Monday, May 21, 2012

March 11 to 17, 2012

March 11 goodbye winter, the temperature got up into the 60s. We went to our land to collect what will probably be about the last of the maple sap. Fortunately the frozen ponds are not that quick to respond to the heat. The ice is retreating behind the Deep Pond dam but only a few feet of pond water is showing.

Since I haven’t gotten a good look at the dam since December, my first impression is to think that a beaver has been working it. The mud is moist after all. The second photo was taken December 27

The comparison shows that the beaver hasn’t just been up at that part of the dam, which makes sense. A wider gap between the ice and dam might be necessary before it can make repairs. When Leslie saw dark mud mounds just west of that section of the dam, she was sure it was fresh work, but looking at a photo from January 2, I am not so sure.

Farther out along the dam there is a large enough gap between the ice and dam for a beaver to comfortably repair the dam. I don’t think it had but it is instructive, I guess, to recall what that section of the dam looked like on January 26.

There definitely was a leak there as can be seen by this photo from February 27:

And today that leak seems to have been tamed, although not completely patched.

So here I am again debating whether a pond healed its own dam (I think of ponds as living organisms) or if a beaver did a pinpoint repair, a deft touch, rather than the usual larding on. Then again, on some days water seems so much slower. When everything is damp from a thaw, the whole world seems to be leaking and any given leak blends in with the mass migration of water. All to say, I don’t know. As I walked below the dam to get another view, barely keeping my feet wet, I saw the fur of a dead animal drying up on some matted grass. Another conundrum.

Was it from a muskrat or a rabbit? What killed it? Why was it below the dam, killed there, dragged? To all questions, I don’t know. Back to the supposed dam repair. I tried to get a view of where there had been a gaping hole through the dam. Today I couldn’t see a hole in the dam, but there certainly was a good bit of water flowing around my feet.

Unfortunately it was difficult getting close to where that hole was, or may still be.

There was plenty of open water behind the dam and bubbles under the surrounding ice suggesting the beaver had been there. Indeed, we saw the beaver there a week ago.

I put a photo of the hole taken February 8 below a close-up of the hole today.

Water is clearly still flowing through the dam there. A beaver may have nosed about it, but I certainly can’t say the beaver patched it. There is no reason to dam up water now with so much water flowing into the pond. Perhaps the beaver tends the holes to keep them from widening too much due to the incessant flow of water. My brain is more engaged if I think the beaver’s brain is even more engaged than mine.

March 12 Another warm day and we went to our land for more sap. Here is how the upper Last Pool looked. The second photo shows how it look on March 11, 2011.

Quite a difference without the usual winter snowfall and without beavers in the pond. There was less water in the pond than the extent of the ice suggested. Along the shore the gap between the ice and water below ranged from 2 inches,

To almost 6 inches.

I think Boundary Pond will indeed be a pond after all the ice melts.

The ice extends about as far as it can and where it is retreating there is not much of a gap between it and the water below. There are no beavers here either and until today I didn’t think there was much life in, on or around it, but a large coyotes poop along the edge of the ice argued otherwise.

Last winter beavers did not venture under the ice here. They stayed up in the Last Pool. So below today’s photo I have to use of a photo taken March 9, 2010, to show how beavers add life to a pond.

Back in 2010, I saw a beaver nibbling up on the ice two days later. Whenever I checked the dam here this winter, I could see that there was a slow leak. I never saw any holes made by animals in the ice behind the dam, and saw few tracks. The west side of the dam looked lifeless as the ice retreats behind it.

Then in one gap in the ice, farther out on the dam, I saw some lush green grass, but no signs that it had been bunched together by a muskrat.

There were holes in the ice above the slow leak in the dam. No signs that animals used them to get under the ice behind the dam or through the hole deeper in the dam.

There seemed to be no rush of water out from the dam, but generous pooling.

