Weasels (And Other Mustelids) of Connecticut
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There are numerous carnivorous mammals that make their home in Connecticut. Residents may notice foxes in their neighborhood and black bears are becoming increasingly common in less developed parts of the state. What you may not realize is that Connecticut is home to other carnivores that can be so secretive that they are practically invisible. These are members of the weasel family, or Mustelidae.
Mustelidae contains weasels and their relatives, including otters, badgers, and wolverines. Skunks used to be considered mustelids but now are classified in their own family, Mephitidae. No badgers live in Connecticut and thus all local mustelids follow the basic weasel body plan: A long slender body, short legs, and a long tail. There are six species of mustelid in Connecticut, and they may be living right under your nose.
Fisher (Also Known as the Fisher Cat)
The fisher is the subject of many misconceptions. It is sometimes called a fisher cat, but it is not any sort of feline. They weigh 4 - 14 pounds and are 30 - 40 inches long, making them the second largest member of the weasel family in the state.
Due to the combined forces of habitat loss and overhunting, fishers were considered extirpated from the state by the early 1900s. Fortunately, reforestation, reintroductions, and reduced hunting pressures have allowed fishers to thrive in Connecticut once more.
Fishers will eat fruit, nuts, or carrion if available but are primarily carnivorous. They prey on small animals like squirrels, mice, rabbits, birds, and frogs. Contrary to their name, fish do not make up a large part of their diet. They can climb trees but usually hunt and forage on land and rely on stealth and ambushes to make their kills.
There is significant mythology regarding fishers and their ferocity. They are said to be aggressive and fond of devouring pets, screaming in the night and sometimes attacking humans too. These assumptions are all incorrect. Fishers are naturally quiet animals and don’t scream. A nocturnal cacophony is more likely to be made by foxes, owls, or raccoons. Fishers rarely attack pets and typically only tussle with cats or small dogs that are left outside alone at night. As for attacks on humans, they are exceptionally unusual and only occur when the fisher is cornered or feels threatened.
River Otter
River otters are the longest and heaviest mustelids in Connecticut and weigh 12 - 25 pounds. They can be found near streams, lakes, rivers, and marshes. Their webbed feet and powerful tails make them agile swimmers and a waterproof fur coat and thick layer of fat keeps them warm. They frequently hunt and forage for food underwater and can hold their breath for up to 4 minutes. They eat small animals that can be found in or near the water such as fish, frogs, shellfish, and sometimes insects, turtles, worms, or small birds and mammals.
River otters are shy and hard to spot during daylight hours. Those who do manage to see the river otter in its native habitat may find its antics charming. They are known for being energetic and playful and enjoy wrestling with other otters, tossing things in the water and chasing them, and sliding on their bellies.
American Ermine (Short-Tailed Weasel) and Long-Tailed Weasel
The short-tailed weasel, or ermine, and long-tailed weasel are so similar in looks and behavior that they are often mistaken for the same animal. They both have short brown fur and pale bellies and both develop a white winter coat in snowy climates. They prefer habitats with plenty of places to hide, like dense brushy thickets and wooded areas. They enjoy carnivorous diets composed of small prey like rodents, birds, fish, frogs, and sometimes rabbits or squirrels. Their flexible bodies and short legs let them pursue prey into burrows and dens, and they are very effective predators despite their small sizes.
The long-tailed weasel is a few inches longer on average than the short-tailed weasel but there is enough overlap that size is not a good indicator of species. Looking at their tails is key for a quick identification. The tail of a long-tailed weasel is about half of its body length while a short-tailed weasel’s tail is only around a third of its body length.
Neither of these two species weighs more than a pound upon maturity and their small size and secretive nature can make them hard to spot. If you want a chance to see a short or long-tailed weasel in Connecticut, your best chance may be near an old stone wall. The crevices make excellent homes for small weasels and you may notice them scampering about in the evening.
It is very unusual to have two species with so many similarities in a single area. In this case, it occurred due to their unique evolutionary circumstances. The long-tailed weasel evolved in America while the short-tailed weasel evolved in Eurasia. They lived on different continents in the same evolutionary niche until the Bering Land Bridge allowed the short-tailed weasel to cross over to North America around 500,000 years ago.
Image by Cephas.
Mink
Like the otter, minks are also frequently found near water. Their partially webbed feet make them excellent swimmers but they also climb trees and run quietly through the underbrush. Their adaptability to different environments makes them versatile predators. They enjoy a varied diet of fish, birds, amphibians, and small mammals like muskrats, rabbits, and rodents.
Wild mink rarely weigh more than 4 pounds. Their small size makes them a target for larger predators such as foxes, bobcats, and owls. As an additional line of defense against such attacks, mink can spray a foul odor from their anal scent glands. This unpleasant smell may distract the predator, giving the mink time to escape.
Mink have long oily guard hairs that help waterproof and insulate their dense fur. The high quality of their fur has historically made them a prime target in the fur trade. Today, most mink harvested for fur products are raised on farms. Fur trappers still hunt mink in Connecticut, but not at levels that impact their population.
Kate Dzikiewicz, Science Curatorial Associate
