Island Scrub-Jay likely has the smallest geographic range of any North
American bird species. The entire population is found on one small
island off the coast of California, Santa Cruz Island. There, recent
estimates put the total population at no more than 4,000 individuals, and
there may be as few as 1,000 breeding pairs in existence. While the
current population appears to be stable, given the very small breeding
range, they are susceptible to a single disturbance or disease event.
Given that West Nile Virus has taken a heavy toll on other Jay species in
parts of North America, there is some concern that the arrival of West Nile
Virus on Santa Cruz Island could have a strong negative impact on Island
Scrub-Jay populations. Note that the Island Scrub-Jay, the
Western Scrub-Jay, and the
Florida Scrub-Jay were until
relatively recently all considered one Scrub-Jay species.
Habitat: Found in oak woodlands, or scrub oak
mixed with chaparral, on their small island range on Santa Cruz Island.
Diet: Omnivorous, feeding heavily on insects and
other small invertebrates, but also feeding on seeds, nuts, and acorns, and
less often on small vertebrates and eggs of other birds.
Behavior: Foraging may occur on the ground or in
the foliage and branches of trees and shrubs, depending upon the food item
Nesting: The nest of an Island Scrub-Jay is
constructed of sticks and twigs, lined with finer material such as grasses
and rootlets. It is placed in a shrub or small tree, anywhere from
ground-level to 40 feet up. The female lays between 2 and 5 eggs. The
female alone incubates the eggs, with the male bringing her food during the
incubation period. When the eggs hatch, both parents help tend to and
feed the young. The young leave the nest after about 18 days.
Song: Has a series of harsh calls, usually given
in multiple phrases. Also has some low-pitched clucking sounds.
Migration: Considered a permanent resident on
Santa Cruz Island.
Similar Species: Similar in appearance to the
other Scrub-Jay species, the Western
Scrub-Jay and the Florida
Scrub-Jay. However, the Island Scrub Jay is the only Jay species
found on Santa Cruz Island, so in range, it is unmistakable. They can be
distinguished from the other Scrub-Jay species by their larger size, their
larger and thicker bill, and the increased amount of black on the forehead
and nasal tufts.