish- 

 able by their lengthened and slender middle tail-feathers, 

 and the black and white of their plumage. This Skua does 

 not appear to be a permanent resident in any part of the 

 British dominions, for Low, in his " Fauna Orcadensis," de- 

 scribes it as a migratory bird, arriving there and in Shetland 

 in May, and departing in autumn, or as soon as the duties 

 of reproduction have been effected. From its absence, in 

 the adult state, from our southern coast, it would seem that 

 the line of its winter migration is more to the eastward ; and 

 this agrees with the statement of TEMMINCK, who gives as 

 its habitats the shores of the Baltic, of Norway and Sweden. 

 It breeds upon several of the Orkney and Shetland Isles, 

 and is gregarious during that period ; and the situations se- 

 lected for nidification are the unfrequented heaths at some 

 distance from the shore. The nest is composed of dry grass N est, &c, 



