A Mysterious Mountain Dweller: The Taiwan High Mountain
Least Weasel By Professor Lin Liang-kang
(Department of Biology, Tunghai University)
Drawings by Chen Tung-liang
Translated by Hu Tsung-hsiang
Living in the high mountains of Taiwan, the least weasel has long been mistaken as the young of the Siberian weasel. Recently, through DNA matching and chromosome analysis, it has been identified as a new species peculiar to Taiwan and a close relative of the Japanese least weasel. Scarce and elusive, it is not easy to study. We can only surmise that it shares common traits with the Siberian weasel and the Japanese least weasel, all members of the genus Mustela. Dr. Kano Tadeo, who became an ardent lover of Taiwan's natural environment during the Japanese occupation, once described the wildlife in the alpine areas of Taiwan as having two characteristics. First, a large proportion of the species were endemic. Second, the distribution of species closely related to those outside of Taiwan was discontinuous, often disappearing in certain intermediate regions. Mistaken The alpine wildlife in Taiwan was formed one to two million years ago, much earlier than in lower-altitude regions. Between 750,000 to 10,000 years ago, under the cyclic effect of the expansion and withdrawal of glaciers, the average annual temperature in Taiwan could drop as low as five degrees Celsius. This contributed to a high mountain wildlife that preserved certain frigid and temperate-zone plants and animals which had dispersed to Taiwan during the glacial epochs, such as the Formosan landlocked salmon (Oncorhynchus mason formosanus) and Sonani's salamander (Hynobius formosanus). However, these relict glacial-epoch life forms now exist only in segregated ranges and small numbers, on the verge of extinction. | |
|
