Siberian Weasel (Mustela sibirica)
The pelage colour is widely variable, but darker in the summer; the underparts are only a little lighter than the upperparts. There is usually a distinctive dark mask, often confined to just the muzzle. The throat may be reddish, whitish or white with red spots. There are 4 pairs of mammae, 2 more than M. strigidorsa.This species has marked sexual dimorphism with the female smaller. The soles of the feet are hairy around the pads. The skull is a typical Mustela skull, long and narrow, with a well filled out braincase. The post orbital area is long and parallel sided. The forehead may be swollen due the presence of filariae in the frontal sinuses, an infection found in all weasels. The occipital crests form a straight line (curved in M. nudipes. The baculum is hooked with the tip not noticeably bifid. The dental formula as one less lower premolar than in M. stigidorsa.
This species is found in Northern Myanmar, Lao PDR, China,
Japan, DPR Korea, Republic of Korea, Pakistan, Nepal, India (Himalayas), Bhutan,
Russia (from Kirov Province, Tataria and western Ural Mountains throughout
Siberia to Far East), Taiwan, and Northern Thailand (Pocock 1941,
Duckworth 1997, Wozencraft, 2005). In Japan, it has been introduced to Honshu,
Shikoku, and Kyushu Islands (Abe, 2005). It is native on the islands of
Sakhalin, Kamishima, and Jeju (Abe, 2005). The distribution in southeast Asia is
poorly known (A. Abramov pers. comm. 2006). The species was recorded recently in
two locations in national parks in Thailand (Kanchanasaka pers. comm) and
in one location in Lao PDR, Nakai-Nam Theun National Biodiversity Conservation
Area in 1996 (Duckworth, 1997; sight record only). Gao and Sun (2005) conducted
a study of the effects of this species on Liadong oak (Quercus wutaishanica) in
Beijing Forest Ecosystem Research Station (BFERS, 40 00 N, 115 26 E), one of the
research stations affiliated to the Chinese Ecosystem Research Network (CERN) of
the Chinese Academy of Sciences (CAS). This species seems to prefer mountains
from 1500 to 5000 m in the southern part of its range (Lekagul and McNeely,
1988) but there is one provisional sighting in Khammouan Limestone National
Biodiversity Conservation Area in valley semi-evergreen forest amid karst at
about 500 m in 1998 (Robinson and Webber, 1998).
Bhutan; China; India; Japan; Korea, Democratic People's Republic of; Korea, Republic of; Lao People's Democratic Republic; Mongolia; Myanmar; Nepal; Pakistan; Russian Federation; Taiwan, Province of China; Thailand; Vietnam
The species is widespread and abundant in Siberia and China
(Abramov pers. comm). It is also common in northern central Korea as well, where
few other mammals other than rats and squirrels are currently easily seen (W.
Duckworth in litt. 2006).
Population Trend: Stable
Habitat and Ecology:
This species is found in "a wide variety of habitats,
including dense forest, dry areas, and human villages and towns, where it dens
in any convenient shelter, including burrows of other animals (Lekagul and
McNeely, 1988)." It occurs in primary and secondary deciduous, coniferous and
mixed forests, as well as open areas with small patches of forest enclaves and
forest steppe. It is also found along river valleys. It is found from to over
3000 m in Nepal. In Bhutan, it is found as low as 1500 m and up to 4800 m
(Thinley, 2004). In China, its altitude can reach up to 5000 m. It feeds on
small mammals, such as voles, squirrels, mice and pikas, amphibians, fish, and
carrion. During the summer time, it feeds on pine nuts. In Lao PDR this little
known species has been observed in primary evergreen forest at 1000 m (Duckworth
1997a), and possibly in valley semi-evergreen forest amid karst at about 500 m
(Robinson and Webber 1998a; M. F. Robinson, 1998). It occurs commonly down to
sea-level in the north of its range, e.g. Korea (J. W. Duckworth pers. comm.).
There are no major threats known to this species. It is
legally hunted in Russia for its fur (A. Abramov pers. comm.
2006)."Unfortunately, the small forest carnivores are not well protected by
either the local forest managers or the residents living in the forest areas in
China, though most of them are listed as protected animals by the national or
local governments. Weasels and badgers are largely hunted for their hides and
meat. (Gao and Sun, 2005)". Unsustainable hunting for skins, for international
trade. However, hunting levels are low at present, reflecting the low commercial
value of skins. Competition for resources with sable (Martes zibellina)
and natural wildfires also constitute minor threats.
In Lao PDR, this species was observed in Nakai-Nam Theun National Biodiversity Conservation Area in 1996 (Duckworth 1997a), and provisionally sighted in Khammouan Limestone National Biodiversity Conservation Area in 1998 (Robinson and Webber, 1998a; M. F. Robinson, 1998). Gao and Sun (2005) conducted a study of the effects of this species on Liadong oak (Quercus wutaishanica) in Beijing Forest Ecosystem Research Station (BFERS, 40 00 N, 115 26 E), one of the research stations affiliated to the Chinese Ecosystem Research Network (CERN) of the Chinese Academy of Sciences (CAS). This species is listed on CITES Appendix III (India) and is on the Tibet wildlife protection list (Li et al. 2000). It is on the China Red List as Near Threatened, and it nearly met the criteria for Vulnerable A2cd. There is a conservation need to establish a sustainable harvest level through population monitoring.