(Mustela frenata). Patient Number 23-197.

Date of admission: May 20, 2023.
Reason for admission: Orphaned.

Patient History:

The long-tailed weasel, also known as the bridled weasel, and masked ermine, is distributed from southern Canada throughout all of the United States and Mexico, all of Central America, and into northern South America. Long-tailed weasels evolved almost 2 million years ago in North America. 

Long-tail weasels have long slender bodies. Males are typically larger than females and their long bushy tails make up about 50% of their total body length. Long-tailed weasels have a small, narrow head with long whiskers. They also have short legs. Their fur is short and cinnamon brown in color with a white-yellow underbelly. Long-tailed weasels turn white in winter, while in the south their coat is the same color year-round.

These mammals are not social animals and the genders live apart except in the mating season. Long-tailed weasels are most active at night. They are known to be noisy, usually in response to a disturbance, and will defend their territory aggressively.

The long-tailed weasel is an endearing-looking species but is by far one of nature's most ferocious and relentless predators. They are carnivores and have a fearless attitude about attacking bigger animals. This species mainly eats rodents, but sometimes eats fruits, lizards, and small birds. They are known to store food for later, and may even kill and eat their siblings or offspring if there is no other food available.

Long-tailed weasels have such a high metabolic rate that they can eat around 40% of their body weight every day.

Long-tailed weasels are polygynous, which means that one male mates with multiple females. Mating takes place during mid-summer; however, total gestation is approximately 280 days which means offspring are born in late April through early May. An average of six pups are born, who typically weigh about 3 grams. At 36 days they are weaned and by 56 days they can kill their own prey.

This long-tailed weasel was brought to us from Strathmore, AB, just east of Calgary. He was found in the wheel well of a trailer and the mother had not returned after a day and a half. He was estimated to be about a month old, which is a critical stage where they are entirely dependent on their mother. Because of this, he was immediately brought to AIWC. Despite being orphaned, he is in relatively good body condition and has also just opened his eyes in care. He will remain with us until old enough to be returned to the wild. Thank you for supporting his care!