566 THE BIRDS OF HELIGOLAND 



372. — Pomatorhine Skua [Kugelschwanzige EaubmOwe]. 

 LESTRIS POMARINA, Temminck.i 

 Heligolandish : Uhr-grootst Skeetenjoager = /Scco?Mi largest Skua. 

 Lestris pomarina. Naumann, x. 487. 

 Pomatorhine Skua. Dresser, viii. 463. 

 Stercoraire pomarin. Temininck, Maimel, ii. 793, iv. 495. 



In spring tlie points of the two prolonged central tail-feathers 

 of this species become twisted half-round their shafts, causing the 

 terminal portions of the webs to assume a vertical position, and 

 giving one the impression, when the bird is viewed from some 

 distance, as though it had a globular appendage to its tail. At 

 this season of the year the species is of very rai'e occurrence in 

 Heligoland, having only been shot on two or three occasions 

 during all the time I have been observing thei'C. Young autumn 

 birds, on the other hand, in all stages of j^hmiage, from the 

 uniform blackish-bi'own to the variegated dress spotted with 

 rusty-grey - (rostgrau), occur annually in October and November, as 

 a rule very frequently, and sometimes even very numerously, as 

 for instance in November 1879. I do not remember having ever 

 seen old birds during the autumn months. 



Of the nesting stations of this species very little is known. 

 They are situated on the continent or islands adjacent to the 

 Pole; probably in largest numbers between the Pole and the 

 Jeannette Islands, near the still unknown breeding stations of 

 Tringa islavdica, Larus rossii, and other species already treated of. 

 Von Middendortf found the nest and eggs in the Taimyr Peninsula 

 in 74° N. lat. Dr. Bunge saw the bird still migrating towards the 

 north on Great Lhiakov Island in New Siberia at the end of 

 June, and Ross met with it as high as 82° N. lat. 



373. — Richardson's Skua [Sciimarotzer-Eaubmowe]. 

 LESTRIS PARASITICA, Illiger.^ 

 Heligolandish : Skeetenjoager = iS7cua ; lit. Predaceous Gull. 

 Lestris parasitica. Naumann, x. 506. 



lUchardson's Skua. Dresser, viii. 471. 



Stercoraire Richardson. Temminck, Manuel, iv. 449. 



This is the commonest of the Skuas visiting Heligoland, and 

 this statement applied with even greater emphasis in those earlier 



' StercorariuK pomalorhimi'' (Temin.). 



- Buff-coloured brown. Yai-rcll, liritinh Biidn, vol. iv. p. G72. 



" Utercorariux crepidatus (Gniel. ). 



