Spring is the time to observe otters

Chel Anderson is a North Shore naturalist. She lives here in Cook County and joins us periodically to talk about phenology or what’s going on in the woods right now. Welcome, Chel.

Anderson: Hello!

Well, otters are just plain fun. Everybody enjoys watching their antics. So, what are they doing this time of year?

Anderson: Yeah, otters, what could be a better topic for spring than otters? They are amazingly playful and curious and intelligent, as it turns out. I mean, people actually study these things. They are one of those animals that we may not think of with respect to migration. But, let’s talk a little bit about how that operates with otters.

They actually migrate?

Anderson: Well, I believe that some do on a small scale. You know, we’ve talked about how some groups of animals have major migrations and we’re all really aware of that at this time of year, but there are other kind of smaller-scale, more local migrations that happen. And, this is something that I wasn’t aware of at all until we moved to where we live now which is near the Flute Reed River, so we have this great privilege of being able to view lots of animals interacting with their habitat. Since we’ve lived there, it became very apparent that in the fall, as the winter sort of starts to set in—you maybe get some skim ice forming on the river and on the ponds along the river—that the otters disappear. Over time, watching, observing not just them or evidence of them, but also just thinking about how the habitat changes, I believe that the reason they move is that the Flute Reed in the upper portion is very apt to have parts of it that freeze right now, freeze down to the bottom, because the water gets progressively lower during the winter, the ice gets thicker and even some of the ponds, especially if the beaver dams aren’t functioning as they might have at one time, even the ponds can freeze out or become impassable kind of underwater. So, if you’re an otter who wants to make it through the winter, you have to stay some place where there’ll be a reliable food supply and a reliable place for you to move around in your favorite medium, which is water. So, the otters move out in the fall, and then this time of year, starting in usually the latter part of March, mid- to end of March, we begin to see their tracks returning, and then their tracks become very fresh and regularly moving along the river and around the ponds, but also in getting underneath the ice, you know, using whatever is available underwater, but also roaming through the woods. They’re big explorers; they really travel around kind of ceaselessly whether in the water or on the ground. But, they move around quite a bit and this winter we happened to see where an otter who was touring through the woods encountered a ski trail that was coming at the top of a hill that goes eventually down to the river. We didn’t get to observe it directly, but saw the evidence of how it just slipped right in to one of the firm ski tracks and went like a luge run right down to the river.

Somebody made the otter run for him, right?

Anderson: [Laughs] Yeah, right, I wonder what it thought about all that.

Now do these guys go downstream to the big lake, or where do they spend their winter? Do you know?

Anderson: Well, I don’t know for sure, but again, based on tracks, following tracks, especially now in the spring when they come back, then you can really follow their tracks around. And, it appears that our otters at least start out by going to the Brule, which is just a mile, as the bird flies, away or so. And, so they head out and follow various routes over to the Brule, and whether they stay on the Brule, then, which is a very large river and has very reliable water all winter and probably very reliable fish over the course of the winter. Where exactly in the river or whether some of them go down to the lake, you know, that we don’t really have any idea about, but they clearly do not stay. We definitely know that at least some of them go to the Brule, but where they go from there, I don’t know.

Now, if they are in lakes, I mean regular lakes, they’d stay in the lake?

Anderson: I presume so. At some point, young otters that spend the winter with their parents, their first winter with their parents, have to leave their parents and disperse. So, there are times when otters are moving around. They’re making some kind of migration, maybe not seasonal in the same regard as I just described, but they’re moving around, looking for where their home is going to be that won’t be in competition with something else. You know, otters really have made a great comeback in other parts of Minnesota where they disappeared from in the early 21st century. In southern Minnesota the otters pretty much disappeared, because of habitat destruction and water quality degradation. They’re making a comeback in that part of Minnesota, but we are really blessed with the habitat that supports a very vibrant population of otters, because we have excellent water quality for the most part, we have a surrounding landscape within our watersheds that support that. And otters eat a lot of fish, but they also eat other things, clams, etc.

You know, a number of years ago we were canoeing on Lake Kabetogama and we heard this mulling and hissing and we were fairly close to shore, and then, all of the sudden, two or three of these guys popped up and spit at us and then went back down again and then popped up and hissed. So, we figured right away that we must have come in to a family of otters, and the young ones were still young enough that the parents were concerned about us.

Anderson: Yeah, that’s very, very likely, because they’re going to stick together and learning the ropes, those young otters, and having the chance to play around with each other. Which, like in all mammals, including us, play is a way that we develop as our physical selves as well as our social selves. And, so that’s a big part of what they’ll be doing and they do that with their siblings and with their parents. Otter families might consist of typically more like two to three to four but as many as six young otters in a family, so it’s a lot to take care for the adults, you know, to manage all these youngsters and to keep them busy learning what they need to learn and getting them to places where they can work on their skills at catching their prey. So, parents will catch something and bring it close and let it go and they repeatedly do that to give them a better shot at catching something and get their techniques down. So, there’s a lot of training that will go on over the course of the summer and hopefully they’ll be successful.

Chel Anderson, botanist and plant ecologist. Thanks for helping us understand otters!

Anderson: You’re very welcome!

Airdate: April 27, 2011

Photo courtesy of orkomedix via Flickr.