S78 DISCOVERY REPORTS 



Garrodia nereis, Gould 

 Grey-Backed Storm Petrel 

 This petrel was found on South Georgia by the German Expedition of 1882-3 

 (Pagenstecher, 1885, p. 18) and by Mr Erik Sorling (Lonnberg, 1906, p. 84) in 1904, 

 but it was not seen during the course of the Discovery investigations. The German 

 Expedition found that it nested at Royal Bay in burrows on bare screes, and recorded 

 that it left the island with the young at the end of April. Mr Sorling shot an example 

 as it flew from a tussac hill in Moraine Fjord, Cumberland Bay, on November 27th, 

 1904. He was unable to find the nest, which was evidently there, as the bird, a male, 

 had bare brood spots on the belly. He also found the dried up remains of a half fledged 

 young one of the previous season at Grytviken in the same month. 



Genus Prion 

 Whale Birds 



Whale Birds are extremely common at sea off the island, flying over the waves in 

 large flocks. They breed abundantly ashore but are never seen on land during daylight, 

 as they are there nocturnal. Three species are recorded from the island, and the following 

 notes apply equally to all. 



They feed on small planktonic animals, swimming on the surface with outstretched 

 wings, occasionally diving below it, and scooping up their food into the pouch-like 

 mouth and straining off the water through the lamellae of the bill as described by 

 Wilson.^ The flocks at sea fly and turn together like those of some of the northern 

 sandpipers; as they wheel round all the white breasts flash at once and then simul- 

 taneously disappear as the darker back is shown. 



Ashore they are found nesting in burrows dug amongst the tussac, all round the 

 island, on low ground as well as on hills and headlands. The burrow is not more than 

 three feet deep in the peaty earth and is about three inches in diameter, ending in a 

 small chamber. No nest is made, the single white egg being laid in a hollow of the 

 earth in the terminal chamber. Most of the eggs are laid at the end of November, but 

 some not until well into the following month. Before the egg is laid both birds are 

 usually in the burrow in the daytime, but afterwards the writer has found only one bird, 

 though other observers have found as many as three. When in the burrow the birds make 

 a low grunting noise. If they are pulled out of it they bite and scratch vigorously. 



Whale Birds are killed in large numbers by the Antarctic Skuas, and for this reason 

 they are nocturnal when ashore. 



Prion vittatus, Gmel. 

 Broad-Billed Whale Bird 

 This species is recorded as breeding on the island by Mr A. G. Bennett, the Govern- 

 ment Naturalist of the Falkland Islands. 



^ Wilson, E. A., Report of the National Antarctic Expedition, 1901-4, Vol. 11. Zoology, Pt u. Aves, 

 p. 105, fig. 45. 



