Otters II: My wildest dreams come true

Last time was mostly clues and hints. This time, pay dirt. I saw a dark shape on the far far side of my beaver pond next to a small patch of open water. Thrilled, I realized it was an otter, but then it slipped silently back into the water and under the ice. Luckily I am patient, and I waited. About 15 minutes later it popped up in a different unseen breathing hole at the base of a beaver lodge, and came all the way out.

It had a good roll in the snow, which helps to clean and dry its waterproof fur:

and I even got a short video:

Then it started to climb up the beaver lodge, behind an inconveniently placed tree,

I moved, and to my utter delight I watched it slide down the far side of the beaver lodge, just having fun. Look hard and you can just see it, near the top of the lodge behind the branches.

It went back in the water, and I thought the show was over, but 10 minutes later it returned, and had a good scratch,

and then settled down for a nap, for all the world like a dog.

The next day, on my daily walk, I assumed the otter would have moved on, but before I even reached the pond he was there, and this time closer, so I got some more photos. I like this one because you get a sense of his strength and size and sleekness, though his long tail is submerged and invisible. .

Sometime dreams do come true.

He stayed around for one more day, in the far distance, then left, but I have since seen slide marks and scat, so he is still around somewhere.

Before I started this blog, I went to the Pantanal in Brazil and had wonderful giant otter encounters, so I think next time I might dig out more of my photos from that trip and show you them in action.

PS I found some terrific clear otter tracks after my last post, so I have updated it. If you want to take a look, click January 2021 in the sidebar.

PPS You might think an otter’s feet (which lack fur) would freeze when they are diving under the ice, and sleeping on top of it for that matter. What stops this happening is counter-current circulation, explained here. It is also found in sea mammals like dolphins, and the feet of birds (like the owl from my last post).

Figure 2 A countercurrent heat exchange system. (a) Schematic representation. (b) Blood supply to the flipper of the dolphin, with a schematic cross-section of an artery and the surrounding veins to the left. Arterial blood is shown in red, venous blood in blue. Pink arrows denote heat flow; yellow arrows show direction of blood flow

In Figure 2a, the outgoing (i.e. arterial) blood is shown to the left, on its way to the skin surface. But en route, such vessels run very close to a network of veins that are bringing cool, venous blood back into the body (shown to the right in Figure 2a). Given the closeness of the (warm) outgoing and (cooler) incoming bloods, heat (which would otherwise be lost through the skin) is taken up by the cooler returning blood and carried back inside the animal. The red arrows in Figure 2a show the direction of heat flow; there is comparatively little heat loss from the skin. If you think about it, the system depends on outgoing and incoming blood flowing in opposite directions, which is why it is called a countercurrent heat exchanger.

From https://www.open.edu/openlearn/nature-environment/natural-history/studying-mammals-return-the-water/content-section-2.4