Wednesday, December 21, 2011

December 1 to 6, 2011

December 1 we had more rain and then a night cold enough to freeze ponds, so when we got to our land we checked the Deep Pond to see what we could learn about how the beaver is handling the on-set of winter. As we walked on the road over the culvert carrying the creek down to White Swamp, we could see that there was a good flow of water coming down from the Deep Pond. (Water has been lapping over the smaller Third Pond dam every time it had rained in the past few weeks). Up at the dam, we saw that it was leaking, and that the beaver had just pushed mud and vegetation up on it.

This was a concentrated effort by the beaver. Usually it seems to push up a heave or two and move on. The far end of the patch had more vegetation pushed up than mud.

Those times I’ve seen a beaver pushing things up on a dam, I never got the impression that they were selective about what they pushed up. At this time of year, the low angle of the sun makes it very difficult to make sense of the thin clear ice that forms on a pond after a cold night. It was easy to see that the water behind the dam was open. Looking up pond, it seemed easy to see what looked like trails of open water through the ice both in the middle of the pond and over by the slope at the far end of the pond. Our project for the day was clearing trails, and after I cut a few bushes along my new trail down the wooded slope below the Third Pond, I went over to the high slope of the Deep Pond, and with the sun at my back, I could see that the trails through the ice in the middle of the pond were scarcely noticeable.

The ice over the entrance to the burrow that we saw the beavers dive into a few weeks ago was unbroken and there were no bubbles under it. Because the water level of the pond has gone up several inches, I wasn’t sure if the stick frozen into the ice was new.

There wasn’t the fussing about with logs and mud that beavers usually exhibit late in the fall. But there is only one beaver here. There was open water where the inlet creek flows into the pond, which probably has nothing to do with a beaver swimming there. While there was no broken ice nor open water from the inlet to the bank. I could make out a possible trail that just iced over.

I saw two or three small bubbles under the ice, that don’t show up in the photos I took.

There was what looked like a stick gnawed and stripped by a beaver frozen in the ice at the end of what might have been a trail.

But when beavers gnaw a stick on the ice that often leaves woods chips of some sort behind. All to say, from just looking at the ice, I more or less had little understanding of what the beaver might have done in that corner of the pond the night before or this morning. So I softened my focus and simply enjoyed the complex beauty of the ice,

Crystals shaped like so many keys to heaven.

December 3 we went out to check the East Trail Pond, and, trusting that two cold nights and a day just above freezing had subdued the deer ticks, we used Antler Trail to get over to the South Bay trail. No ticks latched onto our clothes. We went to the crest of the ridge on the East Trail and then veered down the canyon to the pond.As far as I could tell from their gnawing, the beavers have not got as high up in the canyon as they did a few weeks ago. However, they continue to segment the red oak that fell across the trail that crosses the midpoint of the valley.

Then as we continued down the slope, we saw a mink running on the ice leaving the area around the lodge and coming toward the south shore of the pond. There are few things as exhilarating on a cold day as seeing a mink dancing on the ice of a frozen pond. I don’t think the mink saw us so I don’t think its running over to the burrow along the south shore, where I sometimes see bubbles under the ice, had anything to do with hiding for us. I lost sight of it there and then a few seconds later it was running back toward the lodge. It paused to look over toward the north shore

Then it briefly nosed the clump just beyond it in the photo above and then ran toward the dam where we lost sight of it.

Then I heard the ice crack somewhere along the north shore of the pond. I waited for more cracking, but there was none and I assumed that a bit of ice over on that sunny side of the pond collapsed as it was melting. I turned back to the beaver work on the south slope. They were well on the way to cutting a relatively thin red oak some 10 yards above the trail.

The beavers continue to strip the red oak, also relatively small, that fell just above, and roughly parallel, to the trail.

With Leslie with me I tried to not get too wrapped up in examining what the beavers have been doing. This fall I could have made a study of the beavers' daily gnawing but I couldn’t figure out the point of it since everything they gnaw in this pond is accessible to me and easy to spot. They cut down one of the maples next to the clump of ash trees they’ve been cutting. That maple is hung up in other trees and the beavers are cutting a log off the bottom as they did to an ash that got hung up. It looks like they are about to cut off another log off that ash.

