Part 78

The eggs are usually two, sometimes three or four, in number; they are nearly spherical, equally rounded at either end, and more or less granulated on their surface. Their color is a dull white, unspotted, but often stained by incubation to a dirty white or a light soiled drab. Two eggs in my collection present the following measurements: Length 3 inches, breadth 2.75; length 2.88 inches, breadth 2.80. The first was obtained in New Jersey by Alexander Wilson, the ornithologist; the latter by Dr. Trudeau, in Louisiana.

Another, taken from a nest in Texas by Dr. Heermann, measured 2.80 by 2.20 inches. A fourth, from Sitka, measures 2.75 by 2.25 inches. These measurements, so far as they may be taken as typical, exhibit but little variation in size between the most northern and the most southern specimens.

Several nests were met with and the eggs taken by Mr. MacFarlane near Anderson River. They were generally built in high trees not far from river-banks. In a few instances the parents made hostile demonstrations when their nests were robbed, but generally kept at a safe distance, uttering loud and discordant sounds. The nests were built of dry sticks and decayed branches, and lined with deer’s hair, mosses, hay, and other similar soft materials.

Mr. Dall was informed by the Indians that this species breeds among the Alaskan mountains on inaccessible cliffs. This statement, however, may have had reference to the Golden Eagle.

FAMILY CATHARTIDÆ.—THE AMERICAN VULTURES.

Cathartidæ, GRAY, 1842.—HUXLEY, P. Z. S. 1867, p. 463. Cathartinæ, LAFR. 1839. Sarcorhamphidæ, GRAY, 1848. Gryphinæ, REICH. 1850.

The characters of this family have been given in sufficient detail (III, 1), so that a short diagnosis, showing its most readily observable peculiarities, will here be sufficient.

CHAR. Whole head, and sometimes the neck, naked; eyes prominent, and not shaded by a superciliary shield. Cere much elongated, much depressed anteriorly below the very arched culmen; nostrils longitudinal, horizontal, the two confluent or perforate. Middle toe very long, and the hind one much abbreviated. A web between the base of the inner and middle toes.

The family Vulturidæ, as long recognized, included all the naked-headed, carrion-feeding Raptores of both the Old and the New World. The later researches of science, however, have shown the necessity of separating the Vultures of the latter continent from those of the former, and ranking them as a distinct family, while at the same time the Old World Vultures are found to be merely modified Falconidæ. The resemblance between the Cathartidæ and the vulturine Falconidæ is merely a superficial one of analogy, and not one of affinity. Being the scavengers of the countries they inhabit, the latter thus perform the same office in nature as the former, and for adaptation to a similar mode of life their external characters are modified to correspond. Close, however, as is the external resemblance between the two groups, their osteological structure and internal anatomy is entirely different.

The Cathartidæ differ from the Vulturinæ as to their external structure in the following particulars, the osteological structure being entirely different in the two groups, the latter being like the Falconidæ in all the characters which separate the latter family from the Cathartidæ.

=Cathartidæ.= Nostrils horizontal, perforate; a well-developed web between the inner and middle toes, at the base.

=Vulturinæ.= Nostrils vertical, not perforate; no trace of web between inner and middle toes.

In habits, the Cathartidæ resemble the vulturine Falconidæ of the Old World. “They lack the strength and spirit of typical Raptores, and rarely attack animals capable of offering resistance; they are voracious and indiscriminate gormandizers of carrion and animal refuse of all sorts,—efficient and almost indispensable scavengers in the warm countries where they abound. They are uncleanly in their mode of feeding; the nature of their food renders them ill-scented, and when disturbed they eject the fetid contents of the crop. Although not truly gregarious, they assemble in multitudes where food is plenty, and some species breed in communities. When gorged, they appear heavy and indisposed to exertion, usually passing the period of digestion motionless, in a listless attitude, with their wings half spread. But they spend most of the time on wing, circling high in the air; their flight is easy and graceful in the extreme, and capable of being indefinitely protracted. On the ground, they habitually walk instead of progressing by leaps. Possessing no vocal apparatus, the Vultures are almost mute, emitting only a weak hissing sound.” (COUES.)

