The island scrub jay (''Aphelocoma insularis''), also known as the island jay or Santa Cruz jay, is a bird in the genus, ''

Aphelocoma The passerine birds of the genus ''Aphelocoma'' include the scrub jays and their relatives. They are New World jays found in Mexico, western Central America and the western United States, with an outlying population in Florida. This genus belong ...

'', which is

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

Santa Cruz Island Santa Cruz Island (Spanish language, Spanish: ''Isla Santa Cruz'', Chumashan languages, Chumash: ''Limuw'') is located off the southwestern coast of Ventura, California, United States. It is the largest island in California and largest of the ei ...

off the coast of

Southern California Southern California (commonly shortened to SoCal) is a geographic and Cultural area, cultural List of regions of California, region that generally comprises the southern portion of the U.S. state of California. Its densely populated coastal reg ...

. Of the over 500 breeding bird species in the continental

U.S. The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 states and a federal capital district, Washington, D.C. The 48 contiguous ...

and

Canada Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of coun ...

, it is the only insular

landbird species.

Description

The island scrub jay is closely related to the

California scrub jay The California scrub jay (''Aphelocoma californica'') is a species of scrub jay native to western North America. It ranges from southern British Columbia throughout California and western Nevada near Reno to west of the Sierra Nevada (U.S.), Sie ...

(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 Ornithology, from Ancient Greek ὄρνις (''órnis''), meaning "bird", and -logy from λόγος (''lógos''), meaning "study", is a branch of zoology dedicated to the study of birds. Several aspects of ornithology differ from related discip ...

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 Corvidae is a Cosmopolitan distribution, cosmopolitan Family (biology), family of Songbird, oscine passerine birds that contains the crows, ravens, Rook (bird), rooks, magpies, jackdaws, jays, treepies, choughs, and Nutcracker (bird), nutcrackers ...

, 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 In Taxonomy (biology), biological classification, subspecies (: subspecies) is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (Morphology (biology), morpholog ...

, but are now considered four species: the

Florida scrub jay The Florida scrub jay (''Aphelocoma coerulescens'') is one of the species of scrub jay native to North America. It is the only species of bird endemic to the U.S. state of Florida and one of only 15 species endemic to the continental United Stat ...

(''A. coerulescens''), the island scrub jay, the

(''A. californica''), and Woodhouse's scrub jay (''A. woodhouseii'').

DNA Deoxyribonucleic acid (; DNA) is a polymer composed of two polynucleotide chains that coil around each other to form a double helix. The polymer carries genetic instructions for the development, functioning, growth and reproduction of al ...

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 to the mainland. However they were once present on three of California's northern Channel Islands,

San Miguel Island San Miguel Island ( Chumash: ''Tuqan'') is the westernmost of California's Channel Islands, located across the Santa Barbara Channel in the Pacific Ocean, within Santa Barbara County, California. San Miguel is the sixth-largest of the eight Ch ...

, Santa Rosa Island, and Santa Cruz Island where they persist today. 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. The historic observation on Santa Rosa Island is supported by a Pleistocene archaeological record of a single island scrub jay femur from a Late Pleistocene-Holocene site (SRI-V-3) found by Paul Collins of the

Santa Barbara Museum of Natural History The Santa Barbara Museum of Natural History is a natural history museum in Santa Barbara, California. The Santa Barbara Museum of Natural History organization is a 501(c)(3) non-profit which operates both a flagship Mission Canyon campus locate ...

. There are also two Late Holocene archaeological remains found in San Miguel Island cave sites. There are no definite occurrences of a scrub-jay on any other of the Channel Islands, or on the

Coronado Islands The Coronado Islands (''Islas Coronado'' or ''Islas Coronados''; ; Kumeyaay language, Kumeyaay: ) are a group of islands located off the northwest coast of the Mexico, Mexican States of Mexico, state of Baja California. Battered by the wind and ...

, only 13 km (8 mi) from the mainland. 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 A glacial period (alternatively glacial or glaciation) is an interval of time (thousands of years) within an ice age that is marked by colder temperatures and glacier advances. Interglacials, on the other hand, are periods of warmer climate be ...

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.Atwood, Jonathan L (1980) Breeding biology of the Santa Cruz Island Scrub Jay, pp. 675–688 in More recent DNA studies show that, although other island endemics such as the

island fox The island fox (''Urocyon littoralis'') is a small fox species that is endemic to six of the eight Channel Islands of California. Evolved from their mainland gray fox (''U. cinereoargenteus'') recent and larger ancestor, they diversified into ...

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 151,000 years ago. The most recent analysis indicates that the island scrub jay has been evolving in isolation for approximately one million years, i.e. over multiple glacial cycles. Up to about 11,000 years ago, the four northern Channel Islands were one large island, so island scrub jays must have been present on all four islands initially, but became extinct on Santa Rosa,

San Miguel San Miguel, Spanish for Saint Michael, may refer to: Places Argentina *San Miguel Partido *San Miguel, Buenos Aires * San Miguel, Catamarca * San Miguel, Corrientes * San Miguel, La Rioja *San Miguel Arcángel, a Volga German colony in Adolfo Al ...

and Anacapa after they were separated by rising sea levels.

