View source for Douglas squirrel

{{Short description|Species of rodent}}
{{redirect-distinguish|Chickaree|Chickadee}}
{{distinguish|Douglas ground squirrel}}

{{Speciesbox
| name = Douglas squirrel
| image = Douglas_Squirrel_DSC3742vvc.jpg
| status = LC
| status_system = IUCN3.1
| status_ref = <ref name=iucn>{{cite iucn |last1=Cassola |first1=F. |year=2016 |title=''Tamiasciurus douglasii'' |volume=2016 |errata=2017 |page=e.T42586A115192165 |doi=10.2305/IUCN.UK.2016-3.RLTS.T42586A22250640.en |access-date=30 September 2024}}</ref>
| status2 = G5
| status2_system = TNC
| status2_ref = <ref name=NS>{{cite web |title=Tamiasciurus douglasii {{!}} NatureServe Explorer |url=https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.1156423/Tamiasciurus_douglasii |website=[[NatureServe]] Explorer |access-date=30 September 2024}}</ref>
| genus = Tamiasciurus
| species = douglasii
| authority = ([[John Bachman|Bachman]], 1839)<ref>[http://www.cofc.edu/~waddelle/Bachman1839A.pdf Bachman, J. (1839)] {{webarchive |url=https://web.archive.org/web/20090107190936/http://www.cofc.edu/~waddelle/Bachman1839A.pdf |date=January 7, 2009 }}.  Description of several new Species of American quadrupeds. ''Journal of the Academy of Natural Sciences of Philadelphia, 8'', 57-74.</ref>
| subdivision_ranks = Subspecies
| subdivision_ref = <ref name="Thorington">{{cite book|last1=Thorington|first1=R.W. Jr.|last2=Hoffmann|first2=R.S.|year=2005|pages=754–818|editor1-last=Wilson|editor1-first=D.E.|editor2-last=Reeder|editor2-first=D.M|url=http://www.bucknell.edu/msw3|chapter=Family Sciuridae|chapter-url=https://www.departments.bucknell.edu/biology/resources/msw3/browse.asp?id=12400001|title=Mammal Species of the World: a taxonomic and geographic reference|edition=3rd|publisher=The Johns Hopkins University Press|isbn=0-8018-8221-4|oclc=26158608}}</ref>
| subdivision = * ''T. d. douglasii''
*''[[Mearns's squirrel|T. d. mearnsi]]''
* ''T. d. mollipilosus''
| range_map = Tamiasciurus douglasii map.svg
| range_map_caption = Range (does not include ''T. d. mearnsi'')
}}

The '''Douglas squirrel''' ('''''Tamiasciurus douglasii''''') is a [[pine squirrel]] found in western [[North America]], from the [[Pacific Northwest]] (including the northwestern coastal states of the [[United States]] as well as the southwestern coast of [[British Columbia]] in [[Canada]]) to central [[California]], with an isolated subspecies in northern [[Baja California]], [[Mexico]]. It is sometimes known as the '''chickaree''' or '''pine squirrel''', although these names are also used for the [[American red squirrel]].  [[Variant spellings]] of the [[common name]] are '''Douglas' squirrel''' and  '''Douglas's squirrel'''. The [[Native Americans in the United States|Native Americans]] of [[Kings River (California)|Kings River]] called it the "Pillillooeet", in imitation of its characteristic [[alarm call]].<ref name="Muir">{{cite book|last1=Muir|first1=John|year=1989|pages=173|chapter=The Douglas Squirrel |title=The Mountains of California |publisher=The Sierra Club|isbn=0-87156-663-X}}</ref>

==Description==
[[John Muir]] described the Douglas squirrel as "by far the most interesting and influential of the California [[Sciuridae|Sciuridæ]]". At full maturity, it is about {{cvt|33|cm}} in length (including its tail, which is about {{cvt|13|cm|0}} long), and weighs between {{cvt|150 and 300|g}}. Its appearance varies according to the season. In the summer, it is greyish or almost greenish-brown on its back, and pale orange on the chest and belly, while legs and feet appear brown. In the winter, the coat is browner and the underside is grayer; also, the ears appear even tuftier than they do in summer. Like many squirrels, the Douglas squirrel has a white eye-ring.

[[Image:Tamiasciurus douglasii 37808.JPG|thumb|[[Anacortes Community Forest Lands]] ([[Washington (state)|Washington]])]]

==Breeding==
Mating can occur as early as February. Gestation is about four weeks, and the young (which are [[altricial]]) are weaned at about eight weeks of age. There may be up to six kits in a litter, though four is more usual. In the southern and lower parts of their range, they produce two litters each year.

