At MNA, our Mission is to protect special natural areas and the rare species that live there. The goals of our blog are to cover the latest environmental issues affecting these areas and provide information about the efforts of our volunteers. Our weekly “ENDANGERED!” column serves to inform you about the endangered plant and animal species found in and around these special natural areas, and how you can contribute to conservation efforts before it is too late.
By Angie Jackson
Turtles have leisurely roamed the earth for more than 200 million years, making them one of the oldest surviving members of the animal kingdom. A fascinating species with the ability to defend itself by withdrawing into a shell, turtles are revered in many cultures as a symbol of longevity, wisdom and stability.
One species in Michigan, the wood turtle (Glyptemys insculpta), is listed as a species of special concern due to activities such as reduction of nesting areas, water pollution, sedimentation and the commercial pet trade.
Wood turtles are medium-sized with a brown, rugged looking carapace (outer shell) marked with distinct yellow and black lines on the ridges. The turtle’s upper head, neck, legs and tail are black, and the rest of its body is yellow or yellowish orange. The entire carapace ranges from 6-10 inches long, and is characterized by raised, pyramidal growth rings on each scale. Young wood turtles are gray or brown with circular, one-inch carapaces and long tails.
Wood turtles prefer streams, rivers, herbaceous vegetation and sandy nesting places. They can be found near clear, running water in floodplain habitats. Turtles prefer partially shaded and sandy areas with wet herbaceous vegetation such as raspberries, grasses, algae and strawberries. Nesting habitats include cutbanks and sandbars, and when these habitats are not available, wood turtles are known to nest in gravel pits, yards, gardens and even highway bridge crossings.
Michigan wood turtles are active from April to early October and they spend most of these months basking on logs, muddy stream banks or forest openings, and feeding. They live in aquatic habitats from fall through spring, when they then move into nearby terrestrial habitats for the summer months. Mating occurs in shallow water during the active season, most frequently in the spring. Wood turtles generally nest in June after sunset, and females produce a clutch of 5-18 eggs each year. The hatchlings are born in late August.
Wood turtles hibernate in mid-October and overwinter in streams with flowing water, often nestling their way into beaver lodges, muskrat burrows or under overhanging roots. Turtles are known for slow growth and long life spans of up to 50 years.
In Michigan, wood turtles are listed as a species of special concern. They also occur in Nova Scotia, New Brunswick, Virginia and Pennsylvania. Though wood turtles occur in many counties throughout Michigan, these turtles require specific habitats and may only live in small portions of each county.
Throughout the past 30 years, wood turtle populations in Michigan have significantly declined due to poaching and collecting by the public. In addition, human construction, stream channelization and timber harvesting have led to turtle habitat loss.
Wood turtles are resilient, however. They can thrive with moderate levels of human disturbance and in some cases can even benefit from these activities. Yet, the best way to protect this species is to leave it alone.
In Michigan, regulations on the Take of Reptiles and Amphibians deem it unlawful to take a wood turtle from its habitat unless authorized by a permit. The turtle is also protected by the Convention on International Trade in Endangered Species of Wild Fauna and Flora treaty, which prevents commercial trade of the species and requires illegal collection of the species to be reported to authorities. Human disturbance at nesting sites during the active season should be limited.
MNA protects a number of turtle species at sanctuaries throughout Michigan, including box turtles (Terrapene) and Blanding’s (Emydoidea blandingii). To find turtles, you might visit Lyle and Mary Rizor Memorial Nature Sanctuary, Dauner-Martin Nature Sanctuary, Timberland Swamp Nature Sanctuary, or any of our numerous floodplain and/or wetland properties.
How You Can Help:
MNA volunteers are currently working to protect this and other endangered species, and you can help too. Join our efforts as a volunteer removing invasive plants in the special natural areas where this species lives. Or, become a steward and take responsibility for planning efforts to maintain a specific MNA sanctuary. To find out how to get involved, visit our website.