116 BRITISH BIRDS WITH THEIR NESTS AND EGGS. 



to Mr. Wolley, a certain number of heads were required to be sent in by every 

 inhabitant annually. " I do not know," he says, " if this is now strictly enforced ; 

 but I have seen the people collect heads, when they had the opportunity, either 

 of this bird, or the Raven, or the Great Black-backed Gull that is when they 

 were ready killed for them." A less precise injunction has been so efficacious in 

 our islands as to reduce the numbers of these birds almost to the vanishing point. 

 But for the magnanimous protection given to them on the Shetlands, they would 

 by this time have long ago ceased to exist as a British Bird. 



Family -S TERCORARIIDsE. 



POMATORHINE Sl<UA. 

 Stercorarius pomatorhinus, TEMM. 



THIS very fine bird is often named the Twist-tailed Skua, from the two much 

 elongated central feathers of the tail being twisted on their shafts, so that 

 the terminal part of the web stands vertical, and looks as if it had a "bob" to it. 

 This peculiarity, however, is an excellent mark for identifying the bird by when on 

 the wing. The Pomatorhine Skua is a very rare breeder in our islands, if indeed 

 it has ever really done so. In their " Fauna of the Outer Hebrides," Harvie- 

 Brown and Buckley note that: "Though believed to breed, or to have bred, in 

 the Outer Hebrides, there has been no corroborative evidence since Gray wrote ; 

 but there cannot be any doubt as to its frequent, if not regular, summer visits to 

 the coasts of these islands, and the seas to the west of Lewis." It is an autumn 

 and winter migrant, and a few are to be seen along the entire coast lines of 

 England and Scotland almost every year. Occasionally large flocks occur, the 

 coasts of Yorkshire being apparently a favourite rendezvous ; and sometimes a few 



