{{Short description|Species of bat}} {{Speciesbox | name = Yuma myotis | image = Myotis yumanensis (Yuma myotis) (11362476624).jpg | status = LC | status_system = IUCN3.1 | status_ref = <ref name="iucn status 18 November 2021">{{cite iucn |author=Solari, S. |date=2019 |title=''Myotis yumanensis'' |volume=2019 |article-number=e.T14213A22068335 |doi=10.2305/IUCN.UK.2019-1.RLTS.T14213A22068335.en |access-date=18 November 2021}}</ref> | genus = Myotis | species = yumanensis | authority = H. Allen, 1864 | range_map = Myotis yumanensis distribution.png }}
The '''Yuma myotis''' ('''''Myotis yumanensis''''') is a species of vesper bat native to western North America.
==Description== The Yuma myotis is a relatively small myotis, measuring {{convert|3.9|to|4.8|cm|abbr=on}} in head-body length, with an average wingspan of {{convert|24|cm|abbr=on}} and a weight of about {{convert|6|g|abbr=on}}. The simple dental formula of a bat species in the genus ''Myotis'' is {{DentalFormula|upper=2.1.3.3 | lower= 3.1.3.3}}, for a total of 38 teeth. This dental formula applies to ''Myotis yumanensis'' as well. Individuals vary in color across their range, and can be anything from dark brown to pale tan, or even greyish. The fur is short and dull, and significantly paler, sometimes even whitish, on the underside of the animal. The tail is {{convert|2.7|to|4.0|cm|abbr=on}} in length, with only the tip extending beyond the edge of the uropatagium. The calcar is long, extending about 60% of the distance from the ankle to the tail, and, unlike that of many other North American species of ''Myotis'', lacks a keel. The feet are large and broad, and the ears moderately long, with a slim, straight tragus. The head has a short, broad snout, and a rounded cranium.<ref name=Braun2015>{{cite journal | author = Braun, J.K. | date = June 2015 | title = ''Myotis yumanensis'' (Chiroptera: Vespertilioindae) | journal = Mammalian Species | volume = 47 | issue = 918 | pages = 1–14 | doi = 10.1093/mspecies/sev001|display-authors=etal| doi-access = free | url = https://zenodo.org/record/5033286 }}</ref>
It is similar to ''Myotis occultus'',<ref>''The Mammals of Texas'' (2004) by David J. Schmidly and William B. Davis, page 90.</ref> but most closely resembles the little brown bat, from which it can only be distinguished through the examination of a number of different features considered together.<ref name=Rodhouse2008>{{cite journal | author = Rodhouse, T.J. | date = December 2008 | title = Field identification of ''Myotis yumanensis'' and ''Myotis lucifugus'': a morphological evaluation | journal = Western North American Naturalist | volume = 68 | issue = 4 | pages = 437–443 | doi = 10.3398/1527-0904-68.4.437| s2cid = 54658662 |display-authors=etal| bibcode = 2008WNAN...68..437R | url = https://scholarsarchive.byu.edu/wnan/vol68/iss4/2 | url-access = subscription }}</ref>
==Distribution and habitat== First described from specimens captured near Fort Yuma, the Yuma myotis is found throughout much of western North America.<ref name="iucn status 18 November 2021" /> It is found in a variety of western lowland habitats, from arid thorn scrub to coniferous forest, but always close to standing water such as lakes and ponds.<ref name=Duff2007>{{cite journal |author1=Duff, A.A. |author2=Morrell, T.E. |name-list-style=amp | date = May 2007 | title = Predictive occurrence models for bat species in California | journal = Journal of Wildlife Management | volume = 71 | issue = 3 | pages = 693–700 | doi = 10.2193/2005-692|bibcode=2007JWMan..71..693D |s2cid=83481662 }}</ref> When not close to a body of water, the Yuma Myotis can be found in the thousands roosting in caves, attics, buildings, mines, underneath bridges, and other similar structures. There is little information on the migration of this species, but there have been recordings in Texas during the winter season.<ref>{{Cite web|url=http://www.nsrl.ttu.edu/tmot/myotyuma.htm|title=The Mammals of Texas - Online Edition|last=H.|first=Allen|date=1994}}</ref><ref>{{Cite web|url=http://animaldiversity.org/accounts/Myotis_yumanensis/|title=Myotis yumanensis|last=Sims|first=Kelly|date=2000|website=Animal Diversity Web}}</ref>
Six subspecies are recognized:<ref name=Braun2015/>
* ''M. y. iambi'' - limited to central Baja California Sur * ''M. y. lutosus'' - Sinaloa to the State of Mexico * ''M. y. oxalis'' - limited to central California * ''M. y. saturatus'' - British Columbia, western Washington and Oregon, and most of California * ''M. y. sociabilis'' - eastern Washington and Oregon, Idaho, western Montana, and north-eastern California * ''M. y. yumanensis'' - south-eastern California, southern Nevada, Utah and Colorado, and across to western Texas and north-western Mexico