They cut a smaller tree that fell on the maple on the ledge that they have almost completely stripped.

Perhaps with the twiggy crown hanging over that maple, the beavers will finally get around to balancing on the ledge and cutting all the branches off the maple as they harvest the branches on the new tree. The twinned red oaks that the beavers have been girdling gave the impression of being freshly gnawed. Comparing a close-up from today with one from November 27, one can see that a beaver did do some more gnawing on both trunks, but not much.

Farther up the slope the beavers have almost cut what I am pretty sure is a red maple, and there are more there to cut.

The stump oozing with sap on the warm day after the snowfall was a red maple. I noticed a beaver did a bit more gnawing on the trunk still standing. And there was no sap oozing out of the stump. It once again looked its age.

Similar sized sugar maples would be cut and stripped much faster. Back up on the south slope, the beavers are also cutting a choke cherry -- next to another red maple they cut and didn’t do much with.

I followed the beavers’ trail up to the cherry and noticed that on the way, a beavers stopped to gnaw the exposed root of a red oak that had been more or less completely girdled last fall.

We look at the crowns of trees. Beavers keep their nose down. Meanwhile Leslie was patiently sitting on a seat conveniently provided by the beavers.

She makes it look colder than it was, though the ice on the pond was still frozen. Indeed the cold night and early morning seemed to slow the beavers down. We did not see any open water indicating where beavers might have just broken out of the pond. And there weren’t as many bubbles under the ice as there were the other cold mornings when I checked.

However, there was a trail of bubbles, and some triangles of broken ice, leading to the burrow along the bank.

That the mink appeared to go over there to take a sniff seems to favor the idea that a muskrat is using it as minks are in the habit of checking out where muskrats might be. I also checked the ice behind the dam and saw no open water there, and no bubbles under the ice.

Heading around the west end of the pond, I saw that the beavers cut a maple, now hung up, and the wood chips from the cut appeared to be on the surface of the ice. That suggests that a beaver might have been walking around on the ice looking for trees to gnaw.

I am trying to remember if I’ve ever seen beavers standing on ice to cut a tree. Hopefully I’ll soon be seeing them gnawing away as they stand in the snow, both in snow on the ice and on the land. Standing on ice strikes me as a little risky. The beaver might slip if it has to run back to a hole in the ice. Speaking of holes, I saw where something dug into the ground just up from the pond. I didn’t see anything in the hole to explain the digging.

However, a couple yards away, I saw roots uncovered and gnawed by a beaver.

The last time I was here I speculated that a large ash the beavers were cutting might fall conveniently toward the pond. It fell into another tree. And the beavers started cutting the ash next to it, also big but not quite as big as the tree hung up.

With Leslie in tow I asked her to identify the large tree that fell into the pond, that I recollect changing early with very red leaves. She agreed that it is a red maple. The beavers are finally stripping bark off the trunk, both near the stump

and out in the water.

To get up the north ridge we used the beavers’ trail and passed their impressive carving into a small oak that they could easily have cut down if they had concentrated all their gnawing on one plane.

It’s finally dawning on me that beavers like gnawing the bark of a standing tree because the rooted tree provides resistance to its incisors. Of course, after gnawing all it can reach, it can cut the tree down and get to the rest.

Leslie headed up the ridge to look for the red tail hawk we heard as we walked around the pond. Of course, I headed down to the otter latrine and was greeted by two splashes in the water behind a clump of flooded bushes 10 yards off shore below the otter latrine. The splashes sounded like the way a muskrat dives when it is alarmed and the two splashes were about 15 seconds apart so I could assume that one muskrat dove, surfaced and dove again. Of course, I hoped it was an otter and waited for the ice to crack again or a nose to surface and snort in my direction, but all was quiet. Then to my surprise it looked like something had worked over the otter latrine up on the rock. Unfortunately the photo I took today and the one I took on the 27th were in different light.

I looked for a fresh scats and found one, not quite as big as ones I often see here, and it had a much different texture, plenty of fish scales. The otter scatted right on top of the array of old scats.

A close-up shows its scales and tubular shape -- I often see scats shaped like that but not here.

