284 4 STEGANOPODOUS BIRDS. 



six inches in height, is formed of a mass of seaweed and grass placed upon the bare 

 rock ; and in this is laid a single ^^^, which is at first chalky white, with a faint 

 blue tinge. During incubation, the birds become so tame that they will allow 

 themselves to be handled ; and it is somewhat curious, that on the ledges of the 

 Bass Rock almost all the sitting birds have their heads turned towards the cliff'. 

 Gannets feed exclusively upon fish, and commit great devastation upon the shoals 

 of herrings and pilchards, in search of which they often wander for long distances. 

 Couch observes that " the gannet takes its prey in a different manner from any 

 other of our aquatic birds ; for, traversing the air in all directions, as soon as it 

 discovers the fish, it rises to such a height as experience shows best calculated to 

 carry it by a downward motion to the required depth ; and then, partially closing 

 its wings, it falls perpendicularly on the prey, and rarely without success, the time 

 between the plunge and immersion being about fifteen seconds." The serrated third 

 claw of the gannet, like that of the cormorant, appears to be for the purpose of 

 dressing the plumage, and not for aiding in the capture of the prey, which is taken 

 entirely by means of the beak. 



On many of the islands of the southern seas gannets, or boobies, of various 

 species, breed in vast numbers and exhibit remarkable tameness, or rather absence 

 of fear. Among such breeding-places may be mentioned St. Paul's Rocks, Booby 

 Island off Fernando do Noronha, and Raine Island off North-Eastern Australia. 

 The white-bellied gannet (*Si. leiicogaster) of St. Paul's Rocks and Raine Island, 

 makes a slight nest of green twigs and grass on the ground ; while the blue-eyed 

 gannet {S. cyanops) merely digs a hole about an inch and a half deep. The latter 

 species is nearly white, with the naked parts of the face blue and the iris bright 

 yellow : while the smaller Australian, S. piscatrix, differs from both the others by 

 its bright red feet. Moseley writes that " on the low cliffs of Booby Island the 

 noddies [terns] and boobies nest on all the available ledges, and sat on their nests 

 quite undisturbed as we rowed past them. It was curious to see the doves nesting 

 together with these two sea-birds on the same ledges and with their nests inter- 

 mingled." Remains of extinct gannets are found in the lower portion of the Miocene 

 deposits of France ; while the rocks belonging to the middle portion of the same 

 period have yielded bones of a gannet-like bird with wings even longer than those 

 of the albatross, for which the name of Pelargornis has been proposed. Nearly 

 allied to the latter is the so-called Argillornis from the much older London Clay of 

 England. Still more remarkable is the tooth -billed cormorant (Odontopteryx), 

 of the latter formation, which, while apparently allied to the cormorants, differs 

 from all existing birds in having the bony margins of the jaws produced into a 

 number of tooth-like processes. 



The Pelicans. 



Family Pelecanid^^. 



Although pelicans are now quite unknown in Britain, the occurrence of their 

 bones in the fens of Norfolk and Cambridge indicates that comparatively recently 

 they were at least occasional visitors. The largest representatives of their order, 

 these birds are distinguished from all others by the enormous development of the 



