Background

In the early 1900s, red-eared sliders (RES) were captured, farmed, and sold in dime stores as their small size and cheap price was attractive to prospective pet owners. By the 1950’s, millions were being shipped and sold to many parts of the world.

In the later half of the 20th century, with the rise of the popularity of the show Teenage Mutant Ninja Turtles, which were identified as RES they once again became a popular addition to home aquariums. However, with a life expectancy of on average 30 years, and the potential to live to 100 years old in the wild – once they outgrow their owners interest, many are released into the wild as owners view it as the humane option. They are now widespread throughout Long Island and the east coast of the United States. 

Origin

RES are largely native to the Midwestern United States, with their range reaching as far east as West Virginia and southern Ohio, and as far west as eastern New Mexico, and their southernmost range extending south of the Rio Grande River, just into northeastern Mexico.

Habitat & Ecology

They prefer quiet freshwaters such as slow moving or still backwaters of rivers and ponds, often with soft bottoms and dense vegetation. However, they will tolerate nearly any water type from brackish waters, to man made canals, irrigation ditches and park ponds. They are also able to wander and relocate long distances from one body of water to another and rapidly colonize it.

Adults are slightly more herbivorous than juveniles, however both will opportunistically consume aquatic invertebrates such as insects and mollusks. They also eat fish and frog eggs, tadpoles, aquatic snakes as well as a wide variety of aquatic plants and algae. 

Introduction and Spread

Owners release their unwanted pet turtles into nearby waterways. These turtles are highly adaptable as they are able to hibernate.

Ecological Impacts

Red-eared sliders reach sexual maturity at a young age, and are able to reproduce in large numbers. Females are able to lay 2-23 eggs per clutch, with as many as five clutches being laid per year. RES can lay their eggs one month before native turtles do, and tip off predators to ideal nesting locations that native turtles may use as well. They outcompete our native turtles for food and resources as they are notoriously aggressive, bullying the native turtles out of basking sites. Because turtles are cold-blooded, basking helps them to regulate their internal body temperature. As they bask, they absorb warmth and vital UV rays to their shells, and from their shells to their bodies. Lost basking access can reduce our native turtles growth and lead to an increase in mortality.

Captive raised RES may also transmit diseases and parasites that are unfamiliar to native turtle species 

Health Concerns

Red-eared sliders have been associated with Salmonellosis caused by the bacteria Salmonella as all reptiles carry it on their shells and skin and it can be encouraged through stressful captive environments.  It is most easily contracted by young children, the elderly and those with compromised immune systems. Symptoms include nausea, vomiting, abdominal cramps, diarrhea and headache, and often start 12-36 hours after exposure. Symptoms usually last 2-7 days, but may last on surfaces for weeks. 

Identification

An aquatic turtle with a brown, relatively flat, oval-shaped shell and a weakly keeled or smooth carapace. Rear marginals have slightly serrated edges. The plastron is bright yellow with a single grey-brown smudge on each scute, which  may stain to a more brown-orange color.  Younger individuals often have many dark eyelike spots on their yellow plastron. Their legs are green-grey with yellow to white colored lines.

Males are smaller than females in body size but have longer tails, which are used in mating as they “wiggle” their nails at and around a female’s head.

The red-orange stripe behind the eye for which they are named for is a key identification feature

Prevention & Control

Since 1975, it is illegal in the US to sell turtles less than 4” from the end of the neck, to the carapace to the end of the tail. However, RES are still widely sold and when they are no longer wanted they are often illegally released.

Management of this species would involve trapping and euthanizing turtles as well as collecting and destroying eggs. However, due to their wide spread, they are a low priority for management unless found within a high priority ecosystem such as a natural heritage site, or Invasive Species Prevention Zone (ISPZ).

Resources for Unwanted Pets:

Due to the large number of unwanted red-eared sliders, many adoption centers and refuges may not accept these turtles. First, reconsider letting go of your red-eared slider, see https://forgottenfriend.org/sliders/ for solutions to common issues owners have. If you have a turtle or other exotic animal that you can no longer care for, reach out to friends and family to see if they’d be willing to adopt them, or consider donating them to a school, nature center, or returning them to the retailer you purchased them from. Lastly, consider humane euthanasia done by a veterinarian. Red eared sliders are considered a regulated invasive animal, meaning it is illegal to introduce them into a free-living state, and doing so could incur fines of up to $1,000.