{{Short description|Species of rodent}} {{Speciesbox | image = Deer Mouse in Tree (6438329699).jpg | image_caption = In Linn County, Kansas | taxon = Peromyscus sonoriensis | authority = (Le Conte, 1853) }}
The '''western deermouse''' or '''western deer mouse''' ('''''Peromyscus sonoriensis''''') is a rodent native to North America. It is a species of the genus ''Peromyscus'', a closely related group of New World mice often called "deermice". It is widespread throughout the western half of the continent, mainly in areas west of the Mississippi River.<ref name="Greenbaum2019">{{cite journal|author=Greenbaum, I. F. |display-authors=etal|date=October 2019|title=Taxonomy and phylogenetics of the ''Peromyscus maniculatus'' species group|url=https://www.researchgate.net/publication/336616821|journal=Special Publications, Texas Tech University|volume=71|pages=559–575}}</ref>
== Taxonomy == It was formerly confused with the eastern deermouse (''P. maniculatus''), with both species being grouped under ''P. maniculatus'' as the North American deermouse.<ref>{{Cite web|title=Explore the Database|url=https://www.mammaldiversity.org/explore.html#species-id=1002336|access-date=2021-06-19|website=www.mammaldiversity.org|archive-date=2020-10-28|archive-url=https://web.archive.org/web/20201028140029/https://www.mammaldiversity.org/explore.html#species-id=1002336|url-status=dead}}</ref> However, due to the significant morphological variation in the species, there was always long-standing confusion over the actual taxonomy of ''P. maniculatus''. A 2019 study found significant genetic divergence within the species and split it into two, with ''maniculatus'' representing the "eastern" group and ''sonoriensis'' representing the "western" group.<ref name="Greenbaum2019" />
== Description == ''P. sonoriensis'' is a short-tailed deermouse with a distinctive white underside and white feet. Their coat color ranges from fulvous to brownish. They can be mistaken for the eastern deer mouse, which is indistinguishable except by range, or for the white-footed mouse, which has a tail with indistinct bicoloring. Their range splits with the eastern deer mouse along the Mississippi River. They weigh between 15 and 32 grams and are usually around 170 millimeters long.<ref name="TTUUpdate2019">{{cite journal |last1=Bradley |first1=Robert |title=Mitochondrial DNA Sequence Data Indicate Evidence for Multiple Species Within Peromyscus maniculatus |journal=Museum of Texas Tech University |date=10 October 2019 |volume=70 |url=https://www.depts.ttu.edu/nsrl/publications/downloads/SP70.pdf |access-date=26 November 2024}}</ref><ref name="Mammal">{{cite web |title=Peromyscus sonoriensis |url=https://www.mammaldiversity.org/taxon/1002336 |access-date=26 November 2024}}</ref><ref name="Greenbaum2019" />
== Distribution and habitat == ''Peromyscus sonoriensis'' is an abundant species in areas of North America west of the Mississippi River. They are populous in the western mountains and live in wooded areas and areas that were previously wooded.<ref name="Sierra">{{cite journal|author=Jameson, E W|year=1952|title=Food of Deer Mice, ''Peromyscus maniculatus'' and ''P. boylei'', in the Northern Sierra Nevada, California|journal=Journal of Mammalogy|volume=33|issue=1|pages=50–60|doi=10.2307/1375640|jstor=1375640}}</ref> Deer mice inhabit a wide variety of plant communities including grasslands, brushy areas, woodlands, and forests.<ref name="r127">Whitaker, John O., Jr. (1980). ''National Audubon Society field guide to North American mammals.'' New York: Alfred A. Knopf, Inc.</ref> In a survey of small mammals on 29 sites in subalpine forests in Colorado and Wyoming, the deer mouse had the highest frequency of occurrence; however, it was not always the most abundant small mammal.<ref name="r95">Raphael, Martin G. (1987). Nongame wildlife research in subalpine forests of the central Rocky Mountains. In: Management of subalpine forests: building on 50 years of research: Proceedings of a technical conference; 1987 July 6–9; Silver Creek, CO. Gen. Tech. Rep. RM-149. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station: 113–122</ref> Deer mice were trapped in four of six forest communities in eastern Washington and northern Idaho, and they were the only rodent in ponderosa pine (''Pinus ponderosa'') savanna.<ref name="r55">{{cite journal|last1=Hoffman|first1=G. R.|year=1960|title=The Small Mammal Components of Six Climax Plant Associations in Eastern Washington and Northern Idaho|journal=Ecology|volume=41|issue=3|pages=571–572|doi=10.2307/1933338|jstor=1933338|bibcode=1960Ecol...41..571H }}</ref><ref>{{cite web |last1=Sullivan |first1=Janet |title=Peromyscus maniculatus |url=https://www.fs.fed.us/database/feis/animals/mammal/pema/all.html |publisher=Fire Effects Information System, US Forest Service |access-date=20 June 2021 |work=Index of Species Information |date=1995}} {{PD-notice}}</ref>
