74 



E. LÖNNBERG. CONTRTBUTIONS TO THE FAUNA OF SOUTH GEORGIA. 



Its burrows look in section as the accompanying diagrainmatic sketches show. The 

 burrows were always crooked. And it looked sometimes as if the bird had dug 

 searching for a suitable place under a stone. The nest is, namely as a rule, situated 

 below a somewhat larger, flat stone. Usually there is no bedding at all, but some- 

 times a few (2 — 3) straws of tussock-grass are found. Before the egg was laid, Sör- 

 ling found both birds m the burrow, but as soon as the egg was laid, only one bird 

 was present, sitting on the egg, and that was, in the cases investigated, the female. 

 Pelecanoides urinairix like Trion did not dåre to show itself över or near land 

 during day-time. On the open sea it was, however, very numerous swimming and 



flying. When flying it looks almost more 

 like a member of Älcidcé than a petrel. 

 It is subantarctic not extending to the real 

 ice-region. At the South Orkney Islands 

 it was not recorded by the Scottish Ex- 

 pedition (21). 



Fig. 6 



Pelecanoides exsul Salvin 1896. 



1 <j> Boiler Harbonr, Cnmberland Bay, the 15 of 

 April 1905. »Iris black». 





Fig. 6 b. 



Diagrammatic sketches showing the burrow of 

 Pelecanoides urinätrix. 



This bird flew against the rigging, fell 

 down in the anchor-store and was caught 

 that way. This was the only specimen 

 which Sörling with certainty observed as 

 belonging to this form. This is a little 

 peculiar as the three specimens of Pele- 

 canoides collected by the Swedish Antarc- 

 tic Expedition 1902 at South Georgia in 

 the same locality all of them were just as 

 typical exsul (9) as this one with regard 

 to the colour of the plumage. When both forms inhabit the same locality and the 

 only difference between them consists in that exsul has the feathers of the fore- 

 neck provided with a grey subterminal bar, the feathers of the flanks with a grey 

 shaft, and the under wing-coverts with dark shafts, while urinätrix is pure white on 

 the parts mentioned, it appears to me that it is rather probable that these two kinds 

 of birds are not specifically different but only dark and light phases of the same 

 species, in an analogous manner, as for instance, Fulmarus cjlacialis and the Common 

 Skua [Stercorarius parasiticus (Linné)] have a dark and a light phase. As only nrina- 

 ///.r-specimens were found in the burrows it might be possible that exsul is the 

 immature not breeding bird. 



