The Challenge: Treeshrews (order Scandentia) are small-bodied mammals endemic to South and Southeast Asia. Since it was first described in 1820, the Common Treeshrew (Tupaia glis) has had a complex taxonomic history that has led to widely variable estimates of diversity, misidentification of populations, and general confusion regarding it and closely related species. One result is that T. glis has been treated as a poorly defined “wastebasket” taxon encompassing as many as 27 named forms.
The Science: In a series of papers using a combination of cranial characters and fine-scale characters of the hand skeleton revealed by digital xrays, we have better defined T. glis as a species and shown that a number of populations previously synonymized with it belong to other species or are distinct species in their own right. This work greatly reduced the geographic range of the Common Treeshrew, restricting it to the Malay Peninsula south of the Isthmus of Kra, the purported contact zone with its sister species, the Northern Treeshrew, T. belangeri, and adjacent offshore islands. We have further shown the existence of certain biogeographical trends, such as a reverse Bergmann’s response (smaller body size at higher latitudes) and a positive island effect, with larger body sizes on islands than on the mainland, and increasing body sizes with increasing island area. Our studies provide a means of assessing species boundaries among treeshrews, and our results so far note the need for re-assessment of the conservation status of many populations previously thought to belong to T. glis.
The Future: In addition to continuing to refine the Tupaia glis species group, we are undertaking a similar study of the Tupaia splendidula species group, populations of which have been confused with T. glis in the past.
Below are publications associated with this project.
Island history affects faunal composition: the treeshrews (Mammalia: Scandentia: Tupaiidae) from the Mentawai and Batu Islands, Indonesia
Morphological distinctiveness of Javan Tupaia hypochrysa (Scandentia, Tupaiidae)
Using hand proportions to test taxonomic boundaries within the Tupaia glis species complex (Scandentia, Tupaiidae)
Below are partners associated with this project.
- Overview
The Challenge: Treeshrews (order Scandentia) are small-bodied mammals endemic to South and Southeast Asia. Since it was first described in 1820, the Common Treeshrew (Tupaia glis) has had a complex taxonomic history that has led to widely variable estimates of diversity, misidentification of populations, and general confusion regarding it and closely related species. One result is that T. glis has been treated as a poorly defined “wastebasket” taxon encompassing as many as 27 named forms.
The Science: In a series of papers using a combination of cranial characters and fine-scale characters of the hand skeleton revealed by digital xrays, we have better defined T. glis as a species and shown that a number of populations previously synonymized with it belong to other species or are distinct species in their own right. This work greatly reduced the geographic range of the Common Treeshrew, restricting it to the Malay Peninsula south of the Isthmus of Kra, the purported contact zone with its sister species, the Northern Treeshrew, T. belangeri, and adjacent offshore islands. We have further shown the existence of certain biogeographical trends, such as a reverse Bergmann’s response (smaller body size at higher latitudes) and a positive island effect, with larger body sizes on islands than on the mainland, and increasing body sizes with increasing island area. Our studies provide a means of assessing species boundaries among treeshrews, and our results so far note the need for re-assessment of the conservation status of many populations previously thought to belong to T. glis.
The Future: In addition to continuing to refine the Tupaia glis species group, we are undertaking a similar study of the Tupaia splendidula species group, populations of which have been confused with T. glis in the past.
- Publications
Below are publications associated with this project.
Island history affects faunal composition: the treeshrews (Mammalia: Scandentia: Tupaiidae) from the Mentawai and Batu Islands, Indonesia
The Mentawai and Batu Island groups off the west coast of Sumatra have a complicated geological and biogeographical history. The Batu Islands have shared a connection with the Sumatran ‘mainland’ during periods of lowered sea level, whereas the Mentawai Islands, despite being a similar distance from Sumatra, have remained isolated from Sumatra, and probably from the Batu Islands as well. These conAuthorsEric J. Sargis, Neal Woodman, Natalie C. Morningstar, Aspen T. Reese, Link E. OlsonMorphological distinctiveness of Javan Tupaia hypochrysa (Scandentia, Tupaiidae)
The common treeshrew, Tupaia glis, represents a species complex with a complicated taxonomic history. It is distributed mostly south of the Isthmus of Kra on the Malay Peninsula and surrounding islands. In our recent revision of a portion of this species complex, we did not fully assess the population from Java (T. “glis” hypochrysa) because of our limited sample. Herein, we revisit this taxon usiAuthorsEric J. Sargis, Neal Woodman, Natalie C. Morningstar, Aspen T. Reese, Link E. OlsonUsing hand proportions to test taxonomic boundaries within the Tupaia glis species complex (Scandentia, Tupaiidae)
Treeshrews (order Scandentia) comprise 2 families of squirrel-sized terrestrial, arboreal, and scansorial mammals distributed throughout much of tropical South and Southeast Asia. The last comprehensive taxonomic revision of treeshrews was published in 1913, and a well-supported phylogeny clarifying relationships among all currently recognized extant species within the order has only recently beenAuthorsEric J. Sargos, Neal Woodman, Aspen T. Reese, Link E. Olson - Partners
Below are partners associated with this project.