Wood Turtle

(Glyptemys insculpta)

Status: Endangered (ESA 2008), Threatened (COSEWIC 2018 & SARA 2010)

Table of Contents:

Species Identification
Diet
Habitat and Range
Biology and Behaviour
Similar Species
Threats/Reasons for Being Endangered
Conservation and Recovery Strategies
How You Can Help

Species Identification:

Wood Turtles are a medium sized turtle. Adult carapace (top shell) length ranges from 16 cm to 25 cm, and is typically grayish brown or yellowish. The Wood Turtle’s top shell has ridges that give it a sculpted, wood-like appearance. The plastron (bottom shell) is yellow with black spots on outer edges. Their skin is generally brown but often their legs, neck and chin can have an orange or reddish-yellow colouring. The Wood Turtle’s feet are slightly webbed and have large claws. Males are generally larger than females, and they have a longer and thicker tail and concave plastron.

Diet:

Wood Turtles are opportunistic omnivores, but they rely on vegetation and forage more on land than other Ontario turtle species. Wood Turtles like to eat berries, herbaceous plants, mushrooms, soft-bodied invertebrates (especially worms and slugs), amphibian larvae, and carrion.

Map taken from Government of Canada: https://www.canada.ca/en/environment-climate-change/services/species-risk-public-registry/recovery-strategies/wood-turtle-proposed-2016.html#_3_2

Habitat and Range:

Wood Turtles are native to North America. They have a discontinuous range from Nova Scotia west through New Brunswick, south-eastern Quebec and south-central Ontario, down into the United States to Minnesota, Virginia, and Maryland. Approximately 30% of the global distribution of Wood Turtles is in Canada.

They are highly terrestrial for a freshwater turtle species, but they are still dependent on aquatic habitats, since they rarely move more than 300 m from water. Juveniles will remain closer to their home rivers than adults do since they rely on riverine habitats for protection. Wood Turtles will frequently use terrestrial habitats for foraging, nesting, and basking. Aquatic habitats are used for overwintering, mating, dispersal and regulating their body temperature. They often can be found in meandering shallow rivers with sand, gravel, or cobble bottoms. These rivers are typically clear and have moderate current and frequent oxbows, which are horseshoe-like bends. Research has found that large scale habitat selection is determined by foraging needs, and small scale habitat selection is determined by temperature.

Biology and Behaviour:

Wood Turtles emerge from hibernation in the spring once the ice melts and it is warm enough to bask. They are philopatric, which means they use the same general home range throughout the year and also from year to year. Home range size varies based on a Wood Turtle’s age, sex, and distance to nesting and hibernation sites. The males' home range tends to be larger and more linear since they prefer to stay closer to rivers. Females tend to have broader (less linear) home ranges and are more likely to move away from rivers in the summer.

Males are also very territorial and will display dominance hierarchies with other male Wood Turtles. More dominant males will mate with more females than the less dominant and usually smaller/younger males. They mostly forage for food on land, and they will bask on land in the sun to thermoregulate without wasting too much energy, especially in cooler months after coming out of overwintering sites. Wood Turtles are usually found basking near rivers and streams. They are active during the day, but most active in the morning and evening.

They mate throughout their active season, which is April to September, but most commonly in spring and fall. Females will migrate to nesting areas and may stay in their staging area next to their nesting site for several days to a few weeks before nesting. They will dig their nests in late May to early July. Nesting can occur throughout the day or night depending on the weather conditions, but it usually occurs in the evening. She will dig her nest in sand or gravel beaches or banks, as well as road shoulders, gravel pits, and railway beds. Females will lay one clutch a year, and the number of eggs can vary from 1 – 20 eggs. Unlike most turtles, sex determination is genetic, not temperature based.

Wood Turtles hibernate under the water in streams and rivers from roughly October to late April. They will either hibernate alone or communally with other Wood Turtles, or even other turtle species. Overwintering sites are usually on the bottom of deep pools, often with fallen debris that provide structure that prevents dislodging during potential high flooding events.

Main predators of adults include Raccoons, Striped Skunks, Coyotes, Mink, River Otters, Red Foxes, and Ravens. Main predators of hatchlings are large fish species and birds like the Great Blue Heron. Eggs are commonly predated on by Raccoons, Striped Skunks, and Red Foxes.

Similar Species:

The only other native Ontario turtle species with a sculpted shell is a Snapping Turtle, but they are much more aquatic and can be distinguished by their long and spiked tail

Blanding’s and Spotted Turtles can have similar looking plastrons and yellow and orange colouring, but they have smooth carapaces and Blanding’s have a bright yellow chin

Threats/ Reasons for being at Risk:

1. Road mortality: Mortality and injury resulting from being hit while crossing roads in Wood Turtle habitat is their biggest threat, like many other turtle species. They spend a lot of time on land during the summer, and they are relatively slow when travelling so collision probabilities are high if there are roads in their habitat. Females are more vulnerable to this threat because they travel further on land to nest, and because they can be attracted to soft road shoulders to nest. Hatchlings emerging from nests on roadsides are also more likely to get run over, and nests are more likely to be predated by animals that have become accustomed to urbanized settings. Roads also take away suitable habitat, and some can even cause barriers to the rest of their habitat.

