The Plight of the Red-Eared Slider: Invasive or Not?

Red-Eared Sliders (RES), scientific name Trachemys Scripta Elegans, are an aquatic turtle species sold as companion animals in Washington State. They are small turtles native to the Mississippi River basin and commonly sold in pet stores. RES have a life span of 20 - 30 years and can reach 13 inches in length.

RES are the most frequently surrendered and abandoned pet turtles in the United States, due to their large adult size, quick rate of growth, and inexpensive sale price. They're also one of the hardest turtles to place for the same reasons. RES are not native so various park systems cannot include them in displays while reptile sanctuaries across the United States are so overwhelmed with this species that they have to turn away surrenders.

When RES are surrendered to a non-sanctuary shelter, they are often in danger of immediate euthanasia. They require a great deal of staff care, shelter space, equipment and other resources, making it difficult for shelters to keep them available for adoption long-term. Moreover, when they are adopted, new owners often do not understand the full demands of care and the animals may be illegally released into the wild where they compete with native species.

Some Washington State shelters have claimed the animal must be euthanized simply because it is deemed an “invasive species” by the State of Washington.

SAW researched this latter claim and it appears to be more complex than at first glance. RES are not native, but they are also not an invasive species. They are “regulated” and, therefore, allowed in Washington State. However, should a regulated species even be allowed for sale as a companion animal when it is so often misunderstood and abandoned? Where is the logic in this?

Here is a Q&A to help clarify the issue.

What is an invasive species?

Invasive species are broadly defined as species not indigenous to a particular area. They can cause great harm to local species and affect entire ecosystems.

Who determines an invasive species?

The authority for managing animal, plant and forest invasives lies with a division of Washington Department of Fish and Wildlife (WDFW). It is the Washington Invasive Species Council (WISC) and it is a policy-making board that coordinates reporting and action plans with other agencies. It also provides resources for citizens designed to educate us about invasives.

How does Washington regulate invasive species?

Once an invasive species is identified by a citizen and reported to the WISC, the Board refers the information to the appropriate agency. Plant invasives are defined as noxious weeds and are managed by the state’s Department of Agriculture Noxious Weed Control Board, forest invasives are referred to the Department of Natural Resources, and animal invasives are reported to and controlled by WDFW. Animals listed as invasive include the European Green Crab and insects such as the Northern Giant Hornet. Wildlife diseases such as the amphibian ranavirus family fall under the authority of WDFW as well.

What are the categories of invasive species?

Animals listed as invasive species fall into priority species, meaning that the animals have arrived or are an imminent threat, or prohibited and regulated species. Priority species must be eradicated - they must be reported and cannot be possessed. Regulated species are considered a moderate but manageable risk for becoming invasive. Managing animals that are or have the potential to be invasive is tricky, as WDFW depends on voluntary reports from informed residents that have seen and identified the creatures. Thus, the state agencies charged with controlling the pathways to invasion depend on an informed citizenry that will fill out a report after accurately identifying a crab, moth or beetle.

How does all this apply to RES?

Red-Eared Sliders are an example of a regulated species. They compete with our native Western Pond turtles (Enys marmorata) for food, nesting sites and basking space, and carry parasites and diseases that affect pond turtles. Washington does not prohibit the sale or possession of RES as it has not been designated an invasive species, but it has been designated as a regulated species under RCW 77.135.030 and Washington Administrative Code 220-640-060. This classification is used for “nonnative aquatic animal species that pose a low to moderate invasive risk that can be managed based on intended use or geographic scope of introduction, have a beneficial use, and are a priority for department-led or department-approved management of the species' beneficial use and invasive risks.”

The plight of the Red-Eared Slider is an example of the intersection between environmental protection and animal welfare. The issue deserves a broader discussion by environmental advocates, wildlife managers and animal welfare professionals for a more humane and responsible approach. Otherwise, shelter systems and sanctuaries will continue to either euthanize or deny intake, leaving overwhelmed owners to simply release these animals into the wild where they compete with native species. None of these solutions are humane or healthy for the animal or our local ecosystems.

Visit MATTS Turtles site for more information about what to do if you feel you cannot keep your RES.

See the Red-Eared Sliders page in the Global Invasive Species Database for an international perspective on the reptile. North America Invasive is a comprehensive page with all plants, animals, insects and pathogens that are currently identified as invasive.

Author’s comments: both WDFW and WISC could do a better job on clarification of the status of the invaders, the classifications they fall under and the overall interplay between the agencies. For example, RES are “regulated”, but there are three “regulated” classes - A, B and C. WISC does not clarify which animal has which classification. Citizen researchers and scientists would find this topic extremely confusing, which will not help citizens that want to assist with efforts to control invasives.