VERTEBRATE FAUNA OF HOUTMAN's ABROLHOS. 469 



numbers of these birds. During the daytime they are to be seen flying over 

 the sen in the neighbourhood of the islands in small or large flocks. We 

 saw them on one occasion in pursuit of a shoal of fish, on which Roseate 

 Terns, Dolphins, and Bonetas were also levying toll. Unlike the Terns, 

 which dive straight down, the Mutton-birds first settle on the water and then 

 plunge under, apparently with the assistance of their wings. When rising 

 from the water the wings are half-spread, but not flapped, and the bird gets 

 up the velocity required to start it in flight by paddling along the surface 

 with its feet. 



On the islands they appear from their burrows in great numbers as soon 

 as it is dark, uttering the most weird and mournful cries. They are unable 

 to stand on the ground, or to walk, so that they are obliged to use their 

 wings, by whose aid they shuffle about among the bushes in a most awkward 

 manner and are readily captured. They seem to be attracted by a light, as 

 they often flew round the ship in the evening and once- or twice came on 

 board. 



On many of the islands, especially West Wallaby Island and the southern 

 end of Pelsart Island, their burrows are so numerous that when walking over 

 the areas inhabited by them one sinks in, almost up to the knees, at every 

 step. Their burrows were also seen on Rat Island, Long Island, and one of 

 the Pigeon Islands. Fresh eggs were found in them on Pelsart Island, and 

 Mr. Lipfert obtained them on Gun Island. 



During one moonlight night I spent some time watching a Mutton-bird 

 excavating a burrow in the sand. It used its feet alternately, throwing out 

 an almost continuous stream of sand behind it to a distance of about a yard. 

 The burrows when completed extend to a distance of two or three feet into 

 the ground at an angle. 



It strikes one as very remarkable that though the legs of these birds are 

 not strong enough to support the weight of their body, yet they can be used 

 for shovelling away sand continuously, apparently for hours. Moreover, 

 they can use them as paddles on the water sufficiently rapidly to raise them- 

 selves from the surface when about to fly. 



Macronectes giganteus ALBUS {Polls'). Giant Petrel. 



A specimen in the W.A. Museum was obtained at the Abrolhos in 1804. 

 < lampbell states (10), on the authority of Beddoes, that they visit the islands 

 every winter, which is not improbable, as they occur off Fremantle every 

 year during that season. The subspecific name which Mathews uses for the 

 New Zealand and Australian form is singularly unfortunate, aSj so far as 

 T am aware, every specimen obtained in Western Australia has been com- 

 pletely dark in plumage without a single white feather. There are six 

 specimens in the W.A. Museum, and 1 have seen remains of several others 

 washed up on the beach. 



