Amazing Mammalian Encounters

Red Fox

It’s been a wonderful month for encountering fascinating mammals in unusual places. Many species are more visible this time of year as they leave their winter sites to establish breeding territories or look for mates. They are busy out foraging for food now that plants, insects, reptiles and amphibians are more abundant in the ripening spring, waterways are open, and the forest ground is free from snow. Small mammals are no longer hibernating or confined to the strange subnivean world that exists between the ground and its roof of snow. Both predator and prey are more active, and it’s hard not to come across any mammals of interest if you are outside often enough.

My most thrilling mammal encounter came last week when I was out birding at the Beaver Trail. I’d had a wonderful morning birding there, seeing my first Scarlet Tanager of the year, hearing a total of three Winter Wrens on the trails, and picking up eight warbler species: a couple of Ovenbirds, a Black-and-white Warbler, several Common Yellowthroats, a couple of American Redstarts, a couple of Magnolia Warblers, four Black-throated Green Warblers, a pair of Yellow Warblers and a pair of Yellow-rumped Warblers. The birdsong was lovely to hear, and I was delighted to be serenaded with their with music.

I was on the boardwalk at the back of the trail looking out over the pond when I saw something swimming in the water toward me. It was sinuous, like a snake, but much bigger. When I saw its face I realized it was a River Otter – and it was swimming directly toward me!

Northern River Otter

I nearly fumbled my camera trying to turn it on and focus on the rapidly swimming mammal, and it must have seen the movement for it stopped among a tangle of branches and raised its head, staring in my direction. Otters are near-sighted, an adaptation that allows them to hunt for fish and aquatic animals in murky waters, so it probably didn’t quite know what I was. This was only the second time I’ve ever been close to one of these fascinating creatures, and I was enthralled as it spent about a minute in the water, turning its head slightly to the left and right while waiting to see what I would do. When it became apparent that I wasn’t going to “do” anything, it continued on its way through the pond.

Northern River Otter

Otters are typically found in lakes and rivers with shores with steep banks rather than those that gradually slope gradually down to the water. Their preferred habitat includes slow moving waters with deep pools, plenty of vegetation for cover, and sites for denning and resting. Otters use other animal’s dens, such as abandoned burrows, empty beaver lodges, or hollow logs. Dens that are situated on the water’s edge will have an entrance deep enough below the surface to conceal it from discovery or becoming frozen shut in winter.

Otters seem to be more common than they were when I first started birding in 2006. It took me a long time before I saw my first one in the Ottawa River off Shirleys Bay, and it was years before I saw them again at Billings Bridge in 2013. Now I usually see them about once or twice a year, and they are usually in a group. This was the first one I’ve seen alone.

On the other hand, when I see a beaver I usually see just one. When I visited Sarsaparilla Trail at the beginning of the month I saw not one, but two in the reeds right next to the boardwalk, and they appeared to be grooming together! I had never heard of this, but according to Hinterland’s Who’s Who, members of family groups spend much of their time grooming each other.

Canadian Beavers

The beaver has two specialized claws on each hind foot which are used to groom its coat. The inner-most toe curves towards the body, and has a single double-edged claw that opens and closes against a long, soft pad of flesh like a pair of scissors. The second toe also curves toward the body, but has a second nail growing between the real claw and the lobe of its toe which is serrated. The real claw can open and close over the second one, acting much like a fine-toothed comb. Grooming is important to remove dirt, mats, mites, and parasites from the fur, as well as to distribute oil through the fur to keep it waterproof.

Canadian Beavers (Castor canadensis)

The orange teeth visible in the photo above are their most important tool. The orange-enameled incisors grow continuously and are strong enough to fell very large trees. The beaver keeps the upper and lower incisors short and sharp by grinding them against each other, a thought that sets my own teeth on edge!

I’d never seen any beavers grooming their fur before, let alone two, and they seemed to take no notice of me while I took several photos. It was a nice quiet moment and I am happy I got to experience it.

Canadian Beavers (Castor canadensis)

Wetlands are a great place to see a variety of mammals, and Sarsaparilla Trail never fails to surprise me, as three weeks later I saw two otters swimming in the pond there! This isn’t the first time I’ve seen them there, and it made me curious as to how they coexist with the resident beavers. Do the two species simply ignore each other, since they do not compete for food? The otter is a top predator that eats mostly fish, as well as frogs, reptiles, aquatic beetles, crayfish, mollusks, small mammals, birds, their eggs, and very rarely young beavers. Beavers, on the other hand, are herbivores that dine on the bark, leaves, twigs, and buds of deciduous trees, as well as aquatic vegetation.

It appears there is a commensal relationship between these two animals, which is a type of relationship in which only one party benefits. The beaver’s activities benefit the otter in two ways: first, it increases the food supply when fish become trapped by the damming of streams, and second, the beaver’s lodge or burrow provides shelter and den sites. Otters don’t always require the lodge to be abandoned; there are records of both species occupying the same lodge at the same time without any antagonistic or aggressive behaviour!