That suggests to me that the otter’s meal that molded this scat came from another pond or South Bay. The scat looked fresh, but at this time of year scats age slowly. The old scats around it, left November 15th, were still black. There was no cracked ice below, and no coherent trail of bubbles under the ice

Then I heard another splash well off to the left of the other one but I thought I should be able to see where it came from if I climbed higher up on the ridge. I did and saw and heard nothing. Then Leslie came over and as we talked, what I thought was a log out in a patch of open water moved, and that log materialized into a beaver.

We had a few more minutes to study and then it dove

and we didn’t hear it coming back up so it may have gone back to its lodge. Leslie thought she could see an old trail of disturbed ice heading back to the lodge. But I wasn’t so sure.

I kept my camera sheathed on the way home. I already had enough to think about .

December 4 The beaver at the Deep Pond reacted to a steady rain last night that amounted to about an inch by pushing more mud up on the dam and I am getting the impression the beaver has to push up vegetation with the mud because it doesn’t have logs behind the dam to brace the mud.

So all the vegetation amassed behind the lodge is not food but building materials.

By backing more water up the beaver flooded the path we use to get from the dam to the road.

This happened before when a pair of beavers was here and then built an extension to the dam to keep the water from flowing out there. Then I headed off to work on firewood. Seeing that the trail down Grouse Alley was wet, I took my axe and maul into the woods to split the maple logs I had cut. I was delighted to see that the Last Pool had enough water in it to make it look like a pond again.

The temperature had dropped after the rain and there was ice on the shady part of the pond, and I saw some bubbles under the ice, which is the first sign I’ve had in months that a mammal might be using the pond.

The bubbles didn’t tell me a coherent story and I saw nothing on any shore to suggest that a beaver or muskrat had been there. I could only hope that the spreading sheet of water might prove inviting enough that a muskrat or beaver might move into the beaver lodge.

I followed what is now a very wide channel down toward Boundary Pond.

And after I split some logs, I walked down the ridge to Boundary Pond dam where it was easy to see that the dam could back up another foot or two of water, but that water is leaking through the dam principally down the small stream down to what I called Wildcat Pond.

I didn’t go down to investigate the leak, but looking down the valley I could draw some conclusions. The hole in Wildcat Pond dam was rather low and wide, perhaps even made by the beavers in the winter before they moved up pond. Even after a long rainy spell, like this fall has had, water never backed up much behind that dam.

I think the leak in the Boundary Pond dam, which has always been small, has now clogged up enough with the debris that the dam almost repaired itself, and so there is now a creditable pond backed up behind the dam.

Now, if only a beaver would move into the lodge.

After 17 years of watching beavers come and go, I still do not have a theory on what invites beavers to move in and what keeps them away. If I was teaching a class or fancied myself a scientist, I could list various factors and not bother with the exceptions, which is to say, I have seen beavers move into areas where I did not think they could survive and leave areas, like the Last Pool and Boundary Pond, where I thought they could survive for a few more years.

December 6 hunting season ended on the island and the weather finally dried out enough for me to take a soggy tour of the island beaver ponds on a cool cloudy day. I went via Antler Trail and flushed 3 deer along the way. Thanks to the recent rains the Big Pond had not drained away.

I could tell by the rush of water I heard as I approached that beavers had not repaired the dam. Indeed the dam has deteriorated quite a bit with the old holes open more and at least one new major hole a bit farther along the dam in the photo below.

The good news is that all the holes are through the top of the dam and relieving pressure on holes deeper through the dam that otters made over the years and beavers patched. I was last here back on October 12, but I didn’t expect to find that beavers had returned to the pond. My hunch is that returning beavers would first get one of the small ponds upstream in shape, since this dam needs a lot of work. I was hoping to see otter scats at the dam. I saw them at the Lost Swamp Pond a couple weeks ago, and there is enough water in the Big Pond to interest an otter. There were no scats in their usual latrine just south of the dam, but I saw three scats on the north side of the holes in the dam.

The scats were on the back of the dam where the grass had been worn down and worked over by coyotes, I think, given that I often saw coyote poops there. There was one not far from the old otter scat below, but I angled the photo so I could include part of a collection of berries. Not sure what animal collected them there, but I bet a raccoon did it.

