Thursday, April 2, 2015

A Still Point Below the Blow and Bother of Winter: March 12 & 22, 2015

We had to wait for a cold sunny morning after a brief thaw so that the snow would be icy enough to walk on. We were still on snowshoes. The snow in the woods is up to three feet deep. On a cold sunny morning after a brief thaw beaver ponds can begin to look rather basic. On the morning of March 12 the Lost Swamp Pond seemed to be losing it pretenses.

Hard snow merged into that wasted brown ice caused when the whole facade of a pond collapses into what pond water is left after the otters breached the dam. The beaver lodge gave no impression that the beaver or beavers inside ever climbed out from under the ice to have a look around. Not that I expected that since lone beavers or a kitless pair are never very venturesome. I hoped for signs of life at the dam because otters usually scat and renew their claim to their winter domain.

I could see a small array of scat, about where they had been scatting before. My theory is that two otters, mother and pup, have been living here since the first of the year. If that were the case, shouldn't there be a bigger pile of scats? And since the snow was softer during the thaw, why weren't there some fresh prints or slides? The scats did look like they might have been deposited in the last 24 hours. Had they been there longer they would have sunk deeper into the snow.

I tinkered with the photo editing and think I did bring out some urine stains and a hint of a trail in the hard snow.

Then I looked for a hole an otter could use to get out from under the ice. Walking behind the dam is always hazardous especially when you are trying to prove that animals have been swimming in the water under the ice which invariably makes the ice above weaker than it appears to be. So I didn't venture too close to three possible holes behind the middle of the dam. Staring at the photo below, I can fancy that I see several otter trails in snow up the dam but the two on the right could have been made by deer. And why wouldn't the otters slide on the hard snow? There were two pocky depressions in the snow behind the dam maybe caused by sinking otter scats.

But the most convincing evidence that the otters were still there was the water still rushing out through the dam. There was quite a flood in the small usually empty pond just down stream. The brief thaw we just had wouldn't have caused that. The otters must still be digging their hole in the dam deeper, but there will be no proof for that until the final thaw.

When we came back to check the pond on the 22nd, we saw that brief thaws had compacted the snow and the cold of the night before made it so icy hard we didn't have to wear snowshoes. At the Lost Swamp pond we could see more brown ice and the beaver lodge had lost its snow cover.

I didn't see any otter scats on the lodge. There was no evidence that any animal had been on the lodge, no coyotes, no beavers. There was some clear ice in front of the lodge and bubbles frozen under the ice.

Evidently the beavers broke the ice there, had a pool of water to swim in for the first time since December. The water froze again and as the beavers swam under the ice, air escaping from their fur left bubbles under the ice. Of course, the otters could have left the bubbles, or muskrats. I headed to the dam hoping to see otter signs or evidence that a beaver climbed out from under the ice. I went directly toward gaps in the ice behind the middle of the dam, but it was very difficult to see any otter or beaver tracks in the hard snow behind the dam.

But to the right of that hole, in the brown ice behind the dam, I saw otter slides but not at all fresh.

Tracks made in ice or wet snow on ponds can be preserved in the next freeze, covered by snow and then be revealed after a thaw weeks later. I can't be sure when an otter made these tracks, but they don't go far from the dam like the fresh tracks I saw there a month ago. Years ago when beavers maintained several ponds nearby, the otters I watched generally went from pond to pond in February and in March the mother otter tried to separate from her pups to mate and have this year's litter of pups. (The upshot of last Spring's mating, thanks to delayed implanting of the embryos.) But in 2010 when there was only one other pond nearby for otters to go to, as far as I could tell the mother and her two pups stayed together until the snow melted in April and I saw them together in the pond in May. So if these otters spend the whole winter and much of the spring here, I will not be surprised. There are no ponds within almost a mile that could sustain them. But the hard snow and old ice I faced today was hard to decipher. I only saw a few scats sunk in the snow just west of the dam in their usual latrine.

But this was a rather feeble array, possibly not otter at all, and I saw no otter tracks. But I did see an indistinct hole in the snow.

An otter certainly didn't climb out of it. If one had, the edges would be rounded. But I saw a round tunnel going from the hole toward the latrine.

Minks are the consummate tunnel-makers in the snow but minks seem lax about keeping up a latrine next to a dam the way otters do. The tunnel in the snow was wide enough for otters. Over the years, I've stuck my camera down holes in the ice, soaking one camera in the process, and now have a collection of photos showing the otters' world under the ice. Those photos also show the beavers', muskrats' and minks' world too. 

I can't generally see what the camera sees, and in the bright sun can't see the images it captures. So I take several shots and hope for the best. When I got back home, I realized I had taken my best photo ever of the under ice world. It showed the canopy of ice above merging into the thick pond ice and a flat rock in the airy gallery formed as the water level dropped after the otters breached the dam. The rock was comfortably above the current water level. That water was frozen with the flaky look of thin ice.

The green stick was probably the remains of a beaver's meal. I zoomed in with photo editing and think I see fish bones left by an otter or mink.

If I am lucky I'll see all this when the snow melts, but probably not. The water in the pond will rise with the thaw and all this evidence will be washed away.

Back last summer I took a photo of some rocks near the one I accidentally photographed in March. Those summer rocks are about a foot higher.

This pond lost a lot of water thanks to the otters' hole in the dam. Too many naturalists think beavers will not accept such a catastrophe. In my experience, they always accept it, take advantage of it, and often breach the dam themselves. I admit usually the ice covered galleries I've photographed over the years look like dank refuges, but not this year. I found a winter paradise, a comfortable niche in the long airy tunnel formed under the ice that runs behind the dam and along the shores of the pond, all thanks to the otters' hole in the dam.

Good thing I didn't clearly see my under-the-ice photo until I got home. If I had known what I stood over, it would have been hard not to try to crawl under and enjoy that still point below the blow and bother of winter.