Sunday, April 3, 2011

March 23 to 27, 2011

March 23 cold cloudy morning, below freezing last night and I anticipated being able to walk on what a few months ago was the bottom of a relatively deep pond, unless the beavers had started to patch the hole in the Lost Swamp Pond dam. That said, after seeing that beaver in South Bay, I worried that it might have fled from the Lost Swamp Pond. But first I had to check the Big Pond dam. I could see that it had not been patched.

I saw a tiny poop on the grass of the dam near where the otter had scatted before.

It might be otter scat, but might be from a mink, or even a bird. However, there was ice behind the dam at that point and it looked broken, perhaps by an otter.

The beavers had not patched the dam at the Lost Swamp Pond. I could tell that by how low the pond looked. Thanks to the cold night I was able to walk on most of the old pond shore, first walking out on an old dam, almost leveled now, which took me to that pool of water in the main channel that had been popular with the otters all winter.

There were plenty of bubbles under the clear ice there but I couldn’t be sure if an otter, beaver or muskrat left those bubbles. When I don’t see big cracks in the ice I attribute bubbles like that to muskrats.

However, when I looked up pond, I thought I saw a beaver on the ice beside the dam. I planned to head up that way anyway.

First I checked the rock on the south shore where an otter scatted a few days ago. Nothing new there. The animal by the lodge disappeared. So I explored the beaver canal that stabs the pond from the south shore.

I followed it back toward the shore.

The otters had been in and out of holes along this canal. I looked for otter scats but didn’t see any. I did see the stripped sticks that a beaver left here, and when I followed a trail through the brush looking for what the beaver might have cut, I assumed the stripped sticks pointed to the trail they recently used.

And I did find plenty of stumps in the clumps of shrubs. I assume they preferred willows.

I confess being frustrated when I explore these brushy slopes. There seems to be beaver food everywhere, but only evidence of rather picky foraging by the beavers. Standing where the beavers had cut a number of shrubs, I looked through several feet of untouched vegetation and saw a relatively large stump, say 2 inches in diameter, perhaps a young birch tree.

But obviously the beavers are finding things to eat and I shouldn’t fault them for not gorging. This is the most impressive canal to the south shore. There are more of varying sizes. This one extend farthest since it goes through such an extensive flat. Before exploring other canals, I took a hard look at the lodge and I did see what looked liked nibbled sticks and there was a hole in the ice, so good chance I did see a beaver.

And with the water level so low, I saw how these beavers larded in the little dogwood and willow twigs close to the lodge. I can see now how it makes no sense to sink smaller fare like that in a traditional cache farther away from the pond. Then I turned my attention to the next beaver canal up into the south bank. This canal seemed deeper because it cut through higher ground.

The beavers took advantage of the high ground next to their canal finding places to pile and nibble their sticks. When the pond was full, all the ground in the photo below was under water.

I became familiar with these piles of sticks 3 or 4 years ago, more or less when the beavers adjusted to having fewer trees to cut. Two things about the piles impressed. The many little sticks are often left in a circle, and most of them are unstripped.

It’s hard to picture a beaver sitting in the middle of such a pile so they probably take the sticks they want to eat away. But I shouldn’t speculate until I actually see how a beaver operates here. It could float over the sticks, dip its head down and eat little twigs whole. When I continued up the exposed bottom of the pond, I saw a dead mink.

I didn’t see any marks on it. It looked rather pale for a mink and perhaps that is a sign of starvation. Then as I walked along what is the narrowest part of the main channel of the pond, I saw pile of sticks at that would have been the shore of the pond when the pond was full.

Then as I moved up near the wide pool of water at the far east end of the pond, I saw how a muskrat managed one of their grass lodges. There was a long channel from the lodge to the middle of the pond with a smaller channel cutting off it also going to the deeper part of the pond.

Looking at the entrance to the lodge, I could see a short channel cut roughly parallel to the shore. And, as far as I could see, only one entrance to the lodge where the channel went under it.

This little lodge looked undisturbed so it is possible that it wasn’t used that much. The beavers also had stick piles up here, though most of the canals were smaller than down pond, except for one.

I finally reached the area where the otters had a hole. Not surprisingly there was a channel there, rather wide for most of its course.

Beside the channel I found some otter scats, pretty old

Then there were extensive holes and burrows in the ground, like gopher holes.

