WHY DO TURTLES ROAM AROUND IN THE WOODS?

by Whit Gibbons

May 18, 2008

I anticipated that the highpoint of a recent walk with two of my grandchildren, Allison and Parker, would be when the dog, Gilbey, saw a squirrel. The children take turns holding the dog's leash, and when a rottweiler, even an old one, decides that yet another squirrel is taunting him, it can be fun to watch. The squirrel always wins. I prefer other highpoints. And sure enough we were rewarded by something different. Walking the dog through the neighborhood woods we found a snapping turtle.

What could make a routine dog-walking trip on a Saturday morning more enjoyable for two children? Finding a turtle is always exciting. Asking the obvious question, why was a snapping turtle taking a stroll through the woods a half mile from the nearest pond, added an intellectual dimension to the adventure.

Three possibilities for why a snapping turtle would be found in the woods so far from water during the spring came easily to mind. The first hypothesis would be that the turtle was a female with eggs. Most turtles lay their eggs during late spring and early summer. And traveling more than a mile from the water is not unheard of for a female snapper searching for a suitable nesting site. But this was a young adult male, not a female. Hypothesis number one was rejected.

How did we know it was a male and also young? The tail of adult males of most turtle species is significantly longer than the tail of adult females. And Parker asked how old the turtle was, so I counted the growth rings on one of the plates on its shell. Small rings are formed on each of the plates of a snapping turtle each winter when growth ceases. These are similar in appearance to tree rings and can be used to estimate the age. This one had eight rings, making it older than either of the kids.

Another reason an aquatic turtle, especially a male, might range so far away from water is that the mating season was not quite over and it may have been looking for a female. Female snapping turtles may not be pretty to us, but to a male during the breeding season nothing could look finer. In springtime many male aquatic turtles seeking females travel overland between bodies of water. Turtle biologists assume that when a male can find no receptive female, for whatever reason, in one lake it will leave there to search for a female in another lake. The females usually stay put and let the males do the searching. Whether this was a bar-hopping male on a mission to find a mate is unresolved.

The third reason a male snapping turtle, especially a small one, might leave a lake and look for another aquatic habitat is that it had encountered a larger, dominant male in the first lake. Male snapping turtles will fight each other during the mating season, and the loser usually does not hang around for long. The one we discovered was half the size of some of the monsters that can be found here and there, so maybe it just decided that safer turf could be found elsewhere.

The turtle could readily embark on overland travel because it had rained for a couple of days, assuring that dehydration would not be a problem. Contrary to what one might expect of a lake-dwelling turtle, many species, including snappers, mud turtles, and chicken turtles, commonly move overland, some spending as much as one-third to one-half of their lives on land. Although we will never know for sure why we found a nonnesting snapping turtle so far from water, we had fun speculating about what it was doing and why. Asking basic questions about plants and animals increases our enjoyment of natural habitats. Even if we don't know the answers, speculating is a healthy exercise.

A walk on a spring day is sure to reveal something of interest, even if no squirrels are around to taunt the dog. Give it a try.



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