326 



ZOOLOGICAL SOCIETY BULLETIN 



is being; done by the medical staff is not yet 

 available in print, but should one day prove a 

 valuable addition to our knowledge of a study 

 in which our European Zoological staffs have 

 been a little remiss. The literature of such 

 societies is the growth of generations and will 

 doubtless come in good time. Meanwhile the 



THE FRIGATE BIRD, 



Park, which approaches completion, is already 

 a marvelous achievement ; and when Mr. Horn- 

 aday rests from his labors, the science of the 

 outdoor menagerie, conducted on lines at once 

 popular and humane, will know no higher ex- 

 pression than it will find in the glades and 

 valleys of the Bronx. 



THE FRIGATE BIRDS. 



AMONG the rarest and most interesting 

 birds received this year at the Zoological 

 ■ Park are the Frigate Birds, which were 

 collected in Mexico for the .Society, and placed 

 on exhibition late in November. 



These birds render complete the six families 

 of the order Steganopodes, or aquatic birds 

 with webs connecting all four toes. The other 

 five families, including the tropic birds, gan- 

 nets, snake birds, cormorants, and pelicans 

 have all been on exhibition in the Park before. 



The Frigate Bird, {Frcgata aqnila, Linn.), 

 is in some ways the most interesting of all its 

 congeners. Structurally, as well as in habits, 

 the Steganopodes are closely related to the 



more terrestrial birds of prey, the hawks and 

 eagles, and the Frigate Birds are the nearest 

 to a connecting link between the two great 

 orders. 



They are, however, extremely specialized 

 for an aerial life and in comparison with the 

 weight of the body, the spread of wing exceeds 

 that of any other birds. 

 Irrigate Birds inhabit the 

 tropical oceans, and though 

 often keeping near the 

 shore, they are more inde- 

 pendent of the land than 

 any other sea bird, except 

 the albatrosses and petrels. 

 They can not dive, and 

 they walk or swim with dif- 

 ficulty, and in accordance 

 with these habits, the feet 

 and legs are small and the 

 webs between the toes very 

 deeply incised. While the 

 tarsus measures less than 

 an inch in length, the 

 spread of wing is some- 

 times eight feet ! 



With all these apparent 

 handicaps, their marvelous 

 power of flight ensures 

 prey in abundance. When 

 a school of flying fish 

 breaks from the water, it 

 is often because of some 

 fierce aquatic pursuer, but if a Frigate Bird is 

 soaring high overhead, a sudden headlong dive 

 and the snap of a hooked beak sends the flut- 

 tering little fish back in terror to the water, 

 minus one of their number. 



The Frigate Birds, or AIan-o"-War Hawks as 

 they are called, also rob gulls and terns of their 

 hard-earned fish. The birds in the Zoological 

 Park are young, and the heads and necks are 

 white. As the birds attain adult plumage this 

 white color is lost, and finally the entire head 

 becomes a glossy black hue. This is the re- 

 verse of what takes place in the bald eagles, 

 where the dark immature head plumage is re- 

 placed by white in the full-grown birds. 



When the young birds at the Park first ar- 

 rived they were very thin and weak, due to the 

 severe sea-sickness from which they suft'ered 

 on their journey north. Remarkable though it 

 is, this malady attacks many sea-birds, such 

 as the albatross, when they are carried on the 

 deck of a vessel. 



The graceful, long-pointed wings and the 

 deeply forked tail are indicative of the won- 

 derful aerial abilitv of the Frigate Bird, and 