I cannot be certain that otters used these holes and if they did cannot be certain what they used them for. As the water got lower in the pond, they could have slept in these holes. But did they dig them, perhaps while looking for things to eat. Maybe muskrats made the holes for their dens, though I thought I saw signs of minks and weasels around here. I had imagined the world under the ice as an arcade, a crystal palace arcade, when the real attraction for otters might have been holes in the turf under holes in the ice and snow. Much to think about. I crossed over the inlet stream, water was coming down it, and heading back down the pond, back to the west, I soon crossed an extensive area of channels and digging. It looked a bit like simple erosion but there was digging tangential to what could pass as a drainage channel.

There was a canal made by beavers into the brush, with nibbled sticks on its banks. It looked like there was a little grass dam in the canal.

What, I guess, functioned as a dam, looked like grass collected by a muskrat.

While most everything I’d been seeing on my tour around the pond was new to me, when I got down on the north shore even with the lodge, I got a new look at canals and burrows in the bank that I was more familiar with, having seen beavers use them in the winter over the years. There are three canals, all leading to burrows in the bank, that I’ve seen beavers use in winters when less water drained out of the pond. I was surprised at how wide one channel was as it entered the pond, almost a bay.

There were circles of sticks on the bank of the canal.

Unfortunately this is the only time of year I can easily get out there, and it is private property. So these piles seem to me more like geological features that are just there to be explain by some long acting force of nature. I can’t associate a narrative with its development and use other than the obvious: beaver collected these small woody plants, stripped some, left others,

assuming sticks this size will rot within two or three years…. One pile of sticks looks much like any other, unlike the beaver caches I have grown used to over the years. Frustrating for one who walks the swamps primarily to tell himself stories.

A good old fashioned cache can read like a novel to me. Although I was familiar with the burrows into the bank, I was surprised at how much digging there seemed to be at the end of one canal, like the beavers were quarrying for stones. Or were the coyotes digging there trying to get into the burrows?

There was a little water in the canal leading to one burrow dug low into the bank. I think this one had seemed the most popular during the last month. I saw more mink and otter tracks checking it out. I think all these animals like the comfort of water wherever they are, even when it doesn’t amount to much.

There were smaller canals along the north heading down to the point where the otters were hanging out this winter, and where muskrats lurked all the year.

While beavers lurk in straight paths, muskrats make more devious routes. I am surprised that otters preferred going under the ice here.

Maybe the fish concentrate here as they swim up against the flow of water going to the hole in the dam. Here is where the broad pond behind the dam narrows into a channel to get through old dam that was permanently breached years ago. The other day I got a good look at the burrow into the bank the otters used here at the point. With snow still around I could still imagine a broad network of burrows under the point communicating to the other side. But in the cold light of the almost final thaw, that seemed farfetched. I continued around the point and walked the shore of the northeast section of the pond. There were no big canals but some extensive dredging along the shore.

The beavers have four lodges in the whole big pond not associated with burrows into the banks, and only one bank lodge. I get the impression that this dredging was associated with a old beaver burrow, since dug away. Over the years I have often seen beavers and muskrats in this corner of the pond. I’m not sure what the attraction was other than the added depth of water from the dredging. I didn’t go up to the pool farthest to the northwest, I was able to hop over the rivulet of water coming down to the main pond.

The last time I was here, I saw red osiers nipped and nibbled by beavers that were floating in the water behind the dam. There was enough newly formed ice around the lodge near the dam to reveal some large air bubbles.

And on exposed rocks behind the east end of the dam, I saw some freshly nibbled osier.

I didn’t check this area the other day, but, since the bubbles were under the ice, I think the beaver had been out here early this morning. If it had been, it certainly didn’t do anything toward patching the gaping hole down at the far west end of the dam.

One way beavers patch big holes in their dam is by moving in part of a dead tree trunk into the hole perpendicular to the dam. They did that here years ago and the trunk now serves as a sign post for muskrats. I saw that it had just been freshened with poop.

There was nothing around the pond side of the hole. Some stripped sticks had collected in a snag just on the creek side of the hole. Over the years, I have gotten the impression that beavers patch holes from the pond side, but often they do fashion a new dam below the breached dam to back up more water into the hole. But this dam is rather big and slopes down precipitately.

