By Kurt A. Buhlmann
Click image to enlarge
Red-eared sliders are considered semiaquatic turtles. Their captive habitats should include land and water areas. |
There are numerous freshwater turtle species in the United States, but probably none are as well recognized as the red-eared slider turtle.
Trachemys scripta elegans is familiar to people who grew up boating and fishing in the southeastern states, but urbanites and suburbanites in other regions who saw hatchlings in large numbers in pet stores in the 1960s and 1970s are also aware of it. Ask people on the street what a slider turtle is, and they may give you a blank look, but if you describe it as a small green turtle with a red stripe on the head, then most — if they are 30 years old or older — will certainly recall an image of a red-eared slider turtle from their childhood.
Considered a semiaquatic turtle, the red-eared slider turtle is a member of the family Emydidae. The red-eared slider turtle is one of three subspecies of Trachemys scripta. The other two are the yellow-bellied slider (T. s. scripta) of Georgia, the Carolinas and Virginia; and the Cumberland slider (T. s. troostii) of the Tennessee River drainages. The native range of the red-eared slider turtle includes the drainages of the Mississippi extending from Louisiana northward to southern Michigan, and extending westward through Texas, Oklahoma and Kansas.
There is substantial variability in slider turtle morphology and coloration among the subspecies that make up Trachemys scripta. The red-eared slider turtle is arguably the most handsome of the three with its characteristic broad red stripe that extends from the back of the eye and onto the neck. Black smudges on all plastral scutes also make the red-eared slider turtle distinctive from other subspecies. Of course, the three subspecies intergrade over a large area, particularly through southern Mississippi and Alabama.
The Generalist
If we were to look for a turtle species that can surmount most odds, survive in harsh places, colonize distant lands, survive rough treatment and still come out swinging, it would undoubtedly be the red-eared slider turtle. This turtle is tough. If the rest of the world’s turtles had nearly this much resilience to degraded environmental conditions, as well as the red-eared slider’s adaptability to new and varied habitats, the collective biodiversity of turtles would not be in such grave danger of extinction.
The red-eared slider turtle can adapt because it is a classic habitat generalist. In its broad native range, it demonstrates a tolerance for a wide range of temperature conditions. The red-eared slider turtle may be active year round in the steamy bayous of Louisiana, but it may be buried under ice and snow during in Illinois winter.
The red-eared slider turtle may be found in most types of freshwater habitats including the slower-moving sections of large rivers and the adjacent flood-plain swamps. Red-eared sliders are usually not found in the fastest sections of rivers, but when those stretches are dammed and reservoirs are created, it is the red-eared slider turtles that increase in number while other turtles, such as cooters, decline in abundance.
Slider turtles are able to traverse long distances over land, and they are frequent colonizers of farm ponds and natural seasonal wetlands. Studies on the Savannah River Site in South Carolina with yellow-bellied sliders have found them able to travel repeatedly between seasonal wetlands three miles distant from each other. They seem to know when to arrive at wetlands after spring rains have filled them with water and tadpoles. Likewise, they know to leave and head overland to a permanent wet flood-plain swamp when the seasonal ponds dry. Hence sliders are able to colonize new habitats, and this may help explain their large range relative to many other turtle species.
Besides being a habitat generalist, the red-eared slider turtle is also a dietary generalist. Hatchling red-eared sliders are primarily carnivorous, and like most hatchling turtles, they grow fastest on a protein diet obtained by eating tadpoles, aquatic insects, crustaceans and snails. Larger red-eared slider turtles scavenge dead fish, crayfish and frogs. Probably underappreciated is the role that slider turtles play in consuming aquatic vegetation. Elodea, eelgrass, pondweed and various algae are frequently consumed. Red-eared slider turtles do not hunt and kill game fish as many folks erroneously believe.
Click image to enlarge
A slider basks on a platform provided for turtles in a Southern pond. |
A red-eared slider basks on an anchored log in a 300-gallon Rubbermaid tub. Basking sites must allow turtles to completely dry off. |
A male red-eared slider basks on a log in an outdoor turtle tank. Basking sites with rough surfaces, such as concrete, may cause harmful shell abrasions. |
Metal-mesh lids can be cut and welded to fit any outdoor turtle tank. Lids prevent raccoons from reaching pet turtles and causing heartbreak. |
Red-eared sliders (Trachemys scripta elegans) and yellow-bellied sliders (Trachemys scripta scripta) intergrade over a large part of Mississippi and Alabama. This slider shows characteristics of both subspecies. |
This tough turtle is a habitat generalist. It can adapt to a wide range of temperatures. |
Indoor SlidersOne way to keep red-eared slider turtles in captivity is with an indoor enclosure. Red-eared sliders kept indoors require appropriate lighting, basking sites, warmth, clean water and a balanced diet.
