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Plate XXXIII.—SCOPS ASIO, (Linn.) Bonaparte.—Mottled Owl
Throughout the temperate regions of North America few species among our nocturnal birds of prey have a wider distribution. In New England, and the Middle, Southern and Western sections of our country, it is more or less common, but on the Pacific as far north as Sitka, it gives place to a different and well-marked variety, one whose habits are not materially dissimilar to our Eastern form. McIlwraith gives it as a resident in portions of Canada, near Hamilton and around Montreal, but further north, if it appears at all, it is notably scarce. In the Arctic regions it is evidently unknown, if the failures on the part of Richardson and others to mention it in their travels afford any basis of judgment. Towards the extreme limits of its range there is reason to believe that it prevails in smaller numbers than elsewhere. In Pennsylvania and New Jersey, where its habits have been especially studied by the author, it is our most abundant species.
It courts rather than shuns human society. In some rural districts this familiarity is more manifest than in others, particularly where unduly harassed by boys and equally offensive birds. The immense good which these Owls accomplish in the destruction of vermin should command for them proper respect, but the most cruel persecutions are the only reward which they receive. The evil which some of their less scrupulous and larger brethren commit, reflects upon them, and they, through ignorance and superstition, are made the scape-goats for a multiplicity of sins. But fortunately there are localities where they are held in high estimation by persons of sense and education, and amply recompensed. Here they become remarkably unsuspicious, nesting and roosting in hollow trees, and even venturing into barns and out-buildings to spend the night.
More eminently nocturnal than any of its kind, it does not emerge from its darksome quarters until the day has expired, and gloomy night has assumed the rod of empire. In the uncertain twilight a few individuals, pressed by hunger, may often be seen abroad, but it is not until every trace of day has been obliterated that we find the majority on the wing, in noiseless pursuit of game. When aroused during the daytime its movements are somewhat dubious, and it acts very much like a child who has been awakened from a sound sleep in the midst of a brilliantly-lighted room. In cloudy weather less difficulty is experienced, and its actions are freer. Young birds seem to be better adapted to sunlight than their parents. May it not be that the constant habit of sleeping during the day, consequent upon a night's carousal, has so weakened the visual organs as to render them ill-fitted for day-toil? Animals, accustomed to diurnal occupations, suffer considerable inconvenience for a while when compelled to work at night. A return to day-labor is attended, though perhaps in a less degree, by the same discomfort. The irides undoubtedly habituate themselves to a reversal of habit. It is a notorious fact that the young of the Great-horned Owl can endure the intense light of the sun almost equally with the Eagle, although being mainly nocturnal in habits. It is brought about by the voluntary, rather than the automatic, movements of the iris. This fact associated with the already mentioned circumstance in the history of the present species, strongly favors the hypothesis that all our Owls can in time adapt themselves to a change of habit pari passu with visual modification, as instanced in the case of the Day Owl.
Appetitive gratification is the sole engrossing thought of these birds outside of the mating season. While they devote much of their time veering through the atmosphere in quest of insects which contribute largely to their diet, still they do not deem themselves too aerial to descend to the earth at times when some purpose is to be subserved. They are fond of low meadows, and even premises adjoining barns, barracks, etc., where they make terrible onslaughts upon the small quadrupeds which infest such places. Sailing above the tall grasses, the smallest creature is readily descried, and almost in the twinkling of an eye is captured and borne away in the vice-like bill, or firm grasp of the more powerful claws. When pressed for food they often conceal themselves behind tufts of grasses, and await the appearance of their quarry, or even visit our smaller birds upon their perches.
The nightly rampage of the Mottled Owl is always heralded by a peculiar plaintive cry which strongly resembles the whinings of young puppies. It alternates from high to low, and is occasionally varied by deep guttural trills. From dusk until the clock has ushered in the wee hours of the morning the ear of night is startled by these lugubrious utterances. By some they are supposed to be intended as a summons from the female to her partner, and vice versa. As they are chiefly heard while in pursuit of prey, it is more than probable that they are designed to startle small birds from their coverts, and thus insure their easy capture. The representation of the notes may be quite accurately expressed by wha-a-a-a-a.
Life without variety soon becomes monotonous, and in the case of the human animal often leads to unpleasant results. With birds the dreary autumnal and wintry days, which are spent in sleep and in contriving means for obtaining a subsistence, are no longer a source of enjoyable pleasure when spring returns, and we discover when the proper time arrives that everywhere there exists a feeling to throw off the shackles of such an existence, and to take on newer relationships. This varies with the character of the weather. During favorable seasons the time is earlier, but when the advancing steps of milder days are retarded by frosts and snows, there is sometimes a delay of a fortnight. Not so with the Mottled Owls. The period of mating with them usually begins quite early, on or about the fifteenth of March in extreme southern latitudes, but as late as the tenth of April in cooler northern sections. In the Middle Atlantic States the time varies from the twentieth of March to about the fifth of the succeeding month. It is then that the sexes manifest more than the usual affection for each other. Their courtship is brief, and business is entered into without the display of any of those amusing antics which pre-eminently mark the smaller oscines. The males, according to our experience, seem to select the same partners on each recurrence of the breeding-time, where not debarred by various fortuitous circumstances. As a proof of this position, we might instance a case. In the vicinity of Philadelphia a pair of birds once laid claim to a particular tree on the premises of a kind-hearted gentleman, who would not suffer them to be disturbed. The breeding-season being over, the female retained possession of the cavity which she had used while rearing her young, and the male sought shelter in the same clump of trees, but in a different hollow. As these were the only birds in that locality, and were observed to occupy the same spot for two successive years, there can be no reason to dispute the above question. By the law of analogy, we presume that others do likewise.