Nyctale acadica. Adult.
A specimen (15,917, ♂, Dr. C. B. Kennerly, Camp Skagitt, September 29, 1859) from Washington Territory is exactly similar to the young described above. No. 10,702 (Fort Burgwyn, New Mexico; Dr. Anderson) is much like it, but the facial circle is quite conspicuous, the feathers having medial white lines; the reddish-olive of the breast and the fulvous of the belly are paler, also, than in the type. No. 12,866, United States, (Professor Baird’s collection, from Audubon,) is perfectly similar to the last.
My reasons for considering the N. albifrons as the young of N. acadica are the following (see American Naturalist, May, 1872):—
1st. All specimens examined (including Hoy’s type of N. kirtlandi) are young birds, as is unmistakably apparent from the texture of their plumage.
2d. All specimens examined of the N. acadica are adults. I have seen no description of the young.
3d. The geographical distribution, the size and proportions, the pattern of coloration (except that of the head and body, which in all Owls is more or less different in the young and adult stages), and the shades of colors on the general upper plumage, are the same in both. The white “scalloping” on the outer web of the alula, the number of white spots on the primaries, and the precise number and position of the white bars on the tail, are features common to the two.
4th. The most extreme example of albifrons has the facial circle uniform brown, like the neck, has no spots on the forehead, and the face is entirely uniform dark brown; but,
5th. Three out of the four specimens in the collection have the facial circle composed of white and brown streaks (adult feathers), precisely as in acadica, and the forehead similarly streaked (with adult feathers). Two of them have new feathers appearing upon the sides of the breast (beneath the brown patch), as well as upon the face; these new feathers are, in the most minute respects, like the common (adult) dress of N. acadica.
The above facts point conclusively to the identity of the Nyctale “albifrons” and N. acadica. This species is easily distinguishable from the N. tengmalmi, which belongs to both continents, though the North American and European specimens are readily separable, and therefore should be recognized as geographical races.