El Paso, Mr. Clark saw these birds congregated in such quantities over a mud-hole from which were issuing myriads of insects, that he felt that the discharge among them of mustard-seed shot would involve a wanton destruction. This species is not known, according to his account, to make a swoop in the manner of the common species. It does not utter the same hoarse sounds, nor does it ever fly so high.
Among the notes of the late Dr. Berlandier, of Matamoras, we find references to this species, to which he gives the common name of Pauraque, and in his collection of eggs are many that unquestionably are those of this bird, and which are, in all respects but size, in close affinity to the eggs of the common Night-Hawk. These eggs measure 1.18 inches in length by .87 of an inch in breadth. Their ground-color, seen through a magnifying glass, is of clear crystal whiteness, but is so closely covered by overlaying markings as not to be discernible to the eye. They are marked over the entire surface with small irregular confluent spots and blotches, which are a blending of black, umber, and purplish-gray markings. These combinations give to the egg the appearance of a piece of polished marble of a dark gray color. They are both smaller and of a lighter color than those of the common eastern bird.
Genus ANTROSTOMUS, Gould.
Antrostomus, Gould, Icones Avium, 1838. (Type, Caprimulgus carolinensis, Gm.)
Antrostomus nuttalli.
Gen. Char. Bill very small, with tubular nostrils, and the gape with long, stiff, sometimes pectinated bristles projecting beyond the end of the bill. Tarsi moderate, partly feathered above. Tail broad, rounded; wings broad and rounded; first quill shorter than third; plumage soft and lax. Habit nocturnal.
In what the genus Antrostomus really differs from Caprimulgus proper, we are quite unable to say, as in the many variations of form of both New and Old World species of these two divisions respectively, it is said to be not difficult to find species in each, almost identical in form. In the want of suitable material for comparison, we shall follow Sclater in using Antrostomus for the New World species.
Species and Varieties.[105]
A. Bristles of gape with lateral filaments. Light tail-spaces confined to inner web of feathers.