Although found throughout most of western North America, it is absent from parts of the Southwestern United States and most of Mexico, where it is instead replaced with the similar southern deer mouse (''P. labecula''), cactus mouse (''P. eremicus''), and black-eared mouse (''P. melanotis''); Baja California and most of California south of San Francisco Bay, where it is replaced by Gambel's deer mouse (''P. gambelii''); and the coastal region of the Pacific Northwest from Washington northwards, where it is replaced by the northwestern deer mouse (''P. keeni''), and Yukon in Canada, where it is replaced by the Yukon deer mouse (''P. arcticus'').<ref name="Greenbaum2019" />
== Reproduction and life span == The species is polygynous, meaning that one male mates with multiple females.<ref>{{Cite book|title=Advances in the study of Peromyscus (Rodentia)|date=1989|publisher=Texas Tech University Press|others=Kirkland, Gordon L., Layne, James Nathaniel.|isbn=0-89672-170-1|location=Lubbock, Tex., USA|oclc=19222284}}</ref>
=== Breeding season === In Plumas County, California, deer mice bred through December in good mast (both soft and hard masts) years but ceased breeding in June of a poor mast year.<ref name="r3">Baker, Rollin H. (1968). "Habitats and distribution". In: King, John Arthur, ed. ''Biology of Peromyscus (Rodentia)''. Special Publication No. 2. Stillwater, OK: ''The American Society of Mammalogists'' 98–126.</ref> Deer mice breed throughout the year in the Willamette Valley, but in other areas on the Oregon coast there is usually a lull during the wettest and coldest weather.<ref name="r79">Maser, Chris; Mate, Bruce R.; Franklin, Jerry F.; Dyrness, C. T. (1981). Natural history of Oregon Coast mammals. Gen. Tech. Rep. PNW-133. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Forest and Range Experiment Station.</ref> In southeastern Arizona at least one-third of captured deer mice were in breeding condition in winter.<ref name="r17">{{cite journal|last1=Brown|first1=J. H.|last2=Zeng|first2=Z.|year=1989|title=Comparative Population Ecology of Eleven Species of Rodents in the Chihuahuan Desert|journal=Ecology|volume=70|issue=5|pages=1507–1525|doi=10.2307/1938209|jstor=1938209|bibcode=1989Ecol...70.1507B }}</ref>
=== Longetivity and mortality === O'Farrell reported that a population of deer mice in big sagebrush/grasslands had completely turned over (e.g., there were no surviving adults of the initial population) over the course of one summer.<ref name="r88">{{cite journal|author=O'Farrell, Michael J|year=1978|title=Home range dynamics of rodents in a sagebrush community|journal=Journal of Mammalogy|volume=59|issue=4|pages=657–668|doi=10.2307/1380131|jstor=1380131}}</ref>
== Predators == Deer mice are important prey for snakes (Viperidae), owls (Strigidae), minks (''Neovison vison''), martens (''Martes americana'') and other mustelids, as well as skunks (''Mephitis'' and ''Spilogale'' spp.), bobcats (''Lynx rufus''), domestic cats (''Felis catus''), coyotes (''Canis latrans''), foxes (''Vulpes'' and ''Urocyon'' spp.), and ringtail cats (''Bassariscus astutus''). They are also parasitized by ''Cuterebra fontinella''.<ref>{{cite journal|vauthors=Cogley TP|year=1991|title=Warble development by the rodent bot ''Cuterebra fontinella'' (Diptera: Cuterebridae) in the deer mouse|journal=Veterinary Parasitology|volume=38|issue=4|pages=275–288|doi=10.1016/0304-4017(91)90140-Q|pmid=1882496}}</ref>
== References == {{Reflist}}
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Category:Peromyscus Category:Rodents of Canada Category:Rodents of Mexico Category:Rodents of the United States Category:Mammals described in 1853