The Wood Turtle (\(Glyptemys insculpta\)) is a semi-aquatic species found across the northeastern United States and southeastern Canada, primarily inhabiting riparian woodlands and clear, flowing streams. This reptile is a highly opportunistic omnivore, meaning its diet is diverse and changes with the seasons and local availability of food. During warmer months, they forage both on land and in the water, consuming a wide variety of animal and plant matter to meet their nutritional needs. This flexible approach to feeding allows them to thrive in habitats ranging from riverbanks to adjacent fields and forests.
The Primary Diet: Invertebrate and Animal Matter
The majority of the Wood Turtle’s diet, especially for younger individuals, consists of high-protein animal matter. Earthworms are a particularly important staple, often comprising a significant portion of their food intake when available. These turtles also readily consume a variety of terrestrial and aquatic invertebrates, which are easily captured within their riparian habitats.
Slugs and snails are frequently eaten. Other common prey items include various insects and their larvae, such as beetles, millipedes, and caterpillars, along with leeches and crayfish. The Wood Turtle is not strictly limited to invertebrates and will occasionally prey on small vertebrates like tadpoles, frogs, and newborn mice. They also scavenge, consuming carrion such as dead fish and bird remains when they encounter them.
Essential Plant Foods and Fungi
While protein is a major component, the Wood Turtle supplements its diet with a broad array of plant-based foods. Soft fruits and berries provide a valuable source of energy, becoming especially important later in the summer and into the fall. Wild strawberries, raspberries, blackberries, and blueberries are highly sought after, with turtles sometimes leaving their usual areas to find patches of ripe fruit.
Beyond fruits, they will consume various leaves, grasses, and even algae, showing a preference for certain flowering plants like dandelions and violets. Fungi are also a significant seasonal food source in some populations. Specific fungi species, including certain Amanita and Leccinum, are known to be consumed when they emerge in the damper, forested parts of their range.
Unique Foraging Methods and Seasonal Opportunism
The Wood Turtle employs an unusual and effective foraging strategy to acquire its preferred prey. This behavior, often called the “turtle dance” or “foot-stomping,” involves the turtle rapidly and alternately striking the ground with its front feet or the front of its shell. This action creates ground vibrations that earthworms mistake for the sound of rain or an approaching predator like a mole, causing them to rise to the surface where the turtle can easily seize them.
Seasonal Shifts in Diet
This species is a true opportunist, with its diet shifting significantly based on the time of year and localized resource booms. In the late spring and early summer, they focus heavily on protein, capitalizing on the abundance of invertebrates like earthworms after spring rains. As the season progresses into late summer and fall, they often move into upland areas to exploit the seasonal availability of fruits and fungi. This flexibility allows the Wood Turtle to utilize the full scope of its environment, from the aquatic stream bed to the adjacent forest floor.