I walked along the exposed shore below the north bank of the west end of the pond, where I had often seen otter slides in the winter. The last time I was here I saw fresh prints in the mud. Today the mud was frozen and I didn’t see any new prints. Because the mud was hard I could get farther into the network of dead tree limbs

I think I discovered where the otters wedged themselves under the ice and in the crotch of dead thick tree limbs to do their scatting.

I have often seen scat piles outside of the holes the otters use in the winter. At White Swamp, the piles can be 6 inches high. So I can’t say that it is typical to find piles like this, not outside the hole, but on the old pond bottom after the snow and ice melt. But I am sure this is where the family of otters here spent much of their winter. The pile of scats testifies to how well they lived under the ice.

There was still snow in the south corner of this section of the pond and the snow had just thawed from where the otters first latrine had been at this end of the pond. The ground was too wet for me to go out and look for scat piles. There are less thick logs around here and perhaps it is not as cozy and protective for the otters.

I saw some black scats high on a clump of grass in an area never flooded by the pond. The scats looked relatively fresh and the otters here commonly scatted on grass clumps like this, although not down here. They only seem to congregate here in the winter.

So I think an otter left these scats in the last few days. It’s not a case of scat up on the snow settling down on the grass. I headed home via the Big Pond dam, and realized that I could walk on the lip of exposed mud behind the dam until I got to the holes in the dam. And when I got near where the water was gushing out, I saw a dry hole into the dam, stuck my camera down behind it and snapped a photo.

I was surprised to see what looked like a double hole, like an animal had a little den in there and then it or another animal dug deeper and busted through the dam. Then water rushed through the hole until the pond lowered, and that rush of water created the channel which water in a deeper hole farther along dam found. I think this hole is the work of muskrats, maybe all the holes in this dam are. As the hole in the Lost Swamp Pond dam shows, when these otters breach a dam they do it on a grand scale, the better to get wide openings under the ice. Just before I got to where the water flows out of the dam, I saw pocks in the mud that could be construed as otter prints.

Then when I walked away from the dam I saw new scats along the path leading to the south end of the dam where, over the years, otters have often left their mark.

So, with my head swimming with otters and beavers, who now have so little water to swim in, I headed home resolved to not take my camera out again. When I saw four deer grazing along the Antler Trail down in some woods where the snow had just melted away, I just asked them how their spring was going and didn’t taken any pictures. They blended so well into the little swale of brown, first I thought there was one deer, then I saw another, then another, and four ran off.

March 24 I got the chance to take a brief look at the Last Pool. It was cold enough last night to freeze the pond, but the beavers either kept a pool of water open through the night or broke some nice as they raided their cache pile this morning, probably the latter.

Then I had get to work, and I looked for dead ironwoods to cut which took me up to the Turtle bog. Often on a sun drenched day in late March the Blanding’s turtles will come out of their hibernation. But today, the bog was almost all ice.

The Valley Pool, where Blanding’s sometimes lurk, did not have quite as much ice.

The cold is slowing down the spring. Even the usual run off has been slowed. When we get a string of hot days in the 50s and nights in the 40s, we should have another pulse of flowing water everywhere. However, it is possible that the moisture content of the many snowfalls this winter was less than usual even though the snow was two feet deep.

March 25 I reprised my tour of the beaver ponds and Leslie came along. I didn’t see any evidence that the otter returned to the Big Pond dam, nor did any beaver. We did see green vegetation behind the dam, which a beaver could have left, but I think a beaver would push up a dollop of mud on the dam too. So one of the muskrats in the pond probably came by.

There was a string of tiny bubbles under the clear ice.

Leslie noticed how exposed the nearby muskrat lodges are, and I took a photo because it shows that the water level is still dropping steadily.

Then we headed to the real show -- the almost empty Lost Swamp Pond. We walked out on the very old dam to the channel. There were no signs of otters disturbing the clear ice but there was a bit of red osier there, probably left by a beaver.

We saw an animal on the ice a bit beyond the beaver lodge in southeast end of the pond. I thought it looked like a muskrat and as we walked closer it didn’t get any bigger.

There was also a pair of geese in the water beside the lodge. The muskrat dove into the water and disappeared, but the geese tolerated us.

There were also a few noisy killdeers working the wet shore. Back in the winter Leslie tracked an otter up the longest beaver canal. She walked up the canal farther than I did the other day and found an old otter latrine on top of what looked like a former ant mound.

