Neotamias quadrimaculatus

Long-eared Chipmunk
(*Neotamias quadrimaculatus*)
Long-eared Chipmunk (Neotamias quadrimaculatus)
Range
Taxonomic classification
Order:	Rodentia
Suborder:	Sciuromorpha
Family:	Sciuridae
Subfamily:	Xerinae
Tribe:	Tamiini
Genus:	Neotamias
Binomial details
	Neotamias quadrimaculatus (J. E. Gray, 1867)
Other resources
	Full taxonomic details at MDD

From Kelt et al. (2023): "Because [Neotamias] quadrimaculatus has the smallest geographic range of any Sierra Nevada sciurid, it may be at risk of local extirpation or substantial range restriction in the face of climate change, large-scale high-severity wildfires, and other stochastic threats."

Decription

From Clawson et al. (1994): "one of the reddest species of [Neo]tamias, has large ears, a white-edged tail (Allen, 1890), and a large white postauricular patch. In winter pelage (October-May), the top of the head is sayal brown mixed with grayish white and fuscous (general tone is near cinnamon drab), bordered on the sides with fuscous. The sides of the nose are clay color or sayal brown. The dark facial stripes are fuscous black. The malar stripe (below the eye) extends beneath the ear and connects with the large and creamy white postauricular patches. The submalar stripe is shaded with mikado brown, it is broad, and it reaches back beneath the ear to the postauricular patch. The pale facial stripes are grayish white. The ears are fuscous or fuscous black on the anterior one-half and grayish white on the posterior one-half. The median dorsal stripe is fuscous black; other dark stripes are fuscous and mixed with mikado brown. The median pair of pale stripes is grayish white, often mixed with sayal brown; the outer pair is creamy white. The sides are sayal brown to snuff brown. The rump and thighs are neutral gray , mixed with fuscous, and sprinkled with grayish white. The hind feet are deep pinkish-cinnamon or pinkish buff; the forefeet are colored similarly, but paler . Dorsally, the tail is fuscous black overlaid with grayish white (the ochraceous bases of the hairs sometimes show); ventrally, the tail is ochraceous tawny or mikado brown, bordered with fuscous black and edged with pale smoke-gray. The underparts are grayish white (color nomenclature follows Ridgway, 1912-Howell, 1929). Summer pelage (August) is similar to winter pelage, but the upperparts are more ochraceous (less grayish) in general tone. The anterior region of the back, including the median pair of pale stripes, nearly always is strongly washed with cinnamon. The sides are sayal brown to mikado brown. The rump and thighs are more buffy (less grayish) in summer, with a faint wash of cinnamon buff (color nomenclature follows Ridgway, 1912-Howell, 1929). Autumn pelage (October) is similar to postbreeding pelage, except the rufous suffusion of the flanks is darker, and the gray of the rump occupies the posterior one-half of the dorsal region; the anterior one-half is rufous and forms a scapular mantle. The ears are more reddish in front, the dark facial stripes are darker, and the malar stripe terminates in a dusky patch beneath the ear (Allen, 1890). Autumn molt occurs in October; the winter pelage first covers the tail and then proceeds to the rump (Howell, 1929)."

Museum images

Lectotype: USNM 186458. Neotamias quadrimaculatus. Sierra Nevada Mountains of central California, Placer County, California. Collected 6 October 1885.
Lectotype: USNM 186458. Neotamias quadrimaculatus. Sierra Nevada Mountains of central California, Placer County, California. Collected 6 October 1885.
Lectotype: USNM 186458. Neotamias quadrimaculatus. Sierra Nevada Mountains of central California, Placer County, California. Collected 6 October 1885.

External measurements

Length measurements are in millimeters (mm) and weight measurements are in grams (g), unless stated otherwise. If available, the sample size (n=) is provided. If a range is not provided and n= is not given, then the listed measurement represents an average.

Part of range	Reference	Total length	Tail length	Hindfoot length	Ear length	Mass
California	Jameson & Peeters (2004)	200–250	85–118	34–37	18–24	52–100

Skull

Lectotype: USNM 186458. Neotamias quadrimaculatus. Sierra Nevada Mountains of central California, Placer County, California. Collected 6 October 1885. Dorsal view of the skull.
Lectotype: USNM 186458. Neotamias quadrimaculatus. Sierra Nevada Mountains of central California, Placer County, California. Collected 6 October 1885. Ventral view of the skull.
Lectotype: USNM 186458. Neotamias quadrimaculatus. Sierra Nevada Mountains of central California, Placer County, California. Collected 6 October 1885. Lateral view of the skull.
Lectotype: USNM 186458. Neotamias quadrimaculatus. Sierra Nevada Mountains of central California, Placer County, California. Collected 6 October 1885. Lateral view of the skull. Dorsal view of the mandible.
Lectotype: USNM 186458. Neotamias quadrimaculatus. Sierra Nevada Mountains of central California, Placer County, California. Collected 6 October 1885. Lateral view of the skull. Lateral view of the left mandible.

Similar species

From Clawson et al. (1994): "its large size and white-edged tail, but the long ears, narrow and shallow rostrum, long nasals, and relatively great zygomatic width distinguish it from all other California members of the group (Johnson, 1943). In addition to these characters, its dark color, long and slender ears, and conspicuous, white postauricular patches distinguish quadrimaculatus from all other chipmunks (Grinnell and Storer, 1924)."

Comparison with Neotamias senex

From Kelt et al. (2023): "[Neotamias] quadrimaculatus and [Neotamias] senex are closely related and they share similar ecological requirements (Grinnell and Storer 1924; Johnson 1943; Sutton 1995). They may be very challenging to distinguishable in the field (Sutton 1995), and they are known to hybridize (Frare et al. 2017)." In order to confidently differentiate these two species, DNA analysis is needed (see DNA analysis method in Kelt et al. 2023 and Demboski and Sullivan 2003)."

References

Clawson RG, Clawson JA, Best TL. 1994. Tamias quadrimaculatus. Mammalian species (469):1-6. https://doi.org/10.2307/0.469.1

Demboski JR, Sullivan J. 2003. Extensive mtDNA variation within the yellow-pine chipmunk, Tamias amoenus (Rodentia: Sciuridae), and phylogeographic inferences for northwest North America. Molecular Phylogenetics and Evolution 26:389–408.

Frare CF, Matocq MD, Feldman CR, White AM, Manley PN, Jermstad KD, Hekkala ER. 2017. Landscape disturbance and sporadic hybridization complicate field identification of chipmunks. Journal of Wildlife Management 81:248–258.

Grinnell J, Storer TI. 1924. Animal life in the Yosemite: an account of the mammals, birds, reptiles, and amphibians in a cross-section of the Sierra Nevada. University of California Press, Berkeley, California, USA.

Johnson DH. 1943. Systematic review of the chipmunks (genus Eutamias) of California. University of California Publications in Zoology 48:63–146.

Kelt DA, Coppeto SA, Van Vuren DH, Sullivan J, Wilson JA, Reid N. 2023. Niche conservatism versus niche differentiation in sympatric chipmunks in the northern Sierra Nevada. Journal of Mammalogy 104(5): 979-992.

Sutton D.A. 1995. Problems of taxonomy and distribution in four species of chipmunks. Journal of Mammalogy 76:843–850.