Endangered squirrels

Background

Squirrels belong to an order of mammals known as Rodentia, or rodents. They are characterised by enlarged incisors which are used for gnawing and long bushy tails. Flying squirrels have membranes attached to their limbs that are used for gliding through the air. Tree and ground squirrels do not have this extra piece of skin. Singapore is home to many species of squirrels, with the Plantain Squirrel being the most common. But several are in danger of becoming extinct in Singapore, namely, the Cream-coloured Giant Squirrel, Shrew-faced Ground Squirrel, Red Giant Flying Squirrel and Red-cheeked Flying Squirrel. These four are listed as "critically endangered" in The Singapore Red Data Book (2008), but fairly little is known about them.

Cream-coloured Giant Squirrel
Description
The Cream-coloured Giant Squirrel is one of the largest squirrels in the world. It can grow up to 38cm long and its tail can be up to 44cm in length. It weighs around 1kg. It was first described from Singapore in 1821 by Sir Stamford Raffles, who reported that it was abundant in the woods. In fact, this squirrel was so common that it was captured for food or for sale as pets up to the late 1960s.

It is a diurnal animal, meaning it is active during the day. It lives and forages in the upper storeys of tall tropical forests and seldom comes to the ground. Its diet consists mainly of fruits and other plant matter, supplemented by a small amount of insects. The upper parts of its body are dark brown, while the underparts are creamy in colour.

Distribution
Besides Singapore, this species can be found in Peninsular Malaysia, Sumatra (Indonesia), Borneo and Thailand. Those found in Singapore tend to have darker upper coats than those in Johor, Malaysia. In Singapore, they are likely to be restricted to the Bukit Timah and Central Catchment Nature Reserves, though they have not been seen since 1995. It is believed that there are less than ten individuals remaining in the wild.

Variant Names
Scientific name: Ratufa affinis
Common names:
- English - Cream-coloured Giant Squirrel, Pale Giant Squirrel
- French - Ratufe Dorée, Écureuil De Raffles, Écureuil Géant Commun
- Swedish - ljusbrun Jätteekorre

Shrew-faced Ground Squirrel
Description
The Shrew-faced Ground Squirrel, as its name suggests, lives on the forest floor, where it feeds on earthworms and insects such as ants, termites and beetles. Typical of ground squirrels, this secretive and solitary animal is active during the day. It has a long and pointed snout like the Tree Shrew (another type of mammal) and much smaller incisor teeth than other species of squirrels. The upper parts of its body are dark brown but its underparts are white or buff. It is a medium-sized squirrel with a body length of up to 23cm and a tail length of up to 17cm.

Distribution
This species occurs in Singapore, Peninsular Malaysia, Sumatra (Indonesia), Borneo and Thailand. It used to be common in the Changi jungle in Singapore in the early 1900s. However, it is now rarely seen and has been sighted only in the Bukit Timah Nature Reserve in 1985, 1989, 2004 and 2007.

Variant Names
Scientific name: Rhinosciurus laticaudatus
Common names: Shrew-faced Ground Squirrel, Shrew-faced Squirrel

Red Giant Flying Squirrel
Description
The Red Giant Flying Squirrel can measure up to 46cm in length and its tail can grow up to 50cm long. It lives in the forest, nesting in holes in tall trees and surviving on a diet of fruits, leaves and shoots. It is a nocturnal animal and usually moves about in pairs. It is also an arboreal species and travels from tree to tree by gliding through the air. The body is mostly reddish-brown except for some black on the nose, ears, feet and tail.

Distribution
This species is found in various parts of Asia, including Singapore, Peninsular Malaysia, Sumatra and Java (Indonesia), Borneo, Thailand, Myanmar, India, Pakistan, Nepal and China. It was considered common in Singapore in the earlier part of the 20th century. However, it has not been seen here for over 20 years, prompting fears that it may already be extinct. The last two sightings were in 1982 and 1986, in the Bukit Timah and Central Catchment Nature Reserves, respectively.

Variant Names
Scientific name: Petaurista petaurista
Common names: Red Giant Flying Squirrel, Common Giant Flying Squirrel

Red-cheeked Flying Squirrel
Description
The Red-cheeked Flying Squirrel is very small, with a body length of up to 18.4cm excluding the tail, which can grow up to 16.6cm. Like other flying squirrels, it is a nocturnal animal. It lives in the forest and nests in small holes on the trunk of tall trees. It has a round head and a blunt snout, and its tail is long and feather-like. The upper parts of its body are dark grey-brown with rust-coloured markings, while its underparts are white with orange tinges. The base of its tail is distinctly orange and its cheeks are orange-brown on grey.