I looked up pond from the dam and took a photo to show the extent of water the otters had to forage in. The photo exaggerates the extent of the pond. For the last 16 years at least, the pond would extend over those grasses in the foreground and all the grasses in the background.

It once was, indeed, a big pond. I also took a photo looking toward where the lodge along the north shore used to be. It may still be there but this summer the grasses grew around and over it, and it is no longer perceptible from the dam.

I headed up to the Lost Swamp Pond expecting to see more otter scats and hoping some would be fresh, from this morning. Since the leaking dam there would be simple for a beaver to patch, I hoped to see some beaver work there too. And as I came down the southwest slope of the pond, I saw gnawing renewed on two of the big red oak trunks that have been gnawed over the years. I always assume beavers do this, but I know, that porcupines can do it too, so I looked for more evidence.

Today, the only other gnawing I saw was on another huge red oak trunk.

I didn’t make a close study of the teeth marks but I think they are large enough to be a beavers. I didn’t any signs of porcupine gnawing up in a tree. Last year I saw the same type of gnawing in the fall and soon saw more beaver foraging and soon saw the beaver. So maybe I am seeing evidence that a beaver just came back to the pond. If so, I should be able to tell next time I hike out here. Looking down from the rock above the mossy cove latrine, I saw at a glance that an otter had been there recently. The leaves were scraped up into scent mounds and some grass and moss had been scratched down to dirt.

Last year, otters here frequently came up on the rock to scat and scratch. This otter, or otters, only made it a few feet up the rock.

I didn’t see any scats up on the rock but there were some down on the grass slope down to the pond where an otter had scratched the ground. None of the scats looked fresh enough to have been left this morning.

The scent mounds that an otter scraped up at the bottom of the slope did look new made. At the East Trail Pond latrine, I’ve seen how scent mounds can collapse in a few days.

The scat on the scent mound did not look that fresh, but it did look grayer than the others.

With snow and pond ice that otters can break holes in, I should be able to tell how many otters are here and how they get from this pond to the East Trail Pond and where else they might go. Yes, I know that a wily tracker should come up with instant answers but experience has taught me to be patient. I usually enjoy speculating but this year I am stumped. I have heard one otter and I’ve seen piles of scat that I usually associate with a group of otters. I’ve seen several scent mounds, one large rolling area, and one possible slide in the dirt that looked relatively large. I hope I’m seeing signs of a mother, her two pups and her sister. We’ll see. I kept looking up and out at the pond hoping to see answers to my questions. All I saw was a pond large enough to accommodate otters and beavers. For the moment all I saw were geese way off in the southeast corner of the pond, and a few mallards.

I didn’t bring binoculars so I can’t say that the spur next to the lodge was a cache pile. A beaver moving into the pond could find osier to nip and collect up at that end of the pond, but that spur may well be the remnants of what beavers here last year collected. There were no signs of beavers doing anything at the closer lodges.

Ten years ago otters used to always scat along the north shore of the pond. For the last five years otters have concentrated their scatting along that shore up at the dam. This year they scatted at one of the old latrines and I saw that they had done so again.

There was nothing new in the latrine up higher in the moss and closer to the dam that these otters have used quite a bit. Then I saw that the latrine next to the dam and slightly down the rocky slope from the dam was rather worked over. But before photographing all that I took a photo of the dam and it was plain to see that no beaver had patched the leak.

The gap in the dam appears to be getting wider but after the recent rain there appears to be plenty of water in the pond. Of course, the otters made the breach in the dam last winter, and there coming back to the pond now as the dam still leaks demonstrates, I guess, that they don’t worry about leaking dams like I do. As usual a photo of the whole latrine area doesn’t reveal that otters have been there several times.

On the rock next to the pond, there is a pile of grass which I think we can call a scent mound though there is no scat on it or any stain of urine. It’s probably been there for awhile and has dried out.

The scats on the grass nearby are still black but not fresh.

Scats on some nearby moss didn’t look fresh either.

Most of the scats were spread on the lower part of the latrine. The otters used that area quite a bit last fall.

The scats here looked more recent but nothing from this morning, I think.

