Wednesday, November 27, 2013

Muskrats in Winter

Just before the ponds freeze, the muskrats spin stalks into refuges from the coming cold. Two to four feet high and often almost perfectly circular with a diameter of three to five feet the stalk mounds guarantee that a muskrat can get out from under the ice and breath. More importantly since the mounds are based under the pond water, they guarantee that a muskrat can burrow through them and get back under the ice which is a safe place to be when minks are roaming on top of the ice.

The appearance of the mounds signals the beginning of winter for me because I often see them during my first skate around the beaver ponds usually in December. In 2003 as I skated around two large ponds I took photos of 11 mounds. I blush to say I have never made a study of these mounds either from the aesthetic or scientific angle.  I like the texture of the one below.

This next one seems strategically placed since it must be the nexus of many channels through the grasses 

In the deeper part of the ponds, the muskrats often incorporate old stumps or shrubs into their mound

Perhaps I’d get a better sense of how the muskrats use the mounds by analyzing how they are grouped together. There are three along the shore in the photo below.

But I find it hard to be scientific on skates, and then mounting snow, which will also force me to leave the skates at home, defeats any attempt to figure out how the muskrats use their mounds. However, at the end of the winter of 2010-2011, that pond lost most of its water and on March 23 I saw how one mound along the shore related to the pond and got some idea of how the muskrat used it.

Pressed down by snow, and dug into by minks and coyotes, muskrat mounds don't look too famous in March.  You might say minks wire them with their trails.

Judging from the tracks coming in and out of that muskrat mound, a mink made a home of it.

I can’t easily see what the muskrats are doing under the ice. Before snow covers the ponds I can try to track them by the bubbles they leave under the ice.  There are clear bubbles, white bubbles, lines of bubbles, bubbles of bubbles

Go figure indeed. The muskrats also continue to live in beaver lodges and burrows into the banks of the pond. I skated over one muskrat swimming under the ice. It scooted back into a burrow.

In December there are usually enough warm days and nights to open large patches of pond water and the muskrats sit on the ice and dive down and bring up greens to eat. Then the cold freezes the pond again and I can walk around and see the grassy leftovers.

But I know I should know a lot more about what the muskrats are doing. The sight of all the mounds in December always reminds me of how I have neglected keeping track of the muskrats in the pond. Muskrats and their works are easy to neglect in the fall. The beavers in the same pond are doing some magnificent lumbering, completely stripping bark off the trunks of trees they cut down

And otters in the fall can be rather diverting.

I generally don’t pay close attention to muskrats in the fall. So much to say, that I have never seen muskrats build a mound, but I think I would have noticed if it took them a long time, more than a day.

But the cold winters here which last at least three months have a way of framing animal life and death in stark relief. In the first week of March 2006, I was hiking on snow covered White Swamp tracking otters. I had some dumb luck. A half mile from where I was walking, I saw a family of otters leaping in the air outside a snow covered mound.

The otters disappeared, and I don’t think I scared them. Of course I walked up to check the mound and saw their slides, and prints and scats

And I saw a dead muskrat.

Since minks use the same holes, and coyotes dig into the mounds, I can’t be sure the otters killed the muskrat. The wound on the muskrat, who was no bigger than my glove, was quite small and otters have big teeth.

But this is a grim topic. I check every mound I see that's been dug into and usually see no signs of a muskrat being killed. Of course, when a mink kills a muskrat it usually drags it back to its den. 

Mink tracks generally give the impression of an animal dancing through the snow

but sometimes the tracks look quite labored

and there is a line, almost a trough on one side of the trail. That's made by the dead muskrat the mink is dragging. On the January day I took that photo, I followed the trail to a hole into the mink's den and there was a drop of blood outside the hole.

Coyotes are not very subtle when they dig into a mound and its hard to imagine a live muskrat being caught.

Minks seem to be a bigger threat to muskrats. They can make a surgical hole into a mound.

There are advantages to stalking something bigger than you.

But “surgical hole” is not the right phrase. The mink, even in midwinter, is too happy go lucky to ever be compared to a surgeon. In February 2006 I gave an aspiring nature photographer a tour of the ponds during a thaw. I hoped to show him otter slides at least and a beaver in the sun. Then a mink and a muskrat diverted us. The mink led us to the muskrat who was curled up on a small beaver dam grooming itself in the warm sun.

The mink looked to have all the advantages: the element of surprise, the high ground, and it had been active outside much of the winter while the muskrat eked out a living in small dark mounds. It looked bad for the muskrat.

But water is elastic and muskrats are complete masters of water.

