Larry Lyons: Why aren’t the snapping turtles nesting?

Published 7:54 pm Wednesday, June 9, 2010

lyonsWe live on a creek, have a good-sized pond in our yard and there’s a plowed agricultural field adjacent to the yard.  All of this adds up to snapping turtle heaven.

Every spring we see up to a half dozen big ol’ snappers wandering about the yard in the early morning hours, either still searching for that just right nesting spot or returning back to the water after her hard day’s night. For a number of years the wife has kept records of our snapper sightings and nearly all occur within the last eight or nine days of May and the first few days into June.

But something’s wrong this year. That time has passed, and we haven’t seen a single snapper and there’s only one nest in the freshly plowed field. Nor have I seen any wandering snappers in the roads during my travels, which is highly unusual. I doubt they’re simply running behind schedule.  Most spring events here in southern Michigan, such as the various plants greening up and mushrooms and mosquitoes emerging, consistently ran two weeks ahead of schedule.  If anything, the snappers should have nested early.

Curious, I asked a local farmer who plows a huge amount of land all over this area if he’d been seeing the normal amount of snappers. He hasn’t seen a single one either. In fact, the only snapper sighting I’ve heard of was one my son saw at the Conservation Club. Along this same line, we normally see a number of box turtles wandering about at this time. I’ve only seen two this year. I have no idea what’s going on. Let’s just hope it’s a localized anomaly rather than something more sinister.

The snapping and box turtles are just two of ten turtle species we have here in Michigan. A word synonymous with turtles is old. They are one of the oldest animals on the planet with fossils dating back 225 million years ago.  They walked amongst the dinosaurs and have changed very little since. Somehow, they survived whatever event killed off the dinosaurs. They are also one of the oldest living of animals with some species living well beyond 50 years.

This longevity is not without drawbacks. It takes a long time for most turtles to sexually mature. Some species mature within ten years, a comparatively long time for a wild critter. Snapping turtles take around 15 years to mature while Blanding’s and wood turtles take up to twenty years. This means they can’t quickly rebound from catastrophic events. It also means they have a long time for toxic pollutants to build up in their bodies which eventually affect health and breeding. If they start into a decline for whatever reason it’s hard for them to turn it around.

Some of our turtle species are holding their own quite well but others not. In the latter category are box turtles, wood turtles, spotted turtles and Blanding’s turtles, all listed as special concern or threatened species here in Michigan and fully protected by law. Golly, I remember when box and spotted turtles were all over the place and now here they are on the deep doo-doo list.

Though all our turtles except the box turtle are aquatic they all lay their eggs on land. The female comes ashore and digs a depression in the ground. She lays the eggs and without so much as a glance at her creation covers them up and departs, leaving the rest to fate. Most choose sites close to the water’s edge, but snappers may roam a mile or more away from their home water. The gender of the soon-to-be turtles depends on the egg temperature during a certain critical period of development. Cooler temperatures tend to produce females while warmer weather promotes males.

In recent times raccoons have been digging up virtually every nest around here. Because of the turtle’s long life span they can go a few years without successful nesting. Hopefully, the coon populations will cycle frequently enough to allow the turtles to pull it off now and then and all will be happy.

Carpe diem.

Larry Lyons writes a weekly outdoor column for Leader Publications.
He can be reached at larrylyons@verizon.net