Thursday, November 19, 2009

October 19 to 23, 2009

October 19 I had another chance to tour the Last Pool and Boundary Pond. This is the best time of year to be forced to only have a few hours every few days to check on the beavers because as they prepare for winter they are quite active and it is easy to picture what they’ve been doing. They continue to strip the bark and branches off the aspen/poplar they cut down. As I mentioned before this tree was none too healthy, a bit rotten in the core and part of the crown. When exposed, poplar wood dulls quicker than the wood of most trees, but this stressed tree’s wood dulled rather quickly. So though down only a couple weeks, it looks like the beavers stripped it months ago.

Keyed up to see fresh beaver work, on this sunshiny day I once again thought the beavers had been gnawing on the first poplar that fell into their pond. I keep saying I’ll study old photos to prove it, but I never do.

Walking down the east shore of the Last Pool I saw more smallish hornbeams and the continuing tendency to forsake girdling of large trees, even tasty poplar, for cutting down smaller trees.

Well, I shouldn’t say cutting down. Beavers can cut down any tree under ten inches in diameter in one night, and even with small trees I see that they progress by fits and starts.

And today I discerned another lesson. These beavers tend to strip trees closer to the water. For example, a tree trunk many yards from the water had one log cut off it, but no gnawing on the trunk

But that birch that fell right next to the channel has been complete stripped of bark.

This suggests that beavers are just more comfortable around water. Otherwise it might make more sense for them to cut up the trees closer to water because it is easier to haul the logs away. Well, they are cutting so many trees, there is little point in cataloguing them all, unless I want to make a scientific study of it, and I don’t, and I don’t because I don’t want to impose a pattern of behavior on the beavers merely from my observations of what I see around the pond when the beavers are not there, because every time I see the beavers I don’t see a pattern to their foraging. I do see them rather businesslike when it comes to maintaining the dam and dredging, but not foraging. Well, here I am arguing myself into a reason for a scientific study if only to prove beavers fickle and capricious eaters. But instead, I am drawn to the aesthetically pleasing work, like the neat low cut on a large elm just behind the dam.

Now this pleasure I get probably is beside the point because the beavers probably don’t have any sense of the beauty of their gnawing

much as I’d like to prove that they often suspend their work just so they can have a few more days to step back and admire it like I do. Here again, I wish I could have seen which beaver gnawed this. Cutting just above the water level with such relatively small gnaws, I wonder if it was the largest kit. But wondering that I trip over my own theories, to wit, I think the adults restrict the kits from certain areas of the pond when the adults are cutting large trees. This theory made sense when they started cutting large tree a month ago, but now such lumbering is commonplace. For example they are cutting an ironwood on the west shore that might fall onto the lodge.

Of course, I can wiggle out of that by suggesting that the kits go through a rapid learning process, that from September to October they learn to pay attention to the big trees being cut. There is no more frog bit to distract them from the dangers above. Cutting this elm and ironwood so near the lodge goes against another one of my theories, that the beavers save such trees for cutting down in the dead of winter when the ice and snow makes is difficult to venture far from the lodge. Indeed they even cut a hornbeam just behind the dam which would have been perfect midwinter fare.

I am seeing nibbled sticks along the dam, which again is something you see more in the dead of winter.

These beavers never pack their lodge with mud, nor the dam, because flooding a forest floor they don’t have much mud to work with. However, the side of the lodge facing the dam, where I think their main living chamber is, is now stained dark evidently packed with what muck they can dredge.

And their cache continues to grow.

Because the pond is relatively low water, I can get closer to the cache than I usually can in the fall

Another aesthetic pleasure, for me, but that close packing of sticks is a survival necessity for the beavers.

October 21 I got out earlier this morning to look for otters, heading off at 8:30 and headed to the Big Pond dam. But I didn’t move along as quickly as planned. A couple of weeks ago I began seeing deer ticks on my pant legs, then we had a series of very cold mornings, and I only saw a few ticks on those mornings. Now we have normal temperatures, and warm rain yesterday. Going through a patch of blueberry bushes about ten yards wide, I picked up three deer ticks. I continued to get them when I went through stickers or the woodier shrubs. So I picked off about a dozen ticks by the time I got to the Big Pond dam. I didn’t see any otters in the Big Pond, but the latrine at the south end of the Big Pond dam has been expanded. There were new scats on flattened grass just on the dam.

Of course I nosed over them to see how fresh they were. They didn’t smell, but they certainly looked fresh, and included brown and whitish goo, much like the scats I saw at this latrine a few days ago.

I took a close-up which proves nothing, I suppose, but suggests to me that otters have complicated lives, or, at least, complicated stomachs and bowels.

The other mystery about these scats is that they are positioned right on a trail through the tall grass that goes down below the dam.

This trail has been here for weeks. Does the positioning of the scats prove that the otters are using it? But first things first, I walked along the dam heading for the Lost Swamp Pond to see if the otters were there. I didn’t see any and went down to the mossy cove latrine where I think I saw the same old scats along the shore.

There certainly were no juicy blacks scats with goo about, just the tighter blackened boli laced with fish scales. As I scanned the pond looking for otters I saw that the cache beside the beaver lodges continues to grow as well as the muskrat lodge in front of it.

I walked around the west end of the pond to the dam, and here I thought there was more scat than when I was here a few days ago, but nothing juicy.

As I’ve mentioned before rain can revivify old scats, so I tried to be skeptical. Then over on the rocks there were scats I hadn’t seen before.

But why no scats like what I saw at the Big Pond dam? I went down to the marsh below the Upper Second Swamp Pond dam and saw no new scats there. I hadn’t checked the north shore of the Second Swamp Pond for scats in a while. When I am looking for otters, I am not as thorough checking on latrines. Fortunately deer ticks don’t seem to thrive on dams and the wet meadows below them and the pond has lost enough water so that I could walk through rushes along the north shore and avoid stickers. While there were no scats in the old latrine up on the rocks along the north shore, east of the lodge, I did see a few old scats down above an old beaver/muskrat burrow right along the shore.

