The pen-tailed treeshrew (''Ptilocercus lowii'') is a

treeshrew The treeshrews (also called tree shrews or banxrings) are small mammals native to the tropical forests of South and Southeast Asia. They make up the entire order Scandentia (from Latin ''scandere'', "to climb"), which split into two families: the ...

of the family Ptilocercidae native to southern

Thailand Thailand, officially the Kingdom of Thailand and historically known as Siam (the official name until 1939), is a country in Southeast Asia on the Mainland Southeast Asia, Indochinese Peninsula. With a population of almost 66 million, it spa ...

, the

Malay Peninsula The Malay Peninsula is located in Mainland Southeast Asia. The landmass runs approximately north–south, and at its terminus, it is the southernmost point of the Asian continental mainland. The area contains Peninsular Malaysia, Southern Tha ...

Borneo Borneo () is the List of islands by area, third-largest island in the world, with an area of , and population of 23,053,723 (2020 national censuses). Situated at the geographic centre of Maritime Southeast Asia, it is one of the Greater Sunda ...

, and some

Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania, between the Indian Ocean, Indian and Pacific Ocean, Pacific oceans. Comprising over List of islands of Indonesia, 17,000 islands, including Sumatra, ...

n islands. It is the only living species in the genus ''Ptilocercus''. All other treeshrew species are grouped in the family

Tupaiidae Tupaiidae is one of two families of treeshrews, the other family being Ptilocercidae. The family contains three living genera and 19 living species. The family name derives from ''tupai'', the Malay word for treeshrew and also for squirrel which ...

Distribution and habitat

The pen-tailed treeshrew occurs from southern Thailand and the Malay Peninsula to northern Sumatra, Siberut,

Bangka Island Bangka is an island lying east of Sumatra, Indonesia. It is administered under the province of the Bangka Belitung Islands, being one of its namesakes alongside the smaller island of Belitung across the Gaspar Strait. The 9th largest island in ...

and northwestern

. It inhabits foremost

primary forest An old-growth forest or primary forest is a forest that has developed over a long period of time without Disturbance (ecology), disturbance. Due to this, old-growth forests exhibit unique ecological features. The Food and Agriculture Organizati ...

up to an elevation of , where undergrowth is dense.

Behaviour and ecology

Pen-tailed treeshrews studied in Malaysia spent several hours per night consuming naturally

fermented Fermentation is a type of anaerobic metabolism which harnesses the redox potential of the reactants to make adenosine triphosphate (ATP) and organic end products. Organic compound, Organic molecules, such as glucose or other sugars, are Catabo ...

nectar Nectar is a viscous, sugar-rich liquid produced by Plant, plants in glands called nectaries, either within the flowers with which it attracts pollination, pollinating animals, or by extrafloral nectaries, which provide a nutrient source to an ...

of the bertam palm. This nectar contains one of the highest alcohol concentrations of all natural foods. The pen-tailed treeshrews did not show any signs of intoxication, although they frequently consumed large amounts of this nectar, equivalent of 10–12 glasses of wine adjusted to body weight with an alcohol content up to 3.8%. Measurements of a

biomarker In biomedical contexts, a biomarker, or biological marker, is a measurable indicator of some biological state or condition. Biomarkers are often measured and evaluated using blood, urine, or soft tissues to examine normal biological processes, ...

alcohol dehydrogenase Alcohol dehydrogenases (ADH) () are a group of dehydrogenase enzymes that occur in many organisms and facilitate the interconversion between alcohols and aldehydes or ketones with the reduction of nicotinamide adenine dinucleotide (NAD+) to N ...

suggest that they may be metabolizing it by a pathway that is not used as heavily by humans. Their ability to ingest high amounts of alcohol is hypothesized to have been an evolutionary adaptation. How pen-tailed treeshrews benefit from this alcohol ingestion or what consequences of consistent high

blood alcohol content Blood alcohol content (BAC), also called blood alcohol concentration or blood alcohol level, is a measurement of alcohol intoxication used for legal or medical purposes. BAC is expressed as mass of alcohol per volume of blood. In US and many i ...

might factor into their physiology is unclear.

Taxonomy and evolutionary history

The Ptilocercidae are a family within the order Scandentia. Numerous morphological and genetic differences support the classification of the Ptilocercidae as a separate family from the rest of the treeshrews which diverged around 60 million years ago. Treeshrews are considered very close relatives of primates, with the

colugo Colugos (), flying lemurs, or cobegos (), are arboreal gliding euarchontogliran mammals that are native to Southeast Asia. Their closest evolutionary relatives are primates. There are just two living species of colugos: the Sunda flying lemur ...

s being closer to primates.

References

External links

Zelkowitz, R. 2008. Now That's a Party Animal
Mammals described in 1848 Taxa named by John Edward Gray Mammals of Borneo Mammals of Brunei Mammals of Indonesia Mammals of Malaysia Mammals of Thailand Treeshrews Taxonomy articles created by Polbot {{Mammal-stub