Article published Sep 24, 2006
My Turn
  Wild beauties What turtles tell me about humans' unwise ways

By David Carroll
For the Monitor


 

Last week, New Hampshire naturalist David Carroll was awarded a MacArthur grant. He is best known for his work with turtles. Why turtles? the Monitor asked him. Here is his answer.

In talking about turtles, I am happy to be able to avoid using the "canary in the coal mine" analogy applied to frogs, salamanders, trout and other life forms most vulnerable to human degradation of the biosphere. If turtles go belly up due to our host of pollutants and other environmental stresses, it is likely that we - the human species, Homo sapiens, "wise man,"as we have so modestly named ourselves -will have preceded them.

As a venerably ancient and remarkably unchanged group, turtles are incredibly well-adapted to living on Earth. Considered "evolutionarily conservative," they have stayed essentially the same, more so perhaps than any other four-legged vertebrate, since their appearance in the fossil record some 250 million years ago.

These slow and deliberate animals, which we count in such sad numbers crushed on roads as they attempt to continue to follow seemingly timeless pathways, have ebbed and flowed with eons of Earth's fitful and often extreme upheavals and transitions: the advance and retreat of glaciers, volcanic eruptions, impacts of asteroids and whatever else it was that took away the dinosaurs.

Turtles have adapted to environments as diverse as deserts and oceans, forests and plains, swamps and marshes, rivers and streams. It is more than their famous shells - a unique rearrangement of the vertebrate body plan - that has enabled them to persist.

 

 

 

 

There are turtles in our part of the glaciated Northeast that can go for up to six months under the mud of winter wetlands,

at temperatures of around 36 degrees without access to oxygen (there is zero oxygen below as little as three millimeters of mud). Other species can go as long without air-breathing, submerged in oxygenated water.

They can pass half a year or more in hibernation without eating. Hatchling painted turtles can, and far more often they do, survive entire winters in nests in the earth in which temperatures fall well below freezing. A hatchling painted turtle digging out of a nest in late May could well have spent an entire year in that chamber only 1½ to 3 inches deep, as a developing embryo within an egg and a fully formed turtle out of its eggshell waiting to dig forth and take up that critical nest-to-water journey.

Remarkably resistant to death by bleeding and to infection, turtles can have legs chewed off, and then heal and go on for years. Wood turtles in particular can survive the loss of limbs to predators such as otters, living for years after losing even both front legs. Recent research has indicated that female spotted turtles can live 110 years. These survival traits are unparalleled in the vertebrate kingdom.

But these marvels of biological adaptation do not sum up "turtle" in human consciousness.

A sharp decline

Certainly I was not aware of these characteristics or much of anything else related to this natural history when, as a solitary 8-year-old boy wandering a wetland for the first time, I had my first, and for me literally life-changing, encounter with a free-living spotted turtle in a wild swamp. In the long and ongoing "turtle man"aspect of my life (its principal aspect, I'd say), I have met an extraordinary number of people who have a turtle connection. The turtle's role in prehistoric to contemporary human culture, from Chinese to Native American, is well known.

It is ironic, and not a favorable reflection on human land-use policies, that such an ancient and durable survivor-group has come to include in its ranks so many that have declined to the point of receiving designations ranging from "special concern" to "endangered." This forlorn terminology that has come to be applied to them throughout their ranges has arisen from the sharp decline of the species in question from formerly robust populations.

Here in New Hampshire, spotted, Blanding's and wood turtles are ruggedly suited to the terrain and climate they have lived in for at least several million years. Primarily due to habitat loss, alteration, fragmentation and degradation, they have in a short time been driven to the ranks of species of special concern.

This is a de facto designation, as there are no state-listed turtles here, although the Nongame and Endangered Species Program of the state Fish and Game Department has adopted regulations that prohibit taking these species from the wild or possessing them. Unfortunately, habitat protection remains unaddressed.

Spotted, Blanding's and wood turtles are species of broad, contiguous ecosystems. They require an integrated landscape, an extensive mosaic of wetland, riparian and upland habitats. They must have cover and habitat complexity. Human land use patterns of the day have relentlessly driven the landscape in the direction of ecological simplicity.

To picture the difference between complexity and simplicity in this sense, compare and contrast wild, untrammeled, natural-flood-managed floodplains (if you can find them) to golf courses, agricultural fields, lawns, parking lots, roadways, shopping malls and housing developments.

These turtles species of special concern are not alone in their landscape requirements. Biodiversity itself has the same suite of requisites. And ultimately, so does the human species.

"In wilderness is the preservation of the world" may be Thoreau's most familiar statement. We need the wildness, the wild beauty Thoreau and so many other eloquent voices have spoken of. It is a vital component of the spirit and stardust of which we are composed.

Our menace, too

Turtles cannot run, jump or fly. They are literally grounded to the water, mud and sand; earth, stones and plants of their landscapes. They are marvelous and simply beautiful reminders that Earth is a theater for life in the universe, as far as we yet know the only such theater in incomprehensible dimensions of space and time. And if there are other places with forms of life, they reduce any human word for "rare" to utter meaningless and do not relieve us of our responsibility to the life of which we are an integral part (though we too easily forget it) and of which we are a product (though some would deny it).

The declining status of these ancient living symbols of a whole Earth is one of those all-too-ignored beacons that tell us we cannot continue in the arrogant ways by which we have allowed ourselves to overpopulate the Earth, to alter the very terms of existence for life on Earth and to inflict our unsustainable numbers, needs and desires on all living things.

Ethics and esthetics must be allowed into the land-use and land-preservation debate. The pervasive and monumentally out-of-balance limitation of this debate to self-serving human economics menaces turtles and humans alike.

(David Carroll lives in Warner.)