Snakes In The Sun And Bugs On The Water


SnakesBugs062410Mixdown.mp311.6 MB
Chel Anderson is a botanist and plant ecologist with the Minnesota Department of Natural Resources. She lives in Cook County and joins us periodically to talk about phenology or what’s going on in the woods right now. Welcome back, Chel.
Anderson: Hi, Jay.
Well, in the heat of the summer, that’s when snakes are basking in the sun. So, let’s talk about what kind of snakes we have here and what are they doing.
Anderson: Great time of year, best time of year to see snakes out and about. Whenever it’s warm and sunny especially, but warm is good enough. We have common Garter snakes. They are definitely the most abundant snakes and most likely to be seen. We also have Red-Bellied snakes, which don’t have those light dorsal lines that the Garter snakes have.
They’re kind of black.
Anderson: Yes, dark on the top and get a little bit lighter on the immediate kind of mid-sides, but then their bellies, and you can see this if they’re not deep in the vegetation, you’ll be able to see this orangish-red coloration of their bellies. They tend to be a little smaller, they have a maximum size of about a foot only, whereas the Garter snakes might be two, you know, other parts of the state they might get up to three feet long. There are also some documentation of Green snakes here, but mostly in wet places, but hard to say how many. It doesn’t like this far east and north that there are very many. They are busy doing what most, both amphibians and reptiles are doing, which is breeding, feeding, trying to grow and get ready for winter. And in the case of snakes, part of the growing over the course of the summer is shedding your skin. Snakes have to find very warm, protected, preferably dry air environments is ideal for snakes to cast off their skins.
Now, why do they cast off their skins? Is it a matter of growth or do they just want a new wardrobe?
Anderson: Well, unlike us, it is a matter of growth. They can’t fit in it anymore, so they have to lose it and then they have to kind of cure that new skin. When the scales are first exposed, they take some time to become road-worthy, so to speak, to be able to handle the elements and all the materials that the snake is going to be moving over. So, it’s important, like I said, for snakes to find a safe place to do that. So, they might pick, oh, if you have some place that’s covered so it doesn’t get easily rained on and is kind of loose, dry material, maybe a compost area that has a roof over it, that would be a very likely place for a snake to go and burrow into, because the process takes quite a long time to get that old skin off and they utilize the materials of whatever they are in as a way of helping coax that skin off, kind of move it off, scrape it off, or they might use a place where there’s a bunch of dry grass, you know, some kind of a thatch that plants have created.
Well, I know that snakes eat a lot of insects and speaking of insects, there’s one that they probably don’t eat, but I want you to talk about it because they’re fascinating little things. In lakes and ponds, you’ll find little beetles doing strange things in the water. What are they and what are they doing?
Anderson: Yeah. Whirligig beetles, I think, are the easiest one for people to think about having maybe seen or to go and look for, because they tend to hang out in groups in the daytime, and groups right on the surface of the water. They form, might be hundreds up to thousands of them, form these rafts together, and in the daytime, you know, if you’re down by the lake, sitting on your dock, out in your boat, canoe, if there’s some still water usually close to the shore, fairly close to the shore, you’re likely to encounter one of these rafts. Often, you’ll see within visual distance you’ll find, you’ll see other rafts of Whirligig beetles, and these groups of rafts are called aggregations, and they are important little communities that eventually do some interacting and trading off of individuals. But, one of the curious things to me always about Whirligigs is they don’t seem to do anything, except hang out together. You know, like, are they all teenagers? What have we got going on here? Well, it turns out, you know, digging into things a little bit, what people have unraveled about Whirligigs is that they do spend these times together during the day when they’re most vulnerable to predators as big groups, because, of course, if you’re part of a big group, there’s less chance that you’ll be the one that’s going to get picked off by the fish, usually it’s fish, or some other kind of predacious insect. But, Whirligigs are kind of low on the feeding priorities for things, because they taste really terrible.
Is this from experience, Chel?
Anderson: I wouldn’t admit that. But, no, it’s not, but people have gone to the effort of trying to figure out why is it that they can be so obvious kind of and part of it is that they have a very powerful chemistry that makes them very unpalatable, and people have actually seen something like a frog eat one and then regurgitate it immediately.
So, besides moving around in these rafts, and they kind of spin, don’t they, which is why they are called Whirligigs, what are they doing? Are they feeding?
Anderson: Not during the day. Turns out, Whirligigs only feed at night, that’s why we see them hanging around apparently doing nothing. Once darkness falls, they start to move out as individuals and they go out along the shore looking for things to feed on, and this would be other smaller aquatic invertebrates. So, they spend the night out feeding, and if you go out on a moonlit night or you bring out your headlamp or flashlight and sit out and look, you can see this beautiful ‘V’ of these little Whirligigs cruising up and down the shore.
Well, we’ve been cruising with Chel Anderson, who is a DNR botanist and plant ecologist. Thanks for helping us understand things like snakes and those funny little bugs.
Anderson: You’re welcome.

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