WatchList Search

Status: Population size: 9,000 Photo by Peter LaTourrette.

Island Scrub-Jay
(Aphelocoma insularis)

This species has been split from the Western Scrub-Jay because of its brighter plumage and different genetic makeup. It is restricted to the island of Santa Cruz off the California coast, where its entire population would be threatened by any major disturbance.

Identification
Like the other scrub-jays, the Island Scrub-Jay has blue upperparts and white underparts with a blue-gray breast band. The species is brighter and more vibrant blue than Western and Florida Scrub-Jay. It is also distinguished from other scrub-jays by its larger size. It has a long tail typical of most other jays. It has a large gray-brown patch on the upper part of its back. Juveniles are grayish-white overall, but have blue wings and tail. They have a raspy "shreep" call, among others. Their undulating flight is similar to that of the Blue Jay, but Island Scrub-Jays lack the white on the tips of the wings and tail.

Distribution and Population Trends
The Island Scrub-Jay is restricted to Santa Cruz Island, the largest and most topographically diverse of the Channel Islands. Santa Cruz is 29 km off the coast of California and directly south of Santa Barbara. The Channel Islands IBA recognizes the importance of the islands to this specialized bird and other endemics.

Ecology
This species breeds in coast live oak woodland or chaparral dominated by scrub oak. A permanently monogamous pair defends territories formed in the breeding season throughout the year. Most foraging and other maintenance activities occur inside territory boundaries, with territory boundaries being stable from year to year. Agonistic behaviors for defending territories include mostly vocalizations and chasing, although dominant jays have been observed pecking subordinate individuals. Breeding habitat appears to be saturated on the island, causing young individuals to delay breeding for up to several years. Unlike the Florida Scrub-Jay, this species does not cooperatively breed. Until breeding space becomes available, unmated individuals use marginal habitats not suitable for breeding. Nonbreeders do not defend territories, but rather forage and roost in loose groupings or on their own.

Nesting peaks during the last two weeks in March when the chaparral plants are flowering and growing new leaves. This period also coincides with an increase in arthropod abundance, indicating that this may be a strong influence on the timing of nesting in Island Scrub-Jays. Nests are located in dense bushes and trees and are often well-concealed. Nests are constructed of coarse sticks, lined with finer twigs and rootlets, and can be placed anywhere from ground level to 12 m off the ground. Two to five eggs are laid, but nest predation by snakes, Western Spotted Skunk, Island Fox, Common Raven, and possibly other Island Scrub-Jays is high. However, once the chicks fledge, average life expectancy is 4.8 years.

Threats
The population is endemic to the island of Santa Cruz, which makes it susceptible to any major disaster, a disease outbreak, or widespread land-use changes, any of which could potentially wipe out the population or cause a severe population decline. Habitat on the island has been negatively impacted by introduced sheep and goats.

Conservation
The Channel Islands are afforded some protection via the Channel Islands National Park. Some work is underway to control introduced sheep and pigs which have severely degraded habitat on the islands.

What Can You Do?
Audubon's Important Bird Area program is a vital tool for the conservation of Island Scrub-Jays as well as other species. To learn more about the Important Bird Areas program, and how you can help, visit: http://www.audubon.org/bird/iba/.

References
Atwood, J. L. 1980. Social interactions in the Santa Cruz Island Scrub Jay. Condor 82:440-448.

Atwood, J. L. 1980. Breeding biology of the Santa Cruz Island Scrub Jay. Pp. 675-688 in D. M. Power, ed., The California Islands: Proceedings of a multidisciplinary symposium. Santa Barbara Museum of Natural History, Santa Barbara, California.

Madge, S. and H. Burn. 1994. Crows and Jays: A guide to the crows, jays, and magpies of the world. Houghton Mifflin Company, Boston.