Petaurillus

Diversity

Petaurillus is a genus commonly known as pygmy flying squirrels, and consists of three identified species. Petaurillus emiliae is the smallest flying squirrel and is only reported to be found in Sarawak, Malaysia. Petaurillus hosei is a small flying squirrel found in Northern Borneo (Malaysia) and looks similar in color and markings to Petaurillus emiliae but is twice the size. Petaurillus kinlochii is also found in Malaysia and is sized in between Petaurillus emiliae and Petaurillus hosei . All three species rely on dense forests for nutrition and shelter but live in areas that are affected by heavy deforestation.

Geographic Range

Petaurillus individuals are found in the Oriental Region of the world and is endemic to the peninsula and island of Malaysia. Petaurillus kinlochii has only been found near Selangor (peninsular Malaysia) in areas that have recently succumbed to deforestation. Petaurillus hosei is found in Northern Borneo (Malaysia) near Sabah and Sarawak. Petaurillus emiliae is found nearby in the forests of Sarawak, Malaysia.

• Biogeographic Regions
• oriental oriental
  • native native

• Other Geographic Terms
• island endemic island endemic

Habitat

Petaurillus live within the tropical region of Malaysia and are highly arboreal. Individuals live within trees where they can reach their main source of nutrition which consists of fruits and seeds. Petaurillus hosei have been found using tree cavities as nest holes for shelter and to care for their young.

• Habitat Regions
• tropical tropical

• Terrestrial Biomes
• forest forest

Systematic and Taxonomic History

Petaurillus is within the tribe Pteromyini . 'Ptero' is a Greek word meaning wing and 'myini' means small. Petaurillus hosei is named after zoologist Charles Hose, however no recent literature states the reasoning behind the names of the other two species within the genus.

Physical Description

Physical descriptions are known through observations of only five specimens. Flying squirrels in the genus Petaurillus are known for their small size and feather-like tails. Petaurillus weigh less than 1 kilogram with the smallest species Petaurillus emiliae weighing an average of 27 grams. Flying squirrels are distinguished from other squirrels by a small membrane that extends between their wrists and ankles that extends when gliding. Recorded measurements of the five specimens consist of head to body length of 80-96 mm, tail length 61-94 mm, and ear length 10-16 mm.

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

Reproduction

No information is listed in current literature about the reproduction of Petaurillus , however, other species within the family Sciuridae are polygynandrous. Multiple males may mate with multiple females in a single breeding season.

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

• Key Reproductive Features
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual sexual

No information is listed in current literature about the parental investment of Petaurillus , however, other species within the family Sciuridae show that the female will provide care and nutrition for the young until they mature.

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

Lifespan/Longevity

There is limited research on the lifespan of Petaurillus , but one specimen was observed to live 2 years in the wild. However, because these pygmy flying squirrels are endemic to small regions in Malaysia that are undergoing heavy urbanization, the longevity of this genus is threatened.

Behavior

Pygmy flying squirrels are arboreal and nocturnal. Although they have a thin membrane that stretches from their wrists to their legs, these are not considered wings and pygmy flying squirrels do not actually fly. Instead, these squirrels glide through the air as they move through the treetops. They nest within trees where they raise young and aggregate with other pygmy flying squirrels for warmth. This genus of squirrels does not hibernate, as they live in a warm climate.

• Key Behaviors
• arboreal arboreal
• glides
• nocturnal nocturnal
• motile motile

Communication and Perception

Although Petaurillus are nocturnal, they have not been observed to use echolocation. Instead, these pygmy flying squirrels are similar to tree squirrels in that they use a few distinct vocalization cues, but rely mostly on body language to communicate with each other and with other animals around them.

• Communication Channels
• visual visual
• tactile tactile
• acoustic acoustic

• Perception Channels
• visual visual
• tactile tactile
• acoustic acoustic
• chemical chemical

Food Habits

No information is reported about the food habits of Petaurillus but other arboreal species tend to be omnivores, eating a diet of seeds, nuts, insects, fungi, and fruit.

• Primary Diet
• herbivore herbivore
  • frugivore frugivore
  • granivore granivore
• omnivore omnivore

Predation

Little is known about the natural predators of Petaurillus but because these species are endemic to specific areas in Malaysia that are experiencing heavy urbanization, humans are a huge threat to these animals. Species within Petaurillus are arboreal and when the forests that home them are removed for human urbanization, they become threatened.

