| Angel Island mouse | |
|---|---|
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Rodentia |
| Family: | Cricetidae |
| Subfamily: | Neotominae |
| Genus: | Peromyscus |
| Species: | P. guardia |
| Binomial name | |
| Peromyscus guardia Townsend, 1912 | |
The Angel Island mouse (Peromyscus guardia), or La Guarda deermouse, is a species of rodent in the family Cricetidae. [2]
It is endemic to Mexico, where it is historically known only from the island of Ángel de la Guarda and nearby islets in the northwestern Gulf of California, Baja California.
The species is believed to be extirpated from the three smaller islands, and may be extinct on Ángel de la Guarda, as well. The species is threatened by predation by feral cats, and by competition from introduced rodents.
The Angel Island mouse has pale grey-brown fur with white underparts and feet, and large, hairless ears. It is most readily distinguished from closely related species on the mainland by subtle characteristics of the skull, or through genetic or biochemical analysis. Adults range from 19 to 22 cm (7.5 to 8.7 in) in total length, including tails 9 to 12 cm (3.5 to 4.7 in) long. Females have four abdominal teats. [3]
The Angel Island mouse is endemic to Ángel de la Guarda Island, a mountainous 359 sq mi (930 km2) island off the east coast of Baja California Sur, and to three much smaller islands in the same group. Within the islands, the species appears to be confined to sandy beaches, and perhaps to rockier areas nearby, and has not been found in the high mountainous terrain that forms most of their land area. [3]
Three subspecies are formally recognised, although two of these are now extinct:
The Angel Island mouse is believed to be descended from an isolated population of cactus mice, [4] possibly belonging to the P. e. fraterculus species or subspecies [5] The critically endangered San Lorenzo mouse, which inhabits a smaller group of islands to the south, may be descended from the same stock, isolated when the islands separated from the mainland as sea levels rose at the end of the last ice age. [6] The two species remain able to interbreed, although it is not known whether the resulting hybrids are fertile. [3] Little is known of the behaviour or detailed biology of the species, although it is believed to breed in the spring. [3]
As recently as the 1960s, the Angel Island mouse was reported to be abundant on at least three of the four islands it was known to inhabit. [7] However, no specimens have been found on the islands since 1991, despite a number of surveys. The main risks to the species come from feral cats, and from introduced house mice and black rats, which compete with the endemic species for resources. [1] [3] The subspecies resident on the two northern islets are now listed as extinct, [8] while the entire population on the southern islet of Estanque was probably driven to extinction by a single cat, present on the island only between 1998 and 1999. [9]
The house mouse now occupies the habitat and the trophic niche that the Angel Island mouse occupied when it was abundant. This replacement of species in a habitat enhances the biotic homogenization of species. [10] The species is currently listed as critically endangered by the IUCN, but since no living specimens have been seen for 20 years, as of 2011 [update] , it may well be entirely extinct. If the species still survives, it is likely restricted to an area of no more than 10 km2 (3.9 sq mi). [1]
Peromyscus is a genus of rodents. They are commonly referred to as deer mice or deermice, not to be confused with the chevrotain or "mouse deer". They are New World mice only distantly related to the common house and laboratory mouse, Mus musculus. From this relative, Peromyscus species are distinguished by relatively larger eyes, and also often two-tone coloring, with darker colors over the dorsum (back), and white abdominal and limb hair-coloring. In reference to the coloring, the word Peromyscus comes from Greek words meaning "booted mouse". They are also accomplished jumpers and runners by comparison to house mice, and their common name of "deer mouse" is in reference to this agility.
Oryzomys nelsoni is an extinct rodent of María Madre Island, Nayarit, Mexico. Within the genus Oryzomys of the family Cricetidae, it may have been most closely related to the mainland species O. albiventer. Since its first description in 1898, most authors have regarded it as a distinct species, but it has also been classified as a mere subspecies of the marsh rice rat (O. palustris).
Burt's deer mouse is a species of rodent in the family Cricetidae. It is endemic to Mexico, where it is found only on Montserrat Island off the east coast of Baja California Sur. The species is threatened by predation by feral cats.
Dickey's deer mouse is a species of rodent in the family Cricetidae. It is endemic to Mexico, being found only on a small island in the Gulf of California. The species is named for Donald Dickey, who sponsored the expedition that first discovered the animal.
The cactus mouse or cactus deermouse is a species of rodent in the family Cricetidae. It is a species of the genus Peromyscus, a closely related group of New World mice often called "deermice". They are native to desert areas of western North America.
Eva's desert mouse is a species of rodent in the genus Peromyscus of the family Cricetidae found only in the Baja California peninsula of Mexico.
Hooper's mouse is a species of rodent in the family Cricetidae. It is the only member of the Peromyscus hooperi species group, and is found only in Mexico. The species is named for Emmett Hooper, a researcher into the taxonomy of the genus Peromyscus.
The San Lorenzo mouse is a species of rodent in the family Cricetidae. It is endemic to Mexico, where it is found only from the islands of San Lorenzo Norte, San Lorenzo Sur, and Salsipuedes off the east coast of Baja California. The species is threatened by predation by feral and domestic cats, particularly on San Lorenzo Sur.
The Tres Marías island mouse or Tres Marías deer mouse is a species of rodent in the family Cricetidae. It is found only on the Islas Marías off the west coast of Mexico. When last assessed, it was common on María Cleofás Island, but rare or absent on the other, more disturbed, islands.
The Puebla deer mouse is a species of rodent in the family Cricetidae. Only two specimens are known, both from Puebla, Mexico, with the last collected in 1947. It is therefore possible that the species is now extinct, although it is currently listed as Critically Endangered by the IUCN.
The black-tailed mouse is a species of rodent in the family Cricetidae endemic to Mexico.
The tawny deer mouse or marsh mouse is a species of rodent in the family Cricetidae. It is found only in Mexico.
The false canyon mouse or Coronados deer mouse, is a species of rodent in the family Cricetidae. It is known only from Coronados Island, a small island in the Gulf of California, part of Baja California Sur, Mexico. The species is threatened by predation by feral cats, and the IUCN has assessed its conservation status as "critically endangered".
The Santa Cruz mouse is a species of rodent in the family Cricetidae. It is endemic to Mexico, where it is found only on two small islands in the southern Gulf of California. Feral cats on Santa Cruz Island are a threat.
Slevin's mouse, also known as the Catalina deer mouse, is a species of rodent in the family Cricetidae. It is endemic to Isla Santa Catalina off the east coast of Baja California Sur, an island with an area of about 40 km2 (15 sq mi), and it is the only native mammal on the island. It is named for Joseph Slevin, a curator at the California Academy of Sciences.
The San Esteban Island mouse is a species of rodent in the family Cricetidae. It is endemic to Mexico, where it is known only from San Esteban Island in the northern Gulf of California.
Winkelmann's mouse is a species of rodent in the family Cricetidae found only in Mexico, and is named for John R. Winkelmann, who collected the first specimens.
The Baja pocket mouse is a species of rodent in the family Heteromyidae. The species occurs in southern California, Baja California and on islands in the Gulf of California.
The Northern Baja deer mouse is a species of deer mouse native to Southern California and the Baja California peninsula as well as several islands in the Gulf of California. P. fraterculus was previously considered a subspecies of the cactus mouse prior to a 2000 study which identified genetic differences and suggested P. fraterculus is more closely related to Eva's desert mouse than to P. eremicus.
Neotoma insularis, the Angel de la Guarda woodrat, is a species of rodent in the family Cricetidae. It is found in the Mexican state of Baja California on Angel de la Guarda Island.
