CLASS AVES. BIRDS 



459 



Figure 333. An elephant bird {Acpyornis), a 

 restoration of this large, flightless, and strange bird, 

 which once lived in Madagascar. (Courtesy of Chi- 

 cago Natural History Museum.) 



Order Diatrymiformes 



These were large forms which could not 

 fly because the wings were atrophied. They 

 had three toes and a huge bill. They lived 

 during the Eocene in western United States. 



Other extinct birds 



Passenger pigeons (Fig. 334), as well as 

 great auks, dodos, Labrador ducks, heath 

 hens, and various other birds, have become 

 extinct in recent times. Alexander Wilson 

 in 1808 saw a flock of passenger pigeons in 

 Kentucky that contained over two billion 

 birds, and Audubon writes of flocks that 

 darkened the sky like the approach of a 

 tornado. The last known passenger pigeon 

 died of old age in the zoological park in 

 Cincinnati in September, 1914. Probably the 

 slaughter and persecution of this bird by 

 man was an important factor in its becoming 

 extinct. Every great food market from St. 

 Louis to Boston received hundreds of barrels 

 of pigeons every season until man realized 

 too late that this bird needed protection. 



Figure 334. The passenger pigeon, Ectopistes 

 migratorius, which became extinct after incredible 

 slaughter. Length 16 inches. (Courtesy of the Amer- 

 ican Museum of Natural History.) 



RELATIONS OF BIRDS 

 TO MAN 



Birds are of great commercial value; they 

 augment our food supply and furnish feath- 

 ers for various purposes. Before the wearing 

 of wild bird feathers was prohibited by law, 

 vast numbers of birds were killed for their 

 plumes. The American egrets (Fig. 336) 

 were almost exterminated in order to secure 

 the tuft of feathers or aigrettes that resem- 

 ble spun glass. In certain regions, the excre- 

 ment (guano) of sea birds exists in large 

 quantities and is of great value as a fertilizer. 

 The most valuable deposits are on small 

 islands near the coast of Peru; these may 

 amount to as much as 750 tons per acre per 

 year. Cormorants (Fig. 335) are largely re- 

 sponsible for the production of guano. Game 