Ecosystem Roles

Not enough is known at this time about the ecological role of Petaurillus , however, because the species are arboreal and feed on native fruit and seeds, their role in forest development and seed dispersal is similar to other tree squirrels.

Economic Importance for Humans: Positive

No information is listed in credible literature about the known positive effects of Petaurillus on humans.

Economic Importance for Humans: Negative

There are no known adverse effects of Petaurillus on humans.

Conservation Status

The conservations status for the species within Petaurillus are listed as "unknown" by the IUCN.

Additional Links

Encyclopedia of Life

Contributors

Madison Martin (author), Colorado State University, Audrey Bowman (editor), Colorado State University.

References

Amori, G., S. Gippoliti, K. Helgen. 2008. Diversity, distribution, and conservation of endemic island rodents.. Quaternary International , 1: 6-15.

Arbogast, B. 2007. A Brief History of the New World Flying Squirrels: Phylogeny, Biogeography, and Conservation Genetics. Journal of Mammalogy , Volume 88, Issue 4: 840-849. Accessed February 13, 2022 at https://academic.oup.com/jmammal/article/88/4/840/908936?login=true .

Duckworth, J., C. Francis. 2008. "Hose's Pygmy Flying Squirrel" (On-line). Accessed March 19, 2022 at https://www.iucnredlist.org/species/16715/115137752 .

Gannon, W. 2007. Squirrels: the animal answer guide. Journal of Mammalogy , 3: 824-824.

Jackson, S. 2012. Gliding Mammals of the World . Clayton, Australia: Csiro Publishing.

Li, G., Y. Lwin, B. Yang, T. Qin, P. Phothisath, K. Maung, R. Quan, S. Li. 2020. "Taxonomic revision and phylogenetic position of the flying squirrel genus Biswamoyopterus (Mammalia, Rodentia, Scuiridae, Pteromyini) on northern Indo-China peninsula" (On-line). Accessed February 02, 2022 at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7341418/ .

Lu, X., D. Ge, L. Xia, Z. Zhang, S. Li, Q. Yang. 2012. The Evolution and Paleobiogeography of Flying Squirrels (Sciuridae, Pteromyini) in Response to Global Environmental Change. Evolutionary Biology , 40: 117-132.

The Editors of Encyclopaedia, 2020. "

"flying squirrel"

Thorington, R., R. Thorington, Jr., K. Ferrell. 2006. Squirrels: The Animal Answer Guide . Baltimore: Johns Hopkins University Press.

Thorington Jr., R., K. Darrow. 2000. Anatomy of the squirrel wrist: Bones, ligaments, and muscles. Journal of Morphology , 2: 85-102.

Thorington Jr., R., S. Jackson. 2012. "Smithsonian Contributions to Zoology" (On-line pdf). Gliding mammals: taxonomy of living and extinct species. Accessed February 02, 2022 at https://repository.si.edu/bitstream/handle/10088/18186/SCZ638_Jackson_FINAL_web.pdf .

Thorington Jr., R., D. Pitassy, L. Pappas, C. Schennum. 2005. The difficulties of identifying flying squirrels (Sciuridae: Pteromyini) in the fossil record. Journal of Vertebrate Paleontology , 4: 950-961.

Thorington Jr., R., J. Koprowski, M. Steele, J. Whatton. 2012. Squirrels of the World . Baltimore: Johns Hopkins University Press.

Thorington Jr., ., D. Pitassy, S. Jansa. 2002. Phylogenies of Flying Squirrels (Pteromyinae). Journal of Mammalian Evolution , 9: 99-135.

Yoon Ling, C., T. Ean, H. Pei, M. Hazilas, N. Majid, L. Hock. 2016. "NOTES ON THE COLLECTIONS OF THE SELANGOR PYGMY FLYING SQUIRREL, Petaurillus Kinlochi (RODENTIA: Sciuridae) IN MALYASIA" (On-line). Accessed February 02, 2022 at https://www.researchgate.net/profile/Kuang-Lim-2/publication/357956855_Cheong_Yoon_Ling_Biomedical_Museum_Institute_for_Medical_Research_National_Institutes_of_Health_Ministry_of_Health_Malaysia/links/61e918869a753545e2e302ea/Cheong-Yoon-Ling-Biomedical-Museum-Institute-for-Medical-Research-National-Institutes-of-Health-Ministry-of-Health-Malaysia.pdf .