While it seems as though otters and beavers more or less happily coexist together, beavers and muskrats may merely tolerate each other, as both consume many of the same plants and vegetation. However, because muskrats also feed on frogs, fish, crayfish, clams, and snails, the overlap in food consumed by the two species is small. Muskrats also are able to manoeuver through dense cattail forests, which it feeds on and thus clears channels that beavers are able to navigate. Muskrats, on the other hand, benefit from the stable water levels provided by beaver dams, and have even been known to take up residence in an occupied beaver lodge. The beavers already living there may tolerate this occupancy because the muskrats provide more eyes to watch out for predators.

I got lucky seeing a muskrat eating out in the open at Bruce Pit, munching away on some fresh cattail stems fairly close. Bruce Pit is another spot with a pond full of activity – I’ve seen beavers, otters, muskrats, and even mink there, all right from the bridge that crosses the creek!

Muskrat

Away from the water, Snowshoe Hares have been particularly noticeable this time of year – so far I’ve seen one at Sarsaparilla Trail and two at Jack Pine Trail this month. I usually also see lots of Eastern Cottontails around in the spring, but even at the Eagleson storm water ponds there seem to be fewer this year. This may be due to coyote activity in the area. (Now, a coyote close enough to photograph is something I’d love to see, but hopefully not too close!) The Snowshoe Hares were in various degree of molt; one was entirely brown while two still had white bellies and feet. Scientists have been studying the effects of climate change on the timing of the winter molt on Snowshoe Hares, which is triggered by the decreasing amount of daylight in the autumn and takes about a month to complete. With the snow falling and accumulating later due to increased temperatures, a hare that is completely white before any snowfall stands out just as much as a hare that is still brown when it eventually falls and blankets the earth – both are vulnerable to predators without their seasonal camouflage.

This Snowshoe Hare has completed its spring molt and is completely brown

One 2023 study from the Yukon Territory, which reviewed the timing of the hares’ winter molt over a period of 44 years, shows that as the region has warmed, the winter molt in the hares has been delayed to better align with the start of winter. However, the data also suggest that too long of a delay can have a negative impact on survival…hares that were still more brown than white in autumn were less likely to survive the winter. As such, getting the timing right for each seasonal molt is critical, and with the earth’s temperature still rising and the length of time of significant snow cover decreasing, it is heartening to see that some species are already beginning to adapt.

Studies such as this are important for two reasons: first, the Snowshoe Hare is a keystone species of the boreal forest because it is a source of food for many different predators in the ecosystem. Its success in responding to climate change is crucial to the population health of many others species. Secondly, the study shows just how important and valuable long-term monitoring is – without data from the past, we will never be able to compare the ecological health and trends of the volatile present to those of more stable times in the past.

This Snowshoe Hare still had a lot of white fur present in its pelage

My last surprising encounter was with a fox…except when I first saw it I didn’t realize it was a fox. I was getting ready for work one morning, and keeping an eye on my birdfeeders outside from a second floor window as one does when it is May and migration is under way. I saw something walking along the top of a fence several backyards away and thought it was a dog. I did a double take when I realized it was a fox and ran for my camera!

Red Fox in its unnatural habitat

Now, foxes aren’t something I see every day in the “wild”, let alone in the suburbs of Ottawa. In fact, I am lucky if I see one a year – they have a knack for hiding themselves from human eyes. To see one on the fence out back was completely astonishing. It looked on the thin side, so I presumed it was looking for something to eat. Sure enough, shortly after I started watching it it jumped down into one of the yards, stayed there for a minute or two, then jumped back up onto the fence. It did this two more times, leaving me to wonder if there was something particularly appetizing in that yard.

Red Fox on the fence

Foxes are omnivores, and their diet changes with the seasons: carrion and small mammals, including mice, voles, squirrels, hares and rabbits in the winter, and plants, berries, earthworms, insects, fish, and bird eggs and nestlings in the spring and summer.  They are also readily attracted to pet food and garbage left outside. Clearly the fox had found something of interest in that yard, possibly food left outside for a cat or dog, or possibly a small animal of sort – I didn’t begrudge it the meal, though I did worry about the reactions of the neighbours.

After about 10 minutes the fox turned around and walked back across the fences toward the opposite end, so I can’t claim it as a sighting on my own property. Still, what an incredible mammal to see from my yard, and what a peculiar sighting! This definitely qualifies as the most “WTF?!” mammal sighting of 2023!

Now that May is coming to an end, mammals will become more difficult to spot as the vegetation starts growing taller, thicker and greener and as they become more secretive during the breeding season. I saw a wonderful variety of species this month, most of which were much closer than I’m used to seeing, and many of which were true encounters rather than just a fleeting glimpse. If only all of my mammal encounters were this amazing!