Urocitellus townsendi (Bachman, 1839)
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publication ID |
https://doi.org/ 10.5281/zenodo.6840226 |
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DOI |
https://doi.org/10.5281/zenodo.6818976 |
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persistent identifier |
https://treatment.plazi.org/id/064D0660-FF90-ED6D-FFC8-FA8BFE2DFA9F |
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treatment provided by |
Diego |
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scientific name |
Urocitellus townsendi |
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204. View On
Townsend’s Ground Squirrel
French: Spermophile de Townsend / German: Townsend-Ziesel / Spanish: Ardilla terrestre de Townsend
Taxonomy. Spermophilus townsendii Bachman, 1839 View in CoL ,
“On the Columbia River, about 300 miles [483 km | above its mouth.”
Restricted by A. H. Howell in 1938 to W bank of Walla Walla River, near the confluence with Columbia River, Wallula, Walla Walla County, Washington, USA.
It has been suggested that nancyae is actually a subspecies of U. mollis. Two subspecies recognized.
Subspecies and Distribution.
U.t.townsendiiBachman,1839—Washington,SoftheYakimaandNoftheColumbiarivers(USA).
U. t. nancyae Nadler, 1968 — Washington, N of the Yakima and W of the Columbia rivers (USA).
Descriptive notes. Head-body 200-232 mm,tail 320-540 mm; weight mean 174 g (males) and 125 g (females). Dorsal pelage of Townsend’s Ground Squirrel is a uniform pale smoke-gray, suffused with pinkish buff. Cheeks and hindlimbs are washed with red to rust, and ventral fur is white to cream, washed with pinkish buff. Tail is grizzled smoke-gray on upper side and cinnamon on ventral side. Chromosome complement of nominate subspecies townsendii is 2n = 38, FN = 66. Subspecies nancyae is slightly lighter in the dorsum, and has a chromosome complement of 2n = 36, FN = 68.
Habitat. High desert sagebrush (Artemisia, Asteraceae) regions and cultivated fields.
Food and Feeding. Townsend’s Ground Squirrel consumes shoots,leaves, flowers, and seeds of grasses, forbs, shrubs and crops. Seeds and other plant reproductive structures are more common in the diet during periods before hibernation, probably reflecting availability of these items. Although mostly herbivorous, it has been noted to consume insects when available.
Breeding. Breeding occurs only once a year, soon after emergence from hibernation. A litter of 1-13 young (average 9-4) is born within burrow. Young weigh 2-2-5-1 g each (averages of 3-3 g, 3-7 g, and 3-9 g in different locations). Juveniles emerge from the burrow four weeks after birth, in late March or April, and females reach sexual maturity at one year of age. Females produce only one litter a year. Due to differential reproductive strategy, males and females also have differences in growth rate and annual weight cycles.
Activity patterns. Townsend's Ground Squirrel is diurnal and terrestrial. It hibernates from late May (males) or June (females and young) until late January to February.
Movements, Home range and Social organization. There is no information available for this species.
Status and Conservation. Classified as Vulnerable on The IUCN Red List. Current population trend is decreasing. Less than 10% of habitat in its native distribution remains in good condition and most individuals reside on privately owned land. Townsend's Ground Squirrel is poisoned or shot as a pest in many areas of its distribution. Remaining populations in this habitat are fragmented and isolated, making them more vulnerable to stochastic events. No estimates of population density exist and further research is needed to establish density levels locally and acrossits distribution.
Bibliography. Hayssen et al. (1993), Howell (1938), O'Hare et al. (2006), Rickart (1999), Sharpe & Van Horne (1998), Thorington et al. (2012).
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.
