Sundasciurus lowii

Geographic Range

Low’s squirrel is found in regions of Thailand, Malaysia, Sumatra, and Borneo (Saiful & Nordin, 2004). Studies conducted on this squirrel species have been located in sites such as Kinabalu National Park and Danum Valley Conservation Area.

• Biogeographic Regions
• oriental oriental
  • native native

Habitat

Low’s squirrel inhabits lower montane and lowland regions. There have been reports of these squirrels occurring in Singapore, but these have not been confirmed to date. These squirrels have also been found in primary and secondary growth forests, as well as in decimated regions prone to deforestation (Saiful & Nordin, 2004). These squirrels forage and exists mostly on the forest floor, though they have been observed to occasionally exhibit arboreal tendencies. Low’s squirrels create nests utilizing leaves and interwoven plant fibers- these nests can be found on the ground or tucked between low branches of trees. Some sighted nests have also been located in tree cavities (Saiful & Nordin, 2004) .

• Habitat Regions
• tropical tropical
• terrestrial terrestrial

• Terrestrial Biomes
• rainforest rainforest
• mountains mountains

Physical Description

The average mass of the Low’s Squirrel is approximately 76 grams, with a total length of about 25cm (Hayssen, 2008). Other information suggests that the squirrels’ weight is higher, at about 96 grams, however sample size was so small that the number may not be completely accurate for the entire existing population (Baker, 2021). These squirrels can reach up to 13 cm in body length – their tail alone being 10 cm. (Baker, 2021). These squirrels are mostly identified by their thick tail and very white underbelly. They are small, with a rounded head and small ears.

• Other Physical Features
• endothermic endothermic
• bilateral symmetry bilateral symmetry

• Sexual Dimorphism
• sexes alike

Reproduction

There is little to no information on the reproductive activity of the Low’s squirrel. Based on other squirrel species that reside in the same habitats, it can be assumed that the gestation period and activity is similar. It is known however, that the average litter size of these squirrels is 2 kits (Hayssen, 2008). Another squirrel species that resides in Malaysia (the Prevost’s squirrel) has a gestation period of 40 days, with a peak mating season between June and August. These squirrels birth altricial young, and the female provides the young with milk and some care.

• Mating System
• polygynandrous (promiscuous) polygynandrous (promiscuous)

• Key Reproductive Features
• seasonal breeding seasonal breeding
• year-round breeding year-round breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual sexual

See Reproduction: Mating Systems

• Parental Investment
• altricial altricial
• female parental care female parental care

Lifespan/Longevity

Sources state that the average lifespan for the squirrel is 11 years, however there is conflicting information that states that 11 years is only when the squirrels are kept in captivity.

Behavior

Low’s squirrels are scansorial, allowing them to climb trees and large shrubs to attain food, or create nests on lower branches (Whitten & Whitten, 2015). The nest location is a good indicator of primary foraging activity. They are also diurnal, with most, if not all activity taking place during the daylight hours (Hinckley et al., 2020).

• Key Behaviors
• scansorial
• motile motile
• sedentary sedentary

Home Range

See Geographic Range

Communication and Perception

There is little information found about communication, however in other squirrel species communication occurs through chattering, especially when predators are present.

• Communication Channels
• acoustic acoustic

• Perception Channels
• tactile tactile
• chemical chemical

Food Habits

Low’s squirrel is an omnivore, eating insects, bark, fungi, and fruit. It’s diet is similar to the other squirrels that live in the same regions of Malaysia, especially the Slender squirrel- which shares the same habitat region on the island of Borneo (Whitten & Whitten, 2015). The food eaten by these squirrels can depend on the specific region which they live. It has been observed that in parts of Indonesia, the diet of S.lowii consists primarily of bark. They can be picky in their selection, and chose trees that featured smooth bark that flaked easily (Whitten & Whitten, 2015). Stomach analyses revealed that bark was a very large portion of their diet, and animal remains were observed, but only occupied about 39% of the stomach cavity. Trees that showed signs of bark stripping fell into three general categories – low tannin and low alkaloid concentration, rich with condensed tannins, and containing hydrolysable tannins. These specific tannins undergo hydrolysis by weak acids or bases to create carbohydrates. Bark was stripped from the families Endospermum, Hydnocarpus, Alangium¸and Sloanea.