The mink was going down, the muskrat forward. To make a long story short, the muskrat escaped under the ice. But muskrats are tough. It surfaced in the open water and the mink, that had gotten back up on the dam, attacked again and the muskrat got away again. The mink didn’t leave this time but sat up on the ice, but the muskrat didn’t surface. The mink scampered around the nearby beaver lodge, likely the muskrat’s den, then gave up and went on its merry way. Then I thought the muskrat was coming back, but instead a beaver surfaced behind the dam and found something to nibble.

Then the muskrat surfaced and made a quick dive, seemingly more afraid of the beaver than the mink. (Beavers seem to welcome muskrats in their lodges but out in the pond seem to prefer that the much smaller muskrats keep out of their way.)

During that February thaw I got the impression that muskrats might come out from inside their mounds and walk around on the snow. I saw muskrat tracks going from the open water in a pond to a mound.

I was not sure what the muskrat did outside the mound. Make some repairs?

But let me hasten to add, I've never seen them make repairs. Once I was tracking otters in a large swamp and I saw where coyotes had completely destroyed a muskrat mound. Then not far away I saw a large muskrat out in the snow, not in a panic, but seemingly getting a bite to eat.

Usually the muskrat tracks I see in the winter go back and forth, which suggests foraging. But once I found tracks going from a large pond, up a road about a quarter mile and into a small pond.

Muskrats can survive the winter in a shallow ditch and while they can live in deep bodies of water, like the St. Lawrence River where I often see them diving off ice sheets looking for greens or clams or small invertebrates to eat, they thrive in marshes.

Scientific studies muskrats in that ideal marsh environment suggest that a strong family structure helps muskrats survive. Minks usually kill the muskrats that are fending for themselves. I suspect that familial vigilance protects the muskrats when they winter under the ice. Minks might be at a disadvantage when there is plenty of water under the ice, but often water drains away so minks can run under the ice. A mink is more agile on land than a muskrat.

But muskrats are high strung animals and from what I've seen winter doesn't slow them down.

The day before, January 3, I had checked on that lodge and saw three beavers up on the ice nibbling sticks. On the 4th, after the muskrats dived back into the lodge, a beaver surfaced and had a meal.

Still by the end of winter the muskrats I see on the edges of the retreating ice seem to have their mind on solely on eating. Even honking geese defending nests sites don't disturb them.

As for the muskrats mounds, few survive the winter.

The big ones ribbed with live saplings and built around a old beaver lodge have a better chance

Some mounds that coyotes dug into seem to be cradled to rest by clumps of neighboring grass

As for the muskrats, they go where the grass is greener, first diving into the holes in the ice at the deep center of the pond

then they muddy the shallows as the ice retreats revealing green life

Looking at that photo one might think life becomes easy for muskrats again. But muskrats move in the spring which means claiming territory. In the warming sun, I forget about muskrat mounds and scan the rocks and logs along the shore for their pellet-like black poop.

They are not, as that photo might suggest, between a rock and a soft place. Muskrats have a very intense spring -- a subject for another post.

Wednesday, November 13, 2013

November 7: Sunset at the East Trail Pond

Usually the wind is an ally when I watch beavers. I sit with the wind in my face and wait. But the East Trail Pond is in a bowl with three narrow canyons funneling wind over the pond. A wind over 10 knots raking the island I live on from any direction is going to dance down those canyons and any large nose floating in the middle of the pond is going to smell anything out of the ordinary lurking anywhere around the pond. Beavers have large noses and this year I have been out of the ordinary.

The East Trail Pond is my last beaver venue. For most of the last 20 years, when I took a hike into the State Park I had five to choose from. No longer dividing my time I should be at the pond frequently. But the beavers there and I go way back. I’ve watch them survive droughts, and a succession of winters. I’ve watched them rebuild after floods only to be flooded out again. I found one of the parents dead under a tree the beavers had been cutting down.

Alas, I don’t think humans can watch or study the so-called lower animals without sometimes feeling a tad god-like. One evening as I watched the beavers, it struck: what if these beavers did indeed think I was their god…, then, given what they had been through, how angry would they be with me. In another pond once, where I sat to watch the beavers almost nightly, the beavers lost their last kit to a predator. The next time I saw the parents, I was sitting close to their lodge. Of course they saw me. They exchanged hums, dove into the lodge and I never saw them again.

So I check on the East Trail Pond beavers every week or two, keep my distance and the wind in my face.

I knew I had to break that rule tonight, if they came out. The sun went down a little before 5pm, and from November through January the sun up north casts few lingering rays. The beavers had over 12 hours of complete darkness for foraging.

But you don't have to see beavers to enjoy a beaver pond. On clear days the quick sunsets of November have a tendency to be golden which puts a shine on the beavers’ latest gnawing.