When I last saw an otter family in this pond, in the fall of 2005, there were often scats on those low rocks as well as up on the slope. These were definitely old scats and when I got down on the bank lodge (not occupied by beavers for a few years) I smelled scats. The otters had been scatting on the east side of the lodge, now they are doing the west side.

The scats I could see didn’t look fresh enough to smell, so I kept looking. Since beavers have not repaired the lodge in a long time, it is quite porous with holes

Perhaps the fresh scats were down below. I am lazy in my observations. The character of this pond has changed a good bit over the years, or I should say, the vegetation along the shore has changed. It is thicker now which I should think limits the areas where the otters can scat, and forcing them to squirt out scats in places harder for me to see. Anyway, as I moved along I took a photo showing how the lodge nestled along the shore in the Fall of 2009.

I remember Falls in which there was much more mud, and scats all along it -- drought years. I had not seen scats on the Second Swamp Pond dam this year. Today I saw several arrays.

Of course, a few weeks ago the grasses were tall and firm here, so if an otter had squeezed among the towering green, I probably wouldn’t have seen it as I pushed my way through. Again, most of the scats seem over a week old.

I decided to go back to the Big Pond. I was looking for otters and that’s where I saw them last and that’s where I saw the freshest scat. They still weren’t there, but I saw scats on the grass in the middle of the dam,

Little ones, but fresher than what I had just seen on the Second Swamp Pond dam.

So, I am getting the impression that the otter family is slowly shifting its focus, and now is spending most of its time in the Big Pond. When I get more time, I would like to prove that the two adults and two pups I see in these ponds are not the same as the two adults and two pups I’ve seen around Picton Island almost a mile away. In other years, I have tracked families that visited all the beaver ponds on the west end of the Wellesley Island and even went down into South Bay. These beavers seem so much more insular, so I bet I am seeing two otter families, which is good news. I tested this thesis by checking the small old dam below the Big Pond dam. All the grasses along the meager stream down to it were matted down, but I saw no signs of otters hurrying down, or using the little pool of shallow clear water behind the little dam, nor going up on the dam.

I had to get over to the land today and I made a point of going late enough to see beavers. I tried to relive those memorable September evenings when I watched the beaver family from my chair up on the ridge west of their lodge. The pond looks different, of course, the leaves are down. I can see farther up it.

I got into my seat at about 5pm. I heard humming from the lodge at 5:10 and in a few minutes as adult beaver came out, dove around the cache where I couldn‘t see it and then I saw ripples along the still shaded east shore (hemlocks) almost down to the dam. Then it went up the east shore and eventually swam up the channel. I heard humming that sounded like it came from a kit inside the lodge. This was promising. But a kit didn’t hurry out, and when one did come out, it bit a twig off a log in the cache and promptly dove back into the lodge to be greeted by a hum. Then the adult beaver came back down the channel. It was carrying a stick

It didn’t add it to the cache as I expected it would but dove with it into the lodge. It came back out and settled into the far end of the cache, where I couldn’t see it and gnawed away. No other beavers came out, but I kept hearing humming from inside the lodge. It was a cloudy night, threatening rain and it got dark early and I headed home.

October 23 I took a hike with Ottoleo around South Bay. We went over the ridge via Antler Trail and I only picked up one tick -- probably because it was cloudy and cool. We checked all the otter latrines and saw no signs of recent visits. The river water level is low for this time of year, almost as low as it gets in the dead of winter, so I didn’t expect to see otter or beaver activity at the end of the coves. We did see a heron ankle deep in water well up the north cove. It flew off before I could get a photo. We were able to cross on the out wash of the creek coming down from Audubon Pond, Ottoleo led the way. And we stayed on the rocks along the shore. It looks like a beaver did climb up the rocks to get at a willow trunk.

And started gnawing again on an old cut. A little farther up the bay I got a better shot showing how a beaver may have come up on the rocky shore.

Of course, the water may have been a bit higher when the beaver was gnawing. The only latrine I expected an otter might have visited was up at the entrance to South Bay. A friend, Jason, saw an otter crossing the Narrows nearby, heading for Murray Island, about a week ago. But no more visits to the latrine I watch. Heading up to Audubon Pond we saw a mushroom sprouting out like a kitten on a tree.

The beavers at Audubon Pond are still trimming trees they cut down onto the embankment.

I thought that because the trunks were cut right at the trail that maybe the park staff did it, but no, clearly a beaver job.

They are also stripping the trees they cut below the embankment, which I think is rather brave of them. The pool of water down there doesn’t afford much protection.

Last time I was here, I noticed some neat gnawing on a trunk and took a photo from the top of the embankment. Today I went down to it, scaring two little deer along the way, and took another photo.

I guess the spotty gnawing means the inner bark was not that tasty. Meanwhile up in the pond, building the new drain proceeds slowly. It started to rain so we didn’t walk around the whole pond. We saw two trails coming up out of the pond, through the mud to get to the plants along the causeway.

Evidently a beaver is getting over the causeway, mucking through the shallows and cutting a tree on the steep south slope of the pond to the east.

I don’t think a beaver would come down the ridge to get to the tree.

Meanwhile Ottoleo was fascinated with the clam shells. Thanks to the zebra mussels in the river this is the only place around here you can see clam shells.

When Bob Wakefield supervised the making of the pond 40 years ago, he brought clams up from the river, and they are still propagating.

Back on the South Bay trail, I saw some beaver gnawing on a tree that we missed seeing as we walked up the trail.

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