The scat was not from this winter, as there was no body to the flakey gray scales.

We both think this is the likeliest route for the otters to use to get over to the Big Pond, and were frustrated at never finding clear evidence of that while snow was on the ground. The otters didn’t go back and forth between the ponds much, and evidently when they did the snow was too hard to show their tracks. Then we continued walking around the pond and I showed off all the wonders I saw yesterday, except the mink carcass was gone. Leslie noticed the many dead snails along the exposed pond bottom.

Then she saw something that I missed two days ago, if it was indeed here then, what looked like fissures in the turf and ground.

Even the grass stalks lying flat on the ground were cut.

We saw another “fissure” but not as dramatic. We didn’t probe to see how deep it was. As we continued around the pond, I tried to repeat the route I took two days ago, and jump over the little flow of water coming down from the far northeast end of the pond. Today my jump sank my lead foot into a foot of mud. Leslie continued around the far end of the pond, affording me time to contemplate the big muskrat lodge along the north shore that I walked by yesterday without taking a photo.

The muskrats evidently didn't spend much here. Maybe the water got too low too soon in the winter. On the exposed rocks between the lodge by the dam and the dam, we saw freshly stripped red osier.

There was a trail of clear bubbles under the ice that formed early this morning.

I assumed the beaver was in the nearby dam lodge, but Leslie pointed out that there was open water around the lodge in the middle of the pond.

So the beaver is probably lodging there, or, I should say beavers. There is a big hole in the dam that has to be patched. We didn’t see any signs of that, not even a push of mud up on the dam.

We crossed the Second Swamp Pond dam and then I went to inspect the East Trail Pond dam. The pond has filled up nicely. These beavers put their dam in order as soon as possible.

Of course this dam is small, not much more than two feet high facing down stream.

No otters visited this pond; the dam had leaked; freezing and thawing had made the dam porous at several points, as I saw during the winter and several days ago. But when I was last here I saw some mud pushed up on the dam. There are still leaks in the dam but nothing major.

So a good deal of the height of the pond is from the thaw. The last time I was here, I walked on the dam as it was frozen hard enough to support my weight. Not so today. I had to walk gingerly below it.

The black line of mud, I think, reflects the beavers work, though I am use to seeing a greater gobs of mud.

I’ve long thought that beavers have to wait until the mud warms up before they can properly repair the dam, though I have never thrust my hand down in the water behind the dam to see how pliable the mud is. It was easy to see how fragile the dam is and who knows better how to keep it viable than the beavers. It was too touch and go along the dam so I made a break to get down to the boardwalk. (Leslie was watching, with some amusement, from the south ridge.) I went up to the East Trail. I didn’t see any signs that the beavers had been in the two little pools they formed in the creek coming down from Shangri-la Pond (now more or less a meadow.) Once up on the ridge, I took a photo of the lodge rising triumphantly, I fancied, over the full pond testifying to the beavers’ surviving the winter.

As I moved up the ridge, I thought I saw a beaver swimming in a clump of bushes not far from where their principal hole in the ice had been during the winter. Then three wood ducks flew out from the area. Plus I heard a strange noise in the pines above me and a large bird flew out. Leslie said it was an eagle, and she saw a hawk flying over head. I tried to figure out if the beavers had been up the ridge cutting or trimming more trees. They have trimmed the last one they cut high up on the ridge, but I am not sure how recently they did that.

I don’t think they did any more gnawing on the red oak, where I saw a beaver dining back on the 7th. However the tree has dropped lower, almost on the ground now.

Then we headed home. The continuing cold weather makes beaver watching difficult, especially in this pond which is the last to thaw. But the beavers must be rather hungry and I should be able to see where they are eating. Not having that much of a cache pile they must be finding something to eat away from the lodge.

March 27 I took a morning tour of the ponds and otter latrines, starting by going out to the end of South Bay. On the little causeway at the end of the south cove of South Bay, I saw a fisher scat.

Fishers often mark down here. I’m not sure exactly what that means but I’ve long suspected that they use some dead trees just up the valley as dens. The cold night left a good fringe of new ice along the shore of the bay and I looked for wrinkles in the ice that I might over-interpret.

