SULIDAE 



73 



often met with many hundred miles from land; they will then hover 

 constantly about n vessel, or even alight fearlessly on the rigging. 

 They traverse the air with rapid sweeping flight, accompanied by 

 constant quick pulsations of the wings ; at one time soaring aloft 

 to wheel in circles, at another plunging into the water from an 

 immense height, though appearing again in a moment to float upon 

 the surface. Their gait on land is shuffling, while they can hardly 

 rise from level s-round : the note is a harsh croak or chatter ; the 



Fig. 20.— Tropic Bird. PluuHhon adherens, x l 



food consists of hsh, squids, and other produce of the sea. No nest 

 is made, but a single reddish-brown or buff egg, with spots and 

 frecklings of red-brown," purplish or grey, is deposited in a hole or 

 crevice in a cliff, among rocks, or even in a cavity in a rotten tree, 

 lioth sexes assisting in incubation.^ The parents sit very closely, 

 screaming, pecking, and snapping when disturbed ; in some places 

 they are habitually caught while breeding, and deprived of the 

 long tail-feathers, which are used for decorations. 



Fam. II. Sulidae. — Sula hassana, the Gannet or Solan Goose, 

 which nests at several stations off tlie west of Great Britain, in 

 Ireland, and on the well-known Bass Iiock.extends thence to Iceland, 

 and down the American coast to Nova Scotia, while it strays to 

 Greenland, and in winter reaches the Gulf of Mexico and northern 

 Africa. The plumage is white, witli a buff tinge on the head and 

 neck, and black primaries ; the bill is whitish, the feet dusky, and 

 the naked skin round the eye and down the centre of the throat 

 l)lackish-blue. S. ca2)ensis of South Africa and aS'. serrator of 

 Australia are similar to the above, but the former lias the rectrices 

 black, the latter the four median feathers blackish-brown. 



^ Cf. E. Newton, Ihh, 1861, pj.. 180, 276 ; Layanl, i>2K clt. 1863, p. 248. 



