Tamias amoenus, J.A.Allen, 1890

Don E. Wilson, Thomas E. Lacher, Jr & Russell A. Mittermeier, 2016, Sciuridae, Handbook of the Mammals of the World – Volume 6 Lagomorphs and Rodents I, Barcelona: Lynx Edicions, pp. 648-837 : 785-786

172.

Yellow-pine Chipmunk

Tamias amoenus

French: Tamia améne / German: SumpfkieferBackenhornchen / Spanish: Ardilla listada de pino Amarillo

Taxonomy. Tamias amoenus J. A. Allen, 1890 ,

“Fort Klamath, [Klamath County,]

Oregon,” USA.

Fourteen subspecies are recognized.

Subspecies and Distribution.

T.a.amoenusJ.A.Allen,1890—SCWashington,SthroughC&EOregonandSIdahotoNECalifornia(USA).

T.a.affinisJ.A.Allen,1890—SBritishColumbia(Canada)andNCWashington(USA).

T.a.albiventrisBooth,1947—betweenAsotinandGarfieldcountiesinSEWashingtonandinNEOregon(USA).

T.a.canicaudusMerriam,1903—EWashingtonandNIdaho(USA).

T.a.caurinusMerriam,1898—OlympicMts,NWWashington(USA).

T.a.celerisHall&Johnson,1940—PineForestMts,HumboldtCounty,NWNevada(USA).

T.a.cratericusBlossom,1937—ButteCounty,SIdaho(USA).

T.a.felixRhoads,1895—WaputickMtsinMtBakerRange,SWBritishColumbia(Canada)andNWashington(USA).

T.a.ludibundusHollister,1911—boundaryareabetweenBritishColumbiaandAlberta(Canada).

T.a.luteiventrisJ.A.Allen,1890—SAlberta(Canada),WMontana,andNWWyoming(USA).

T.a.monoensisGrinnell&Storer,1916—aridcrestandEslopesofCSierraNevada,ECalifornia(USA).

T.a.ochraceusA.H.Howell,1925—SiskiyouMtsregionofSOregonandNWCalifornia(USA).

T.a.septentrionalisCowan,1946—WCBritishColumbia(Canada).

T. a. vallicola A. H. Howell, 1922 — Bitterroot Valley and adjacent foothills, W Montana (USA).

Descriptive notes. Head—body 119-3-123-2 mm, tail 86-5-95-5 mm; weight 43-58-3 g. The Yellow-pine Chipmunk is a small species of Tamias. Dorsum is reddish brown, dark in appearance, with five dark stripes, usually black. Each lateral dark stripe is bordered by a white stripe, and the more median light stripes are grayish. Females are larger than males, and body size is generally smaller than the Lodgepole Chipmunk (T. speciosus). The Yellow-pine Chipmunk is similar in appearance to several other species of Tamias and it is suggested that genital bones may be necessary to make a positive identification. Nominate amoenus has well defined black dorsalstripes, sprinkled with rufous. The two inner light stripes are grizzled gray and the outer pair of light stripes is white. Head is a mixture of gray, rufous, and black, with a dark ear patch. Subspecies affinis is indistinguishable in appearance from amoenus. Subspecies albiventris has grayish dorsal pelage and whitish or cream ventral pelage. Inner pair of light stripes is smoke-gray and outer pair is whitish. Subspecies canicaudus has a general vinaceous gray dorsum with broad dorsalstripes, and tail is edged with gray. Subspecies caurinus is similar to amoenus, but darker and with reduced ear patches. Subspecies celeris is a smaller and paler subspecies, very similar to monoensis. Subspecies cratericus has a dull gray pelage, with smoke-gray light stripes. Outer pair of light stripes is lighter than inner pair. Subspecies felix has a heavy suffusion of ocher on sides, cheeks, and underside of tail. Upperparts are a rusty brown tone and dorsal stripes are broad. Subspecies ludibundus is the largest subspecies, with dark and tawny sides and yellowish ventral fur. Subspecies luteiventrisis similar to amoenus, with a strong suffusion of ocherous buff on ventral pelage. Subspecies monoensis is a paler and grayer subspecies, with whiter light stripes. Subspecies ochraceus is larger than amoenus, with paler dark dorsal stripes

and a more ocherous head and dorsum. Subspecies septentrionalis is a large subspecies, with the inner pair of light stripes being reddish brown anteriorly and becoming paler posteriorly. Outer pair oflight stripes is white with a faint reddish brown wash. Subspecies vallicola is similar to amoenus, but with an overall paler coloration. Chromosome number of the Yellow-pine Chipmunk is 2n = 38. The karyotype is type B for Tamias and consists of five pairs of metacentric autosomes, six pairs of submetacentric autosomes, four acrocentric autosomes, three pairs of small metacentric or acrocentric autosomes, a submetacentric X chromosome, and a small acrocentric Y chromosome.

Habitat. Dry forests in the transition zone, but may inhabit lower areas in the Canadian zone. The Yellow-pine Chipmunk can be found at elevations of up to ¢.3000 m in the extreme south ofits distribution. It appears to prefer open areas and can be found on meadows with forbs, grasses, and sedges, but also in brushy habitats usually associated with Jeffrey pine (Pinusjeffreyi, Pinaceae) or lodgepole pine (P. contorta). It can be very abundant in degraded areas, such as logged forests, regenerating stands, and clearcuts, and several studies indicated higher capture rates in these areas than in primary or mature forests.

