THE PELICANS igg 



overloaded pelican, can fish on its own account, plunging downwards 

 from a great height, but because it prefers not to wet its non-oily 

 plumage it deftly scoops its prey from the surface. Most of its food, 

 however, is obtained parasitically by robbing other birds, skua-like, 

 on the wing. Its powers of flight are truly magnificent — the normal 

 floating progress by easy beats of the half-open wings suggests a great 

 reserve of power, which is proved when it easily overtakes the fast- 

 flying boobies. 



Gannets, boobies and tropic-birds dive for their food; they live 

 principally on surface-swimming fish (mackerel, herring, pollack, 

 garfish, haddock, whiting, sea-trout and gurnard are recorded for 

 the gannet). Cottam & Uhler (1937) state that the more sluggish 

 surface-feeding and shallow-water fishes not utilised by man greatly 

 outnumber the valuable species and are more easily captured, and in 

 consequence they compose the bulk of the diet of fish-eating birds. 

 In 191 8 the American Federal Food Administration found that the 

 eastern brown pelican [Pelecanus 0. occidentalis), to the surprise of its 

 accusers, was innocent of consuming large quantities of food-fish, and 

 that it lived principally on the menhaden, an oily fish never used for 

 human consumption. Shags (see p. 118) feed mainly on fish of no 

 commercial value (Lumsden and Haddow, 1946, who examined the 

 stomach contents of 81 shags in the Firth of Clyde). Flat fish form 

 about 40 per cent, of the diet of European cormorants (Steven, 1933). 

 Other fish commonly taken include pollack, wrasse, haddock, codling, 

 whiting, garfish, sand-eels, herring, mackerel, small conger-eels, plaice, 

 mullet and sticklebacks. They are coarse feeders, especially the cormor- 

 ant which has frequently been known to attack crabs, and to eat 

 carrion — a kitten eleven inches long was found in the stomach of a 

 British-taken cormorant. Both cormorant and shag, when diving, 

 may sink under from the surface with scarcely a ripple, but the usual 

 habit is to make a semi-circular leap out of and back into the water, 

 so gaining impetus for swimming below. When travelling fast under 

 water, the bird keeps its wings closed; and the body is propelled with 

 simultaneous strokes of both feet. The wings are only used when the 

 bird is beating about on the bottom of the sea hunting for flounders and 

 other fish concealed there. It has been suggested that a silvery "flash" 

 of light, reflected from the back of the cormorant's head, as 

 observed in a cormorant in an aquarium, attracts fish towards the 

 bird, but there seems to be no proof of this as a fact of such 

 biological importance. 



