. The bird; its form and function . Fig. 183. —Bill of Avocet, recurved for probing. 240 The Bird then pried open and eaten. The bill of this bird showsthe wear and tear of forcing apart the shells, and it issometimes slightly bent to one side. The short-billedgulls are denied the power of opening these oysters andmussels, but they sometimes get an unlawful feast by fol-lowing up and robbing the Oyster-catchers of the shellswhich the latter have opened. The bill of the Shell Ibis of India may be likened toan ordinary lemon-squeezer, having a cavity in which. Fig. 184.—Bill of Oyster-catcher; u
. The bird; its form and function . Fig. 183. —Bill of Avocet, recurved for probing. 240 The Bird then pried open and eaten. The bill of this bird showsthe wear and tear of forcing apart the shells, and it issometimes slightly bent to one side. The short-billedgulls are denied the power of opening these oysters andmussels, but they sometimes get an unlawful feast by fol-lowing up and robbing the Oyster-catchers of the shellswhich the latter have opened. The bill of the Shell Ibis of India may be likened toan ordinary lemon-squeezer, having a cavity in which. Fig. 184.—Bill of Oyster-catcher; used for piying open the shells of mollusks. the half-lemon rests before it is compressed. Whenthe mandibles of this bird are closely opposed the centralportion of the beak gapes slightly. In this cavity thebird firmly holds the shells of the land-snails upon whichit feeds, until it can bring the pressure of both mandiblesto bear and so crush the shell of the mollusk. The asymmetry of the bill—as seen in the Oyster-catcher—is not accidental, but constant, in the Crook-billed Plover of New Zealand. In this bird the bill is Beaks and Bills 241 permanently bent to the right, a beautiful adaptationto help the bird in its search for insects, which, in thedry country that it inhabits, are found almost entirelyunder stones. As a rule, beaks are rather immovable throughouttheir length, but in the woodcock, and to a less extent
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectbirds, bookyear1906
