Petaurilluspygmy flying squirrels
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. (Thorington Jr. and Darrow, 2000; Thorington Jr. and Jackson, 2012; Thorington Jr., et al., 2005; Thorington Jr., et al., 2012; Thorington Jr., et al., 2002)
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. (Thorington Jr., et al., 2012)
- Other Geographic Terms
- 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. (Thorington Jr. and Darrow, 2000; Thorington Jr., et al., 2012)
- Habitat Regions
- tropical
- Terrestrial Biomes
- 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. (Duckworth and Francis, 2008; The Editors of Encyclopaedia, 2020)
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. (Jackson, 2012; Yoon Ling, et al., 2016)
- Other Physical Features
- endothermic
- 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. (Jackson, 2012; Thorington Jr. and Jackson, 2012)
- Mating System
- polygynandrous (promiscuous)
- Key Reproductive Features
- gonochoric/gonochoristic/dioecious (sexes separate)
- 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. (Jackson, 2012; Thorington Jr. and Jackson, 2012)
- Parental Investment
- altricial
- 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. (Thorington Jr. and Jackson, 2012; Thorington Jr., et al., 2012)
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. (Thorington Jr. and Darrow, 2000; Thorington Jr. and Jackson, 2012; Thorington Jr., et al., 2012)
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. (Thorington, et al., 2006)
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. (Thorington Jr. and Darrow, 2000; Thorington Jr. and Jackson, 2012)
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. (Thorington Jr. and Jackson, 2012)
-
- Known Predators
-
- Human
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. (Thorington Jr. and Darrow, 2000)
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.
-
- IUCN Red List [Link]
- Not Evaluated
Contributors
Madison Martin (author), Colorado State University, Audrey Bowman (editor), Colorado State University.
Glossary
- acoustic
-
uses sound to communicate
- altricial
-
young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.
- arboreal
-
Referring to an animal that lives in trees; tree-climbing.
- bilateral symmetry
-
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
- chemical
-
uses smells or other chemicals to communicate
- endothermic
-
animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.
- female parental care
-
parental care is carried out by females
- forest
-
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
- frugivore
-
an animal that mainly eats fruit
- granivore
-
an animal that mainly eats seeds
- herbivore
-
An animal that eats mainly plants or parts of plants.
- island endemic
-
animals that live only on an island or set of islands.
- motile
-
having the capacity to move from one place to another.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- nocturnal
-
active during the night
- omnivore
-
an animal that mainly eats all kinds of things, including plants and animals
- oriental
-
found in the oriental region of the world. In other words, India and southeast Asia.
- polygynandrous
-
the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.
- sexual
-
reproduction that includes combining the genetic contribution of two individuals, a male and a female
- tactile
-
uses touch to communicate
- tropical
-
the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.
- visual
-
uses sight to communicate
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"" (On-line). Accessed February 26, 2022 at https://www.britannica.com/animal/flying-squirrel.
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.
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, R., R. Thorington, Jr., K. Ferrell. 2006. Squirrels: The Animal Answer Guide. Baltimore: Johns Hopkins University Press.
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.