The beavers are preparing for their fourth winter in the pond. I thought they’d bail out before their third winter. To make the pond they built a long dam across a valley that used to be a grand beaver pond that had supported beavers off and on for 20 years. They made a viable pond out of the shallow end of the old pond. It had not recovered from previous beaver use. There was a short supply of trees 2 to 3 inches in diameter that beavers like to lard into their winter caches. Most of the those convenient trees are gone from the pond and nearby shore. Now, in the pond itself only grasses and a few clumps of winterberry remained.

The sunlit lodge in the photo above was their home for two winters. Then last fall they built and moved into a lodge nearer the north shore.

That winter they not only cut red oaks and white oaks on that slope, most over 5 inches in diameter, they cut down several pines. Then when the kits, two of them I think, made their entrance this summer, there was precious little kit-sized fare along the north shore, so the beavers refurbished an old beaver burrow and bank lodge on the south shore and cut down some maples which fell into the water in front of the bank lodge.

The kits', and yearlings', nightly nibbling raised that muddy halo around the crown of the tree. Then shortly after I saw that the beavers started assembling a cache of food for the winter just off the south shore, and judging from what I saw today, are still adding to it,

I thought the beavers were going to winter in that convenient bank lodge. But today I didn’t see any mud packed on it, and by now beavers start preparing lodges for winter.

Looking around the pond I could see that all the trees the beavers were cutting were along the lower south shore of the pond, a few at the dam,

A few more on the east side of the bank lodge,

And a few more just to the west of it.

I agree 100% with the assertion that the more trees beavers cut the more trees will grow back, but, in the short term which is the reality for beavers and a reality rapidly creeping up on me, we are not going to see many trees where the beavers have foraged around this pond. Here what’s their cupboard two years ago looks like now.

I was pretty sure that if I stayed on the south shore and waited, I might get a close look at the beavers. But the wind was slapping my checks left and right and then raising the hairs on the back of my neck. So I walked around to the north shore of the pond.

The wind was quieter there and the winterberries had lost all their leaves (flooded too long, apparently, to have any of their beautiful red berries), so I would have a pretty good view of beavers below if I sat up on the high rock.

But the wind soon found me. Plus on that spot I couldn’t see the lodge where I reasoned the beavers had to be. However, especially on a golden November evening when the wind zithers this way and that over the pond, I can sit by a beaver pond and enjoy the view and almost forget about the beavers responsible for it all.

Well, they have nothing to do with the clouds.

Years ago, somewhat to my surprise, I discovered that the best place to watch beavers is right next to the pond slouching under a fallen tree as close as can be to fern covered rocks. You present no silhouette and nest in damp odors that might conceal your own. I didn’t have that option by this pond, but for the past two months the beavers have been digging the dirt in the slope

leading up to the roots of a red oak and maple that have seen better days.

Plus there was a downed tree trunk that I could lean against.

I had a perfect view of the lodge, and saw the preparations for winter suggesting the beavers were there and soon enough I heard humming from the lodge.

Promising but I mainly studied the view

Two weeks ago, with no wind, I waited in vain for the beavers to come out.

Then a beaver came out of the lodge and started swimming toward the golden dam. Oh yes, the wind. It hadn’t forgotten me and seemed to gather my odor and waft it toward the beaver. The beaver turned and almost went back into the lodge,

But whose pond is it? The beaver angled toward me, then crossed a Rubicon of a log, so to speak,

And then the last 20 years of my life (watching beavers) flashed before my eyes. The beaver enriched the pond water with wide ripples as sniffing nose up it picked up speed

Then full of the stench of me it turned away from the big rock I sat on

And its back to me, it slapped its tail

Head right back up and it was at me again, unflinching gaze

And unforgiving tail

Poetic language about animals always sounds good, but it’s never true. They don’t dance to our stanzas. The beaver tolerated me, swimming off toward the dam which had appeared to be its original destination. Then it thought better of that and swam to the middle of the pond where it began gnawing on some logs.

I didn’t strain to see exactly where. I’ve learned that the proper reaction to a tail splash is not to move a muscle. Beavers have a tolerance for sedentary types. It went about its business and I waited for another beaver to come out. The one that splashed me looked like a yearling and for the past year another yearling usually came out into the pond with it. But nothing came out of the lodge.

When the sun goes down up north in the late fall, the temperature drops and I am getting too old to run home to ward off a chill. Walking back around the pond, taking a high route, I noticed that the wind had died down. I soon saw two beavers in the pond, the other one, I think, came out while the first beaver was slapping its tail at me (which shows what I think of the endlessly repeated saw that beavers slap their tail in alarm to warn other beavers away; they slap to warn you away.)

One beaver tried to find something to eat on dead stalks in the pond. The other beaver had the pick of the cache.

Yearlings never wait until winter to eat their winter cache. Who could blame them on this golden November evening?