736 FRIGATE-PETREL. 
of New Zealand, and in other similar places. The ‘Challenger’ 
Expedition found it in burrows on Nightingale Island, one of the 
Tristan da Cunha group, in the South Atlantic ; while as a wanderer 
northward it has occurred on the coast of Massachusetts. 
Mr. Grant obtained many specimens from the burrows on the 
Great Salvage Island, and there, strange to say, the sitting birds are 
often killed and have their brains eaten by mice, which also suck 
the eggs. Out of twelve sitting birds three were males; and the 
most advanced eggs were but half-incubated on April 27th. These 
were white, more or less finely spotted—and often zoned towards 
the larger end—with dark red and purplish dots, but a few were 
uniformly spotted all over the shell: measurements 1°4 by 1 inch 
(f- Ibis 1896, pp. 51-53). On the Rombos islets, belonging to 
the Cape Verde group, Mr. Boyd Alexander found that all the 
incubating birds were females ; three males, which were also captured 
in the burrows, being merely “keeping company.” Here, as on the 
other islets, breeding was earlier than in the Salvages. The birds 
which were disturbed ran along the ground in a dazed condition, 
and were promptly picked up by Black Kites; in fact the general 
evidence seems to be that this species is very nocturnal in its habits. 
The note is described as grating, or grunting. 
The adult has the crown of the head, nape, and a patch behind 
the eye dark slate-grey ; forehead, lores and eye-stripe white ; upper 
part of mantle grey, wing-coverts brown, quills blackish ; lower back 
and tail-coverts clear grey, with some white at the bases of the 
feathers ; tail-feathers black, ashy at their bases; under surface 
white, mottled with grey on the sides of the neck, flanks, and 
under tail-coverts; bill and feet black; webs of toes yellow. 
Length 7°75 in.; wing, 6°25 in males and 6°38 in females. 
