Tuesday, September 4, 2007

Pond Sharks

The picture here is of a Common Snapping Turtle (Chelydra serpentina). It was taken almost two months ago when we saw our little pond shark decide to take a sun bath (to avoid scaring it, I did a belly-crawl for a hundred feet). This was the only time we saw the animal on land.

Hearing my mom screaming something outside the door to my dad, I knew it wasn't good. I ran up the stairs to see Mom pointing vigorously out the back door at something. "Something's got the duck!" she screamed. I jumped out the back door and ran to where my dad was just standing by the edge of the pond staring and looking furious. One of our 7 week old ducklings was floating upside down with the flesh stripped from it's neck and a turtle head the size of goose egg disappearing in a mud cloud. "It's that snapper," he mumbled. "Where's your fish net?" Although my fishing net probably couldn't catch something that was 15 pounds and cement jaws, it was worth a shot. I got the net and came back. My dad was still staring at the mass of algae not far from shore. We waited with the net for about twenty minutes. Twice, the same head appeared a couple inches from the surface and bobbed there for a few seconds to check it out. But after that second time, it probably figured that it couldn't finish its duck.

That's just snappers for you. And we wondered where all of our ducklings that our ducks hatched went. Probably just more victims of our pond shark. It's just nature, but it would be nice if they could just go for all of the fish in the pond as opposed to our gorgeous ducks. There's no saying how old the turtle is since all of the resources that I'm finding are saying different things. Some are saying that wild snappers only live to 30 and others are talking around 100. Agreeing with the latter, I'd have to say that this turtle is close to twenty years old.

The pictures here are of a baby snapping turtles that are probably around six months old (they hatch in fall). I found this one in a puddle about ten feet away from the creek. I brought it to the house and weighed, measured, and photographed it. The funny thing is that I found another baby snapper two days later taking a swim down the creek. I knew it wasn't the same one though because of its measurements and weights. These two measured 1' in length and width and both around half an ounce. These were definitely not hatchlings since when they first come out of the shell, they're only about the size of a quarter. They had to have been from the same nest, considering they were only 1/8 of an ounce or an inch apart in size. And since we live up north where it's cold, they probably stayed in the nest for the winter, and had just come out for spring. They also looked the exact same, so they had to have been the same sex. I'm not sure how to tell the difference in sexes at that age, but female and male's plastron (under-shell, as pictured above) are slightly different along with their tail as shown in this diagram from Ehponline (scroll down, till you see an illustration with an upside down turtle). You see, just like crocodiles and alligators, the sex determination of the animal is based upon the temperature when they were incubated. Males will hatch if incubated between 22 and 28°C, and females are produced if outside that range of temperature. Considering the crazy weather we've had the past year, it wouldn't surprise me if these were females.

Unfortunately, there's a chance that the turtles that I have caught are already dead. It's very unfortunate to be a turtle. The chance of them surviving to adulthood is very little. The female will lay around 50 eggs, but there's a good chance that a raccoon, coyote, fox, or any other carnivore will dig up the nest before they even have the chance to hatch. Even after hatching, they have to survive without being eaten by large fish, herons, minks, or raccoons. It doesn't really help that it can't curl up in its shell as tight as most turtles can. As you can see, the baby turtle here is trying its best but not succeeding that well.

Well, unless we want all of our ducklings to disappear, we'll have to figure out some way to catch those snappers... without harming them. We still want them in our area, just not in our pond eating our ducks. (We started with 14, now we're down to 8.) Then again, it wouldn't surprise us if the coyotes are helping with those numbers. So if there is a way of catching them, we'll just relocate them to the creek where there are plenty of other snapper friends.

4 comments:

Anonymous said...

While I have seen snapping turtles here and there driving on country roads, I have not think of them as hunters of ducklings! But judging by the one I removed from a 2 lane road one day (it was as big as a 12" cast iron skillet) I do believe they could hunt and eat little ducks. This is very interesting to know. Now when I think of snappies, I think of sharks!

Katherine said...

I hope I didn't make them sound too bad. They're still awesome animals, it's just that this certain snappie likes duck over fish for his meat course.

Anonymous said...

You mention that you still want them in your area, and wonder why that is? Is there something that they do or provide, such as spiders keeping down mosquitos or bees pollenating flowers? Or is it jsut because you love animals that you want as many different types around as you can?

Katherine said...

Well, they eat fish and stuff, but I'm not sure if they eat enough that the ecosystem would go out of balance if they went extinct or anything.

I think it's mainly because snapping turtles happen to be one of my favorite animals and I couldn't stand harming them. :-)