The Eagleson Pond Mink

American Mink

The American Mink is a relatively new addition to the list of fauna found at the Eagleson storm water ponds. I had first heard that there was one there in 2019, but had never seen it for myself. Then when Sophie found one killed on the road later that year I figured my chances of seeing one there had vanished. Fortunately Sophie saw another one there in March 2020, very much alive. It took me until May 2nd to see it for the first time, running along the rocks near the footbridge. I managed to get ahead of it, and got one photo for my iNaturalist project when it popped its head up while trying to find a way to get by me (I didn’t mean to block its path; I hadn’t realized it had swum across the channel beneath the bridge to the side where I was standing).

I saw the mink two more times in May: on May 9th it was running along the shore toward the small building by the central pond, and on May 30th I saw it swimming in the water!  I thought it was a muskrat until it climbed up onto a rock, scurried over it, and then went right back in.  When it emerged again it had a fish in its mouth, and then swam to the shore still carrying it.  My next sighting occurred on July 14th, near the small circular pond by the little building.  I heard a duck quacking continuously, and decided to investigate.  The duck was floating in the middle of the small pond, calling, but the mink had just climbed out of the water and disappeared into the rocks while I watched.  I’m guessing the duck recognized the mink as a threat and was trying to warn the other ducks or scare it away.  That was the last time I saw the mink that summer.

My next sighting occurred on October 4th, and once again it was running along the rocks near the footbridge. It seemed to be actively hunting, investigating the deeper pools of water and weaving its way in and out of the rocks as I have seen it do so many times before. It spent a few minutes on the rock bridge on the east side of the bridge, slipping in and out of the water before making its way beneath the metal footbridge. I thought it was going to disappear on me again, but to my surprise it spent several minutes fishing there!

As mink are semiaquatic, having partially webbed toes, they find most of their food near the water’s edge. They often dive beneath the water’s surface to check various underwater nooks and crannies, and that is exactly what this one was doing. I watched it emerge in the same spot, shake itself off, then disappear below the water’s surface again. It emerged a second time, still carrying nothing. This was the longest I’d ever seen it out in the open, and it was fascinating to watch it hunt (all photos are from that day).

Mink are carnivores, feeding on frogs, salamanders, fish, crayfish, muskrats, worms, insects, small rodents, waterfowl, and other ground-nesting bird. Mink are skilled predators that are able to subdue and kill larger prey by biting them in the neck. They may also kill more prey animals than they can eat at one time, bringing the extra food back to their den for later. While these are traits that help enable the mink to survive, they have also led to mink being described as “vicious”.

My final sighting of the year demonstrated its hunting prowess. Yesterday I was at the ponds looking for crossbills (two found!), and when the geese and ducks in the southern pond started honking and flying in circles, I began to wonder if a predator was in the area as they refused to settle. By the time I got there I saw the final stages of the struggle between an American Black Duck and a mink: the duck and the mink were thrashing together in the water next to the shoreline. Before I could get my camera ready, the mink pulled the duck under the water and into its burrow. At least, I presume this is what happened since neither one resurfaced in the 10 minutes that I watched. This was an interesting encounter to witness, both heartbreaking for the duck and a fascinating glimpse into what it takes for a top predator to survive.

Although the storm water ponds are bordered by houses on the eastern and part of the western sides, the wild natural habitat surrounding the ponds makes it suitable for a mammal even as large and secretive as the mink. Mink prefer water bodies such as rivers, lakes, marshes, or ponds with rocky shorelines and forest or thick vegetation growing close by. Although they are not typically found in open areas, once I was surprised to see one running along the roadside ditch on Shea Road right in the middle of the agricultural area between Kanata and Richmond. Den sites are usually found in areas dominated by coniferous trees such as spruce and cedar, with the entrance hidden among the dense shrubs. Dens may consist of hollow logs or tree stumps, or the narrow spaces beneath tree roots. Mink also often use burrows in the bank of a river or lake. They will either build their own burrows and dens, or take over existing dens from other animals. While mink do not hibernate for the winter and are active all year round, they often retreat to their dens or burrows during cold or inclement weather.

Mink are generally solitary animals, except during the mating and breeding season in spring. In Ontario mating season occurs between late February and early April. Gestation lasts on average about 51 days; however, because mink can delay egg implantation in order to time the birth of their offspring during favourable environmental conditions, gestation can range between 40 to 75 days.  The litter is born in April or May, with the number of kits ranging from two to eight. Weaning occurs at six weeks of age, although the young kits do not become independent for several months and stay with their mother until fall. At that time they will strike out on their own to find and establish their own territories.

The mink is just as much a part of the local ecosystem as any of the colourful songbirds, delicate butterflies, or fragrant wildflowers that humans find much pleasure and value in. I am happy that there is now one living at the ponds, as they are secretive and elusive animals, and I so rarely see them – until this year, I usually see maybe one each year, if that. Having one so close to home means I have a better chance of being able to study and photograph it, and hopefully learn more about it!