WHITE-THROATED SWIFT.
Cypselus melanoleucus, Baird, Pr. A. N. Sc. Phil. VII, June, 1854, 118 (San Francisco Mountains, N. M.).—Cassin, Illust. I, 1855, 248. Panyptila melanoleuca, Baird, Birds N. Am. 1858, 141, pl. xviii, f. 1.—Sclater & Salvin, Ibis, 1859, 125 (Guatemala).—Sclater, P. Z. S. 1865, 607.—Kennerly, P. R. R. X, b, 36, pl. xviii, f. 1.—Heermann, Ib. X, c, 10.—Cooper, Orn. Cal. 1, 1870, 347.
Sp. Char. Wings very long; tail forked; tarsi and feet covered with feathers. Black all over, except the chin, throat, middle of the belly as far as the vent, a patch on each side of the rump, the edge of the outer primary, and blotches on the inner webs of the median tail-feathers, near the base, which are white, as is also a band across the ends of the secondaries. Length, 5.50; wing, 5.50; tail, 2.70.
Hab. Nevada, Utah, Colorado, Arizona, and southern Rocky Mountains, to Guatemala. Localities: Cajon Pass (Cooper, Pr. Cal. Ac. 1861, 122); Arizona (Coues, P. A. N. S. 1866, 57); San Diego (Cooper).
Although there is no difference in size between Rocky Mountain and Guatemalan specimens, the only two of the latter in the collection are darker colored, showing scarcely any indication of the frontal and supraloral whitish so conspicuous in most northern skins. In the Guatemalan female (30,837, Dueñas, February 13) the dusky of the lateral, and white of the medial, portions of the breast blend gradually together, there not being that sharp
line of junction seen in all the others, including the male from Guatemala (30,836, Dueñas, Nov.).
Panyptila melanoleuca.
Habits. This new species was first discovered by Dr. Kennerly on Bill Williams Fork, New Mexico, February 16, 1854. He speaks of it as a very curious and interesting bird, found by him only among the cañons of that stream, and not observed elsewhere during their journey. Large flocks could be seen at any time in the vicinity of those cañons, flying and circling around very high, and far beyond the reach of shot. Towards the close of the day, when the sun had sunk behind the hills, they occasionally descended lower. He only met with them where the walls of the cañons were very high, and consisted of almost perpendicular masses of rock. At times they were seen to sweep low down, and then to ascend nearly perpendicularly very near the stones, as if examining them in order to select a place for their nests. The construction of these had obviously not then commenced. Dr. Kennerly saw none engaged in the work, nor did he observe any old nests, unless they build after the manner of the common Cliff Swallow, which were also abundant in that region. Mr. Möllhausen was of the opinion that these birds build in the holes and crevices of the cliffs. In their flight and habits they appeared to closely resemble the common Chætura pelagica.
Dr. Heermann met with this species several times, first in San Fernando Pass, near Los Angelos, and again near Palm Spring, between the Colorado desert and Vallicita, at another time near Tucson, and once also in Texas. He always found them flying at a great height, either far beyond or on the extreme limit of gunshot range. From the extent of their wings they seemed formed to live in the air, where they pass most of their time gliding about in extensive circles, with apparently very little motion of the wings. During pleasant weather they found their insect prey in the upper air, but, when cloudy or rainy, they flew nearer the ground in their pursuit. When on the ground, they were observed to rise with difficulty, owing to the shortness of their legs and the length of their wings. When they rest, they always alight on some elevated point whence they can throw themselves into the air, and take to wing. Numbers were observed flying about the rocks near Tucson, but none were heard to utter a note. They were sociable among themselves, gathering in large flocks, but never mingled with the Swallows. He states that they construct their nests in