Then as I continued on the east end of the dam I saw two round holes, one in the ice just behind the dam and the other in the dirt of the dam right next to the ice. These holes looked more mysterious than the others,

especially the one in the dirt. Since I recently saw coyotes dig a similar hole in the dirt of the Second Swamp Pond dam on the island where they got a muskrat, I assume a coyote dug this one.

Before leaving Boundary Pond, I took a photo of the dormant lodge.

I wish I could think of them as volcanoes that may erupt. I walked up the east shore of the pond and since it is less in the sun the ice is quite solid. And the other lodge in this valley, back up at the Last Pool,

was also dormant. Leslie saw a mourning cloak butterfly.

March 14 warm temperatures are rapidly melting the ice in the pond and the beaver can freely swim along all the shores of the Deep Pond. No edge of ice is keeping the beaver from pushing mud up on any part of the dam. At first look I thought the beaver had pushed mud up on the west part of the dam.

But comparing the photo above with photos taken a few days ago, it is clear that water has backed up in the pond and is leaking over the dam making all the dirt along it wet which give the impression that it is fresh mud pushed up on the dam. However the water level is rising which suggests that the dam is less porous than it was. Looking at the middle of the pond the photo below shows more logs pushed over the dam than earlier photos.

The low west shore of the pond is flooded. Before the pond iced over in November the beaver had nipped several hornbeam saplings there. Due to the high water, I couldn’t walk directly over there. I had to go back up on the road, up the hill a bit and then down a bank to the west side of the pond.

I soon saw that the beaver had recently been on the shore. I saw its foot print in some soft dirt.

I stood back from the print and pondered if the beaver had pushed the mud up on the shore. Probably not.

On the other side of the little cove there were two small piles of vegetation up on the shore. I’ve seen the beaver, and I haven’t seen a muskrat. So I think the beaver made the marks, though as beaver marking goes, it is pretty modest.

I got as close to the lodge as I could without going up and over the knoll. I didn’t think I would get a better view doing that. There is a good bit of open water in front of the lodge and it is still surrounded by ice. There appeared to be stalks of dead grass in the water. There were possible trails on the ice.

But the possible trails in the ice looked a bit too regular. As for the rotting ice in the middle of the pond, there appeared to be spots of open water which could have been formed by a beaver butting its head up.

However I shouldn’t jump to conclusions without getting a closer look and I can’t walk on that ice. I went back to where I saw the two little piles of wet grass on the shore. I saw beaver stripped sticks in the water.

I had seen stripped sticks around here back in the fall. But these looked fresh to me. I looked over the sapling stumps that the beaver cut in the fall and found a clump where the leaves around the stumps were wet.

The beaver here has never left a wide swath showing what it has been doing, except as it worked its way through the water lilies. But there is no doubt about that beaver print.

March 15 thunderstorms moved through the area early in the morning. I waited for the sun to come out and then headed for the East Trail Pond. I approached the pond walking down the high valley south of the pond and I immediately tried to find a seat with a good view of the pond so I could take a long last look at the remnants of winter that were rapidly disappearing with the heat and now the rain. Two low granite boulders proved too sharp so I sat on a log just up from the pond. I gazed at the pond until I realized that something had just visited the grassy area in front of the log.

This area is just up from the burrow into the bank that minks and probably an otter used during the winter. But there was what looked like rather fresh scratching in the dirt right in front of me.

I found three old otter scats, pretty sure they are the three I saw in the snow a month ago, and next to them is some coyote poop.

I have not made a close study of coyote poop so perhaps this is fresh. There is still ice on this side of the pond and clear ice in front of the burrow.

There were no bubbles under the ice suggesting that no animal had been swimming there. There was ice on the pond all the way to the lodge, though some of the ice was flooded due to the melting and the rain.

I walked down to the dam and saw a clear sign that a beaver had been out there, fresh gnawing on a red maple a few feet from the dam.

But it was only a few gnaws, and over at the dam, if a beaver had pushed something up on, it didn’t amount to much.

