ZOOLOGICAL SOCILTV BILLLTIN 



3'5 



AMERICAN WOOUC 



between luimmiiigbirds 

 and insects, due entirely 

 to the similar'ty in their 

 feeding habits-. Certain 

 flowers are especially 

 adapted in structure to 

 attract certain bees or 

 moths, which in return 

 unconsciously cross-fer- 

 tilize the blossoms ; and 

 certain of the various 

 bills of hummingbirds 

 reflect the exact contour 

 of the corollas in which 

 the birds seek their food. 

 Among hummingbirds 

 the various shapes of 

 bills of otiicr groups are 

 reproduced again. Hum- 

 ming through the air 

 about us in the tropics 

 speed miniature avocets. 

 ibises, stilts, mergansers, 

 and we realize, as never before, the 

 never-ending devices of Nature, providing 

 for the needs of all, from the greatest to the 

 least : endless patterns paralleling each other. 

 but never identical. Indeed, in the great family 

 of South -Vmerican birds known as wood- 

 hewers the diversity in shape, size, and direc- 

 tion of bills is so great that it seems as if not a 

 niche, or crack, or hollow in the bark of any 

 tree in the forest where these birds abound 

 would afford a safe retreat to an insect! 



It remains to mention the woodpecker's bill, 

 which is used chisel-like for excavating his 

 home as well as in boring for grubs. With his 

 beak the nuthatch hammers his acorns, and the 

 tailor-bird sews his nest. The thick conical 

 beaks of all sparrows and finches are for 

 cracking seeds : while the weaker, more slender 

 beaks of warblers, thrushes, and wrens retlecl 

 a diet of insects. Among the finches is a group 

 of several species which, by a thrust of the bill, 

 have at their command a new source of food, 

 one which there are none to dispute with them. 

 Roth mandil)lcs of the crossbill are curved into 

 sharp hooks which cross one another, either to 

 right or left, thus forming a unique pair of 

 pliers, with which the bird pries out the seeds 

 shut tight behind the over-lapping scales of 

 pine-cones. 



The beak of a bird is always growing, and in 

 captivity from lack of proper use, the mandi- 

 bles sometimes grow to a great length, and, 

 unless trimmed, will often interfere with the 

 bird's feeding. 



Perhaps the most re- 

 markably adapted beaks 

 in the world are those 

 of the male and female 

 Huia birds — natives of 

 .\ew Zealand — in which 

 not only is the bill of the 

 species designed for a 

 special method of pro- 

 curing food, but the bills 

 ( >f the two sexes are very 

 different in form and 

 use, and complement 

 each other's methods. 

 Concerning the peculiar 

 use of the bill in the 

 Huia birds, Professor 

 .Newton writes: "Its fav- 

 orite food is the grub 

 of a timber-boring bee- 

 tle, and the male bird 

 with his short stout bill 

 attacks the more deca\ed 

 portions of the wood, and chisels oui his prey, 

 while tile female with her long slender bill 

 probes the holes in the sounder part, the hard- 

 ness of which resists his weapon; or when he, 

 having removed the decayed i)ortion, is unable 

 to reach the grul), the female coma's to his aid 

 and accomplishes what he has failed to d >." 



The bill of a bird, besides serving in so many 

 other ways, is invaluable in jireening the plum- 

 age, arranging disordered feathers, dr\ing 

 them, and, most imjiortant of all, in pressing 

 out the oil from the gland on the lower back, 

 and with it carefully dressing all the feiithers. 

 giving to them that hriglitness and gl'iss and 

 also the water-proof quality — so surely a sign 

 of perfect health in a bird. When, after the 

 bath of a caged bird, you see the drops roll 

 from its feathers, literally like "water off a 

 duck's back,'' then the good health of the bird 

 is certain. 



The all-important use of the bill as a needle, 

 shuttle, pick and shovel, auger and trowel in 

 nest-building does not concern us here, nor 

 does its function in expressing emotion, or in 

 taking the place of the voice or of the foot. All 

 this is expressive rather of the mental than the 

 physical life of the bird. 



Within a period of five minutes I have ob- 

 served the following uses of the beak of a par- 

 rot perching in my study : With its mandibles 

 it picked up a sunflower seed and comminuted 

 it : it then hooked the upper mandible into a 

 wire and swung itself along: gnawed at a hole 

 it had begun to excavate : nibbled gently at my 

 fincrer. showinsr affection : bit fiercciv in anger 



