rhamphotheca:

eximago:  Least Weasel (Mustela nivalis)

The least weasel is the smallest known member of Mustelidae. It’s native to a vast range across Eurasia and northern North America, as well as a small part of North Africa. The least weasel evolved its drastically small stature over a 5-7 million year period as the planet cooled and northern forests receded, creating more grassland. This caused a boom in burrowing rodent species which created a niche for small specialized predators that the least weasel came to fill.

It is voracious predators, adapted to chasing rodents and other small mammals like shrews into their burrows. It kills with either a bite to the back of the head or to the neck. When food is plentiful, it will sometimes just harm the animal enough to cause brain damage, but not death, extending the time before it begins to decay by keeping it alive. It will then store the debilitated prey in its burrow for later consumption. It is also known to take larger prey such as rabbits and small birds. These prey items are usually die due to blood loss and shock.

Like most other Mustelids, they are territorial with males occupying large territories that overlap with several females. The size of these territories vary with the availability of food, with territories growing as food becomes harder to find. As a result, territories can change in size throughout the year with the changing of seasons.

Regionally, the least weasel can be quite variable and several subspecies exist. Northern specimens have smoother fur than southern specimens, for instance, and the color of the fur can also vary from a deep brown to chestnut to a sandy color. In many regions, its fur will turn white in winter.

As small animals, least weasels are threatened by predators as well. Birds of prey such as owls and buzzards, foxes, snakes, and larger Mustelids are all known to prey upon them.

Least weasel in its winter coat with prey