42 VOYAGES OF A NATURALIST 



coloured back and head, with white, or in some 

 individuals grey, underparts. These birds were 

 just commencing to breed in the holes and crannies 

 in the rocks. The other petrel (CEstrelata trini- 

 tatis), which is dark brown all over, with black 

 legs and feet, was less numerous, but higher up the 

 ravine a few were tending their well-grown young, 

 which were sitting in hollows in the rocks and under 

 overhanging ledges. The young birds were covered 

 with long thick brownish-grey down, and resembled 

 big " powder-puffs." They were extremely fat, 

 and when handled they ejected a greenish fluid 

 from their tube-like nostrils. The old birds 

 circled overhead in great numbers and screamed 

 at us angrily. 



Occasionally a long bubbling note, not unlike 

 the call of a female cuckoo, was heard. This note 

 was only uttered by the Wilson's petrels. The 

 plumage of the birds of this species showed two 

 distinct varieties or " phases." The majority 

 had pure white breasts, but many others had these 

 parts of a smoky-grey colour : these may have 

 been younger birds. I caught many pairs of 

 Wilson's petrels at their nesting-places, and in 

 every case the birds had white breasts, and 

 although I handled a good many petrels (a hundred 

 at least) on South Trinidad, I never found a light- 

 breasted bird in company with a dark-breasted 

 one. It may well be, therefore, that the dark- 

 breasted ones are birds not fully adult. All these 