I saw some patterns of disruption in the ice coming straight out from a willow, where there is open water right at the shoreline, which gave more of an impression of a beaver than an otter or muskrat. I checked where I saw beaver work along the shore last time I was here and didn’t see anything new. Then as I stood by a section of the bay where there was open water between a few yards of ice on the shore and the old ice back 20 yards out in the bay, I saw the wake of something swimming underwater. It was a narrow, straight wake, and nothing surfaced so it was probably a big fish. Then where the new ice once again stretched from the shore to the old ice, I saw results of more violent action on the ice, which suggested otters had been there.

When I got to the Docking Rock latrine, almost half way up the north shore of the bay, I got to interpret bubbles.

I did find a small black blob of poop up on the rock, which could have been from an otter, or a duck, or perhaps a mink. I continued up the shore looking for dramatic signs of head butts up into ice which an otter might do, or longer plates of cracked ice looking like they would be lifted up slowly which a beaver might do. But all I saw was a line of bubbles under the ice farther out and a collection of bubbles here and there close to the shore.

But at those rocks where, over the years, otters have latrined, I didn’t see any broken ice, and the line of bubbles went to willows that beavers have gnawed over the years. However, that gnawing on the tree leaning out over the water in the photo below was rather old.

So, I got the feeling that after a fashion I was tracking a beaver’s path under the ice. Then I got to the otter latrine overlooking the entrance to South Bay.

There were fresh scats on a rock well up in the grass,

And broken ice and bubbles under the ice below the rocks.

I think what I am seeing is evidence of an otter fishing just before dawn, breaking the ice that formed during the night while it was still cold enough for the broken ice to refreeze. I have never seen an otter swimming under the ice so I am uncertain how to interpret the bubbles under the ice. I saw another scat up on the grass, not very big, so I think I am seeing signs of at least two otters. The north wind kept the water just outside the bay open.

Some of the bubbles under the ice were clear blobs of air not white, so I walked up to the point of rocks overlooking the entrance the Narrows actually thinking I might see some otters. I didn’t, and the north wind was rather cold, though only blowing a few small blocks of ice out of Eel Bay.

I headed up to Audubon Pond, and though it is completely exposed to the sun, it is still mostly covered with ice. The main patch of open water is near the drain, and there was much broken ice there, but I couldn’t make any sense of it and there was nothing on the shore there suggesting that beavers had gone up the embankment

and over to the smaller pond below the embankment which has been open and where trees the beavers half stripped in the fall remain.

I didn’t get any sense that beavers had been down there recently, though there were bubbles under the ice. As I walked back down the trail to South Bay, I walked over a dead small mouthed bass. Obviously some bird had fished it out of the bay. It looked depleted but not really eaten except for the eyeballs. I went back down the South Bay trail, just the way I came up, but this time I flushed a pleated woodpecker who was down on the trail, and then I flushed several wood ducks who were under some bushes along the shore. I walked up to the Lost Swamp Pond via the south shore of the old Otter Hole Pond which is now mostly meadow. There is enough water there, however, to attract a heron and it flew off back toward the bay as I walked by.

When I got to the Second Swamp Pond I flushed a small raft of ducks. I went directly to the Lost Swamp Pond dam and saw in an instant that a beaver or beavers had been there once again eating osier and once again not doing anything to patch the hole in the dam.

Half the osier they collected had been stripped, leaving a good bit for another meal.

That is not necessarily a sign that the beavers will be back because beavers often leave twigs and branches half eaten and in time evidently forgotten. I checked my journal from last year. The hole in the dam was not quite as big as this year, and the beavers patched it promptly after the thaw. I don’t think I can blame cold mud for the beavers not getting to work on this dam. The wind must have played on this pond last night because the water behind the dam going back to around the lodge was open so I couldn’t track beavers by the bubbles under the ice.

My guess is that only one beaver has been down here, and while I have seen one beaver patch a dam, maybe it takes two to get the repair work going expeditiously. I checked for otter scats, and I might have seen a new one, but there are too many old ones in the this latrine, I can only be sure of the very fresh scats. I took the quickest route to the Big Pond, and found that the ice there had melted enough so that the mallards could forage in the lower end of the pond.

The beavers have made no move to patch the dam here, either. Last year there was a similar breach and the otters patched as soon as the thaw allowed. I saw some confusion in the newly formed ice behind the dam,

But nothing that would suggest that a beaver been there. No signs of otters either.

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