Some of the stalks floating in the water behind the dam were green and were perhaps left behind by a foraging beaver. I headed back up the south shore of the dam and at the west end there were two trees that had fallen a month or so ago after the ice got too thick for the beavers to forage at that end of the pond. A beaver might be able to get out there now, coming along the north shore and around the west end of the pond. None had because nothing had been trimmed from the crowns of the downed trees.

I walked around the west end of the pond and as I looked down the north shore it looked like a beaver had done some fresh gnawing on the red maple trunk that had fallen into the pond last fall.

At least I think it is a red maple. I will have to try to recall all these trees in their prime. That so little has been gnawed off it suggest that it was a red maple. Then I saw a trail of blackened leaves coming up from the pond. Something brought the leaves up out of the pond where they had been rotting.

I suspect a beaver was a bit tentative or clumsy as it tried to form a scent mound. A few yards farther down I saw a more shapely collection of leaves, though certainly not many.

Hardly enough leaves for a beaver to begin to make a scent mound. In the fall I had seen a beaver nibbling sticks along this shore and there is still a nice pile in the water. It is difficult to tell if any were recently stripped of bark.

Nearby there were some greens pushed up on a sunken log. Beavers gob up vegetation like this, but so do muskrats,

Then there were more blackened leaves up on the shore, now on the pine straw. Muskrats make displays like this too, but generally closer to the shore.

When beavers make a scent mound they often add stripped sticks to a mound of leaves and grass. Right along the shore I saw two stripped sticks next to a few dead leaves.

But maybe my imagination had begun running away. The reality of what I was seeing was not much. I climbed up the cliff north of the pond, and got the impression that no beaver had done that recently. I didn’t see any fresh gnawing up there. Looking back down at the pond, where the beavers had their hole in the ice, I saw that they had not gnawed on the pine tree since I was last there. The thickets of shrubs from which they had nipped some branches above and under the ice still looked as thick as usual.

I took a photo of where the beavers’ hole in the ice had been. I just saw a few stripped twigs in the water and not any of the logs that I had tried to carefully keep track of when this hole was the main attraction in the pond.

As always I looked over at the otter latrine on the nearby granite rock sloping down to the pond. It hadn’t been used by an otter since November. It looked a little different today with what looked like fresh scratching in the dirt.

I took a closer look and it certainly looked like an otter’s scratching.

There was fresh otter scat at the back of the scratching.

Of course I looked around for more signs and really saw none, save that my imagination was once against churning and I wondered if the beaver had refurbished the otter proofing on top of its lodge.

On the low ground to the side of the rock where the otter scatted, I saw a definite beaver scent mound just up from the water. It had the wet leaves with a stripped stick.

Still rather small as beaver scent mounds go but often the beaver keeps adding to it all spring. I walked back up the ridge, heading for the dam, when I remembered that I hadn’t checked the line of gnawing beavers did north of the trail up on the ridge. I walked back there and didn’t see any new beaver gnawing, but I did that a porcupine gnawed on a thin pine tree.

That dead tree behind the gnawed pine is a pine tree blown down by a storm over a year ago. As I walked along the ridge heading for the dam, I looked back and saw what looked like fresh gnawing on a large tree just up from the water, probably a red maple.

Looking out at the pond, I was struck by how bare the bottom looked. Maybe there had been some muskrats under the ice foraging all winter.

I took a photo looking down at the dam. In its prime the pond filled the whole valley.

From that distance it didn’t look like the beavers had pushed up any mud on the dam lately. But as I walked over to the dam, I saw that beavers had been there. Each tree in a clump of red maples next to the dam had been gnawed.

As I walked out on the dam from the north end, I was first struck by a confusing image: what looked like a fresh push of mud up on the dam but also fresh gnawing on a root in the dam. So it was hard to tell if the beaver was foraging or repairing the dam.

I soon got to a section of dam where it looked like there was some methodical repair work, though it is possible that it is just a case of old work made to look fresh by the rising and then receding water of the pond.

