COURTSHIP AMONG BIRDS in 



No less remarkable is the performance of the Frigate- 

 bird {Fregata)y a tropical species allied to the Pelicans 

 and Boatswain-bird, and to our own more familiar Cor- 

 morants and Gannets. It might well be called a marine 

 Swift, having excessively short legs and small feet, and 

 a wonderful expanse of wing. As with the Swifts, of 

 course most of its time is spent on the wing; the feet 

 are only useful for supporting the body when ashore, 

 they are never used for walking, at any rate, for more 

 than a few steps. The wings afford the only means of 

 locomotion. Our knowledge of these birds when under 

 the stress of sexual excitement we owe to Dr. C. W. 

 Andrews, who had the good fortune to study the 

 species known as the Great Frigate-bird {Fregata aquila) 

 during his task of surveying Christmas Island (Indian 

 Ocean). 



" About the beginning of January," he remarks, " the 

 adult males begin to acquire a remarkable pouch of 

 scarlet skin beneath the throat ; this they can inflate 

 till it is nearly as large as the rest of the body, and a 

 dozen or more of these birds sitting on a tree with out- 

 spread, drooping wings and this great scarlet bladder 

 under their heads are a most remarkable sight. When 

 a hen bird approaches the tree the males utter a peculiar 

 cry, a sort of ' wow- wow- wow-wow,' and clatter their 

 beaks like castanets, at the same time shaking their 

 wings. When they take to flight the air is allowed to 

 escape from the pouch, but occasionally they might be 

 seen flying with it partly inflated." %, 



Here again there can be no doubt about the purpose, or 

 perhaps one should say the stimulus, of this strange per- 

 formance. This pouch, I have been enabled to ascertain 

 from dissection, is not formed by inflating the gullet, 