Food and Feeding. Diet of the Yellow-pine Chipmunk consists of several kinds of seeds, fruits, flowers, tubers, fungi, insects, and even avian eggs. It may be a spore-disperser of hypogeous fungi, which compose a significant part ofits diet. It is both a larderand scatterhoarder, and dueto its scatterhoarding behavior,it disperses seeds of some plant species, such as antelope bitterbrush (Purshia tridentate, Rosaceae), chinquapin (Castanopsis sempervirens, Fagaceae), Jeffrey pine and sugar pine (P. lambertiana). Several factors, including seed quality, mast patterns, pilferage risk, cache-site selection, cache depth, spatial memory, and olfactory capabilities affectits scatterhoarding decisions, with potential consequencesto the Yellow-pine Chipmunk’s seed dispersal pattern.

Breeding. The Yellow-pine Chipmunk appears to have a promiscuous mating system, with low variability in male mating success. Mating season occurs late April to early May, a few weeks after the end of hibernation. Females produce onelitter per year. Gestation lasts ¢.28-30 days and average litter size is 4-5 young, with a maximum of nine. Young weigh ¢.2-6 g. There is strong evidence for sperm competition and little evidence for inbreeding. Young are weaned at c.6 weeks and reach sexual maturity at c.1 year.

Activity patterns. The Yellow-pine Chipmunk is diurnal and hibernates during the winter months, emerging in April. Nests are built in burrows, which are usually under logs, stumps, and rocks, although occasionally a grassy nest built in vegetation is reported. It appears to be more sensitive to temperature extremes than other species of Tamias. Testosterone levels in plasma appearto affect the overwinter survivability of the Yellowpine Chipmunk by reducing levels of glucocorticoid, and thusfat reserves.

Movements, Home range and Social organization. Reported population densities vary 1-2-7 ind/ha, depending on location and habitat characteristics. The Yellow-pine Chipmunk is territorial and aggressive toward other Tamias species, being sometimes dominant over the Least Chipmunk (7. minimus), but subordinate to Townsend's Chipmunk (7. townsendii). This interaction with other Tamias species may affect the elevational distribution of the Yellow-pine Chipmunk in part of its distribution.

Status and Conservation. Classified as Least Concern on The IUCN Red List. The current population trend is stable and no major threats to the Yellow-pine Chipmunk are noted acrossits distribution. On a local level, populations may be negatively impacted by loss offorests from fires, die-offs, or logging.

Bibliography. Anthony (1928), Briggs & Vander Wall (2004), Demboski & Sullivan (2003), Good et al. (2003), Kuhn & Vander Wall (2008), Linzey & NatureServe (Hammerson) (2008y), Morris (1996), Place (2000), Roth & Vander Wall (2005), Schulte-Hostedde & Millar (2000, 2004), Schulte-Hostedde, Gibbs & Millar (2000, 2001), Schulte-Hostedde, Millar & Gibbs (2002, 2004), Sullivan & Klenner (2000), Sullivan, Lautenschlager & Wagner (1999), Sullivan, Sullivan & Lindgren (2000), Sullivan, Sullivan, Lindgren & Ransome (2005), Sutton (1992, 1995), Thayer & Vander Wall (2005), Thorington et al. (2012), Vander Wall (1993a, 1993b, 1993c, 1993d, 1995a, 1995b, 1995¢, 1995d, 1998, 2000, 2003), Vander Wall & Peterson (1996), Vander Wall et al. (2003), Waters & Zabel (1998).

Figures

148. Spotted Giant Flying Squirrel (Petaurisia elegans), 149. Yunnan Giant Flying Squirrel (Petaurista yunanensis), 150. Taiwan Giant Flying Squirrel (Petaurista lena), 151. Hainan Giant Flying Squirrel (Petaurista hainana), 152. Japanese Giant Flying Squirrel (Petaurista leucogenys), 153. Siberian Flying Squirrel (Pteromys volans), 154. Japanese Flying Squirrel (Pteromys momonga), 155. Woolly Flying Squirrel (Eupetaurus cinereus), 156. Black Flying Squirrel (Aeromys tephromelas), 157. Thomas's Flying Squirrel (Aeromys thomasi), 158. Smoky Flying Squirrel (Pteromyscus pulverulentus), 159. Hairy-footed Flying Squirrel (Belomys pearsonii), 160. Northern Chinese Flying Squirrel (Aeretes melanoplerus), 161. Complex-toothed Flying Squirrel (Trogopterus xanthipes), 162. Long-clawed Ground Squirrel (Spermophilopsis leptodactyla), 163. Barbary Ground Squirrel (Atlantoxerus getulus), 164. Striped Ground Squirrel (Euxerus erythropus), 165. Unstriped Ground Squirrel (Xerus rutilus), 166. Damara Ground Squirrel (Geosciurus princeps), 167. South African Ground Squirrel (Geosciurus inauris), 168. Pere David’s Rock Squirrel (Sciurotamias davidianus), 169. Forrest's Rock Squirrel (Sciurotamias forresti), 170. Siberian Chipmunk (Tamias sibiricus), 171. Least Chipmunk (Tamias minimus), 172. Yellow-pine Chipmunk (Tamas amoenus), 173. Townsend’s Chipmunk (Tamias townsendii), 174. Red-tailed Chipmunk (Tamias ruficaudus), 175. Shadow Chipmunk (Tamias senex), 176. Uinta Chipmunk (Tamias umbrinus)