THE BIRD ROOKERIES OF LAY SAN. 



329 



of all the avian world, and have the habit of soaring with extended 



wings for hours at a time. The males have an inflatal)lc air-sack 



under the throat which can be distended at will into a great red pensile 



bag, resembling both in color and size the red toy balloons in which 



children delight. These birds are 



probably the most inveterate thieves 



and pirates of all the feathered 



tribe, robbing other birds of their 



fish, and even making them disgorge 



for the benefit of their persecutors. 



They lay a single white egg, and 



young in all stages of development 



were numerous. "When the rookery 



was disturbed the incubating birds, 



both male and female, reluctantly 



left their eggs or young, in some 



instances carefully depositing a fish 



beside the young before leaving. 



Afterward, greatly to our surprise, 



they would swoop down, actually 



grazing our faces with their wings, and deftly seize a nestling by the 



head and make off with it, circling around high in air, finally dropping 



it to the ground, where it was eventually devoured. We could not 



Fig. 



15. Young of Shearwater showing 

 PkotectiveColokation. 



Fig. 16. Shearwaters near Burrow. 



determine whether the parents actually destroyed their own young or 

 not, but it is probable that this revolting form of cannibalism must 

 be added to the other crimes charged to their account. 



