Snapping Turtles Meet Their Match

snapping-turtle-bryan-pfeifferAt first I thought the big black shape in the lane was a piece of burst tire. Then the tire held out a slow, prehistoric foot and took a step. Its long neck shifted into view as I drove by, and I realized it was a huge snapping turtle. In the few seconds I’d been watching, several cars had already whizzed past, missing it by inches. It was halfway across the first of eight lanes of traffic it would need to traverse to reach the other side of I-93.

I don’t normally cry over road kill. But a mile down the road I pulled into the breakdown lane and burst into tears. I imagined a cop stopping to help with the emergency and discovering, inside the Subaru Forester with, of course, Vermont plates, a young woman sobbing over a turtle who last she saw was unharmed.

The futility of its journey had overwhelmed me. The turtle, moving with the confident plod that has served its species for 40 million years, had looked so out of its element on the highway. It had completed only a fraction of an impossible crossing. This creature, steadfastly putting one foot in front of the other, was utterly screwed.

Early each summer, snapping turtles leave the water to lay eggs on land, traveling up to four miles from home. The one I saw last June may have been a mother looking for a good spot to dig a nest, or a young turtle dispersing from its original home range. Unlike most animals, female snapping turtles disperse over greater distances than males and keep similarly sized home ranges (eight acres on average, in the north). Some nomadic females have no home range at all; others return to the same nest site annually. Since they can retain sperm in their bodies and use it over multiple seasons, they do not need to mate every year.

This strategy has worked well for Chelydra serpentina—so well that it is the ancestor of 80 percent of all living turtles. In fact, snapping turtles have hardly changed in appearance from the earliest turtle, which evolved over 200 million years ago. In other words, proto snapping turtles had already been around for 150 million years when Tyrannosaurus rex appeared on the scene.

Having survived two major extinction events in close to their current shape, modern snapping turtles faced virtually no predators once full grown until a century ago, when the automobile was invented. Now most females living in developed areas die on roads after only a few nesting seasons. Their natural life spans, although they average 30 years, can last over 80 years. In other words, the individual I saw on I-93 could have been older than the highway itself.

This time of year, snapping turtles have buried themselves in the mud of a pond, swamp, or slow-moving stream and begun hibernation, deep enough that the mud around them will not freeze. While they often do spend the winter within their home range, they can travel up to two and a half miles away to hibernate and then return to their territories in the spring. Individuals sometimes stay faithful to a few particular hibernacula, rotating between them year after year. If a site becomes popular, turtles can end up stacked on top of each other for the winter. This group hibernation makes them vulnerable to occasional predation by otters.

Still, I think a turtle stands a better chance unconscious against an aquatic carnivore than crossing an interstate highway. I can only hope that my turtle had already laid her eggs and was on the way back to her pond. Perhaps her hatchlings, if not she herself, now lie safe in the mud, waiting till spring.

Sonia DeYoung is a second-year student in the Field Naturalist Program.

Information gathered from “Snapping Turtles” by Susanne Kynast on The Tortoise Trust website, Naturally Curious by Mary Holland, and Animal Diversity Web.

Cryptic Croakers

Northern leopard frog among fallen maple leaves.

Northern leopard frog spot on with a fallen maple leaf

Hiding in plain sight

Hiding in plain sight

Imagine that you are the size of a Reese’s cup and, to many animals, equally delicious. You occupy a precarious position in the food chain; you are a danger to many, and safe from few. You dine on insects, slugs, snails and even the occasional small bird. Predators that hover above include herons, hawks, and waterfowl. Raccoons, foxes and snakes lurk behind stumps on the ground, awaiting your misstep. Water, your true home, swarms with otter, mink and bullfrogs, each hungry for their main course delicacy. How do you, a northern leopard frog (Lithobates pipiens), survive such an onslaught?

Many of us may think that we witness a frog’s primary defense as it jumps away. But this erratic hopping demonstrates a last-ditch effort to stay alive. Before he leaps for his life, stillness keeps him hidden among the leaves; camouflage is his best friend. Numerous amphibians employ camouflage to protect themselves from potential predators, but few excel in this department as well as the northern leopard frog. Under the cloak of camo, this frog gains the opportunity to find dinner without always becoming it.

The waning months of summer in Vermont bring about new dangers for these cryptic croakers, as they venture from the water’s edge into meadows to forage for food. Luckily, hues of green and brown underlie rounded black spots that decorate the skin in a pattern that serves function over fashion. These colors blend in inconspicuously to the fields of forbs, grasses, and goldenrods in a cloak of camouflage. This crypsis is termed background matching.

The use of background matching is not uncommon elsewhere in the animal kingdom. A white-tailed deer fawn (Odocoileus virginianus) resting on the forest floor, an eastern screech owl (Megascops asio) waiting motionless in the hollow of a tree, or a spring peeper (Pseudacris crucifer) hiding amongst the autumn leaves are all able to avoid detection with their special camouflage. Whether feather, fur or frog, these animals are a rare treat if your eye can pick them out of the patchwork.

With the warmer portion of fall still upon us, spend a Saturday in the meadows of the Champlain Valley and try to catch a glimpse of a leopard frog during its feeding forays. Vermont winters hit hard for these amphibians. Soon, they’ll head for the trenches with the northern map turtles (Graptemys geographica). Both of these cold-blooded critters move to well-oxygenated waters to escape the brutal winter winds and hunker down into hibernation. They begin to tuck themselves in by late October to early November, and won’t fully emerge until February or March. By then, it will be time to fatten up, find a mate, and blend into their surroundings once more.

Gabe is a first-year Field Naturalist student at UVM

Freshwater Sharks

Snorkeling in frigid waters for a species at-risk

By Levi Old                                                               

Salvelinus confluentusOn a dead-still summer night, I army-crawl upstream.

“We have a large adult!” says Jen.

I rise to one knee and pull the fogged snorkel mask off my head. “A big one?” I mumble in a haze.

“Yeah, really big. Much larger than I’ve ever seen this far up the creek,” she replies, pointing to where it kicked its caudal fin gently against the downstream flow. “It’s right there beside you.”

I cinch the mask on my face, place the snorkel in my mouth, and dunk back into the frigid water:

Twenty-six inches of wildness.

Jen pops her head out of the water and says, “Isn’t that just a beautiful creature?”

She snorkels one side of the creek and I snorkel the other. An assistant in waders walks the creek, tallies our fish sightings and makes sure we do not go hypothermic. Continue reading