3IO 



ZOOLOGICAL SOCIETY BULLETIN 



AMERICAN RAVEN. 



HOW BIRDS GET THEIR FOOD 



By C. William Beebe 



Curator of Bmns 



IF we should tie a man's hands and arms 

 tightly behind his back, stand him on his 

 feet, and tell him that he must hereafter 

 find and prepare his food, build his house, de- 

 fend himself from his enemies and perform 

 all the business of life in such a position, 

 what a pitiable object he would present! Yet 

 this is not unlike what birds have to do. 

 Almost every form of vegetable and animal 

 life is used as food by one or another of the 

 species ; birds have most intricately-built 

 homes, and their methods of defense are to 

 be numbered by the score ; the care of their 

 delicate plumage alone would seem to neces- 

 sitate many and varied instruments ; yet all 

 this is made possible, and chiefly executed, by 

 one small portion of the bird — its bill or beak. 



If one will spend an afternoon at the New 

 York Zoological Park (or with any good col- 

 lection of live birds), watching the ways in 

 which the bills of various species are used, 

 one will not boast of his own accomplish- 

 ments, when it is realized how much more, 

 comparatively, the bird is able to achieve 

 with the aid of two projecting pieces of horn. 



More than a single volume could be filled 

 with interesting facts about the bills of birds 

 and the uses to which they are put — hardly 

 any two species using their beaks in a similar 

 manner. Our language is too often lacking in 

 phrases expressing delicate shades of mean- 

 ing, and thus we are compelled to identify 

 structures among the creatures which rank 

 below us, with portions of our own anatomy 

 corresponding only in relative position or a 

 eeneral vague likeness of function. We arc 



accustomed to speak of the iiiouth of a star- 

 fish, the arms of a sea-anemone, the foot of 

 a snail : in these respective cases, structures 

 specialized for receiving food or for progres- 

 sion being understood. But no one would 

 think of alluding to a bird's lips or nose ; both 

 are included in the terms beak, or bill, and 

 nostrils. 



The finding and securing of food being the 

 most important problem which birds have to 

 solve for themselves, it is for these purposes, 

 and especially the last-mentioned, that we find 

 bills most adapted. This is so universally the 

 case that we may often judge accurately of 

 the kind of food of a certain bird from a 

 glance at its bill. 



As is the case with so many other avian 

 structures, the horny, toothless beak or bill 

 is duplicated elsewhere in Nature only in a 

 group of reptiles, the turtles and tortoises, 

 whose mandibles furnish a splendid example 

 of parallel evolution. 



In certain of those long-e,xtinct Dinosaurs, 

 such as Triceratops, an interesting transi- 

 tional condition is found. The front of the 

 mouth was beak-like and horny, while farther 

 back were the masticatory teeth. 



Starting with the generalized beak of the 

 Archeoptcryx, which was furnished with 

 teeth, we are almost at a loss in which di- 

 rection to turn, so many and so varied are 

 the beaks of modern birds. No trace of 

 teeth, however, is to be found in the adults of 

 any of them. The bill of a crow or raven, 

 and, to a lesser extent, that of his near rela- 

 tives, the jay and the blackbird, is perhaps in 

 shape most like that of the "bird of old," and 

 is suited to the many purposes which the 

 varied life of these intelligent birds re- 

 quires. 



SNAKEBIRD. 



