The island scrub jay (Aphelocoma insularis), also known as the island jay or Santa Cruz jay, is a bird in the genus, Aphelocoma, which is endemic to Santa Cruz Island off the coast of Southern California. Of the over 500 breeding bird species in the continental U.S. and Canada, it is the only insular endemic landbird species. Description The island scrub jay is closely related to the California scrub jay (the coastal population found on the adjacent mainland), but differs in being larger, more brightly colored, and having a markedly stouter bill. 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. Taxonomy The island scrub jay was first described by American ornithologist Henry Wetherbee Henshaw in 1886 and an archaeological specimen at site SCRI-192 dating from the 1780s-1812 on Santa Cruz Island is the earliest evidence of the bird in the historic period. 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 treated as a single species, the scrub jay (as Aphelocoma coerulesens), with five subspecies, but are now considered four species: the Florida scrub jay (A. coerulescens), the island scrub jay, the California scrub jay (A. californica), and Woodhouse's scrub jay (A. woodhouseii). DNA studies indicate that the island and coastal forms have long been isolated from their relatives inland. The relationships within the genus have been studied in several papers (e.g. ) Island scrub jays seem to be incapable of crossing significant bodies of water. Reliable historical observer records for island scrub jays in addition to Santa Cruz Island include only a single 1892 account on neighboring Santa Rosa Island, only about 10 km (6 mi) away. 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. The historic observation on Santa Rosa Island is supported by an archaeological record of a single island scrub jay femur from a Late Pleistocene-Holocene site (SRI-V-3). Early studies 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