by Greg Mayer
A couple of Sundays ago, June 17, 2018, my wife and I took a paddle along the Root River, in Racine, WI. Starting out at the Root River Environmental Center (REC), we went upstream, around the island in Island Park, and back down to the REC. Along the way we saw quite a few turtles– 15-20, although at least a few were the same turtles seen going both up and back.
Here, a shelled reptile and a glorified reptile share a tree trunk in mid stream.
On the next picture, it’s a bit of “spot the turtle”– the smaller one is inconspicuous. Both these two and the one in the previous picture appear to be map turtles (Graptemys). These turtles are typically more riverine than lacustrine, and thus might be expected in the river, except that the Root River is outside the range of map turtles, which occur in Illinois to the south and along the larger rivers of western Wisconsin. The map turtles of southeast Wisconsin are almost certainly introduced. What species they are is not clear to me. The species-level taxonomy of map turtles is not completely worked out, especially down South, where each river that drains into the Gulf of Mexico seems to have a more or less distinctive population of map turtles.
Although it might be natural to think that one of the midwestern species was introduced into southeast Wisconsin, southern turtles can be found in the pet trade, and there may be more than one species present in the Root River. (In Kenosha, just south of Racine, I’ve seen at least two map turtle species.) It’s not known if they are breeding, and if so, whether different forms are crossing. I did find a hatchling in Kenosha, but I can’t rule out– in fact I lean toward– the possibility that it was released, rather than bred, there.
This next turtle is definitely a map turtle. Note the hint of serration or knobs on the shell along the midline, and the white neck markings.
The next turtle is a snapping turtle (Chelydra serpentina), hauled out on the island in Island Park. It’s not a very good picture– that’s its tail you’re looking at– as the turtle slipped into the water as we maneuvered for a better shot, but snapping turtles so rarely bask on land that I though it worth showing. (They often float right at the surface, which is their usual way of ‘basking’.)
The species we saw the most of were midland painted turtles (Chrysemys picta marginata), which, like snapping turtles, are more of a pond than river species. The Root River is shallow and slow-moving, though, so the conditions are fairly pond-like. You can tell it’s the midland subspecies because the seams between the costal (‘rib’) scutes don’t line up with the seams between the vertebral scutes
We saw a bunch, but the gal above let us get the closest, so she gets a closeup. (You can tell it’s a she by the large size and the short ‘fingernails’– males are smaller, and have longer front claws.)
We did see two or three of southeast Wisconsin’s classic native river turtle, the smooth softshell (Apalone mutica). They are baskers, but very skittish, and thus hard to approach. I was using a 55-200 zoom lens on this trip, and got a decent picture of one. Notice that the ‘log’ it is on is actually an old piling or dock piece– note the bolt, nut, and metal plate.
Finally, towards the end of our two-hour paddle, we encountered what I believe to be the same two map turtles we saw at the start of the trip, who are in the first picture above– it is the same log. Sexual size dimorphism is stronger in map turtles than painted turtles, so this could be a female and a male.
The possible male dove first, but we got close enough to see the neck markings and hint of dorsal serration in the probable female. Of the two native map turtles in western Wisconsin, the plain old map turtle, Graptemys geographica, is less serrated than the false map turtle, Graptemys pseudogeographica, so this would be a geographica, except that the two Wisconsin species aren’t the only possibilities. (One of the two map turtle species I’ve seen in Kenosha is definitely a ‘white-eyed’ southern form.)
Given that it’s a small river hemmed in by human development on all sides, with a past history of industrial usage, four species of turtle, all reasonably abundant– all with multiple sightings during the trip, except for the snapper, which, as a non-basker, is often not seen– is actually a decent amount of biodiversity.