Distribution and habitat

The island scrub jay is found today only on

, the largest of California's Channel Islands with an area of 250 km² (96 mi²). The island is a

nature reserve A nature reserve (also known as a wildlife refuge, wildlife sanctuary, biosphere reserve or bioreserve, natural or nature preserve, or nature conservation area) is a protected area of importance for flora, fauna, funga, or features of geologic ...

, the eastern 24% being administered by

National Park Service The National Park Service (NPS) is an List of federal agencies in the United States, agency of the Federal government of the United States, United States federal government, within the US Department of the Interior. The service manages all List ...

as the part of the

Channel Islands National Park Channel Islands National Park is a national park of the United States, which consists of five of the eight Channel Islands off the coast of California. Although the islands are close to the shore of the densely populated state, they have been ...

and the rest of the island by the

Nature Conservancy The Nature Conservancy (TNC) is a global environmental organization headquartered in Arlington, Virginia, United States. it works via affiliates or branches in 79 countries and territories, as well as across every state in the US. Founded in ...

. Retrieved 20 May 2012. Fossil remains for island scrub jays have been found on Santa Rosa and San Miguel Islands. Island scrub jays occur in oak chaparral and bishop pine (''

Pinus muricata ''Pinus muricata'', the bishop pine, is a pine with a very restricted range: mostly in California, including several offshore Channel Islands, and a few locations in Baja California, Mexico. Stands of Bishop Pine are also found in Point Reyes Nat ...

'') woodland on Santa Cruz Island. Island scrub jays in pine habitat have longer, shallower bills than individuals in oak habitat; variation in bill shape is heritable, and individuals mate nonrandomly with respect to bill morphology.

Breeding

Females lay 3 to 5 eggs. Incubation lasts approximately 20 days. These jays are generally monogamous and, unlike some other jays, are not cooperative breeders. Both sexes build a nest to above the ground. Further details in.

Etymology

The genus name, ''Aphelocoma'', comes from the

Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

ized

Ancient Greek Ancient Greek (, ; ) includes the forms of the Greek language used in ancient Greece and the classical antiquity, ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), 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

for "from an island".

Conservation status

The island scrub jay is classed as vulnerable on the

IUCN Red List The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is an inventory of the global conservation status and extinction risk of biological ...

because its small range makes it potentially vulnerable to a catastrophic incident such as disease or a large fire that destroys their habitat. Population size in 2008 and 2009 was estimated to be 1700 – 2300, making this one of the rarest songbird species in the United States. The entire range of island scrub jays is currently protected in Channel Islands National Park and the species is not at imminent risk of extinction. However, the establishment of

West Nile virus West Nile virus (WNV) is a single-stranded RNA virus that causes West Nile fever. It is a member of the family ''Flaviviridae'', from the genus ''Flavivirus'', which also contains the Zika virus, dengue virus, and yellow fever virus. The virus ...

(WNV) in southern California in 2003 may pose a threat if it crosses to Santa Cruz Island from the mainland.

Corvid Corvidae is a cosmopolitan family of oscine passerine birds that contains the crows, ravens, rooks, magpies, jackdaws, jays, treepies, choughs, and nutcrackers. In colloquial English, they are known as the crow family or corvids. Curre ...

s are especially vulnerable to WNV. In addition, the increased occurrence of wildfires in southern California may portend a catastrophic fire there. Shrub cover has increased since the removal of

sheep Sheep (: sheep) or domestic sheep (''Ovis aries'') are a domesticated, ruminant mammal typically kept as livestock. Although the term ''sheep'' can apply to other species in the genus '' Ovis'', in everyday usage it almost always refers to d ...

(1980–91) and

feral pig A feral pig is a domestic pig The pig (''Sus domesticus''), also called swine (: swine) or hog, is an omnivorous, domesticated, even-toed, hoofed mammal. It is named the domestic pig when distinguishing it from other members of the g ...

s (2005–07) from Santa Cruz Island, which may increase the fire risk.

Overgrazing Overgrazing occurs when plants are exposed to intensive grazing for extended periods of time, or without sufficient recovery periods. It can be caused by either livestock in poorly managed agricultural applications, game reserves, or nature ...

by non-native

ungulate Ungulates ( ) are members of the diverse clade Euungulata ("true ungulates"), which primarily consists of large mammals with Hoof, hooves. Once part of the clade "Ungulata" along with the clade Paenungulata, "Ungulata" has since been determined ...

s may have caused extirpation of island scrub jays on Santa Rosa Island. Re-establishing a second population of island scrub jays on Santa Rosa Island and San Miguel Island may accelerate the restoration of native plant and tree species because of the scatter-hoarding seed caching behavior of ''Aphelocoma'' species.

Human interaction and uses

The

Chumash people The Chumash are a Native Americans in the United States, Native American people of the central and southern coastal regions of California, in portions of what is now Kern County, California, Kern, San Luis Obispo County, California, San Luis O ...

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.

References

External links

Island scrub jay
– Smithsonian Migratory Bird Center *Audubon WatchList
Island scrub jay
Retrieved 26 February 2007. {{Authority control island scrub jay Island scrub jay Endemic birds of the Western United States Fauna of the California chaparral and woodlands Island scrub jay island scrub jay island scrub jay Native birds of the Western United States Taxobox binomials not recognized by IUCN