78 RESIDENTS AND MIGRANTS. 



COMMON SKUA. Lestris catarractes (Linnaeus). 



Thirty years ago there were three separate breeding- 

 stations in the Shetlands : one is now completely de- 

 serted ; and in the other two the birds which resort 

 there to nest are annually becoming less numerous. 

 Towards the approach of winter this species migrates 

 southward ; and it is at this season of the year that it 

 is most frequently met with in Great Britain. 



BICHAKDSON'S SKUA. Lestris parasiticus (Linnaeus). 



Breeds in Sutherland and Caithness, and in all three 

 groups of the Scottish Isles. Migrates to the more 

 southern British coasts after the breeding-season. 

 Some interesting remarks on this species by Mr. L. 

 Edmondston will be found in vol. vii. of the Edinb. 

 Phil. Journal for 1822. 



BUTTON'S SKUA. Lestris longicaudus, Vieillot. 



An occasional visitant, chiefly in autumn. A good 

 account of the breeding-habits of this species, as 

 observed in Lapland, will be found in Wheelwright's 

 ' Spring and Summer in Lapland,' pp. 355-359. 



POMATOEHINE SKUA. Lestris pomatorhinus *, Tem- 

 minck. 



First noticed as a British bird in the sale catalogue 



* The specific name of this bird is generally written " pomarine," 

 "pomarinus ; " but the above is the correct orthography : th. 

 s, o%>erculum, and pis, piros, nasus. 



