the common House Pigeon.
Dr. Gambel, who observed this bird in California, states that he has occasionally found it in solitary burrows, and also that it often makes use of the holes dug by the Spermophilus beecheyi. They occasionally dig their own burrows, and live in scattered companies of four or five. Dr. Gambel also states that the bird is a resident of California throughout the year.
Mr. Darwin, in the Zoölogy of the Beagle, met with the var. cunicularia in crossing the pampas of South America. In Banda Oriental, he says, it is its own workman, and excavates its burrows on any level spot of sandy soil; but in the pampas, or wherever the Bizcacha is found, it uses those made by that animal. It usually preys on mice and reptiles. Lieutenant Gilliss gives a similar account of it, from observations made in Chile.
Mr. Nathaniel H. Bishop met with cunicularia on the banks of the river San Juan, in Banda Oriental, where a few pairs were seen, devouring mice and insects. After crossing the river Las Vacas, and coming upon a sandy waste covered with scattered trees and low bushes, he again encountered it. Upon the pampas of the Argentine Republic they were found in great numbers, from a few miles west of Rosario to the vicinity of San Luis, where the pampas end. On these immense plains of grass it lives in company with the Bizcacha (Lagostomus trichodactylus), dwelling with it in perfect harmony, and during the day, while the animal is sleeping, a pair of Owls stand a few inches within the main entrance of the burrow, and at the first sound, be it near or distant, leave their station and remain outside the hole, or upon the mound that forms the roof of their domicile. At the approach of man, both birds, with their irides dilated, mount above him in the air, and keep up an alarm-note until he passes. Then they quietly settle down in the grass, or return to their former place. On the pampas Mr. Bishop did not observe them taking their prey during the daytime, but as soon as the sun had set, the Bizcacha and Owls both leave their holes in search of food, the young of the former playing about the birds as they alight near them. They do not associate in companies, there being but one pair to a hole. Each couple keep separate from their neighbors, and at night do not stray from their homes.
It is both diurnal and nocturnal, and feeds at all hours. Outside the town of San Juan, which lies upon the eastern base of the Andes, Mr. Bishop had a fine opportunity to watch their habits in a locality differing entirely from the pampas. The country around San Juan is a dreary desert, covered with low thorn-trees, and over this waste a few Owls are found, principally near the town itself, in the vicinity of the pastures that are cultivated by irrigation. They mate in September and October. “One evening,” Mr. Bishop writes, “I was attracted by a strange sound that I supposed proceeded from a frog, but it proved to be the love-note of a little Athene cunicularia, and which was answered by its mate. It alighted upon a post, and commenced turning around upon it, with throat dilated, and emitting a guttural sound. These antics were continued for more than a minute, it occasionally bowing its head in a mysterious manner. The female soon after joined it, and they flew away. Each night it perched upon a tall flagstaff and uttered its love-note. Close by the house was a lagoon, the borders of which were swampy, and over this a pair often hovered in search of food. I watched one that kept on the wing for nearly two hours, some fifty feet from the ground, and during that time did not change its position in any other way than by rising or falling a few feet. A boy brought me a female with five eggs, that had been taken from a burrow five feet from the mouth. The bird was very fierce, and fought me with her wings and beak, uttering all the while a long shrill note, resembling a file drawn across the teeth of a saw. I supplied her with eleven full-grown mice, which she devoured during the first thirty-six hours of her confinement. It is said to place a small nest of feathers at the end of the hole, in which are deposited five white eggs.”
The eggs of the var. cunicularia are of a rounded-oval shape, more obtuse at one end than at the other, measure 1.30 inches in length by 1.05 in breadth, and are of a uniform white color, with a slightly bluish tinge.
6885 ½ nat. size.
Strix pratincola. (See page 10.)
The egg of the A. hypogæa is of a rounded-oval shape, equally obtuse at either end, and averages 1.35 inches in length by 1.13 in breadth, and is of a uniform clear white color. This description is taken from an egg obtained by Mr. E. S. Holden near Stockton in California. Captain Bendire writes that he has found as many as nine, and once even ten, eggs in the nest of the North American species.
NOTE
The crania of the Owls present many features of interest, which may serve a good purpose in the definition of the sections and the genera, and to which attention has been occasionally called in the preceding pages. The tendency to asymmetry is especially marked in some species, and the better to illustrate this and other features we append several plates, in which the corresponding views are placed side by side.39 The figures and accompanying lettering tell their own story, without any necessity of a labored description.
Syrnium aluco (copied from Kaup).
Athene noctua (from Kaup).
Nyctale richardsoni.
7449.
428.
4886.
7272.
7899.
414.
773.
628.
7897.
437.
7449. Strix pratincola. Natural size.
4886. Otus wilsonianus. Natural size.
7272. Scotiaptex cinereum. Two thirds.
7899. Nyctale richardsoni. Natural size.
414. Scops asio. Natural size.
773. Bubo virginianus. Two thirds.
628. Nyctea nivea. Two thirds.
7897. Surnia ulula. Natural size.
428. Glaucidium ferrugineum. Natural size.
437. Spheotyto hypogæa. Natural size.
428.
7449.
4886.
7272.
We give, above, three well-marked illustrations of asymmetry: two relating to the auditory apparatus of the two sides of the head, and one of opposite sides of the skull.