A little farther on I saw a more convincing heave of mud and could even see the holes left behind the dam when the beaver scooped up the mud.

Then I came to several feet of major repairs with mud and dead cattail stalks. Here was a sure sign that the beavers planned to stay in the pond -- that scent mound is a good sign of that too, I suppose.

Of course I eventually want to get a good photo of the repaired hole in the dam, but this was not the day to attempt that. I could see that the beavers had done a good bit of work larding on mud, dead cattail stalks and long logs. I didn’t want to muck up what they had done with my heavy boots.

In my experience pushing logs perpendicular to the dam is a common way beavers patch holes. Often they push a log into the hole. From where I stood I couldn’t see if they had done that. But there definitely was a log over where the hole had been.

Since I saw evidence of a recent otter visit to the pond, I headed for the Lost Swamp Pond to see if an otter left a scat there. That was where the otter who came to the East Trail Pond came from during the fall and I tracked an otter coming from that pond back in late January. I went around the Second Swamp Pond on my way and didn’t have my camcorder ready when I burst on the scene there. A considerable number of ducks and geese flew off. All the ice was gone from the pond. By the way, there were several wood ducks and a pair of mallards in the East Trail Pond. I did have my camcorder ready when I walked up to the Lost Swamp Pond dam, but no ducks were there. Most of the pond is covered with rotting ice. Of course, I hoped to see that a beaver patched the hole in that dam, but none had. The leak through the dam was worse, and the hole widened considerably.

There were no signs that an otter had recently visited the latrine beside the dam. As I walked around the west end of the dam, I took a photo to show the extent of the pond. It looks quite large, but a 10 yard strip along the shore that is usually covered with water is now high and dry.

There were geese on the Big Pond. The photo I took from the dam shows a diminished pond.

The thaw is humbling the dam, wearing it down lower.

Water was also pouring out of a hole deep in the dam that formed two years ago but that had been patched before beavers left the pond last year. Of course it is obvious that the longer beavers wait to repair a dam the more difficult any repair will be, but there is more to this dam than meets the eye. There is a mound of silt that has been accumulating for over 30 years. What is missing around this pond are trees. But I am loath to count beavers out of any valley. They continually surprise me with their resourcefulness.

March 16 we got to our land just as the mist was clearing after a heavy warm rain. Water was raging over the dam.

There was no way to calculate any beaver activity along the dam. There was still a circle of rotting ice in the middle of the pond and still a bit of ice in front of the lodge.

Again it was difficult to tell if the beaver had been floating around there last night. I looked for any beaver markings along the shore and found none. I followed a possible path coming up from the pond near the lodge, and it led to a pile of fur and bones, too small to be a beavers.

It seemed a bit large for a muskrat; perhaps a raccoon. Then I followed a short path from the pond up to the little pool west of the pond. By the south side of the pool, I saw where the beaver cut some birch saplings.

Unfortunately, we’ll be away until the beginning of April and I’ll miss the final melting of the ice and what repairs on the dam I hope the beaver will do while I’m gone.

March 17 I headed out to check the East Trail Pond and then Audubon Pond and the otter latrines along South Bay. As I went up Antler Trail I saw my first garter snake of the year.

As usual I approached the East Trail Pond coming down the slope to the middle of the south shore. I saw what looked like freshly nibbled stalks in the water in front of the bank burrow on that shore.

But there was still ice in front of the burrow just off shore. It was hard to picture a beaver nibbling those stalks. I headed over to the north shore where there is no more ice and where the beavers have been nibbling and marking the shoreline with leaves. I saw two more half stripped logs left on shore.

There were more stripped twigs in the water just off shore.

A little farther down the shore the pile of nibbled sticks in the water had grown.

