Animal Life in the Yosemite
NPS Arrowhead logo

THE BIRDS

CALIFORNIA SPOTTED OWL. Strix occidentalis occidentalis (Xantus)

Field characters.—Of medium large size for an owl, less than that of Great Horned; head round (no ear tufts) (fig. 39f); eyes lead-color (not yellow); plumage brown, with numerous abruptly contrasted white spots in transverse rows. Notes: Varied; perhaps most often a series of yelps like the barking of a small dog.

Occurrence.—Resident in the Transition Zone. Positively identified only in Yosemite Valley, north side, 4000 to 5000 feet altitude, on Sweetwater Creek, 3800 feet, near Feliciana Mountain, and near Bower Cave, 2500 feet. Strictly a night owl, and an inhabitant of woods.

The California Spotted Owl came to our attention first on the evening of October 12, 1914, when we heard its notes from the golden-oak talus near the foot of Yosemite trail, on the north side of Yosemite Valley. These notes differed from those of any other owl of the region, in that they were abrupt rather high-pitched calls, in tone like the distant barking of a dog: whu, whu; whu. The first two were loudest. There was no suggestion of the deep intonation of the Pacific Horned Owl.

Subsequently on many occasions one or more spotted owls were heard near the same place, sometimes farther down toward Rocky Point, but always in or near the golden-oak belt. There could be little doubt that a pair nested there; for the birds were heard at various times throughout the summer of 1915.

The notes were never given until late dusk; for example, on June 7 at 7:50 P.M.; on June 23 at 8:00; on July 24 at 7:32; on July 28 at 7:30; on October 23 at 5:25; and on November 18 at 5:10. It will be observed that these hours closely accord in the changing seasons with a certain degree of darkness.

In only one instance were the numerous attempts to sight this owl in Yosemite Valley successful. On June 23 the first notes for the evening happened to be given by a bird close to the spot where the observer had taken his stand. A little manoeuvering brought the latter beneath the cedar in which the owl was perched; an opening in the foliage permitted a glimpse of its silhouette against the sky; and a quick shot brought it down. Even though here beneath the shaded north wall of the Valley daylight had nearly gone, the bird appeared quite stupid in its lack of fear. The notes heard at this time, close at hand, and as set down at the moment, were thought to resemble the syllables howk, howk, howk, given in a rather hollow tone. The specimen procured was an old female in full molt, evidently long past nesting.

Notes, probably of a spotted owl, were heard at Gentry's, 5800 feet altitude, on the evening of October 24. During the last week of October, similar notes were heard in the vicinity of Feliciana Mountain, 3800 to 4000 feet, which proved unquestionably to be given by a spotted owl. On October 30, at about 8 o'clock in the morning, the same owl note was heard, and presently a California Gray Squirrel began barking furiously. This signal was followed up, but without success. Fifteen minutes later, some kinglets, both Ruby-crowned and Golden-crowned, were heard remonstrating in excited fashion, and their interest was found to focus within a Nuttall dogwood. Scrutiny of this tree resulted in the discovery of what was at first thought to be a big wasp's nest among the branches about forty feet above the ground. This object, however, soon resolved itself into the outlines of an owl, all hunched-up, so as to quite obscure its true identity. The bird was shot and proved to be an old female spotted owl. Mr. C. A. McCarthy, a rancher in the neighborhood, said that a pair of these owls had lived in the vicinity for three years, to his knowledge, and had raised a brood of young each year. He appreciated the birds for the variety of their evening voicings.

In the late afternoon of July 23, 1920, on a wooded ridge-slope near Bower Cave, Mr. Donald D. McLean found himself within hearing of a clamor of bird voices. Following the clue he worked cautiously up the slope and discovered the center of the disturbance to be a spotted owl which was perched in an incense cedar, close to the trunk on a branch about 60 feet above the ground. The throng of excited birds included 19 Blue-fronted Jays, 5 or 6 California Jays, half a dozen California Woodpeckers, one Sierra Creeper, and many Cassin, Hutton, and Warbling Vireos, Black-throated Gray Warblers, and Western Flycatchers.

The stomach of the California Spotted Owl obtained in Yosemite Valley was empty—the bird was waylaid probably too early in the evening for it to have dined. The Feliciana Mountain bird taken in the morning had fared well, its stomach containing a mass of foodstuff in which were recognized parts of a wood rat (Neotoma fuscipes streatori), a white-footed mouse (Peromyscus), and a grasshopper.



<<< PREVIOUS CONTENTS NEXT >>>

Animal Life in the Yosemite
©1924, University of California Press
Museum of Vertebrate Zoology

grinnell/birds52.htm — 19-Jan-2006