2. Agricultural practices: During active season both river and terrestrial habitats are important for Wood Turtles for foraging, thermoregulation, nesting, and commuting. Habitats especially in southern Ontario and Quebec are being used for agricultural purposes. A threat analysis using reported sightings showed that agricultural lands covered between 43% - 98% of Wood Turtle habitat for nine streams located south of the St. Lawrence river. Local wood turtle populations that are exposed to agricultural machinery show unsustainable levels of mortality and injury.

3. Illegal collection for pets and food: Wood Turtles are particularly vulnerable to collection because of their attractive appearance, terrestrial habits, and low capacity to evade capture on land. Collection generally occurs for traditional medicine, pet trade and food. Eggs are also collected for incubation and trade.

4. Residential and commercial development: Residential and commercial development, especially in terms of residential and cottage development can destroy or alter habitat and reduce connectivity to habitats. Increased human populations can also attract urbanized predators like Raccoons, Skunks, Coyotes, and Red Foxes. The shoreline development that is often done with developing waterfront can also destroy Wood Turtle habitat.

Conservation and recovery strategies:

The Federal Government has deemed the recovery of the Wood Turtle as feasible. They acknowledge that road development, agriculture, and urbanization are the main threats to this species. In order for the Wood Turtle to once again thrive, the government would need to restrict road development in important habitat areas, and reduce road mortality by identifying road mortality hotspots, putting up signs, and reducing speed limits in these areas. Increasing the amount of Provincial and Federal protected lands is needed, especially in areas of known Wood Turtle habitat. Currently, only 10% of turtle habitat in Canada is found in Provincial and Federal parks. Currently, recovery strategies are restoring and protecting habitat , specifically forested river habitats through land acquisition, stewardship, restoration projects and in partnership with other organizations and the public. However, more needs to be done soon to stop development projects, especially along shorelines.

How can you help?

Landowners should not alter their shorelines, forests, or rivers on their property.
Report sightings of Wood Turtles to appropriate agencies like The Land Between and iNaturalist, but do not share locations or pictures on social media. This can attract poachers to the area which can endanger local Wood Turtle and other turtle populations.
Drive slowly and cautiously, especially during nesting season (late May to early July). Move any turtles you see across the road in the direction they are travelling.
Protect a nest on your property with a nest cage.
Support organizations dedicated to helping turtles.
Call us at 705-457-1222 if you see a turtle nesting or in need of help!

Quick Facts:

A cool foraging strategy Wood Turtles have is called “worm stomping”, where they stomp their forefeet and plastron on the ground in order to attract earthworms up to the surface or to flush them out of the leaf litter
They display “anting behavior”, which means they will allow ants to remove organisms on their body, and they will also remain still in water when being cleaned by the small minnow species
For first 25 years they can be aged using growth ridges on their carapace (top shell)

Additional Resources:

Fact sheet on Wood Turtles by the State of Connecticut Department of Environmental Protection
Fact sheet on Wood turtles by the Massachusetts Division of Fisheries and Wildlife
Pamphlet on facilitating recovery of Wood Turtles in Nova Scotia
Ontario Nature page on the Wood Turtle
COSEWIC 2018 Assessment and Report on the Wood Turtle

Sources:

Kaufmann, J.H., 1986. Stomping for earthworms by wood turtles, Clemmys insculpta: a newly discovered foraging technique. Copeia, 1986(4), pp.1001-1004.

McCurdy, D.G. and Herman, T.B., 1997. Putative Anting Behavior in Wood Turtles. Herpetological Review, 28(3), pp.127-127.

Kaufmann, J.H. 1991. Clemmys insculpta (Wood Turtle) cleaning symbiosis. Herpetological Review 22(3):98

Kaufmann, 1992. The social behaviour of wood turtles Clemmys insculpta in central Pennsylvania. Herpetol Monog.

Galbraith DA 1991. Studies of mating systems in wood turtles Clemmys inscuplta and snapping turtles Chelydra serpentina using DNA fingerprinting. Phd thesis. Queens University.

Thompson, D.G., T. Swystun, J. Cross, R.L. Cross, D. Chartrand, and C.B. Edge. 2018. Fine- and coarse-scale movements and habitat use by Wood Turtles (Glyptemys insculpta) based on probabilistic modeling of radio- and GPS-telemetry data. Canadian Journal of Zoology

SARA. 2016. Wood turtle (Glyptemys insculpta): proposed recovery strategy 2016. Species at Risk Act. Retrieved from https://www.canada.ca/en/environment-climate-change/services/species-risk-public-registry/recovery-strategies/wood-turtle-proposed-2016.html

COSEWIC. 2018. Wood Turtle (Glyptemys insculpta): COSEWIC assessment and status report 2018. Committee On the Status of Endangered Wildlife In Canada. Retrieved from https://www.canada.ca/en/environment-climate-change/services/species-risk-public-registry/cosewic-assessments-status-reports/wood-turtle-2018.html