48 OCEAN BIRDS. 



their behaviour, as they are just as easy to catch iu the clay-time. It is thus described 

 by Gould, in his 'Birds of Austraha,' under the title of Sidafusca: — 



" The plumage of the two sexes is so precisely similar that it is utterly impossible 

 to distinguish them by external observation ; it is true that the colouring of the feet, 

 face, and other soft parts is not always alike, but this difference I believe to be the result 

 of age, rather than of a difference in sex ; and if this opinion be correct, the bright 

 yellow-coloured feet are indicative of the bird being fully adult, and the olive-brown of its 

 being immature. Head, neck, breast, aU the upper surface, wings and tail dark chocolate- 

 brown ; under surface pure white, separated from the brown of the breast by a sharply 

 defined line ; irides very pale yellow, blotched before and beneath the eyes with bluish ; 

 eyelash light ash-grey; legs and feet pale yellow." 



Messrs. Sclater and Salvin, on birds collected by H.M.S. 'Challenger' (Proc. Zool. Soc. 

 1878, p. 651), describe two specimens as follows : — 



"Specimen 141, male, Eaine Island. Eyes grey; feet light green; bill bluish towards 

 the base, white at the tip." 



" Specimen 610, female, at sea. Eyes white or light grey. Stomach had cuttle-fish ; 

 feet yellow with green tinge ; bill flesh-colour, cere greenish." 



As might be expected of such a bird, it lays its one egg on the bare rocks. Sometimes 

 this dainty is devoured by a Hermit-crab, which allows itself to be sat upon during the 

 process, persuading the boobyish mother it is another egg ! 



The Eed-legged Gannet {Sula piscatrix). — This Gannet may be met with as we near 

 Australia. It is easily recognised by its red legs and the red at the basal part of bill. 

 It is considerably smaller than the rest of the species, and is therefore often called the 

 "Lesser Gannet." It is thus described by Gould, in his 'Birds of Australia': — "The 

 adults have the entire plumage huffy white, with the exception of the wings and tail ; the 

 former of which are blackish brown, washed with grey, and the latter pale greyish brown, 

 passing into grey, with white shafts; irides grey; legs and feet vermilion." In the young 

 bird the white is a dull brown. 



Messrs. Sclater and Salvin, in the 'Proceedings of the Zoological Society' for 1878, 

 thus describe a specimen collected by H.M.S. 'Challenger': — " No. 123, female, off Cape 

 York at sea. Eyes brown ; bill and throat light blue, reddish towards the base, and the 

 tips of both mandibles brown ; feet coral-red. The stomach contained cuttlefish about 

 S^ and 4 inches long." 



This bird breeds in trees. See 'Ibis,' 1864, p. 379. 