The Cathartidæ all belong to the tropical and warm temperate portions of the continent, only one species (Rhinogryphus aura) extending its range as far as the border of the colder regions. The famous Condor (Sarcorhamphus gryphus) of the Andes and the equally large California species (Pseudogryphus californianus) are among the largest birds of flight in the world, being exceeded in size by none, and rivalled but by one or two of the Vultures of the Eastern Hemisphere.

The following diagnoses based upon the external structure are sufficient to characterize the very well-marked genera and subgenera of this family. The distinctive osteological characters which accompany these external features afford still more decided differences, and are illustrated by the figures.

Genera and Subgenera.

=A.= Crop naked. Male with a fleshy crest, or lobe, attached to the top of the cere. Bill very robust and strong, its outlines very convex; cere much shorter than the head.

1. =Sarcorhamphus.= Entire neck bare; nasal cavity entirely open; posterior claw very thick and strongly curved. Tail even.

Sexes different, the female lacking any fleshy caruncles, or appendages, on the head and neck. Frontal lobe, or fleshy crest of male, extending from the anterior border of the cere to the middle of the crown; throat with a median wattle, or “dewlap”; side of the neck with a somewhat convoluted or twisted caruncle, extending from the side of the occiput obliquely downward, across the neck to near the lower extremity of the gular wattle; lower part of the foreneck with a pendent fleshy appendage. Plumage beginning below the neck by a crescentic ruff of soft white down, or cottony feathers, around the posterior portion. Primaries longer than the secondaries; front of the tibio-tarsal joint feathered …

Sarcorhamphus.

Sexes alike, the female possessing the caruncular appendages of the head as well as the male. Frontal lobe attached to only the middle portion of the cere, above the nostril; throat without a median wattle; side of the neck without any caruncles; no appendage on the foreneck; auricular region with longitudinal corrugations, and occiput densely haired. Plumage beginning below the neck by a ruff of broad, well-developed, normal feathers. Primaries not longer than the secondaries. Front of the tibio-tarsal joint naked …

Cathartes.

=B.= Crop feathered. Male without a fleshy crest, or other appendages, on the head. Bill less robust, variable as to strength, its outlines only moderately convex; cere nearly equal to the head in length. Sexes alike.

a. Entire neck bare; plumage commencing abruptly in a ruff of lanceolate, or penicillate feathers, these continued on the breast and abdomen. Head much elongated, the upper outline a slightly convex plane, the forehead depressed below the level of the very elevated dorsal outline of the cere. Posterior claw very thick and strongly curved.

2. =Pseudogryphus.= Nostril occupying only the posterior third of the nasal orifice, its anterior end acute. Bill weak, the terminal hook only slightly developed, the mandibles broader than deep, the lower as deep as the upper. Head and neck without corrugations or caruncles. Tarsus slightly longer than the middle toe; fourth or fifth quill longest; extremities of the quills reaching to or beyond the end of the tail. Tail even. (P. californianus.)

b. Only the upper half, or less, of the neck bare; plumage commencing gradually with normal, broad feathers; feathers of breast and abdomen broad and normal. Head only moderately elongated, the upper outline irregular, the forehead elevated above the dorsal outline of the cere. Bill strong, the terminal hook well developed. Posterior claw weaker, less curved.

3. =Rhinogryphus.= Nostril occupying the whole of the nasal cavity, its anterior end broadly rounded; cere as deep as broad, the upper and lower outlines divergent posteriorly, the former considerably arched; lower mandible much less deep than the upper. Skin of the neck without corrugations; a semicircular tuft of antrorse radiating bristles in front of the eye. Wing very long, the primaries reaching to or beyond the end of the tail. Tail much rounded. (R. aura and R. burrovianus.)

4. =Catharista.= Nostril occupying only the posterior half of the nasal cavity, its anterior end contracted and acute; cere depressed, much wider than deep, its upper and lower outlines parallel, the former not perceptibly arched; lower mandible as deep as the upper; skin of the neck transversely corrugated; no tuft of bristles in front of the eye. Wing short, the primaries reaching scarcely to the middle of the tail. Tail even, or slightly emarginate. (C. atratus.)