• Primary Diet
• carnivore carnivore
  • eats terrestrial vertebrates
  • insectivore insectivore
• herbivore herbivore
  • lignivore
• omnivore omnivore

• Animal Foods
• insects

• Plant Foods
• wood, bark, or stems
• fruit
• lichens

Predation

Predators of the Low’s squirrel vary slightly from region to region, however predation consists of raptors, snakes, and terrestrial carnivores (Tamura & Yong, 1993).

Ecosystem Roles

Although this species of squirrel eats mainly bark and insects, fruit does feature in some of their diet. Seeds from these fruit may be dispersed throughout a region by these squirrels. Other squirrel species residing in these regions are also seed dispersers.

• Ecosystem Impact
• disperses seeds

Economic Importance for Humans: Positive

There are no known effect, positive or negative, of the Low’s squirrel on human populations. Deforestation could potentially pose a problem for squirrels that rely on fruits and bark for the large parts of their diet.

Economic Importance for Humans: Negative

There are no known adverse effects of Sundasciurus lowii on humans.

Conservation Status

The Low’s squirrel was last assessed for its status in 2016, wherein it was stated to be of least concern with a stable population trend ( Meijaard , 2016).

Other Comments

The Low’s squirrel lives in close proximity to the Slender squirrel in Sumatra, so behaviors may be similar when it comes to reproductive behaviors, communication, food habits, etc.

Additional Links

Encyclopedia of Life

Contributors

Isabelle Hoecherl (author), University of Washington, Laura Prugh (editor), University of Washington, Tanya Dewey (editor), University of Michigan-Ann Arbor.

References

Baker, N. 2021. Low's Squirrel- Sundasciurus lowii. Accessed (Date Unknown) at https://www.ecologyasia.com/verts/mammals/low's_squirrel.htm .

Hayssen, V. 2008. Reproductive Effort in Squirrels: Ecological, Phylogenetic, Allometric, and Latitudinal Patterns.. Accessed (Date Unknown) at https://academic.oup.com/jmammal/article/89/3/582/861078. .

Hinckely, A., M. Hawkins, A. Achmadi, J. Maldonado, J. Leonard. June 5, 2020. "Ancient Divergence Driven by Geographic Isolation and Ecological Adaptation in Forest Dependent Sundaland Tree Squirrels." (On-line). Accessed May 05, 2021 at https://www.frontiersin.org/articles/10.3389/fevo.2020.00208/full?&utm_source=Email_to_authors_&utm_medium=Email&utm_content=T1_11.5e1_author&utm_campaign=Email_publication&field=&journalName=Frontiers_in_Ecology_and_Evolution&id=539170. .

Meijaard, E. 2016. "The IUCN Red List of Threatened Species" (On-line). Accessed May 05, 2021 at https://www.iucnredlist.org/species/21158/22249977 .

Saiful, A., M. Nordin. 2004. "Diversity and Density of Diurnal Squirrels in a Primary Hill Dipterocarp Forest, Malaysia" (On-line). Accessed May 05, 2021 at http://offcampus.lib.washington.edu/login?url=https://www.jstor.org/stable/4091884. .

Tamura, N., H. Yong. 1993. "Vocalizations in Response to Predators in Three Species of Malaysian Callosciurus (Sciuridae)." (On-line). Accessed May 05, 2021 at https://academic.oup.com/jmammal/article-abstract/74/3/703/940691 .

Whitten, J., A. Whitten. 2015. "Analysis of Bark Eating in a Tropical Squirrel." (On-line). Accessed May 05, 2021 at https://www-jstor-org.offcampus.lib.washington.edu/stable/2388731?seq=8#metadata_info_tab_contents .