Callosciurus erythraeus

59. Pallas’s Squirrel Callosciurus erythraeus French: Ecureuil de Pallas / German: Pallas-Schénhérnchen / Spanish: Ardilla de Pallas Other common names: Formosan Squirrel, Red-bellied Squirrel Taxonomy. Sciurus erythraeus Pallas, 1779, Original type locality not known. Restrict- ed by J. L. Bonhote in 1901 to Assam, In- dia, and further restricted by J. C. Moore and G. H. H. Tate in 1965 to the Garo Hills of Assam. Reports of this squirrel often occur under the name C. flavimanus. Significant further study of the many named and the likely many as yet undocumented subspecies is required; it is possible that some may merit species level distinction. Generally, 26 subspecies are recognized, some of which were divided into four groups as below by G. B. Corbet and J. E. Hill, 1992. Subspecies and Distribution. The C. e. erythraeus group, Sikkim to Assam, India to Myanmar, W Thailand and Peninsular Malaysia, N Vietnam, and Taiwan: C.e.gordoniJ.Anderson,1871—NMyanmar. C.e.shanicusRyley,1914—NCMyanmar. C.e.bhutanensisBonhote,1901—Bhutan. C.e.rubeculusMiller,1903—Pahang,Malaya. C.e.erythraeusPallas,1779—GaroHillsofMeghalaya,India. C.e.erythrogasterBlyth,1842—Wbank,ChindwinRiver,Myanmar. C.e.castaneoventrisGray,1842—Hainan,China. C.e.atrodorsalisGray,1842—areasurroundingMawlamyaing,Myanmar. C.e.thaiwanensisBonhote,1901—NWTaiwan.TheC.e.flavimanusgroup,Laos,Cambodia,andSVietnam: C.e.flavimanus1.GeoffroySaint-Hilaire,1831—CVietnam.TheC.e.sladenigroup,betweentheChindwinandIrrawaddyriversofMyanmar: C.e.harringtoniThomas,1905—areasurroundingHomalin,upperChindwin,Myanmar. C.e.intermediusJ.Anderson,1879—Assam,India. C.e.sladeniJ.Anderson,1871—Thizyain,upperMyanmar.TheC.e.styanigroup,EChina: C.e.ningpoensisBonhote,1901—vicinityofNingbo,China. C.e.styaniThomas,1894—Kahing,SEChina.OthersubspeciesnotassignedtoagroupbyCorbetandHill: C.e.bartoniThomas,1914—upperChindwin,Myanmar. C.e.bonhoteiRobinson&Wroughton,1911—Chinchiensan,Sichuan,China. C.e.gloverThomas,1921—Nagchuka,WSichuan,China. C.e.grisesmanusMilne-Edwards,1867—nearSaigon,Vietnam. C.e.hendeeiOsgood,1932—NVietnam. C.e.hyperythrusBlyth,1856—SMyanmar,SWThailandonMalayPeninsula. C.e.michianusRobinson&Wroughton,1911—Yunnan,China. C.e.pranisKloss,1916—KohLok,Pran,SThailand. C.e.siamensisGray,1860—Thailand. C.e.thaiKloss,1917—Raheng,CThailand. C. e. zimmeensis Robinson & Wroughton, 1916 — Chiang Mai, N Thailand. This species is found in much of C & S China (including Hainan I), Taiwan, NE India, Bangladesh, and mainland South-east Asia. Introduced and naturalized in Japan (S Honshu, Kyushu, and several surrounding small islands), Hong Kong, Western Europe (the Netherlands, Belgium, and France), and Argentina. Descriptive notes. Head-body 209-227 mm, tail 176-216 mm; weight 286-375 g. There is considerable variation in the coloration among the forms of Pallas’s Squirrel. It is generally recognizable by the reddish coloration of venter (varying from dark maroon to creamy buff) and the olive-brown agouti dorsum. Nominate subspecies erythraeus group has reddish brown or reddish (sometimes agouti) underparts, commonly with a mid-ventral wedge or stripe of agouti dividing reddish brown coloration into two parts. Subspecies flavimanus group has feet that are paler than dorsum and (usually) venter. Subspecies sladeni group has a muzzle and feet that are similar in color to venter. Subspecies styani group has a venter that is pale cream to dull orange-brown; dorsum is pale and gray; and feet are agouti but not dark. Chromosome number is 2n = 40; FN = 70-72. Karyotype consists of seven pairs of metacentric autosomes, eight pairs of submetacentric autosomes, two pairs of subtelocentric autosomes, two pairs of telocentric autosomes, a metacentric X chromosome, and a subtelocentric Y chromosome. Chromosomal complement of subspecies flavimanus is 2n = 40; FN = 74. Habitat. Primary and secondary subtropical montane evergreen and broadleaved forests. In China, Pallas’s Squirrel is present in subalpine coniferous forests, or in a mix of conifer and broadleaf trees, at elevations above ¢.3000 m; occursalso in tropical and subtropical forests at lower elevations. In far northern Laos,it is found in heavily degraded scrub landscapes with small degraded forest patches. It will occupy pine (Pinus, Pinaceae) plantations that are more than 16 years old if protected, but, in unprotected areas, not until plantations are 31 years old, apparently because human activities decrease important vegetation diversity on forest floor. In Peninsular Malaysia, Pallas’s Squirrel is described as being common in forests and woodlands in the hills. It was introduced to Tomogashima Island in Japan, where it prefers both broadleaved and coniferous evergreen trees. In Argentina, these introduced squirrels are reported in fruit plantations. Food and Feeding. Overits wide distribution, Pallas’s Squirrel seems to be extremely adaptable in its diet. On Tomogashima Island, Japan,it feeds extensively on camellia flowers (Camellia japonica, Theaceae), bayberry fruits (Myrica rubra, Myricaceae), and Japanese pine seeds (Pinus thunbergii, Pinaceae). In total, it eats 36 species of plants there: mainly camellia blossoms in January-March, leaves in April and May, and fruits (mostly seeds) in June-December. In addition, it consumes the bark of 23 plant species, eats insects (mostly ants and cicadas), and drinks water that accumulates in knotholes. In China,it has also been reported to feed on bird eggs and fledglings. In Malaysia, the stomach contents of three individuals included a significant proportion of insects, as well as starchy vegetable matter. Breeding. Mating bouts start early in the morning and last for many hours. The most dominant male chases other males away and then breeds with the female, after which he guards the female for an average of 33 minutes by giving the post-copulatory call, causing nearby males and the female to adopt their immobile anti-predator response. The female subsequently mates with another male, mating 4-11 timesin all during her estrus. Although not specified in the study, the assumption is that these other males also give a post-copulatory call. Mating bouts occur throughout the year, and the average litter size at weaning is 1-4 individuals. Activity patterns. There is no specific information available for this species, but Pallas’s Squirrel is diurnal and arboreal. Movements, Home range and Social organization. In Kamakura City, Japan, where they have been introduced and are now common, both males and females have overlapping home ranges, with fewer females overlapping with other females (2-3 in winter—spring, 1-6 in autumn-winter) than males overlapping with other males (12-6 in winter—spring, 8-7 in autumn-winter). Male home ranges were 2:6 ha in the winter— spring season and 1-2 ha in the autumn-winter season. Female home ranges were 0-7 ha and 0-5 ha in the same two seasons. Status and Conservation. Classified as Least Concern on The IUCN Red List. Pallas’s Squirrel is widely distributed, has a presumed large population, and has a tolerance of some degree of habitat modification. There are no major threats to this species, although hunting for local consumption has depleted some South Asian populations. Bibliography. Bertolino (2009), Bonhote (1901), Duckworth, Timmins & Molur (2008), Corbet & Hill (1992), Guichon et al. (2005), Jordan et al. (2005b), Lurz et al. (2013), Men Xingyuan et al. (2006), Moore & Tate (1965), Oshida et al. (2006), Setoguchi (1990, 1991), Shankar Raman et al. (1995), Smith & Yan Xie (2008), Tamura (1995), Tamura et al. (1988), Thorington et al. (2012).

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