Distribution
This species is native to Singapore, Peninsular Malaysia, Sumatra (Indonesia), Borneo, Thailand, Myanmar, Vietnam and Laos. In Singapore, it has only been found in the Bukit Timah Nature Reserve, which is where it was first discovered in October 1996.

Variant Names
Scientific name: Hylopetes spadiceus
Common name: Red-cheeked Flying Squirrel

Threats
The biggest threat in recent years has been habitat loss. As a result of rapid urbanisation, the size of forests in Singapore has shrunk significantly. Although it is not certain how many of these endangered squirrels are left in the wild, it is believed that the population size has reached a dangerously low level. Extremely small populations are not sustainable in the long run as there are too few left to breed or increased inbreeding leads to higher risks of disease and deformity.

Conservation
Through the protection of the nature reserves, it is hoped that the habitats of the remaining squirrels and other wildlife in Singapore can be preserved, thereby ensuring their survival. In addition, the trading of wildlife is strictly regulated. In particular, there is a heavy penalty for the smuggling of animals listed in the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), of which Singapore is a signatory. The Cream-coloured Giant Squirrel is listed as a protected species in CITES, which means that anyone caught smuggling it is liable to be prosecuted in court and fined a maximum of S$50,000 for each animal and/or jailed for up to two years.



Author
Valerie Chew



References
Baker, N. (n.d.). Shrew-faced ground squirrel. Retrieved April 8, 2009, from http://www.ecologyasia.com/verts/mammals/shrew-faced-ground-squirrel.htm

Baker, N., & Lim, K. K. P. (Project coordinators). (2008). Wild animals of Singapore: A photographic guide to mammals, reptiles, amphibians and freshwater fishes. Singapore: Draco Publishing and Distribution; Nature Society (Singapore).
(Call no.: RSING 591.95957 WIL)

Convention on International Trade in Endangered Species of Wild Fauna and Flora. (n.d.). CITES species database. Retrieved April 8, 2009, from http://www.cites.org/eng/resources/species.html

Davison, G. W. H., Ng, P. K. L., & Ho, H. C. (Eds.). (2008). The Singapore red data book: Threatened plants & animals of Singapore. Singapore: Nature Society (Singapore).
(Call no.: RSING 591.68095957 SIN)

International Union for Conservation of Nature and Natural Resources. (2008). Hylopetes spadiceus. Retrieved April 8, 2009, from http://www.iucnredlist.org/details/10607

International Union for Conservation of Nature and Natural Resources. (2008). Petaurista petaurista. Retrieved April 8, 2009, from http://www.iucnredlist.org/details/16723

International Union for Conservation of Nature and Natural Resources. (2008). Ratufa affinis. Retrieved April 8, 2009, from http://www.iucnredlist.org/details/19376

International Union for Conservation of Nature and Natural Resources. (2008). Rhinosciurus laticaudatus. Retrieved April 8, 2009, from http://www.iucnredlist.org/details/42460

Ng, P. K. L., & Wee, Y. C. (Eds.). (1994). The Singapore red data book: Threatened plants and animals of Singapore. Singapore: Nature Society (Singapore).
(Call no.: RSING 574.529095957 SIN)

Ng, P. K. L., Murphy, D. H., Lim, K. K. P., Chou, L. M., & Lane, D. J. W. (1995). A guide to the threatened animals of Singapore. Singapore: Singapore Science Centre.
(Call no.: RSING 591.529095957 GUI)

Rajan, T. (2007, May 23). Tommy Koh's green mission: Save 2 species. The Straits Times. Retrieved April 8, 2009, from Factiva database.


Further Readings
Francis, C. M. (2007). A photographic guide to mammals of South-East Asia. London: New Holland.
(Call no.: RSING 599.0959 FRA)

Francis, C. M. (2008). A field guide to the mammals of South-East Asia. London: New Holland.
(Call no.: RSEA 599.0959 FRA)



The information in this article is valid as at 2009 and correct as far as we are able to ascertain from our sources. It is not intended to be an exhaustive or complete history of the subject. Please contact the Library for further reading materials on the topic.