The names and descriptions now given comprise all that have come under our notice, represented as inhabiting North America within our limits.
Of the birds of this family, the names proposed by the older American naturalists and others, are not numerous; and though the group may be regarded as presenting some difficulties to the student, the correct nomenclature of North American species is not difficult to determine. Bartram enumerated six species (Travels, p. 285), to all of which, except one, he gives names for the first time employed to designate the birds to which he alludes, and to a few of which he attaches sufficient descriptions. All of his species had, however, been previously described, and we have, we believe, cited his names as synonymes, so far as they can be ascertained.
The greatest difficulty in the study of the Owls of North America will be found in the intimate resemblance that a few species bear to others of Europe and Asia, and, we may add, in the examination of the birds which we have given in the preceding pages as varieties of the Great-horned Owl (Bubo virginianus). The variations that we have noticed, and especially those of color, may be ascertained by subsequent observation to be so uniform and constant as to constitute specific distinction, though at present we cannot so regard them.
In the Owls of other countries there are several groups in which it is very difficult to determine the species, on account of their resemblance to each other. This is especially the case with the small species of the genus Scops, which inhabit India and other countries of Asia; and there are, too, many of the birds of this genus, of all countries, that are exceedingly perplexing. In fact, we would hardly recommend a student in natural history to begin General Ornithology with the Owls.
With this family we conclude the rapacious Birds.
BUTEO INSIGNATUS.—(Cassin.)
The Brown Buzzard.
PLATE XXXI.—Adult Male and Young Female.
One of the most remarkable facts in the geographical distribution of the birds of western and northwestern North America is, that many species extend their range in northern latitudes almost or quite to the shores of the Atlantic ocean, while not a single instance is on record of the same species having been observed in either of the middle or southern States of the Union. The Magpie, which on the Pacific is commonly found southwardly as far as Mexico, has been noticed by Dr. Hoy, at Racine, in the State of Wisconsin. The Lark Bunting (Emberiza grammaca), another western bird, has also been ascertained by the same gentleman to be abundant in the State just mentioned; and the only specimen that we have ever seen of the Stone Chat of America (Saxicola œnanthoides), a bird discovered some years since on the coast of Oregon, was obtained in the vicinity of Halifax, Nova Scotia.
Many instances tending to demonstrate this extensive and remarkable migration might be produced, but we have unfortunately to acknowledge ourselves unable to offer a theory or even hypothesis attempting to account for it, and must regard the facts as remaining among many in natural history with which naturalists are for the present under the necessity of resting, without inference or application to any established general principles. Important results will yet reward American naturalists who may engage in this interesting field of scientific research.
Instinct is little or nothing more than inherited memory. But we are by no means satisfied that any definition which we have yet met with of the faculty known by the latter name is strictly correct. Whatever memory is, that inherited we are disposed to regard as instinct. And that the impressions on this faculty are transmissable in animals from parents to their offspring, we regard the migration of young birds, particularly those of a first brood, when the parents remain to attend to a second, as clearly substantiating.
The bird now before the reader is a species that appears to perform the extended northward migration to which we have alluded, and is one of the most remarkable instances that has come to our knowledge. It was first described by us from a specimen obtained in the vicinity of Montreal, Canada, and the only instance of its having been observed since, has been by Dr. Heermann, in California; though if ever occurring in the middle or southern States on the Atlantic, in the same latitude as on the Pacific, it has escaped the researches of all previous naturalists or travellers.