Angel Island mouse: Difference between revisions

{{Use dmy dates|date=JulyDecember 20132023}}

| status = CR PE
| status_system = IUCN3.1

| status_ref = <ref name = "iucn status 12 November 2021">{{IUCN2010.4cite iucn |assessorsauthor= Álvarez-Castañeda, S.T., Castro-Arellano, I., |author2=Lacher, T. & |author3=Vázquez, E.|year= 2008|iddate=2018 16664|title= ''Peromyscus guardia'' |downloadedvolume=2018 5|page=e.T16664A22359973 |doi=10.2305/IUCN.UK.2018-2.RLTS.T16664A22359973.en |access-date=12 MarchNovember 20112021}}</ref>

| regnumgenus = [[Animalia]]Peromyscus

| phylumspecies = [[Chordata]]guardia

The '''Angel Island mouse''' ('''''Peromyscus guardia'''''), or '''La Guarda deermouse''' (''Peromyscus guardia''), is a species of [[rodent]]s in the family [[Cricetidae]].<ref name = MSW3>{{MSW3 Muroidea | id = 13000454 | page = 1068}}</ref>

==Distribution==
It is [[endemism|endemic]] to [[Mexico]], where it is historically known only from the island of [[Isla Ángel de la Guarda|Ángel de la Guarda]], and nearby islets. in the northwestern [[Gulf of California]], [[Baja California]].

The species is believed to be [[local extinction|extirpated]] from the three smaller islands, and may be [[extinction|extinct]] on Ángel de la Guarda, as well. The species is threatened by predation by [[feral cat]]s, 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 {{convert|19|to|22|cm|abbr=on}} in total length, including tails {{convert|9|to|12|cm|abbr=on}} long. Females have four abdominal teats.<ref name=Rios2011>{{cite journal | author author1= Rios, E. & |author2=Álvarez-Castañeda, S.T. | year = 2011 | title = ''Peromyscus guardia'' (Rodentia: Cricetidae) | journal = Mammalian Species | volumeissue = 43 | issue = 1 | pages = 172–176 | doi = 10.1644/885.1| doi-access = free }}</ref>

The Angel Island mouse is endemic to Ángel de la Guarda Island, a mountainous {{convert|359|mi2|abbr=on|adj=on}} 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.<ref name=Rios2011/>

The Angel Island mouse is believed to be descended from an isolated population of [[cactus mouse|cactus mice]],<ref name=Lawlor1971>{{cite journal | author = Lawlor, T.E. | year = 1971 | title = Evolution of ''Peromyscus'' on northern islands in the Gulf of California, Mexico | journal = Transactions of the San Diego Society of Natural History | volume = 16 | issue = 5 | url=httphttps://www.biodiversitylibrary.org/page/4303230 | pages = 91–124| doi = 10.5962/bhl.part.15456 | doi-access = free }}</ref> possibly belonging to the ''P. e. fraterculus'' species or subspecies<ref name=Riddle2000>{{cite journal | author = Riddle, B.R. ''et al.'' | year = 2000 | title = Phylogeography and systematics of the ''Peromyscus eremicus'' species group and the historical biogeography of the North American warm regional deserts | journal = Molecular Phylogenetics and Evolution | volume = 17 | issue = 2 | pages = 145–160 | doi = 10.1006/mpev.2000.0841|display-authors=etal | pmid=11083930}}</ref> The critically endangered [[San Lorenzo Mouse|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 [[IceLast AgeGlacial Period|last ice age]].<ref name=Avise1974>{{cite journal | author = Avise, J.C. ''et al.'' | year = 1974 | title = Biochemical polymorphism and systematics in the genus ''Peromyscus'': V. Insular and mainland species of the subgenus ''Haplomylomys'' | journal = Systematic Zoology | volume = 23 | issue = 2 | url=http://sysbio.oxfordjournals.org/content/23/2/226.full.pdf+html | pages = 226–238 | doi=10.2307/2412134|display-authors=etal| jstor = 2412134 }}</ref> The two species remain able to interbreed, although it is not known whether the resulting hybrids are fertile.<ref name=Rios2011/> Little is known of the behaviour or detailed biology of the species, although it is believed to breed in the spring.<ref name=Rios2011/>

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.<ref name=Banks1967>{{cite journal | author = Banks, R.C. | year = 1967 | title = The ''Peromyscus guardia–interparietalis'' complex | journal = Journal of Mammalogy | volume = 48 | issue = 2 | jstor=1378023 | pages = 210–218 | doi=10.2307/1378023| doi-access = free }}</ref> 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 mouse|house mice]] and [[black rat]]s, which compete with the endemic species for resources.<ref name="iucn status 12 November 2021" /><ref name=Rios2011/> The subspecies resident on the two northern islets are now listed as [[extinction|extinct]],<ref name=Alvarez2003>{{cite journal | author author1= Álvarez-Castañeda, S.T. & |author2=Ortega-Rubio, A. | year = 2003 | title = Current status of rodents on islands in the Gulf of California | journal = Biological Conservation | volume = 109 | issue = 2 | pages = 157–163 | doi = 10.1016/S0006-3207(02)00121-0}}</ref> 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.<ref name=Vasquez2004>{{cite journal | author = Vázquez-Domínguez, E. ''et al.'' | year = 2004 | title = Extirpation of an insular subspecies by a single introduced cat: the case of the endemic deer mouse, ''Peromyscus guardia'' on Estanque Island, Mexico | journal = Oryx | volume = 38 | issue = 3 | pages = 347–350 | doi = 10.1017/S0030605304000602|display-authors=etal| doi-access = free }}</ref>

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.<ref name=Blazquez2018>{{cite journal |last1= Blázquez |first1= M.C. |last2= Arnaud |first2= G. |display-authors=etal |date= 2018 |title= Stable isotope analyses suggest ''Mus musculus'' occupies the place of the "possibly extinct" ''Peromyscus guardia'' in Angel de la Guarda Island, (Mexico) |journal= Mammal Research |volume= 64 |issue= 1 |pages= 121–125|doi= 10.1007/s13364-018-0382-0|s2cid= 256122735 }}</ref> 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|lc=y}}, it may well be entirely extinct. If the species still survives, it is likely restricted to an area of no more than {{convert|10|km2|abbr=on}}.<ref name="iucn status 12 November 2021" />

{{reflist|2Reflist}}

[[Category:NeotominaePeromyscus]]

[[Category:AnimalsEndemic describedmammals inof 1912Mexico]]

[[Category:EndemicFauna faunaof Gulf of MexicoCalifornia islands]]

[[Category:MammalsEndemic fauna of Mexicothe Baja California Peninsula]]