Rob Rich

It's about a golf ball-sized lump a lot of times. And I sometimes liken it to shredded wheat or something. It takes that kind of character. And beetrovers are one of the rodents, in addition to the lagomorphs, the rabbits and pikas and whatnot, that will re-ingest their own first poop. And so they will eat that to kind of extract a second round of nutrients out of it.

This is a practice called coprophagy. Delicious. And so by the time it comes out that second time, it is very loose, easily disintegrated lump of sawdust like shredded wheat. Most of the time it's deposited in water. And so it's very prone to disintegration quite quickly.

Great. So the two marks are definitely something you want to look for. And if you don't see them and you know there are beavers there, you want to be looking for a cut on the branch at a 45 degree angle. That's just because of how they kind of turn their head and then how the branch typically falls. It's kind of like this...

angled cut, which is typical of all rodents really, but that sharp angled cut is really important. To see beavers, they are, you know, fascinating because they're at once very conspicuous.

You can see their activity from aerial images, which is fascinating, but they're also kind of cryptic sometimes in that they do prefer to be active at nocturnal or crepuscular kind of dawn dusk kind of times sometimes. So a great time is really to just get out there first thing in the morning,

And you can kind of wake up with them as they're about to tuck in for their time kind of in the lodge or their safe spot for the day. And they'll typically come out in the more dusk hours as well. Those are kind of good times to try. But beavers are not hard and fast about being nocturnal. You can find them during the day as well. Yeah.

Yeah, great question. So again, a lodge, you are correct, the lodge is separate from a dam. And so they're not ever living in the dam, but they are definitely using a variety of different lodge styles. And sometimes they can be like freestanding in the water. And sometimes they can be half affixed to like a bank. Sometimes it can just be a hole dug into a bank and they burrowed in that way. But

Those are the places where they're living and kind of sheltering over winter if it's in an environment where they need to do that. And they are not impenetrable, but they are very difficult to enter for a lot of predators. The ones that are made of sticks and mud are generally like the dam in a way. The sticks are kind of latticed in and then the mud fills in a lot of the cracks.

And so when that freezes in the winter, that can become pretty rock hard. And they do all... All the family is living in there together. One of my most fascinating parts of beaver existence is just that time in the winter of how they're doing that under the ice, in the darkness, in cold environments, in wet environments.

And it's just, you know, we thought COVID was bad and isolation in a lot of ways. I mean, they are very much isolated in that time when they can't come back out above water surface for months at a time, potentially. It does have... different layers, terraces, a lot of times you can see in them.

If you ever are lucky enough to find a abandoned beaver lodge, sometimes I have been able to enter into some of the chutes that go into a lodge and you can see for yourself kind of what the size is like, but it can generally fit them together, generally some body warmth in there involved.

But Casey McFarland, who's a great tracker and wildlife ecologist, he has a great video just showing one of those abandoned beaver lodges, what the interior is like.

But in the lodges, there can be muskrats, particularly one that are often cohabitating with beavers. And there are things like spiders, all sorts of invertebrates and insects that are certainly dwelling in there, sometimes amphibians as well. And then after the beavers leave sometimes, there can be other larger animals that use them as well.

Sage Raymond is a colleague that has done really neat work up in Elk Island National Park in Alberta, just showing that coyotes and porcupines and different animals are following after the beaver to use those where tree sources are limited. And so beavers are incredibly important throughout, again, throughout their temporal history of their wetland complexes is fascinating to me.

Yes. To survive in the winter, most of the times they're relying on what we call a cache. And so it's like this stored up mass of sticks that they will plug into the floor of the stream or pond or whatever water source they're on. And this is just this raft of sticks that they have piled up and are in the bottom of the water source there. And so that is their primary food during the winter.

And they're going in and out of the lodge to access that. There is a certain time before freeze up where it's not quite frozen, but it's not quite flowing water everywhere either. So it's kind of that delicate in-between time. And they will use their flat, thick, scald head to kind of bash up through thinner ice to do that and keep it open as long as they can.

But in my area, there does come a point where there is no more of that bashing to be had. And the ice just takes over. And so once that happens, they are fully locked under there for months at a time.

You can tell activity sometimes. One of the fascinating signs to look for is these bubble trails that go in and out. of air escaping from their interstitial spaces of their fur. There's air trapped in there. And so when they go in and out of their lodge, all those bubbles are escaping from their fur and rising up to the surface of the ice.

And so before the ice gets all snowed over and kind of opaque, you can see those bubbles to see where the beavers have been coming and going. But after that, after the snow gets all over the ice, it is pretty much total darkness for potentially a month at a time.

So it is multi-layered as well. It's super dense. It's one of the most dense furs of animals on the planet, really, right up there with sea otter and other semi-aquatic mammals that are spending a lot of time in really cold water in really cold northerly environments. And so it is dense. The layer on the outside that you would touch first is coarser. It's composed of more guard hairs.