Editing Kaibab squirrel

{{Short description|Subspecies of rodent found in Arizona}}
{{Subspeciesbox
| name = Kaibab squirrel
| image = Kaibab Squirrel.jpg
| image_caption = In [[Grand Canyon National Park]], [[Arizona]]
| genus = Sciurus
| species = aberti
| species_link = Abert's squirrel
| subspecies = kaibabensis
| authority = [[Clinton Hart Merriam|Merriam]], 1904
}}

The '''Kaibab squirrel''' (''Sciurus aberti kaibabensis'') is a [[tassel-eared squirrel]] that lives in the [[Kaibab Plateau]] in the [[Southwest United States]], in an area of {{Convert|20 by 40|mi|km|abbr=}}. The squirrel's habitat is confined entirely to the [[ponderosa pine]] forests of the North Rim of [[Grand Canyon National Park]] and the northern section of [[Kaibab National Forest]]<ref>{{cite web|url= http://www.nps.gov/history/history/online_books/pwro/wildlife_portfolio/mammal19.htm|title=Kaibab squirrel|publisher=[[National Park Service]]|access-date=October 26, 2013}}</ref> around the town of [[Jacob Lake, Arizona]].

This squirrel is [[Endemism|not found anywhere else in the world]].<ref name=sierraclub>{{cite web|url=http://sierraclub.typepad.com/explore/2012/02/north-kaibab-gateway-to-the-grand-canyon.html|title=North Kaibab Plateau, Gateway to the Grand Canyon|publisher=[[Sierra Club]]|date=February 16, 2012|access-date=October 26, 2013}}</ref> In 1965, {{Convert|200000|acre|km2|abbr=}} of Kaibab squirrel habitat within Grand Canyon National Park and Kaibab National Forest were declared the Kaibab Squirrel [[National Natural Landmark]].<ref name=asr>{{cite web|url=http://www.arizonascenicroads.com/northern/kaibab_plateau_article_2.html|title=Kaibab Plateau – North Rim National Scenic Byway|publisher=Arizona Scenic Roads|access-date=October 26, 2013|archive-date=October 29, 2013|archive-url=https://web.archive.org/web/20131029191840/http://www.arizonascenicroads.com/northern/kaibab_plateau_article_2.html|url-status=dead}}</ref>

==Description==
[[Image:Grand Canyon National Park North Rim - Kaibab Squirrel 0188.jpg|thumb|left|Kaibab squirrel at Grand Canyon National Park North Rim]]
Kaibab squirrels usually have a black belly (which is sometimes gray), white tail, tufted ears and chestnut brown back.<ref name=asr/> The tufts on the ears grow longer with age and may extend {{Convert|1 to 2|in|cm|abbr=}} above the ears in the winter, and may not be visible in the summer.

==Ecology==
[[Image:kaibab-squirrel.jpg|thumb|200px|right|A Kaibab squirrel.]]
The Kaibab squirrel lives in ponderosa pine forests,<ref>{{cite web|url=http://www.jacoblake.com/kaibab_squirrel.html|title=Famous Kaibab White-Tailed Squirrel|access-date=October 26, 2013|archive-url=https://web.archive.org/web/20130615055509/http://www.jacoblake.com/kaibab_squirrel.html|archive-date=June 15, 2013|url-status=dead}}</ref> where it builds its nest out of twigs and pine needles. Kaibab squirrels, ponderosa pines, and the fungi which grow in the vicinity of the ponderosas exist in a [[symbiotic]] relationship. The squirrel eats [[acorn]]s, [[fruit]], and [[fungus|fungi]] (especially an underground truffle),<ref name=sierraclub/> as well as the seeds, bark, and twigs of the trees where it makes its home. The Kaibab squirrel's most significant source of food is the seeds found within ponderosa pine cones.<ref>{{cite journal|author=Woodhouse, S.W.|year=1853|title=Description of a new species of Sciurus|publisher=[[Proceedings of the Academy of Natural Sciences of Philadelphia]]|volume=6|issue=110}}</ref> Young squirrels are born between April and August.

In the past the Kaibab squirrel was given species status (''Sciurus kaibabensis''), but it is now considered a subspecies of the [[Abert's squirrel]] (''Sciurus aberti'').<ref>[http://www.wild-facts.com/2012/wild-fact-212-the-grand-relationship-kaibab-squirrel/ Kaibab squirrel]</ref>

The Kaibab squirrel is an example of [[evolution]] occurring through [[Geographical isolation|geographic isolation]], but not because of the canyon.<ref name=sierraclub/> Compared to the Kaibab squirrel, the Abert's squirrel, with its several [[subspecies]], has a much broader distribution and is found on the South Rim of the Grand Canyon. The difference between North Rim and South Rim Abert's squirrels has given rise to the commonly held but incorrect assumption that the canyon itself acted as a barrier preventing gene flow between the two populations. However, modern Kaibab squirrels are descended from populations of Abert's squirrels that dispersed into the Grand Canyon area following the last Ice Age.<ref>{{cite web|url=http://www.sbs.utexas.edu/levin/bio213/evolution/speciation.html|title=Macroevolution: Species Formation|access-date=October 26, 2013}}</ref>

As the climate warmed, ponderosa pine stands and the Abert's squirrels living there were limited to areas of high elevation like the Kaibab Plateau. These isolated populations eventually became modern Kaibab squirrels and, as the climate cooled again and ponderosa pines once again grew at lower elevations, other Abert's squirrel subspecies returned to the Grand Canyon area, filling in their former niches on the South Rim.

==References==
{{Reflist}}
* "Evolutionary Genetics and Phylogeography of Tassel-Eared Squirrels (Sciurus aberti)" Trip Lamb, Thomas R. Jones and Peter J. Wettstein ''Journal of Mammalogy'' Vol. 78, No. 1 (Feb., 1997), pp.&nbsp;117–133

==External links==
* [http://www.naturephoto-cz.com/kaibab-squirrel:sciurus-aberti-kaibabensis-photo-12832.html Photographs of Kaibab squirrels in the wild]
* [https://www.youtube.com/watch?v=onF75QDwgXE Kaibab squirrel on YouTube]

{{Taxonbar|from=Q1721379}}
{{Authority control}}

[[Category:Sciurus]]
[[Category:Endemic rodents of the United States]]
[[Category:Endemic fauna of Arizona]]
[[Category:Natural history of the Grand Canyon]]
[[Category:Taxa named by Clinton Hart Merriam]]
[[Category:Mammals described in 1904]]