Ministry of Environment
|Scientific Name:||Trachemys scripta|
*Exotic species are species that
have been introduced into areas where
they do not naturally occur.
The Slider is not a native species in British Columbia. Its natural range includes the southeastern United States south through Mexico, Central America and Brazil. Due to the thoughtless release by pet-owners into ponds and streams far from home, this turtle is now found as far afield as Australia, California, France, Sweden, South Africa and Canada. The number of Sliders in B.C. waters is unknown. Understanding the distribution of this species is essential, as its spread could have harmful effects on B.C. wetland communities.
The Slider is a medium-sized turtle with a smooth carapace (top shell) ranging from black to olive green. Dark lines, streaks and smudges mark the shell, sometimes with patches of white, yellow or red. The plastron (underside) is yellow, and can be marked with dark blotches. Yellow stripes decorate the head, neck and limbs. A red patch (sometimes yellow) just behind the eye is a key identifying feature of this turtle. Males are smaller than females, who reach a plastron length of up to 28 centimetres. Males also have fantastically long, curved claws, important during courtship.
Baby turtles (hatchlings) are about the size of a one-dollar coin (2 to 3.5 cm long), bright green and round. Yellow markings pattern the carapace and the skin is finely lined with yellow-green to dark green markings. The plastron is yellow with black smudges.
Sliders rarely venture out of water except to lay their eggs. These shy turtles prefer quiet, freshwater systems such as sluggish rivers, shallow streams, swamps, ponds and lakes with muddy bottoms and abundant aquatic vegetation. Partially submerged logs or rocks are important for basking (sunbathing!).
When ponds and streams warm up in the spring, male Sliders spend most of their time chasing females. Males reach sexual maturity after two to five years. At this time a male tries to win over a mate with fancy courtship displays, including swimming backwards in front of the female with forelegs stretched out, palm-side out, waving his long claws. If the female accepts the male, the pair sinks to the bottom of the pond, where breeding occurs.
Within their natural range, female Sliders first nest when they are five to seven years old. Extremely picky about where they lay their eggs, females prefer a spot not far from water with little vegetation and damp soil. Eggs are laid in June or July. After digging a nest with her powerful hind feet, the female lays from 4 to 23 oval eggs with white, flexible shells. Dirt is piled back over the eggs and when she is finished the nest looks like a mud-ball thrown against the ground.
Eggs incubate for 60 to 70 days, growing larger and more rigid as they absorb water from the soil. Hatchlings leave for the pond soon after hatching or may overwinter in the nest and come out the following year. A single female may lay more than one clutch (nest of eggs) in a single year. Sliders are long-lived, typically living from 20 to 40 years.
The number and varied sizes of Sliders seen in B.C.’s ponds suggests that this species may be reproducing successfully in the province.
Young Sliders need up to 40 percent protein in their diet, and are mostly carnivorous. Their habit of eating the tiny fish, tadpoles, small frogs and invertebrates that native species depend on is a growing concern to biologists, who worry that Sliders will drain limited food resources in already shrinking wetlands. If allowed to spread, young Sliders could also harm native frog populations by feeding on tadpoles and froglets.
Adult Sliders prefer eating algae and aquatic plants, but will occasionally poke their noses in the reeds to flush out any animals that might be hiding – including snails, insects, crayfish, tadpoles, frogs and fish. Like most turtles, Sliders will also feed on dead and decaying matter.
Sliders are on the menu for many other animals. Crows, Mink, River Otters, Skunks, Raccoons, fish, frogs, snakes, large turtles, and wading birds can all make a meal of turtle adults, eggs or young.
Sliders are ‘early risers,’ hunting at depths of one to three metres in the early morning hours. On sunny afternoons, these turtles bask on rocks and logs – often stacked one on top of the other competing for the warmth of the sun. At the slightest disturbance, this cautious turtle will quickly slide off its basking spot and plop into the water to hide (hence the name!) During winter, adult Sliders burrow into the mud at the bottom of ponds or hole up in muskrat burrows or hollow stumps near the waterline to hibernate until spring.
It is the classic case of ‘too many cooks spoil the broth!’ Every habitat has its own healthy balance of plants and animals that rely on each other for food. Throw in an alien species, and the balance is lost. While Sliders are fantastic and valuable creatures within their natural habitat, they are not native to B.C. Introduced to food webs where their natural predators may be absent, Slider populations may grow out of control, outcompete native species, and negatively affect wetland communities. As a result, they could harm native frog populations, one of the favourite snacks of young Sliders (remember the 40 percent protein requirement?)
If you have a pet Slider, you can help by not releasing it (or any other aquatic pets!) into a local pond or wetland. Turtles are not trash! Dumping turtles or other unwanted pets can negatively affect native flora and fauna.
Keep an eye out for this species in your local wetland and report sightings of Sliders to B.C. Frogwatch. Reporting Slider sightings will help biologists keep track of the spread of this species in B.C.
- Sliders have a fascinating kind of feeding system called neustophagia, which is similar to the feeding style of the baleen whale. Skimming the pond surface with lower jaw hanging open, a Slider catches floating food particles and stores it in its pharynx. The turtle then closes its mouth, expelling water through its nostrils and swallowing the remaining food…
- In addition to helping Sliders make Vitamin D from the sun and dry out the algae growing on their shells, basking in the sun helps turtles digest their morning meals! Higher body temperature increases enzyme activity and stomach acid production, breaking down food much faster than a ‘cold’ stomach.
- While hunting for food, Sliders can stay underwater up to six minutes without coming up for air.
Photo © Wally Edwards. No reproduction or distribution without permission.