Long-tailed weasel
| Long-tailed weasel | |
|---|---|
 |
|
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Carnivora |
| Family: | Mustelidae |
| Subfamily: | Mustelinae |
| Genus: | Mustela |
| Species: | M. frenata |
| Binomial name | |
|
Mustela frenata Lichtenstein, 1831 |
|
 |
|
| Long-tailed weasel range | |
The long-tailed weasel (Mustela frenata), also known as the bridled weasel or big stoat, is a species of mustelid distributed from southern Canada throughout all the United States and Mexico, southward through all of Central America and into northern South America. It is distinct from the short-tailed weasel, also known as a "stoat", a close relation which originated in Eurasia and crossed into North America some half million years ago.
The long-tailed weasel is the product of a process begun 5–7 million years ago, when northern forests were replaced by open grassland, thus prompting an explosive evolution of small, burrowing rodents. The long-tailed weasel's ancestors were larger than the current form, and underwent a reduction in size to exploit the new food source. The long-tailed weasel arose in North America 2 million years ago, shortly before the stoat evolved as its mirror image in Eurasia. The species thrived during the Ice Age, as its small size and long body allowed it to easily operate beneath snow, as well as hunt in burrows. The long-tailed weasel and the stoat remained separated until half a million years ago, when falling sea levels exposed the Bering land bridge, thus allowing the stoat to cross into North America. However, unlike the latter species, the long-tailed weasel never crossed the land bridge, and did not spread into Eurasia.
The long-tailed weasel is one of the larger members of the genus Mustela in North America. There is substantial disagreement both on the upper end of their size and difference in size by sex by source: one indicates a body length of 300–350 mm (12–14 in) and a tail comprising 40–70% of the head and body length. It adds that I n most populations, females are 10–15% smaller than males, thus making them about the same size as large male stoats, according to a second source. A third states they range from 11 to 22 inches (280–560 mm) in length, with the tail measuring an additional 3 to 6 inches (80–150 mm). It maintains the long-tailed weasel weighs between 3 and 9 ounces (85-267 g) with males being about twice as large as the females.
...
Wikipedia