Mink and Muskrats in NJ

Photos by Richard Angelillo

This month I was contacted by Richard Angelillo who sent the two photos above that he took in Somerset, NJ. He thought at first that it was a muskrat but was told it was a mink. He did not know that we have minks in New Jersey.

He went online and found our article on New Jersey Furbearers.

Besides muskrats, it is easy to confuse a fairly common mink for a less likely fisher. That's especially true when the animals are moving quickly and especially when they are wet.

Can you tell the difference between a mink and a muskrat?

Mink, Muskrat or Otter?  (see comment below)

The muskrat is not the principal prey of the mink but minks are the principal predator of the muskrat. There are a good number of videos online of the two animals battling, with the mink most often coming out the victor.

In NJ and in general, more muskrats are trapped than minks. But as you can see by observation, their fur s different and a mink pelt is more valuable.

Minks are dark-colored, semiaquatic, carnivorous mammals and part of the family Mustelidae, which also includes weasels, otters, and ferrets.

Minks and muskrats also have their predators. Great horned owls, bobcats, foxes, coyotes, and humans are predators of mink.

Mink are sometimes trapped to protect the fish population in lakes and rivers.

Muskrat

Muskrats are fairly common throughout NJ and are sometimes called our "swamp bunnies." They normally live in groups consisting of a male and female pair and their young. During the spring, they often fight with other muskrats over territory and potential mates.

In streams, ponds, or lakes, muskrats burrow into the bank with an underwater entrance, and in marshes, push-ups are constructed from vegetation and mud.

Muskrats are most active at night or near dawn and dusk. They feed on cattail and other aquatic vegetation.

One way to identify a muskrat when it is out of the water by its tapering, almost hairless tail.


Reference document on minks and muskrats

Fisher Followup

Fisher by http://www.ForestWander.com, CC BY-SA 3.0 us, Link

The fisher is a long-bodied and short-legged animal, with a bushy tail that makes up a third of its total body length.

People keep reporting their presence in New Jersey to me. (see other fisher posts) They are increasing in numbers, but a good percentage of the sightings are probably misidentifications.

They are not endangered and have no natural enemies. In NJ, their deaths are mostly from trapping by humans and vehicle collisions.

Here is some information that may help you with identification if you encounter them.

They are solitary creatures and have home ranges between 1-3 square miles, but usually don't overlap. They are territorial. They are active day or night.

Their dens are used year round, often using tree hollows, stumps, debris piles, natural crevices, and underground tunnels. Females with litters will use tree hollows that are far off the ground.

Males weigh in at 8-13 pounds and reach lengths between 35-47 inches, while females weigh between 3 and 7 pounds and are between 30-37 inches long. Males have grizzled fur due to blonde guard hairs on their neck and shoulders, while females are a uniform chocolate brown.

Fishers are predators and compete with coyotes, bobcats, foxes and even raptors and they will travel many miles and cross water to find food.

Fishers are a generalist carnivore species. They will eat anything they can catch which is usually small-medium-sized mammals and birds. They will also eat some carrion and nuts and fruits. In heavy snow conditions, they have been known to take down weak or injured deer.

One unusual diet note is that this is the only predator of porcupines in the country. The fisher will chase a porcupine up a tree until it can go no further and falls and then it will shoot down and attack the stunned porcupine in its unprotected underside.

SOURCE:  www.conservewildlifenj.org

Nutria

The nutria is a large rodent that looks like a beaver but with long, thin tails. They are one of the world's worst invasive species and they possibly exist in New Jersey.

They weigh 12 to 20 pounds. They are primarily nocturnal (active at night), with peak activity occurring near midnight.

Although they are native to Brazil, Paraguay, and Argentina, they have invaded North America, particularly in the southern U.S. They have been seen and trapped in New Jersey in places like Salem County's Lower Alloways Creek Township.

The problem with them, as with most invasive and non-native species, is that they eat vegetation that causes our native animals and fish to lose their habitats.

This large furbearing rodent (Myocastor coypus) was first introduced to the United States in 1899 in California. Between then and 1940,  ranches were established in many states to breed them. A crash in the market for their fur occurred after WWII and ranchers, unfortunately, released their nutria or did nothing to recapture those that escaped. They once existed in 30 states and still exist in about 18. Nutrias can tolerate winters in temperate areas only, but the milder NJ winters have allowed them to stay and breed and they were trapped in the salt marshes of the Delaware Bay back in the early 1980s.

The New Jersey Division of Fish and Wildlife would rather not get any reports of nutria and as far as I can find few valid reports of nutria have occurred recently by trappers via the annual trapper harvest survey.

You can report spotting a nutria (or fisher or bobcat) using the form at http://www.state.nj.us/dep/fgw/pdf/bobcat-fisher-nutria_sighting.pdf

In New Jersey, a Trapper Education course must be passed and a trapping license obtained to trap in the state - see http://www.state.nj.us/dep/fgw/trapping_info.htm

New Jersey Furbearers

American mink

Despite the title of an online article, "The American Mink, one of N.J.’s most common semi-aquatic carnivore," I myself (and I suspect many readers) have never seen a mink in my Jersey travels. The mink (Mustela vison) is native to the state, although it is thought that escapees from mink farms have interbred with wild mink.

The mink is not threatened in the state and has a stable population. Not threatened, unless you consider that The New Jersey Hunting and Trapping Digest lists raccoon, skunk, opossum, weasel, mink, muskrat, red and gray fox, coyote, beaver, otter and nutria as species that have open seasons for trapping in the State of New Jersey. (In New Jersey, a Trapper Education course must be passed and a trapping license obtained to trap in the state - see http://www.state.nj.us/dep/fgw/trapping_info.htm)

Several of these species were not here historically or disappeared and have only returned through re-introductions.

Native to NJ are the river otter (Lontra canadensis), long-tailed (Mustela frenata) and short-tailed ermine (Mustela ermine). Also native are the striped skunk (Mephitis mephitis), raccoon (Procyon lotor) or gray fox (Urocyon cinereorgenteus).

Coyotes, which are now being reported with more frequency in the state, were never present in New Jersey until the past fifty or so years. Their appearance is due to many factors including habitat loss in their previous area of habitation. The current theory is that overall movement (based on DNA sampling) in the last century by the western coyote to the midwest, Great Lake states and through Lower Canada led to some western coyotes mating with gray wolves. Their offspring moved further eastward through Lower Canada and down through the New England states and into the Mid-Atlantic States.

NJ had gray wolves in the state until about the mid-1850s. Today, there are no wolves in New Jersey outside of zoos and preserves. But the eastern coyote appears to be here to stay.

Some of our other furbearing creatures past and present include:

• Marten (Martes americana) historically present but extirpated since the mid-1800s
• The fisher (Martes pennanti) also extirpated but again present in Sussex and Warren counties although few in number. Probably due to re-introduction by New York and Pennsylvania in the last decade
• Beaver (Castor canadensis) had almost disappeared from here by the early 1800s. It is believed that some escapees from the Rutherford-Stuyvesant game preserve in Allamuchy, Warren County established a breeding population. Restocking enabled the beaver to re-establish itself by the mid-20th century. 
• Most common to us is the raccoon which is, was and has always been a native of New Jersey and was a species that the British explorers to this new land reported, since they did not exist in Britain.
• Opossum (Didelphis virginiana) was thought to be numerous in the central and southern part of the state in the late 1860s, but in the last hundred years the range of both opossum and raccoons has extended much further north including into Canada where they historically never existed.

opossum