(Pallas's Squirrel) Callosciurus erythraeus

Taxonomic Notes:

A major structured program of collecting is required to clarify the complex taxonomy of this species in Lao PDR (Evans et al, 2000). Often occurs in reports under the name C. flavimanus even in lists that also include C. erythraeus. This is symptomatic over the general confusion of squirrel identification in the region (Duckworth et al. pers. comm.). There are many named and still unnamed forms in Thailand, Lao PDR and Vietnam some of which have small ranges. Whether any merit species rank is unclear but there is no persuasive reason for any as yet detected form to be considered at risk (Duckworth et al. pers. comm.).


Head-Body Length : approx 20 cm
Tail Length : approx 20 cm
Weight : approx 250 grams

Pallas's Squirrel is a medium-sized tree squirrel, with a head-body length of 16 to 28 cm (6.3 to 11.0 in), and a tail 11 to 26 cm (4.3 to 10.2 in) in length. Both sexes are of similar size and appearance, and weigh between 310 and 460 g (11 and 16 oz). The color of the pelt varies considerably between the many different subspecies, but is generally brownish on the upper body with a more reddish tint on the belly, and often with some black on the tail. The precise pattern and shades of the fur are often used to distinguish subspecies from one another, but make it difficult to distinguish the species as a whole from other, similarly variable, tree squirrel species.

The species is identified by its medium size, its olive-brown upperparts and reddish underparts. The absence of black and buff stripes along the flank distinguishes the species from the similar Plantain Squirrel Callosciurus notatus, which prefers lowland areas.

Range Description:

This species is widely distributed in northeastern South Asia, much of central and southern China, and mainland Southeast Asia. In South Asia, the species is known to occur in Bangladesh and northeastern India (Molur et al. 2005). It is widely distributed in the region. In China, it has been recorded from Sichuan, Yunnan, Guandong, Guangxi, Hunan, Guizhou, Hainan Island, Xizang, Zhejiang, Fujian, Jiangsu, Anhui, Henan and Hubei (Smith and Xie 2008). It has been recorded from the island of Taiwan. In Southeast Asia, it is present in Myanmar, Northern Thailand, Lao PDR, Vietnam, Eastern Cambodia and Peninsular Malaysia .Tree squirrels were considered to make particularly successful invasive species due to their high reproductive potential, ability to disperse effectively, diverse food habits, ability to build nests, and adaptability to human-impacted landscapes (Palmer et al., 2007). Bertolino (2009)


Bangladesh; Cambodia; China; India; Lao People's Democratic Republic; Malaysia; Myanmar; Taiwan, Province of China; Thailand; Vietnam

Habitat and Ecology:

It is diurnal and arboreal species typically occurring in subtropical montane evergreen and broadleaved forests, although in China it is also present in sub alpine coniferous forests or in a mix of conifers and broadleaf trees at altitudes above 3,000 m asl (Smith and Xie 2008). It has been found to occupy tree hollows in mid high canopy. Very flexible in terms of habitat; Duckworth and Robichaud (2005) found in heavily degraded scrub landscapes with small degraded forest patches in far northern Lao PDR, It has a generation time of two to three years.  Three types of ectoparasites are found:  sucking louse Neohaematopinus callosciuri (Anoplura: Haematopinidae), 26 fleas Ceratophyllus (Monopsyllus) anisus Rothschild (Siphonaptera: Ceratophyllidae) and four nymphs of the tick Haemaphysalis flava Neumann (Acari: Ixodidae) Pallas's squirrel (C. erythraeus) is 1 tree squirrel species with body mass of approximately 250–400 g. They are distributed in Southern China and Southeast Asia and are also introduced in Japan and France (Xu and Ran 2004). Pallas's squirrels are found as important pests by gnawing barks and young shoots in many conifer plantations (e.g., Kuo and Liao 1986; Xu and Ran 2004; Tamura and Ohara 2005). Previous studies showed that Pallas's squirrels can hoard plant seeds during fruiting seasons in autumn (Chou et al. 1985; but see Setoguchi 1990). According to recent and ongoing studies in Qingcheng Mt, this tree squirrel is a key scatter-hoarder for the dispersal of large seeds from Fagaceae species and other large-seeded species (e.g., Camellia spp.). The most exciting finding is that Pallas's squirrels remove acorn embryos from several Fagaceae species (e.g., Castanea spp., Quercus spp., and Cyclobalanopsis spp.), like Sciurus squirrels to white oak acorns reported in North America.

Like all tree squirrels, Pallas's squirrels are primarily herbivorous. They eat a wide range of different foods, and have differing diets in different parts of their broad range. However, primary foodstuffs include leaves, flowers, seeds, and fruit. They also eat small quantities of insects, as well as occasional bird eggs. The squirrels breed throughout the year, and may mate again as soon as they have weaned a previous litter. Pregnancy lasts 47 to 49 days, and results in the birth of up to four young, with two being typical. The young leave the nest at 40 to 50 old, and are sexually mature at one year of age. They have lived for up to seventeen years in captivity. Pallas's squirrels are diurnal, and inhabit much of the forest canopy, and construct both leaf nests 7 to 18 m (23 to 59 ft) above the ground, and, less commonly, underground burrows. Females occupy home ranges of just 0.5 to 0.8 hectares (1.2 to 2.0 acres), which usually do not overlap, while males occupy much larger ranges of 1.3 to 3.8 ha (3.2 to 9.4 acres), which overlap with those of both nearby males and females. Like many other squirrels, they have been observed to cache acorns in the autumn. The squirrels make calls to warn neighbours of predators, and have been observed to mob tree-climbing snakes, with females protecting young being particularly likely to join in.Males also make loud calls prior to, and after, mating.

Major Threat(s):

There are no major threats to this species. Hunting for consumption has depleted some South Asian populations (Molur et al. 2005).

Conservation Actions:

 It is known from the following protected areas in India: Eagle’s Nest Wildlife Sanctuary, Kamlang Wildlife Sanctuary, Namdapha National Park, Pakhui Wildlife Sanctuary, Sessa Orchid Sanctuary and Tale Valley Wildlife Sanctuary in Arunachal Pradesh (Molur et al. 2005). It Is presumably present in many protected areas in China and Southeast Asia.