FALCONIDA : VULTURES, FALCONS, HAWKS, ETC. 519 
plumage with age are great, and render the determination of the species perplexing — the more 
so since purely individual, and somewhat climatic, color-variations, and such special conditions 
as melanism, are very frequent. The modes of nesting are various; the eggs as a rule are 
blotched, and not so nearly spherical as those of owls. The food is exclusively of an animal 
nature, though endlessly varied; the refuse of the stomach is ejected in a ball by the mouth. 
The voice is loud and harsh. As a rule, the birds of prey are not strictly migratory, though 
many of them change their abode with much regularity. Their mode of life renders them 
usually non-gregarious, excepting, however, the vultures and vulture-like hawks, which con- 
gregate where carrion is plenty, quite like the American Cathartides. ‘There are upwards of 
300 species or good geographical races, justly referable to about 50 full genera, and divisible 
into two families — Falconid@ and Pandionide. 
81. Family FALCONID4: Vultures, Falcons, Hawks, Eagles, etc. 
= : = Characters as above, ex-- 
clusive of those marking the 
fish-hawks, Pandionide, be- 
yond. No unexceptionable 
division of the family having 
been proposed, and the sub- 
families being still at issue, it 
may be best not to materially 
modify the arrangement pre- 
sented in the earlier edition 
of this work, further than 
to separate Pandiomde from 
Falconide proper. 
The Old World Vultures 
form a group standing some- 
what apart from the rest in 
many points of superficial 
structure and habits, though 
so closely correspondent with 
ordinary Falconide, aud es- 
pecially with Buteonine, in 
all essential respects, that 
Fig. 363. —The Vulture’s banquet; illustrating subfamily Vultwrine of | they can forin at most a sub- 
family Falconide, not represented in America. (From Michelet.) family Vulturine (fig. 363.) 
They have nothing to do with the American Vultures (suborder Cathartides), with which they 
have been wrongly united in a family Vultwride. They are a small group of some six genera 
and about twelve species, of which the most decidedly raptorial is the bearded griffin, Gypaétus 
barbatus; other characteristically ‘‘ vulturine” forms being Valter monachus, Otogyps auricu- 
laris, Gyps fulous, Neophron percnopterus, aud Gypohierax angolensis. 
The South American genera, Micrastur and Herpetotheres, are each described as being 
so peculiar as to form a group of supergeneric value, comparable with those termed subfamilies 
in the present work. Their relationships are with Falconine. (Ridgway.) 
The North Aimerican Falconide with which we have here to do fall in several groups, 
which I shall call subfamilies, without insisting upon their taxonomic rank, or raising the 
question whether the family at large is divisible in this manner. These groups are six in 
number: 1. Circine, harriers; 2. Milvine, kites; 3. Accipitrine, hawks; 4. Falconine, 
