Who’s At Four Mile Run Park this Summer?

While collecting water samples, Four-Mile-Run intern Guy saw a female
snapping turtle selecting her nesting site. Photo Credit: Guy Cardwell

If you walk along the stream this month, you may come across a prickly prehistoric animal doing some important business. Snapping turtles are in their egg-laying season, which in Northern Virginia tends to span the month of June. Female North American snapping turtles (Chelydra serpentina) have been tracked returning to their same general nesting area year after year. Indeed, generations of snapping turtles have been nesting on land for about 90 million years, far longer than humans have been around. So, a female snapper knows exactly where she’s going, although she might be stymied by changes to the landscape from human development, storms, or other factors.

Once the female finds what she deems a suitable spot, the hard work begins. Like all turtles (with just a couple of odd exceptions), a female snapper must excavate a nest hole using her hind legs. It’s an arduous task, likely made more so by the nonnative turf grass that compacts the soil along parts of Four-Mile-Run Park. But, loaded up with seven or more eggs, she’s compelled to complete the task of dropping the eggs, one by one, into the hole. In Virginia, the record clutch size for a snapper is 55 eggs, a startling statistic that only makes sense when you consider that North American snapping turtles can grow to almost 20 inches long (two basketballs side by side). 

Female snapping turtle ejects an egg through her cloaca (reproductive opening) into her nest. Photo Credit: Todd Kiraly

This female snapper (nicknamed “Snappy”) was seen in action earlier this week, dropping what looked like ping-pong balls into her flask-shaped nesting chamber. Typically, turtles urinate while they dig to soften up the soil, but the recent rains likely served that purpose, encouraging females to nest. Like many turtle species, a North American snapper female can store sperm for weeks or months after mating, then choose to fertilize her eggs when she anticipates favorable conditions.

Once a female ejects all her eggs into the nest, she kicks soil over the hole, then smooths it over with sweeping motions of her rear end. It’s arguably the most important part of the job, since it camouflages the nest from egg-loving predators like raccoons and foxes. The incubation period for snapping turtle eggs depends on temperature; for Virginia, it’s typically 75–95-days. So, Snappy’s eggs are likely to hatch toward the end of August. A snapping turtle hatchling is about the size of a quarter with a soft, bumpy shell that hardens gradually. Watch out for the babies later this summer as they make their way from nests to Four Mile Run stream!

Hatchling North American snapping turtle. Photo Credit: D. Diaz, National Park Service.

A snapping turtle hatchling is about the size of a quarter with a soft, bumpy shell that hardens gradually. Watch out for the babies later this summer as they make their way from nests to Four Mile Run stream!