PRIOFLNUS CINEREUS. 



Peru, and the mouth of the Plate River. It is believed to breed in September on 

 Kerguelen Island, the authority being Lieut. R. Harris, R.N., who was wrecked there 

 in 1832. 



The Great Grey Shearwater, or Black-tailed Petrel, as it is called by the American 

 naturalists, is of large size, and differs in its habits from many of the true Shearwaters. 

 Professor Giglioli says that it can be distinguished, even at a long distance, by 

 its more dipping flight, which Mr. Robert Hall compares with the wheeling 

 motions of an Albatros. Darwin relates his experience of this Shearwater 

 when on the " Beagle," and says that it frequented the retired inland Sounds in 

 very large flocks, although occasionally two or three might be seen out at sea. He 

 writes :— " I do not think I ever saw so many birds of any sort together, as I once 

 saw of these Petrels behind the island of Chiloe. Hundreds of thousands flew in an 

 irregular line for several hours in one direction. When part of the flock settled on the 

 water, the surface was blackened ; and a cackling noise proceeded from them as of 

 human beings talking in the distance. At this time the water was in parts coloured 

 by clouds of small Crustacea. ... At Port Famine, every morning and evening, 

 a long band of these birds continued to fly with extreme rapidity up and down the 

 central parts of the channel, close to the surface of the water. Their flight was direct 

 and vigorous, and they seldom glided with extended wings in graceful curves, like most 

 other members of this family. Occasionally they settled for a short time on the water ; 

 and they thus remained at rest during nearly the whole of the middle of the day. 

 When flying backwards and forwards at a distance from the shore, they evidently were 

 fishing, but it was rare to see them seize any prey. They were very wary, and seldom 

 approached within gunshot of a boat or of a ship ; a disposition strikingly different from 

 that of most of the other species. The stomach of one, killed near Port Famine, 

 contained seven prawn-like crabs, and a small fish. In another, killed off the Plata, 

 there was the beak of a small cuttle-fish. I observed that these birds, when only slightly 

 winged, were incapable of diving." 



That they are able to dive, however, is proved by the observations of Dr. E. A. 

 Wilson, who says that they " drop suddenly beneath the surface of the water, with 

 their wings spread, to seize some scrap of food. They unhesitatingly go completely 

 under, and reappear with their wings still spread." Sir Walter Buller also confirms 

 this diving habit. 



Adult. General colour above ashy-grey, with obsolete margins of hoary-grey to 

 the feathers of the upper-surface, these margins whiter on the scapulars, which are a 

 little more dusky than the back ; wing-coverts like the back, the median and greater 

 series darker brown, with hoary-grey margins ; bastard-wing, primary-coverts, and 

 quills dusky-brown, shaded with ashy-grey ; innermost secondaries browner, like the 

 scapulars, and, like the latter, narrowly fringed with whitish ; tail-feathers black, ashy- 

 grey on the inner webs ; crown of head dusky-black, greyer towards the nape, the 



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