==Habitat==
Douglas squirrels live in [[coniferous]] forest [[habitat]]s along the Pacific Coast, from the [[Sierra Nevada (U.S.)|Sierra Nevada]] (mountains) of California, northwards to the southwestern coast of British Columbia. ''Tamiasciurus douglasii'' prefer [[old-growth forest]]s or mature second-growth forests, and some authors regard them as dependent on its presence. [[Mearns's squirrel]] is a distinctive subspecies of the Douglas squirrel that instead inhabits [[Deserts and xeric shrublands|xeric]] pine forests in a small portion of Baja California.<ref>{{Cite journal|date=2016-07-01|title=Revision of widespread red squirrels (genus: Tamiasciurus) highlights the complexity of speciation within North American forests|journal=Molecular Phylogenetics and Evolution|language=en|volume=100|pages=170–182|doi=10.1016/j.ympev.2016.04.014|issn=1055-7903|last1=Hope |first1=Andrew G. |last2=Malaney |first2=Jason L. |last3=Bell |first3=Kayce C. |last4=Salazar-Miralles |first4=Fernando |last5=Chavez |first5=Andreas S. |last6=Barber |first6=Brian R. |last7=Cook |first7=Joseph A. |pmid=27083861 |doi-access=free |bibcode=2016MolPE.100..170H }}</ref>

Throughout most of their range, Douglas squirrels essentially replace the niche of the [[American red squirrel]], which inhabits the coniferous forests of the rest of North America. The two species have very minimal overlap in the territory.

Douglas squirrels are territorial; in winter, each squirrel occupies a territory of about 10&nbsp;000 square metres, but during the breeding season a mated pair will defend a single territory together. Douglas squirrels are active by day, throughout the year, often chattering noisily at intruders. On summer nights, they sleep in ball-shaped nests that they make in the trees, but in the winter they use holes in trees as nests. Groups of squirrels seen together during the summer are likely to be juveniles from a single litter.

==Diet==
Douglas squirrels mostly eat seeds of coniferous trees such as [[Douglas fir]] (''Pseudotsuga menziesii''), [[Picea sitchensis|Sitka spruce]] (''Picea sitchensis'') and [[Pinus contorta|shore pine]] (''Pinus contorta''). They also eat the fleshy scales of green [[giant sequoia]] cones, as well as acorns, berries, mushrooms, the eggs of birds such as [[yellow warbler]]s, and some fruit including strawberries and plums.  Douglas squirrels are [[Hoarding (animal behavior)|larder]] hoarders,<ref>{{Cite web|title = Gray squirrels and scatter hoarding|date = 24 September 2013|url = https://emammal.wordpress.com/2013/09/24/gray-squirrels-and-scatter-hoarding/|access-date = 2015-11-20}}</ref> storing their food in a single location or 'larder' called a [[midden]]. As the squirrel peels the scales of cones to get at the seeds, the discarded scales accumulate into piles that can grow to several meters across as the same site is used by generations of squirrels.

Their predators include [[Pacific marten]]s, [[bobcat]]s, [[cat|domestic cats]], [[northern goshawk]]s, and [[owl]]s; although they quickly acclimatize to human presence, humans can be a threat to them, through robbing of their cone caches to find seeds for tree cultivation and through the destruction of old-growth forest. However, the squirrels' numbers appear to be unaffected by commercial thinning of forests.<ref>{{cite journal | last1 = Ransome | first1 = D.B. | last2 = Sullivan | first2 = T.P. | date = 2002 | title = Short-term population dynamics of ''Glaucomys sabrinus'' and ''Tamiasciurus douglasii'' in commercially thinned and unthinned stands of coastal coniferous forest | journal= Canadian Journal of Forest Research | volume = 32 | issue = 11 | pages = 2043–2050 | doi = 10.1139/x02-126}}</ref>
[[File: Abies amabilis 28201.JPG|thumb|right|Pacific silver fir cone debris from Douglas squirrels feeding, [[North Cascades National Park]]]]

{{Listen
|filename=Tamiasciurus_douglasii.ogg
|title=''Tamiasciurus douglasii'' alarm call
|description=Alarm call of the Douglas squirrel (''Tamiasciurus douglasii'')
|format=[[Ogg]]}}

==References==
{{Reflist}}

==External links==
{{Commons category|Tamiasciurus douglasii|''Tamiasciurus douglasii''}}
{{Wikispecies|Tamiasciurus douglasii|''Tamiasciurus douglasii''}}
*[http://www.bear-tracker.com/dsquirel.html Tracks and calls of the Douglas Squirrel]
*[http://www.yosemite.ca.us/john_muir_writings/the_mountains_of_california/chapter_9.html John Muir's account of the Douglas Squirrel]
*[http://www.mnh.si.edu/mna/image_info.cfm?species_id=399 Smithsonian: "The Douglas Squirrel"]

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{{Taxonbar|from=Q386410}}
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[[Category:Tamiasciurus]]
[[Category:Rodents of the United States]]
[[Category:Rodents of Canada]]
[[Category:Fauna of the Sierra Nevada (United States)]]
[[Category:Fauna of the Western United States]]
[[Category:Fauna of the Northwestern United States]]
[[Category:Mammals described in 1839]]
[[Category:Taxa named by John Bachman]]
[[Category:Least concern biota of North America]]