I’m not sure where the beavers are cutting the sticks but they look like the thin branches from the clumps of shrubs in the pond. I have never satisfactorily identified those shrubs. I’ll try again when they get leaves. The beavers, I think, had been pushing a few dead wet leaves up on this shore, but I didn’t see any signs of that type of activity today. I went up on the ridge, where I didn’t notice any new gnawing, and then sat down just above the otter latrine on the rock just above the water. I didn’t see any new otter activity. I couldn’t see any reason why a beaver wouldn’t come out. I’ve often seen beavers foraging in the middle of the day in the middle of March. I studied the lodge.

No beaver appeared anywhere in the pond. But a few minutes later, I saw a muskrat swimming towards me. It saw me just after I got the camcorder humming and it dove. However, it came toward me under water then surfaced in a nexus of shrub branches just above the water line.

I never got an unobstructed view of it. After chewing some vegetation there, I assume soft stuff it brought up from the bottom, it dove and swam away under water. I waited for it to resurface but I didn’t see it, nor hear it. I have not seen a muskrat here nor signs of a muskrat, other than three lodges that I discovered when I could walk on the ice, since the late fall. Seeing a mink run around the pond, on the ice and under the ice, all winter with impunity, I assumed all the muskrats here had been eaten. So now all the leaves pushed up on the shore were more likely pushed up by that muskrat than any beaver. However, down next to the shore, just below the latrine, I saw that a beaver had built up the scent mound there, pushing up and shaping more dead leaves and mud.

Muskrats generally don’t make such a large statement. I headed down to the dam where I didn’t have to go far to see that a beaver pushed up some fresh mud.

Having seen no fresh otter signs, there was no reason to check the Lost Swamp Pond, and more reason to check Meander Pond, Audubon Pond and the otter latrines on South Bay to see if there were otter signs there. I went back up the ridge on the East Trail, and noticed that the beavers’ off and on gnawing on the big oak just up from the shore had put that oak on the verge of falling over.

And while up on the ridge, I saw the muskrat again, swimming toward the lodge. It splashed its tail there which encouraged me to think that there might have been another muskrat swimming around, but I didn’t see one. The muskrat I saw swam into another clump of shrubs and I could no longer see it. I headed off up the trail and walked around Thicket Pond and checked the ancient beaver/otter path between that pond and Meander Pond. I occasionally see otter scats there and I have this wild idea that an otter mother uses Thicket Pond to birth and raise her pups. I didn’t see any scats today and no evidence that the trail had been used recently. Audubon Pond is still mostly covered with rotting ice. However, there is open water on the west end, where the ice was most exposed to the sun, and I saw that a beaver had come over there and cut a branch off the shag-bark hickory windfall.

As has been the case in the 15 or so winters that I have watched beavers here, the beavers lived off the cache they stored around their lodge. As the ice rotted, large stripped logs made a ghostly appearance in the water.

These large logs were several yards from the bank lodge entrance. There were smaller logs and sticks around the lodge, and many of them not stripped.

Most of what the beavers stored for the winter was never apparent to me. They must have anchored the big logs on the pond bottom well under the ice. The smallest sticks were nearest to the shore, most unstripped, and on the mud there I saw an opened clam shell.

A muskrat could have left that after eating the clam, or a beaver dredged up it up. Only once over 15 years of watching beavers here did I get an impression that beavers might enjoy gnawing on a clam shell. I heard a crunch in a lodge, but I’ve never seen shells broken the way I imagine a beaver might do it. Muskrats have a deft touch and perfectly shaped snout for getting into clams. Seeing the stripped logs from beavers’ winter meals is one of the joys of spring. In some ponds where the beavers were many, I’ve seen jams of stripped logs. I was struck by how much bark was left on logs that these beavers’ cached.

This could be because there were only two beavers eating out of the cache, or because the shag-bark hickory logs and other logs that they collected in their cache are not that palatable. There was nothing new at the South Bay otter latrines, and with all the ice gone, nothing of note on South Bay. We are going south for two weeks so in a way I am glad we had an early Spring so that I can say my winter tracking is completed.

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