Corvidae (Crows and Jays)
Steller's Jay,Cyanocitta stelleri. (Fig. 11.25) Male length 10 3/4 in (27.5 cm), female length 10 1/2 in (26.5 cm); male weight 3 7/10 oz (105 g), female weight 3 1/2 oz (98 g). Fairly common permanent resident locally in the White-Inyo Range. Recorded between 6,200 and 9,500 ft (1,890 and 2,900 m).
Most records of this jay are from streamside willows and aspens, especially where the latter are mixed in canyon bottoms with large Singleleaf Pinyons or, at higher elevations, with Bristlecone and Limber pines. Diet is exceptionally varied; conifer seeds, fruits, large adult insects, caterpillars, and eggs and young of small birds are all devoured. Steller's Jays are also known to pilfer the seed stores of the Clark's Nutcracker. Nests in the White Mountains have been found in dense willow thickets. The breeding cycle starts in early spring so that stubby-tailed young, attended by
Figure 11.25
Steller's Jay.
parents, can be seen in late May. In other regions, Steller's Jays have been shown to defend group territories, where each pair is dominant to other members of the group on a portion of the total territory. These jays are therefore gregarious year-round. The handsome crest reveals the relative degree of aggressiveness (crest erect) or submissiveness (crest flattened) displayed during interactions with other members of their own species or with potential enemies. Reference: Brown (1964).
Scrub Jay,Aphelocoma coerulescens. (Fig. 11.26) Male length 11 1/2 in (29.3 cm), female length 10 3/4 in (27.3 cm); male weight 2 4/5 oz (79 g), female weight 2 3/4 oz (77 g). Fairly common permanent resident in the White-Inyo Range, from 6,000 to 9,500 ft (1,830 to 2,900 m).
This species occurs in Pinyon-juniper Woodland on the slopes of the White-Inyo Range. Willows in canyon bottoms and groves of Mountain Mahogany are also visited if the preferred Singleleaf Pinyon is nearby. Brush near pinyon is used sparingly. The Scrub Jay is omnivorous wherever it occurs: seeds, nuts, fruits, large insects, and eggs and nestlings of small birds are all taken when available. Pinyon nuts are a particularly important food in these mountains. Scrub Jays living in pinyon
Figure 11.26
Scrub Jay.
woodlands of southeastern California are grayer and have longer, thinner bills than the oak-chaparral birds west of the Sierra Nevada. Presumably, the drabber coloration in the arid pinyon environment aids in concealment, and the bill shape is adapted for extracting pinyon seeds from cones. Reference: Ritter (1983).
Pinyon Jay,Gymnorhinus cyanocephalus . (Fig. 11.27) Male length 10 1/2 in (26.5 cm), female length 10 in (25 cm); male weight 4 oz (112 g), female weight 3 1/2 oz (97 g). Common permanent resident in the White-Inyo Range; recorded between 7,200 and 10,500 ft (2,195 and 3,200 m) elevation. Annual numbers fluctuate dramatically in any one place in concert with the availability of pinyon seeds.
Pinyon Jays are one of the most characteristic species of the interior Pinyon-juniper Woodland. The loud kraw call, given in chorus from the tops of trees or in flight, usually announces the presence of these conspicuous birds. When foraging, garrulous flocks, commonly numbering into the hundreds, sift through arid woodlands and over adjacent sagebrush country. Pinyon seeds are the major component of their diet and are also important in feeding displays and other courtship rituals. During the fall and early winter, large quantities of the seeds are harvested, transported in the throat, and stored on traditional nesting grounds. Because pinyon seed production is highly sporadic, the foraging range as well as the size of the flock depend on local seed availability. Pinyon Jays also eat some insects, which are taken from open ground by probing or from bark crevices. Pairs nest in loose colonies in large pinyons or junipers in fairly open woodland. Like other jays, the Pinyon Jay is very aggressive and will commonly harass hawks and other threatening birds of prey, especially when the latter are near the nesting area. Reference: Balda and Bateman (1973).
Clark's Nutcracker,Nucifraga columbiana. (Plate 11.2) Male length 11 1/2 in (29.5 cm), female length 11 1/4 in (28.7 cm); male weight 5 oz (139 g), female weight 4 5/8 oz (131 g). Common permanent resident in the White-Inyo Range; recorded from 6,800 to approximately 11,000 ft (2,073 to 3,353 m).
The Clark's Nutcracker is one of the more conspicuous species in the region and is commonly seen or heard overhead in a variety of habitats. The loud, grating kraaa call reveals its presence 0.5 mi (0.8 km) away. According to other studies, this species conducts seasonal altitudinal migrations in the Sierra Nevada, and it may show similar behavior in the White Mountains. Summers are commonly spent in the timber at higher elevations, and the onset of winter initiates a downslope movement into Pinyon-juniper Woodland. Although Clark's Nutcrackers are opportunistic feeders, they subsist mainly on the seeds of various conifers. Whitebark Pine and Jeffrey Pine are the primary trees utilized in the Sierra Nevada, but in the virtual absence of these conifers in the White Mountains, the local populations must eat the seeds of Limber pine and possibly Bristlecone Pine; little work has been done to document this, however. Nutcrackers also commonly visit pinyon in the summer, and when pinyon nuts are plentiful, they may be an important food source. This species is known to store vast seed reserves throughout the year in the Sierra Nevada. A small sac behind the tongue, unique to nutcrackers in the crow family, enables individuals
Figure 11.27
Pinyon Jay.
to carry seeds long distances between sources and storage sites. In addition to conifer seeds, Clark's Nutcrackers also eat insects and spiders, especially during the warmer months. Uncommonly, berries, freshly killed vertebrates (small mammals, nestling birds), and carrion are eaten. Nests are preferably built in fairly small conifers such as junipers. Typically, the birds begin nesting in late winter or early spring, so that by early summer the fully grown young are able to accompany their parents on long feeding flights. References: Tomback (1978a, 1978b).
Common Raven,Corvus corax. (Fig. 11.28) Male length 21 3/4 in (55.25 cm), female length 21 1/4 in (54 cm); male weight 2 lb (891 g), female weight 1 7/10 lb (767 g). Relatively common permanent resident at all elevations in the White-Inyo Range.
Although the species is conspicuous, total numbers in the region are probably small. Typically a bird of open country, the species is attracted to carrion of livestock and rabbits, large insects such as grasshoppers, and small mammals. Ravens move long distances daily in search of food. Postbreeding movements bring groups of ravens
Figure 11.28
Common Raven.
to largely barren alpine wastes. Nests are bulky piles of sticks placed on shelves in cliffs; buildings may also be used. The Common Raven is commonly harassed in the air by smaller birds such as American Kestrels and Violet-green Swallows. Our largest perching bird, the Common Raven soars like a hawk near windswept crags and over ridges. Reference: Goodwin (1976).