I assume that the otters here are the same that visit the East Trail Pond. Over the years, I’ve seem them take three routes: down to the Second Swamp Pond dam and take a right up the valley to the East Trail Pond; down to the middle of the Second Swamp and take a right before the knoll on the north shore of the pond, and then head up the beautiful granite ridge and then a left down to the East Trail Pond; finally I’ve tracked otters using the two mile long ridge northeast of the East Trail Pond which they can get too by going straight north from the Lost Swamp Pond dam. Since I knew the Second Swamp Pond dam was probably impassable because of the flood of water, I crossed the Upper Second Swamp Pond dam where I didn’t see the least sign of otters coming through. I should add that otters can get to the Second Swamp Pond by going over the ridge north of the Lost Swamp Pond. I angled toward the rock ridge north of the pond but when I got a glimpse of the Second Swamp Pond, I was lured over to take a look at that because there seemed to be more water in it than I expected to see. But when I got to the knoll, I saw that while there was more water thanks to the rain, there was no evidence that a beaver repaired the dam.

Then I went over to look down at the pool of water where a beaver lived for about a month in the early summer, a retreat to where I would not generally look for beavers. The beaver did leave signs on the Second Swamp Pond side of the knoll but I am pretty sure it stayed in this small but deep pool. There was no fresh beaver gnawing today and at a quick glance I couldn’t see any of the old work from a few months ago.

Down in the flat west of the pool, I saw that a porcupine had been busy gnawing in one of the trees permanently bent down by the ice storm in 1998.

On my way to the new East Trail Pond, I checked for any possible otter activity near the old East Trail Pond dam but saw none. The new East Trail Pond, as it were, is quite full and I saw a few heaves mud on the dam.

At this time of year with an almost full pond behind it, I hate to walk along a dam. One false step can cause the beavers added work to repair what damage I might do to the dam. I am certainly not bored touring the shores of this pond and seeing what the beavers are doing, but there is no point in sharing photos of every tree they are working on. Beavers usually don’t complete any job they start in one day or even one week. To me it looked like that sometime in the last three days a beaver gnawed some more on its cut into the choke-cherry tree up the slope near the dam with the intention of cutting it down. A beaver, perhaps the same one gnawing the cherry perhaps not, also gnawed another foot of bark off the nearby maple that fell a month or so ago.

I also saw that work on the thin oak up on the slope that I assumed a beaver did may have been done by a porcupine. Certainly a porcupine did the gnawing up in the tree.

I can’t resist taking a photo of the big dual girdling job on two big red oaks and every day it looks different. Now the beavers are getting deeper into the heart wood of the bigger trunk.

The small tree that fell onto the maple that the beavers almost completely stripped has been cut in half. It doesn’t look like the beavers have gotten much of a meal off it yet.

The smaller maple by the larger ash tree that was hung up is now down thanks, I assume, to the beavers cutting a log off the bottom of the trunk. They continue the same process on the smaller ash tree that they cut a few weeks ago but which hasn’t fallen.

It strikes me that beavers tolerate problems in ways humans can’t but how can you tell if that is because they are insensitive or simply patient. After all, gravity is their great ally and gravity can be gravely slow. The beavers have virtually strip the oak that fell high up on the ridge a week or so ago.

The beavers worked quickly on this tree that fell a week or so ago. When I got closer to the smaller ash tree cut and hung up I couldn’t resist a photo of the next log they are cutting with two previous logs down on the ground down the slope.

I took the high road to the otter latrine on the north shore around and over the beaver work. It would have been nice for my theory of the otters’ behavior this year if there had been fresh signs of an otter’s visit at the latrine, but there were none. Plus judging by the black color of the scats the otters were last here more recently than at the Lost Swamp Pond latrine. However, the latrine at the Lost Swamp Pond gets twice as much sunshine and is exposed to the winds from all directions. The East Trail Pond latrine only gets the south and east winds.

Heading back along the ridge I took a photo showing the beavers’ slow progress girdling the big red maple that fell into the pond almost a month ago.

I’ve been puzzling over poops along the little causeway at the end of the south cove of South Bay. Fishers have often scatted there over the years but foxes have not neglected the area either. I think the fresh scat below is twisted enough to be a fisher’s but their scats are usually dryer.