90 BRITISH BIRDS 
Nest. Usually on ledges in sea-caves, sometimes on a cliff 
ledge or in recesses among boulders by the sea; generally, 
» therefore, unlike the cormorant’s, under cover. 
Material: sea-weed and coarse herbage. The 
species breeds in colonies, : 
Eggs. Usually 3-5. Like cormorant’s, but 
smaller, Av. size, 251x1'51 in, Laying begins 
March-April. Two broods. 
(2) Family: Sulide—Gannets 
179. Gannet or Solan-goose [Sula bassana 
(Linnzeus)]. Resident. Strictly marine species. 
Breeds in large colonies on rocky islands at 
various points round our coasts. 
Bird. Length 33 in. (See No. 177.) Bill strong, 
straight, not hooked, and of a pale lead-blue with deeper slate 
coloured longitudinal lines. Tail graduated to a point, the 
central feathers the longest. Wings long and rather narrow. 
Plumage white, save the wing quills, which are dark brown, 
not black as usually stated. In breeding dress there is a buff 
tinge on the head and neck. The fledgling blackish-slate, 
spotted white. Immature till the fifth year, and recognised 
by the dark brown, chiefly on the back, wings, and tail, which 
colour diminishes season by season till at maturity reduced 
to the brown of the wing quills. 
Nest. Generally on the ledges of 
the precipitous sides of sea-washed 
isles, such as the Bass Rock, Ailsa 
Craig (Scotland), Bull Rock and 
Little Skellig (Ireland). Material: 
sea-weed, grasses from the isle top, 
and any material from the surface 
of the sea. 
Egg. One. Blue, covered or nearly so with a white chalky 
deposit which soon becomes dirty and yellow stained. Av. size, 
3°06 x 1°96 in. Laying begins March-May. One brood. 
XI. ORDER: PROCELLARIIFORMES. SUBORDER: 
TUBINARES 
Family: Procellarvide—Petrels 
180. Manx-shearwater [Pufinus pufinus pufinus (Brin- 
nich); Puffinus anglorwm (Temminck)]. Seen on all our coasts, 
but breeds only on the west, the Irish coasts, Orkneys, and 
Shetlands, 
Bird. Length 15in. Beak long, slender, with hooked tip, and 
dusky brown external tubular nostrils (see No. 182, Fig. 106). 
