Squirrels of the World

350 Urocitellus armatus sult, in U. armatus juvenile survival (about 30%) is observed to be lower than adult survival (60%), and ...

Urocitellus beldingi 351 northwestern Nevada (USA). The dorsal surface is light- est in this subspecies. U. b. oregonus—eastern ...

352 Urocitellus beldingi from both oral and dorsal apocrine glands that are used for the identifi cation of close kin and unfami ...

Urocitellus brunneus 353 natural history: Food habits have only been studied in U. b. brunneus. Its diet, similar to that of U. ...

354 Urocitellus brunneus to agriculture. Between 2004 and 2009, however, habitat res- toration and translocations have resulted ...

Urocitellus columbianus 355 of ground squirrels, adults enter hibernation fi rst, some- times as early as mid-July but usually b ...

356 Urocitellus columbianus does not. Mean litter sizes vary from 2.1 to 4.2 in the wild and from 3.0 to 4.6 in captivity; and t ...

Urocitellus elegans 357 their fi rst hibernation was positively associated with the amount of winter snow and the time their mot ...

358 Urocitellus elegans distribution: This species is found in parts of southeast- ern Oregon, Nevada, and southcentral Idaho; e ...

Urocitellus mollis 359 U. elegans is diurnal, and its activity is bimodal, with peaks occurring in midmorning and evening. Vocal ...

360 Urocitellus mollis habitat: Piute ground squirrels inhabit high desert sage- brush (Artemisia) steppes in well-drained soils ...

Urocitellus parryii 361 geographic variation: Ten subspecies are recognized. U. p. parryii—northern coast of the Yukon and the N ...

362 Urocitellus richardsonii Urocitellus richardsonii (Sabine, 1822) Richardson’s Ground Squirrel description: Richardson’s grou ...

Urocitellus townsendii 363 response to aerial predators. The number of callers in a population indicates the severity of the pot ...

364 Urocitellus townsendii April. U. townsendii is primarily herbivorous but will con- sume insects. Its diet includes shoots, l ...

Urocitellus washingtoni 365 natural history: This species is diurnal. Long-tailed ground squirrels hibernate in burrows from Sep ...

366 Urocitellus washingtoni to agriculture and urban development, in addition to the re- sultant habitat fragmentation. Historic ...

Xerospermophilus perotensis 367 geographic variation: None. conservation: IUCN status—vulnerable. Population trend—decreasing. h ...

368 Xerospermophilus perotensis habitat: Perote ground squirrels live in hig h-elevat ion a rid plains, open scrub, and rocky sl ...

Xerospermophilus spilosoma 369 (México). The dorsum of this subspecies is dark and yellowish. X. s. ammophilus—extreme northern ...