It’s World Turtle Day today—an annual celebration created by the group American Tortoise Rescue to generate admiration and conservation mojo for these shell-toting reptiles.
Turtles, tortoises, terrapins: Whatever they’re called, as a group they date back to the Late Triassic Period, around 220 million years ago, making them among the most ancient of contemporary reptiles.
They can range widely in size: Among the smallest is the bog turtle, which tops out at 4.5 inches and about 4 ounces. The largest is the leatherback sea turtle, which can grow to over six feet long (shell edge to shell edge) and weigh from 500 to 2,000 pounds.
Something these two species share, however, is that they—and many other turtle species around the world–are having a hard time surviving into the 21st century:
- Bog turtles, although widely distributed along the East Coast and into the eastern interior of the United States, are listed as threatened under the Endangered Species Act. The major threats to this small turtle include loss of habitat to urban development, and invasive plants displacing native plants in the marshes, swamps, muddy woodlands, fens, and (yes) bogs that it prefers.
- Leatherback sea turtles are extremely endangered in many of their traditional habitat ranges around the world. Their numbers are being cut by chemical pollution and coastal development, as well as eating floating plastic bags (which resemble jellyfish, their favorite prey), getting netted with fish as “bycatch,” and poaching.
The National Wildlife Federation recently reported that 2010’s Deepwater Horizon oil disaster in the Gulf of Mexico is still affecting many marine species, with around 500 dead sea turtles found in the area every year since 2011– “a dramatic increase over normal rates.”
Over 150 freshwater turtle species (like the box turtle) face equally existential risks worldwide. The New York-based Wildlife Conservation Society is leading a project to breed endangered turtle “assurance colonies”: captive populations that, if successful, help assure a species’ long-term survival, even if goes extinct in the wild. (Elizabeth Kolbert visits several assurance colony breeding programs–the Hail Mary passes of species conservation–in her book “The Sixth Extinction.”) In December the society announced the hatching of five Chinese big-headed turtles, among the world’s most endangered turtle species.