Island Scrub-Jay

Scientific Name
Aphelocoma insularis
Family
Genus
Conservation Status
Vulnerable (VU)

Recent Nearby Sightings

View all 3 sounds

Range Map

Island Scrub-Jay Images

Wikipedia Article

The Island Scrub Jay (Aphelocoma insularis) also Island Jay or Santa Cruz Jay is a bird in the Aphelocoma (scrub jay) genus which is endemic to Santa Cruz Island off the coast of Southern California. It is closely related to the "California" Scrub Jay – the coastal population of Western Scrub Jay found on the adjacent mainland – but differs in being larger, more brightly colored, and having a markedly stouter bill. The large bill size is related to its diet, incorporating the thick-shelled acorns of the Island Oak (Quercus tomentella). They will bury, or cache, the acorns in the fall and may eat them months later. They also eat insects, spiders, snakes, lizards, mice and other birds' eggs and nestlings.
The Island Scrub Jay was first described by American ornithologist Henry Wetherbee Henshaw in 1886. This bird is a member of the crow family, and is one of a group of closely related North American species named as scrub jays. These were formerly often considered as a single species, the Scrub Jay, Aphelocoma coerulesens, with five subspecies, but full species status is now normally given to the Florida Scrub Jay, A. coerulesens, the Island Scrub Jay, and the Western Scrub Jay, A. californica, the latter having three subspecies across its extensive range. The relationships within the genus are not fully resolved: the Western Shrub Jay subspecies A. c. californica may be another candidate for species status, and some authorities already split it into Californian Scrub Jay, A. californica, and Woodhouse's Scrub Jay, A. woodhouseii. The DNA studies also indicate that the island and coastal forms have long been isolated from their relatives inland. The scrub jays seem to be incapable of crossing significant bodies of water. The Island Scrub Jay has never been recorded on neighboring Santa Rosa Island, only about 10 km (6 mi) away, and there are no definite occurrences of a scrub jay on any other of the Channel Islands, or on the Coronado Islands, only 13 km (8 mi) from the mainland. It has been suggested that the ancestor of the present population was storm-borne or carried on driftwood to Santa Cruz, or that the colonization occurred during a period of glaciation 70,000 to 10,000 years ago, when sea levels were much lower and the channel between the coast and the islands was correspondingly narrower. More recent DNA studies show that, although other island endemics such as the Island Fox and the Santa Cruz Mouse may have diverged from their mainland relatives around 10,000 years ago, the scrub jays separated in a period of glaciation around 150,000 years ago. Up to about 11,000 years ago, the four northern Channel Islands were one large island, so the ancestral Island Scrub Jay must have been present on all four islands initially, but became extinct on Santa Rosa, San Miguel and Anacapa after they were separated by rising sea levels.
The Island Scrub Jay is found only on Santa Cruz Island, the largest of California's Channel Islands with an area of 250 km2 (96 mi2). The island is a nature reserve, the eastern 24% being administered by National Park Service as the part of the Channel Islands National Park and the rest of the island by the Nature Conservancy. The Island Scrub Jay is not known to have occurred anywhere else historically, and no fossil remains have been found on the well-researched neighboring islands (Curry & Delaney 2002). Females lay 3 to 5 eggs. Incubation lasts approximately 20 days. These jays are monogamous and, unlike some other jays, are not cooperative breeders. Both sexes build a nest to high. The genus name, Aphelocoma, comes from the Latinized Ancient Greek apheles- (from ἀφελής-) "simple" + Latin coma (from Greek kome κόμη) "hair", in reference to the lack of striped or banded feathers in this genus, compared to other jays. The species name, insularis, comes from the Latin for "from an island".
The Island Scrub Jay is classed as vulnerable on the IUCN Red List because its very small range makes it potentially vulnerable to a catastrophic incident. There are no other known threats, and the apparently stable population of at least 9.000 individuals makes this bird common on Santa Cruz. Active conservation is limited to controlling the numbers of introduced sheep and pigs, which have caused habitat degradation in the past. The Chumash people who were the original inhabitants of the northern Channel Islands may have eaten the local scrub jay, or used its feathers for decoration, since they are known to have made feather bands including jay feathers on the Californian mainland. Human activities may have contributed to the presumed extinction of the Island Scrub Jay from the smaller islands.