Pinyon Jay

DISTRIBUTION, ABUNDANCE, AND SEASONALITY

A fairly common but somewhat local, yearlong resident in coniferous habitats east of the Cascade-Sierra Nevada crest from the Oregon border south to vicinity of Walker Pass, Kern Co. Also found in most major desert mountain ranges, including the arid slopes of ranges west of the deserts, from the White Mts. south to the San Jacinto Mts. and west to the Piute Mts. (Kern Co.) and to Mt. Piños. Preferred nesting habitats are pinyon-juniper (juniper may be absent) and eastside pine. Breeders often range into sagebrush, bitterbrush and grassland habitats to forage. Occasionally wanders to cismontane California, even to coast, in flocks in fall and winter.

SPECIFIC HABITAT REQUIREMENTS

Feeding: Omnivorous; feeds on pine seeds, juniper berries, other seeds and fruits, beetles, grasshoppers, caterpillars, ants, many other invertebrates, and rarely lizards. Nesters appear to require pinyon, ponderosa, or Jeffrey pine seeds, which often are cached in soil or crevices in bark near breeding areas. Hammers, pries, and pecks to extract seeds from cones. Gleans foliage and probes bark and crevices for insects, probes in soil for seeds and insects, hunts for insects on ground, and sometimes hawks flying insects.

Cover: Trees of moderate size, especially pinyon and juniper, afford nesting, roosting, and other cover.

Reproduction: Builds bulky, open-cup nest of twigs, bark shreds, grasses, other plant fibers, wool, hair. Usually placed in pinyon or juniper at height of 0.9-6.2 m (3-20 ft), rarely to 25 m (80 ft), in ponderosa or Jeffrey pine.

Water: No additional information found. Eats snow in winter.

Pattern: Nesters most numerous in pinyon, ponderosa, and Jeffrey pine woodlands with sparse to open canopy, and a well-defined understory of sagebrush, bitterbrush, and other shrubs.

SPECIES LIFE HISTORY

Activity Patterns: Yearlong, diurnal activity.

Seasonal Movements/Migration: Usually resident yearlong, but unpredictable desertion of nesting area occurs sporadically, probably when pine seeds are scarce. At such times, may occur on both slopes of the Cascade-Sierra cordillera, rarely wandering westward to the coast or southward into the mountains and coastal plains of southern California.

Home Range: In New Mexico, a flock ranged over 29 km² (11.2 mi²) (Ligon 1971). In Arizona, a flock ranged over 21 km² (8 mi²).

Territory: Includes only nest and eggs.

Reproduction: May breed anytime from February through October if conditions are propitious, but height of egg-laying probably April through June. Colonial nester with up to 3 nests recorded in 1 tree. As many as 54 nests have been found in a 50 ha (124 ac) area, a density of 1 nest per 0.9 ha (2.3 ac). Monogamous; clutch averages 4-5 eggs (range 3-6). Single-brooded; incubation 16-17 days, by female. Both parents care for altricial young, occasionally assisted by other individuals. Fledging age 20-22 days.