B I R D. 



421 



In the eagles we have a further modification of the 

 bill. It has no decided tooth in any of them, neither 

 is it so strongly formed in proportion to its size as in 

 the high-flying falcons, even in the most powerful of 

 the race ; and in the fishers, the outlines of the tomia 

 are nearly even. New characters present themselves 

 in this division of the order ; they do not contend with 

 their prey in the air and on the wing, and they feed 

 more upon mammalia than the hawks, though they also 

 make great havoc among the larger ground birds. We 

 shall, however, be better able to understand those differ- 

 ences when we come to consider the feet and wings. 



The beaks of the vultures are much feebler than 

 those of any of the species already noticed. Instead 

 of the arched outline, which, though it gets flattened 

 in the others from the falcon downwards, is nearly an 

 unbroken curve from the tip of the beak to the pos- 

 terior part of the skull, the vultures have a depression 

 at the base of the bill, and another in the middle in 

 some of the species. The bill is also much longer 

 and also wider in proportion to its height, and the 

 cutting edges of the tomia are in all the species 

 nearly, and in some of them completely plain; and it 

 is without the sliding action at the points of the man- 

 dibles. Thus it can grasp a larger portion of sub- 

 stance than the beak of the falcon ; but it can separate 

 that only by simple pressure of the mandibles against 

 each other; and, independently of its being without 

 the sliding- or tearing motions, the mandibles are nei- 

 ther so stiff for pressure nor moved by such powerful 

 muscles as those of the other diurnal birds of prey. 



From their mode of feeding, and the substances on 

 which they feed, vultures do not gain from the velo- 

 city of the points of their long mandibles that which 

 they lose in power from the diminished strength. In 

 biros, and in animals generally which snap, the velo- 

 city makes up for the loss of power ; and though the 

 greyhound cannot hold fast like the bull-dog, his 

 momentary bite is sharper. It is the same with many 

 of the long-billed birds ; but the vultures are gnawers 

 and not snappers ; and they are not so able to divide 

 recent flesh as the other diurnal accipitres. There- 

 fore, their chief food is carrion, or the bodies of ani- 

 mals which have become tendei by the progress of 

 putrefaction. 



The annexed sketch of the beak of the vulture may 

 be regarded as the opposite extreme in the diurnal 

 accipitres to that of the jer falcon already given. But 



<he vultures do not lead by a natural gradation from 

 the more typical diurnal preyers to the nocturnal 



ones. They point to another portion, or rather to 

 two other portions of the class. In the forms of their 

 bills they have some approximation both to certain 

 species of the gallinaceous birds, and to certain tribes 

 of that division of Cuvier's great order, Passeres, 

 which, for want of a better name, we shall call om- 

 nivorous ; and it is not a little remarkable that, like 

 the gallinaceous birds, they have naked skin upon 

 the head and neck, and that skin blooms in the season 

 as in these. 



The nocturnal birds of prey have the bill more 

 slender than the day-feeders, generally much hooked 

 from the base, compressed, sharp at the tips of both 

 mandibles, smooth in the outlines of the tomia, and 

 without tooth or notch. It takes up the connexion 

 with the bills of the diurnal feeders rather from one 

 of the characters of that of the kites, than from those 

 of the vultures, which, in their general structure, may 

 be considered as the lowest in the diurnal division ; 

 and this might be expected, as the nocturnal feeders 

 the owls are not feeders on carrion, but in general 

 kill their own game, chiefly mice, and other small 

 mammalia, which have been mentioned as forming, in 

 part, the food of the kites. 



But, though such is the general food of the majority 

 of the owls, and though they have the habit of wound- 

 ing and disabling such prey by the snap of the bill, 

 as well as by the clutch of the talons, there are some 

 of the more powerful species which have different 

 habits, and the bill differently formed, to agree with 

 those habits. These are chiefly inhabitants of the 

 north, and in certain states of the weather they come 

 abroad in the dim twilight sort of day, which, at some 

 seasons and in some states of the weather, obtains in 

 those dreary and inhospitable climes. Mammalia are 

 the general prey of those more powerful owls upon 

 | such occasions ; but it is said that they also attack 

 and despatch birds, especially when these are ex- 

 hausted and overcome by the violence of the weather. 

 They have been described as giving chace on the 

 wing, but it has not been said that they kill prey in 

 the air ; and indeed, the muffled feathers and soft 

 flight of owls do not fit them very well for such an 

 office. They are popularly called "eagle owls;" and 

 if there is any propriety in the name, they should kill 

 their prey on the ground, though they may seek for 

 and in so far follow it in the air. 



In proportion as the birds of this order depart from 

 the type of the jer falcon, they seem to be incapable 

 of depluming their prey, or depriving it of its indi- 

 gestible covering, or taking the flesh from the bones. 

 In proportion as they are thus incapacitated, they 

 take the indigestible parts of the food into the 

 stomach. But these do not pass the pylorus into 

 the intestinal canal. They remain in the stomach 

 till all the parts fit for the nourishment of the birds 

 are separated, and then they are discharged by the 

 mouth in sapless balls, called " castings, " or quids. 

 The species which have this habit cannot, of course, 

 feed upon animals of any considerable size not 

 larger than they can swallow, because they cannot 

 masticate ; and though an owl can separate the 

 viscera of its prey, it is not capable of disjointing the 

 bones even of a mouse. 



We have entered somewhat more into details 

 respecting the bills of this order of birds than we 

 shall be able to do with those of the remaining orders ; 

 but they are not only well marked in their structure 

 and habits, they are also in no small degree the typical 



