Animal Life in the Yosemite
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THE BIRDS

BLACK-BILLED MAGPIE. Pica pica hudsonia (Sabine)

Field characters.—Decidedly larger than any of our jays. Total length about 18 inches. Tail much longer than head and body, streamer-like. Plumage black except for abruptly white belly (pl. 56a) and large white area on hind part of each wing, the latter area showing best in flight. Voice: Not jay-like; various low, chuckling sounds.

Occurrence.—Common resident21 of Transition Zone east of Sierra Nevada, from near Walker Lake eastward to eastern boundary of Yosemite section and beyond. Frequents vicinity of trees and thickets in open country. More or less socially inclined.


21The Yellow-billed Magpie (Pica nuttalli), found in various parts of western California, has been recorded from the west base of the Sierra Nevada both north and south of the Yosemite section and is thus likely to occur within our area; but we did not see or hear anything of it. It differs from the Black-billed Magpie chiefly in the possession of a yellow bill, instead of a black one.


The Black-billed or American Magpie is likely to be one of the first birds to meet the eye of the traveler upon his arrival in the plains-like arid territory east of the Sierra Nevada. In a region where many of the birds and mammals reflect the general tone of their environment by wearing plumage or pelage of a generally pale color, the strikingly contrasted jet black and pure white coloration of the magpie stands out strongly and renders the bird impossible of confusion with any other species in the region.

The deliberate, seemingly slow, aeroplane-like flight of the magpie, with its long tail trailing out behind, makes an impression not soon to be lost. The observer is reminded of the appearance of a black and white ribbon streaming in the wind. Added to this is an illusionary effect in distant flight when the bird seems alternately to appear and disappear as the strokes of the rounded wings in turn hide and expose the large patches of white on the longer flight feathers.

The general demeanor of the Black-billed Magpie appealed to us as being decidedly quieter than that of most of the other members of the jay-magpie-crow family. Its voice is far softer than that of the jays, and it does not 'bawl out' intruders as do those birds. Many of its notes are low and pleasant chuckling sounds, recalling certain notes of the California Thrasher. On one occasion one of our party was attracted by a noise arising in a mountain mahogany bush and sounding like two of the branches rubbing together. It proved to come from a Black-billed Magpie. Even in early fall, when bluejays and nutcrackers are at their noisiest, the magpie is noticeably quiet.

The nests of the Black-billed Magpie are among the most conspicuous of all the bird structures to be seen about Mono Lake. Large to a degree not known even to most hawks, the 'wicker-work' homes of the magpie loom up from afar, sometimes being visible at a distance of half a mile. The large size of the nest is due in part to the quantity of material used, and also to the fact that the nesting cavity is covered by a dome-shaped 'roof' so that the sitting bird or brood is protected from above as well as from below. When our party visited the vicinity of Mono Lake in the fall of 1915 many of these nests were seen; and in the field work in the spring of 1916 a large number were observed, some newly built and occupied by magpies, others constructed in earlier years and often in use by Long-eared Owls. Near the "Salmon Ranch" on the west shore of Mono Lake, on June 19, 1916, fully 20 old nests of this magpie were observed in the course of one morning's visit, several times, in fact, the number of pairs of the birds seen. This testifies to the durability of the nests, some of which undoubtedly last several years, even when not repaired and reoccupied in successive seasons.

A single nest of the Black-billed Magpie was sent to the Museum of Vertebrate Zoology from Laws, Inyo County, southeast of the Yosemite section, and this is the only one available for detailed study. The structure as a whole measures approximately 20 inches in outside diameter, and the height with the dome in place is almost as much; in other words, the nest is practically a sphere of 20 inches diameter. The cavity within is about 7 inches in diameter and the same or slightly more in height. The construction outwardly is loose, many of the twigs being ready to fall away at a touch. The material comprises pieces of all the common woody plants in the vicinity, such as willow, saltbush, and sagebrush. There is an outer portion comprised only of twigs, then a middle framework which includes a considerable amount of mud applied wet, and then the lining of the inner cavity, which consists of small twigs and which is of a relatively soft texture. These three portions grade insensibly into one another. Another nest, found near Mono Lake and measured in the field, was of more compact construction and was neatly lined with fine rootlets and horse-hair. Outside, this nest measured 24 by 18 by 16 inches, while the cavity was about 6 inches in horizontal diameter and 5 inches deep. The nest was placed in a willow thicket, at a height of about 12 feet from the ground. Of the nests found, both new and old, the greater number were placed 10 to 12 feet above the ground in willow thickets and Shepherdia bushes. One was noted only 6 feet above the ground in a Kunzia bush.

The nesting season of this species begins early in the year, before the storms of winter have entirely ceased, and the broods of young are sometimes out of the nest before the willows are in full summer foliage. At the Farrington Ranch near Williams Butte, in 1916, a nest was found with 6 eggs in it on April 27, and another nest with 7 eggs, already about one-third incubated, on May 1. By May 11 all the eggs in one nest had hatched and the oldest members of the brood had their eyes open and their wing quills started. Eight days later, on May 19, the largest member of this same brood was just able to perch on a branch unassisted, and by June 1 this entire brood, as well as another family not noted earlier, had left the nest. On June 3 a young magpie was collected which had its wing feathers still in the sheaths; one taken on June 23 had these feathers nearly full sized. On June 28 a family of young birds almost fully fledged was seen near Mono Lake. The tail in the young birds taken on June 3 and 23 is only partly grown; indeed the full length of the tail seems not to be attained until well on toward the end of the summer. (See pl. 56a).

Residents of the region about Mono Lake were unanimous in condemning the magpie. They accuse the bird of stealing hen's eggs from the farmyards, and, further, of alighting on the backs of horses and cattle to peck at any wounds or open sores, thus preventing such spots from healing. As tending to substantiate the above allegation, one of our party saw a magpie that was making obvious efforts to peck a hole in the back of a cow that was down on the ground, helpless, but still alive. Later, when this cow died, the carcass served as a forage place visited regularly by several magpies.

It might be remarked in passing that Williams Butte, near Mono Lake, is an exceptionally good locality at which to study birds of the family Corvidae. In September, 1915, the Black-billed Magpie and Clark Nutcracker, and the Blue-fronted, Woodhouse and Piñon jays were all seen at that station. At no other locality in this country with which we are familiar can so many members of this family be seen at the same time within a few rods of one another.



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

grinnell/birds96.htm — 19-Jan-2006