Red-eared Slider

The red-eared slider (Trachemys scripta elegans) is a terrapin with an oval, flattened shell that is usually dark green with variable light and dark markings. Hatchlings are leaf green, and the shell darkens to olive or brownish green with age. The head, legs and tail are green with fine, irregular yellow lines, and the plastron is light yellow with dark markings.

The red stripe behind each eye gives the Red-eared Slider its name. Adults usually measure 15 to 20 cm, though a shell can pass 40 cm. Females are generally larger than males.

Red-eared Sliders are almost entirely aquatic, with partially webbed feet for swimming. They are the most commonly traded reptile in the world, partly because of their low price, small size and easy upkeep.

Red-eared Sliders come from the area around the Mississippi River and the Gulf of Mexico, in the warm south-east of the United States and extreme northern Mexico. Their native range runs from south-east Colorado to Virginia and Florida. They are one of three subspecies of the pond slider, alongside the yellow-bellied slider and the Cumberland slider.

They were once known as Troost's turtle, after the herpetologist Gerard Troost, and were also classified under the name Chrysemys scripta elegans.

Their popularity as pets has carried them across the world. In the United Kingdom, the Teenage Mutant Ninja Turtles comics and the first live-action film sparked a craze for keeping them. Many were then released or escaped into the wild, and feral populations now live across England, Scotland and Wales. They are found on every continent except Antarctica and are on the list of the world's 100 most invasive species.

Red-eared Sliders leave the water to bask in the sun, because they are cold-blooded and rely on the temperature around them. In the wild they often bask in groups, sometimes on top of one another, and they slide quickly off rocks and logs into the water, which is another source of their name.

They do not truly hibernate. In cold weather they brumate: they become much less active, stop eating and barely move, though they may rise for air or food. Wild Red-eared Sliders usually become inactive in October when temperatures fall below 10 C, and come up to feed between early March and the end of April.

Courtship takes place underwater. The male swims around the female and flutters his long front claws against her face. A male may sometimes court another male, which can be a sign of dominance. Kept males may also court other household pets.

Their diet changes with age. Juveniles are carnivorous, while adults are omnivores that rely mostly on aquatic plants.

Red-eared Sliders typically live 20 to 30 years, and some live beyond 40. They tend to live longer in captivity, and the quality of their surroundings strongly affects their lifespan and wellbeing. Those that survive the first year or two can generally expect around 30 years.

Like other reptiles, they can carry Salmonella bacteria without showing any signs of illness themselves. Handling chelonians has caused many human infections, and in the US this led to a 1975 ban on selling eggs and chelonians with a shell under 10 cm for general use.

Wild Red-eared Sliders can also transmit diseases and parasites to native turtles. Brightly red ear stripes are linked to a stronger immune response than yellow ones.

This is general awareness only, not veterinary advice. Always consult a vet about your pet's health.

How long do red-eared sliders live?

Most live between 20 and 30 years, and some pass 40. Captive animals tend to live longer than wild ones.

How big do red-eared sliders get?

The typical shell length is 15 to 20 cm, but some grow beyond 40 cm. Females are usually bigger than males.

Do red-eared sliders carry Salmonella?

Yes, they can carry Salmonella without looking ill, and handling chelonians has caused many human infections. The risk of Salmonella exposure can be reduced by basic cleanliness.

Do red-eared sliders hibernate?

Not exactly. They brumate, becoming much less active and not eating, though they occasionally rise for air or food. In the wild this happens over winter at the bottom of ponds.

Why are they called red-eared sliders?

The name comes from the red stripe behind each eye, where the ears would be, and from how quickly they slide off rocks and logs into water.

Red-eared Sliders have no visible outer ear. They hear through a middle ear covered by a cartilaginous disc.

The sex of the young depends on incubation temperature. Only males develop at 22 to 27 C, and warmer temperatures produce females.

A female can lay 2 to 30 eggs at a time, and up to five clutches in one year.

A hatchling opens its egg with an egg tooth that falls out about an hour later and never grows back.

During brumation, their heart rate can drop by about 80%, and they can survive for weeks without oxygen.