488 PROCEEDINGS OF TEE NATIONAL MUSEUM. vol. 56. 



stitute a considerable proportion of the food of pelicans as of the other 

 sea fowl. 



The nests are made on the level ground or on gentle slopes and 

 generally in large aggregations (pi. 66). After the rookery at the 

 Lobos de Afuera Island was broken up in 1907, many smaller rook- 

 eries were found in the following season (Dec, 1907), in addition to 

 one or two that were some acres in extent. Some of these rookeries 

 were connected in a curious rambling way (pi. 67). The nests are 

 less regularly spaced than those of the guanays and naturally are 

 much farther apart; while the guanays average 3 nests to the 

 square meter, the pelican wiU average only about 2 to the square 

 meter. 



The behavior of pelicans on the nesting grounds in some respects 

 appears stupid and inexplicable. An alcatraz on her nest will 

 sometimes reach over with her long neck and bill, take a fledgling 

 from the uncovered nest of a neighbor and throw it away, perhaps 

 into another nest. Once, within a space of 2 square meters, I saw 

 six little "pichones," almost new born, bandied about in a most 

 merciless way, tossed from one alcatraz to another, each seemingly 

 unv/illing to have the little birds in their proximity. Finally three 

 of the fledglings were thrown beyond the margin of the nesting 

 ground and left to die in the sun. I watched a pelican that returned 

 to a nest from which the only fledgling had been transferred by a 

 mischievous neighbor into an adjoining nest. The returning brooder 

 did not appear to notice the loss, but sat composedly on the remain- 

 ing egg ; then, pilfering on her own account, she quietly reached over 

 and stole all of the feathers from the nest in which lay her own 

 offspring (supposedly) among others, to add to the lining of her nest. 

 I questioned if the birds invariably occupied the same nest; on one 

 occasion, at least, a bird was seen to brood on two different nests. 

 The birds near the margin had been frightened away, but, most of 

 them retm-ning, all of the nests were soon reoccupied except the ones 

 nearest to me. An alcatraz, after sitting for 15 minutes on one nest, 

 moved slowly over to another nearer to me, while its place on the 

 first nest was at once taken by a bird that was previously covering 

 an empty nest. The young were trampled dangerously by the old 

 birds as they moved awkwardly about. Perhaps these are abnormal 

 actions, attributable to nervousness caused by the presence of an 

 intruder. 



I never found any considerable nimiber of nests imcovered but 

 once, when I came on a small rookery of some 100 to 200 nests, 

 where there were only a dozen birds. Returning after an hour or 

 less I found the same condition. Supposing the ground abandoned, 

 I opened some eggs from different nests, finding live embryos in aU. 

 The eggs remained warm under the midday sun. Doubtless the 

 insect parasites which swarm on the nesting grounds would occa- 



