NO. 2298. THE GUANO BIRDS OF PERU—COKER. 491 



but the majority of the birds were occupying the westward island, which 

 had not been disturbed. Here, too, were many scattered rookeries, 

 some v/ith birds in small groups, others with nests arranged in long 

 rambling ranks (pi. 67). At the end of the land, however, and con- 

 nected with the last-mentioned series, there was a large rookery 

 including probably 6,000 nests (pi. 66). It was estimated that there 

 were between 10,000 and 20,000 nests on the group of islands. A 

 great many of the birds had apparently removed to the Lobos de 

 Tierra Islands, a few miles to the north. 



The change of conditions noted in successive seasons on the Lobos 

 Islands as regards the nesting of pelicans, was only one of many evi- 

 dences that this species is not easily reconciled to disturbances. The 

 adult pehcan will often stand by its young, but the radical disturb- 

 ance of its nesting ground, as by removal of the guano, seems to be 

 the signal for a change of location in the following season. The 

 pelican is, indeed, relatively timid and clannish by nature. Its 

 nesting grounds were never observed in close proximity to those of 

 other birds.^ It was noted also that the rookeries were generally 

 well removed from the loberias (or rookeries of sea lions), though this 

 may have been due to chance. 



Pehcans are more infested with insect pests than any other of the 

 guano birds. The neighborhood of the nests is, therefore, a most 

 unpleasant place to stand for any length of time. One of these (a 

 MaUophaga?) is abundant all over the ground; it crawls up the legs, 

 body, and neck of the bird to find an attachment within the pouch, 

 where it may always be seen in scores. The great bills are quite 

 helpless against such pests, and the only defense seems to be in the 

 daily baths which the pehcans take in convenient coves. 



Other enemies of the pehcans are the gulls and "gallinazos," whose 

 depredations will be described in the account of the gaUinazos(p. 498). 

 Cats undoubtedly prey upon the young. It is interesting that cats, 

 which have escaped from the guano workers' or fishermen's camps 

 should have estabhshed themselves upon the Lobos Islands, where 

 there is no possible source of fresh water, although an abundance of 

 bird and fish food is to be found in the rookeries and on the beaches. 

 The extermination of these cats is strongly to be recommended, and 

 the conveyance of cats to the islands should be prohibited. 



StiU another enemy of the pelican is the abundant ''lobo," or sea 

 lion, although I can not rate highly the damage done by it. I wit- 



> On the other hand, Forbes, from observations at the Chincha Islands when pelicans and cormorants 

 had just returned after a remarkable and imexplained absence of a year, found the nesting pelicans 

 ' ' crowded together in large colonies, very generally surrounded by still denser and more extensive colonies 

 of Phalacrocomx bougavniUci." He adds: "At this season the birds are extremely timid and rarely allow 

 the near approach of an intruder without taking wing with a recriminating 'wauk' from their nest; In 

 this respect they are unlike their incubating friendly neighbors, the cormorants, which allow one to come 

 comparatively close to them without leaving the nest." (Forbes, The Ibis, vol. 2, 1914, p. 415). 



