^°'i9^2^'] FALLA, \'.Z. Petrels ]\-ashcd Ashore. 207 



found dead on the tide-mark, but, like nearly all the species men- 

 tioned, only during the summer months. 



Pterodroma lessoni. White-headed Petrel. — The remains of this 

 bird may often be found on the west coast beaches durinfj: the summer 

 months. 



Pterodroma cooki. Cook Petrel. — Dead bodies cf Cook Petrel are 

 common on the beaches in summer, and also those of similar species, 

 whose minor differences it is difficult to detect in the mere bundles 

 of bones and feathers which are usually cast up by the sui"f. 



Macronectes gigantea. Giant Petrel. — A regular winter visitor to 

 both coasts of this district, venturing into all the bays and harbours. 

 Here in Auckland they may sometimes be seen circling about within 

 a few yards of the wharves, fighting with the Black-backed Gulls for 

 scraps. They appear in May and leave again in October, although 

 they are absent for a few weeks in mid-winter, evidently going still 

 further north. Their migratoi-y movements thus seem to coincide 

 with these of whales, although probably not so extensive, the latter 

 going as far as Norfolk Island. Dead birds may often be picked up 

 during the early summer. 



Prion.s (all species). — During the winter months, these birds, with 

 an occasional Albatross, are the only Petrels found on the beach. During 

 westerly gales, all four species, with apparently intermediate varie- 

 ties, perish in hundi'eds, being found miles inland, and often blowing 

 right across the island from the west to the east coast. I have not 

 met with specimens of the Blue Petrel [Halobcena ccerulea), but have 

 heard that they occasionally suff"er in the same way. Prions also wash 

 ashore with the other Petrels mentioned during the summer months, 

 when bodies of Prion turtur are more commonly found. 



Pelecanoides urinatrix. Diving Petrel. — The usual December batch 

 of dead Petrels always includes a few of these little birds, in very 

 worn plumage, especially on the wings. 



Albatrosses. — Except for the Wandering Albatross {Diomedca 

 exulans) and the Black-browed {D. mclanophrys) of which occasional 

 specimens are found throughout the year, I have so far been unable 

 to identify with cex'tainty all the birds of this family found. Unless 

 obtained quite fresh, the colours of bill and feet are veiy uncertain, 

 while the comparatively loose plumage is soon blown off, leavmg only 

 a skeleton. The combined effect of hot sand and salt watei on the 

 bodies of smaller birds is to mummify them, thus rendering identifica- 

 tion fairly easy, but this is not the case with the Albatrosses, whose 

 remains are vei-y soon scattered. 



Consideration of the time of year at which the majority 

 of birds above mentioned perish, seems to show that, except in 

 the case of the Prions, heavy weather and gales are not 

 an important cause of mortahty among Petrels. In the 

 case of species breeding locally it may be that the dead 

 birds are the unfortunate surplus left over after a crowded 

 breeding place has been fully occupied, but in the case of Petrels 

 which breed further south it is more probable that the birds found 

 are the stragglers of a migratory movement, who, through acci- 

 dent or weakness, lag behind while the others move south, and 

 finally are caught in uncongenial conditions of summer weather 

 off our coasts, with their usual food supply no longer so 

 abundant in these waters as it was during the winter — Nature's 

 method of weeding out the unfit. 