==Biology and behavior== Yuma myotis are nocturnal, and forage for insects above the surface of slow moving water or in vegetation close to the water's edge. They are maneuverable fliers, with a wing aspect ratio of about 6.45, and can fly at up to {{convert|9|mph|abbr=on}}.<ref name=Hayward1964>{{cite journal |author1=Hayward, B. |author2=Davis, R. |name-list-style=amp | date = May 1964 | title = Flight speeds in western bats | journal = Journal of Mammalogy | volume = 45 | issue = 2 | pages = 236–242 | doi = 10.2307/1376986|jstor=1376986 }}</ref> Food foraging begins at dusk and finishes a few hours after sunset.<ref>{{Cite book|title=Bats of America|last1=Barbour|first1=Roger W.|last2=Davis|first2=Wayne H.|year=1969|isbn=978-0-8131-1186-5|location=Lexington, Kentucky:The University Press of Kentucky.|url-access=registration|url=https://archive.org/details/batsofamerica0000barb}}</ref> They feed on beetles and soft-bodied insects, but are opportunistic hunters with no preference for particular prey. Instead, they feed on whatever is most common in their areas; for example, they feed primarily on moths in Texas,<ref name=Easteria1972>{{cite journal |author1=Easteria, D.A. |author2=Whitaker, J.O. |name-list-style=amp | date = November 1972 | title = Food habits of some bats from Big Bend National Park, Texas | journal = Journal of Mammalogy | volume = 53 | issue = 4 | pages = 887–890 | doi = 10.2307/1379227|jstor=1379227 | doi-access = }}</ref> but on flies in Oregon.<ref name=Braun2015/> Like most bats, the Yuma Myotis will locate insects in flight by emitting ultrasonic sounds known as echolocation, then they either catch the insects in their mouths or use their tail membranes as a pouch to snag larger insect prey.<ref>{{Cite web|url=http://animaldiversity.org/accounts/Myotis_yumanensis/#food_habits|title=Myotis yumanensis|last=Sims|first=Kelly|date=2000|website=Animal Diversity Web}}</ref>
Although their natural roosts include caves, rock crevices, and hollow trees, they are more commonly found today in artificial structures close to water. In suitable locations, they have been reported to establish colonies with as many as 10,000 members.<ref name=Braun2015/> They are relatively inactive during the winter,<ref name=Boyles2006>{{cite journal | author = Boyles, J.G. | author2 = Dunbar, M.B. | author3 = Whitaker, J.O. | name-list-style = amp | date = October 2006 | title = Activity following arousal in winter in North American vespertilionid bats | journal = Mammal Review | volume = 36 | issue = 4 | pages = 267–280 | doi = 10.1111/j.1365-2907.2006.00095.x | bibcode = 2006MamRv..36..267B }}</ref> spending some of the time in torpor, but probably do not migrate any significant distance.<ref name=Dalquest1947>{{cite journal | author = Dalquest, W.W. | date = July 1947 | title = Notes on the natural history of the bat ''Myotis yumanensis'' in California, with a description of a new race | journal = The American Midland Naturalist | volume = 38 | issue = 1 | jstor=2421638 | pages = 224–247 | doi=10.2307/2421638}}</ref> The echolocation calls of Yuma myotis are frequency modulated and sweep abruptly from 59 to 72 kHz down to 45 to 50 kHz.<ref name=Braun2015/>
Yuma myotis typically undergo a polygynandrous mating system, where a female pairs with several males, each of which also pairs with several different females. Males and females are usually around 1 year old at the time of sexual and reproductive maturity, and they will only produce 1 offspring.<ref>{{Cite web|url=http://animaldiversity.org/accounts/Myotis_yumanensis/#reproduction|title=Myotis yumanensis|last=Sims|first=Kelly|date=2000|website=Animal Diversity Web}}</ref> Mating occurs in the fall, but the females retain the sperm for several months, so ovulation and fertilization will not occur immediately. Young are born between late May and late June, and weigh around {{convert|1.4|g|abbr=on|sigfig=1}} at birth. Initially blind and hairless, their eyes open around the fifth day, and they are completely furred by day nine.<ref name=Braun2015/>
==Conservation== In May 2017, the lethal fungal disease white-nose syndrome was recorded in this species for the first time, in the second recorded case in Washington state.<ref name="WNS May17">{{cite web |url=https://www.whitenosesyndrome.org/blog/researchers-work-stop-spread-white-nose-syndrome-washington |title=Researchers work to stop the spread of white-nose syndrome in Washington |last=Froschauer |first=Ann |date=May 11, 2017 |website=white-nose syndrome.org |publisher=U.S. Fish and Wildlife Service |access-date=May 12, 2017 |archive-date=December 13, 2017 |archive-url=https://web.archive.org/web/20171213013009/https://www.whitenosesyndrome.org/blog/researchers-work-stop-spread-white-nose-syndrome-washington |url-status=dead }}</ref> This discovery brings the total number of bat species affected by the disease up to eight (an additional seven species have been documented with the spores on their bodies, but without the symptoms of the disease).<ref name="affected">{{cite web |url=https://www.whitenosesyndrome.org/about/bats-affected-wns |title=Bats affected by WNS |author=<!--Not stated--> |date=<!--Not stated--> |website=White-Nose Syndrome.org |publisher=U.S. Fish and Wildlife Service |access-date=May 12, 2017 |archive-date=February 15, 2018 |archive-url=https://web.archive.org/web/20180215203922/https://www.whitenosesyndrome.org/about/bats-affected-wns |url-status=dead }}</ref>
==See also== *Bats of the United States *Bats of Canada
==References== {{Reflist}}
{{Myotinae nav}} {{Taxonbar|from=Q2810848}}
Category:Mouse-eared bats Category:Bats of North America Category:Bats of Mexico Category:Bats of the United States Category:Fauna of the Southwestern United States Category:Fauna of the Colorado Desert Category:Fauna of the Great Basin Category:Fauna of the Sonoran Desert Category:Fauna of the Yuma Desert Category:Mammals described in 1864 Category:Taxonomy articles created by Polbot Category:Least concern biota of the United States