Hatchling red-eared slider turtles can be maintained in a 20-gallon aquarium. This is the way most turtlekeepers begin their adventure. A hood with a wire-mesh lid keeps the pet cat out of the red-eared slider’s tank. Direct sunlight is the best light source, but it is not usually possible with indoor setups.
Full-spectrum ultraviolet (UVA and UVB) fluorescent lighting should be installed about 1½ feet above the red-eared slider turtle’s aquarium, and it should also be on a timer to mimic day-night cycles. In general, turtle basking lights can be on during the day, and the turtles can sleep when the people do. If you set a timer, then a cycle with lights on for 12 hours and lights off for 12 hours is fine. The basking lamp, such as an incandescent bulb usually less than 75 watts, needs to be suspended over a basking site. All lights should be suspended above a wire-mesh hood to prevent a fixture from accidentally falling into the water below. Full Lighting Information>>
A submersible heater with a thermostat and an unbreakable thermometer to monitor water temperature is also required for red-eared slider turtles. Whether the basking light is on or off, the water temperature should remain about 75 degrees Fahrenheit. When purchasing a heater, consider that 5 watts are required to heat each gallon of water.
An underwater filter will make for increased enjoyment of your red-eared slider turtle tank. A dump-and-fill-type system for keeping water clean is not recommended because this leads to poor quality conditions and burn out on the part of the keepers. A filter reduces the number of water changes and keeps the aquarium looking and smelling clean. However, you still need to change the water in your turtle tank on a regular basis, so consider convenient access to a large sink, toilet or the outdoors before selecting the red-eared slider turtle’s tank’s location in the house.
Adult red-eared slider turtles can be large and rambunctious, so they require more space than hatchlings. Male red-eared sliders can measure up to 7 inches in carapace length, and female red-eared sliders can reach up to 10 inches in carapace length. Therefore, the 20-gallon tank eventually needs to be upgraded. It has been recommended that one adult female red-eared slider turtle requires a 125-gallon tank to provide adequate room, whereas a 75-gallon tank can house a single male red-eared slider turtle. Using plastic Rubbermaid tubs is a cheaper method of housing red-eared slider turtles. Although the red-eared slider turtles cannot be viewed from the sides, moving and cleaning plastic tubs is easier than moving breakable aquaria. Which containers are appropriate for turtles depends on the number of turtles and their size. In general, it is a good idea to keep turtles of similar size together. Do not put hatchlings in aquaria with adults because they can be injured by the size of the larger turtles and occasionally may be nipped.
Red-eared slider turtles are good swimmers. They can be kept in deep water, but it is critical that easily accessible basking and resting sites are provided. Some keepers opt to keep red-eared slider turtles in shallow water where they can rest on the bottom yet reach their heads to the surface without swimming. Either way is acceptable. The choice may depend on the type of display the owner wishes to have.
One of the most important aspects of successful red-eared slider turtle husbandry is maintaining appropriate temperatures. Red-eared slider turtles require a range of temperatures from which they can select. In general, water temperatures for juvenile red-eared slider turtles and adult red-eared slider turtles should be kept in the range of 72 to 76 degrees Fahrenheit. Hatchling red-eared slider turtles may do better at slightly higher temperatures, but temperatures should not exceed 80 degrees. A submersible aquarium heater can easily boost water temperature, but take care while selecting one because turtles can break heaters with glass tubes.
A basking site must be provided, so red-eared slider turtles can emerge from the water and completely dry off. Basking sites can be made from floating or semianchored logs. Ramps can be made from gravel to provide access to land areas in an aquarium with shallow water. However, keep in mind that gravel bottoms often have to be redone when a complete water change is performed. Use of plastic grating also allows red-eared slider turtles to completely dry their plastrons as the air circulates underneath and thus helps prevent shell rot. Wood logs tend to hold moisture and can contribute to shell rot problems. Aim a basking lamp at a dry section of the basking platform, and provide a spot temperature between 85 and 92 degrees. Red-eared slider turtles should always be able to move out of the direct beam of the basking lamp and select lower temperatures elsewhere in the enclosure.
Outdoor Sliders
Red-eared slider turtles are also easily kept outdoors in most regions of the United States. Outdoor ponds dug to a depth of 21⁄2 feet are perfect in the South because they usually can help keep the water temperature buffered against extreme temperatures. A larger and deeper pond, about 4 feet or so, is necessary if the pond will freeze over during winter. The pond cannot freeze to the bottom if turtles are to survive the winter. In general, hibernating red-eared slider turtles outdoors under captive conditions is best left to experts. Likewise, a large aboveground tank cannot be left in the direct sun in the South because the water can get too hot, such as above 85 degrees on a summer day. Provide some shade, perhaps with natural shrubs, for the tank.
Captive red-eared slider turtles active all-year round are best kept indoors when daytime temperatures are lower than 70 degrees, but red-eared sliders certainly benefit from being outdoors in natural sunlight during the summer. In general, if the outdoor temperatures are similar to the indoor temperatures recommended in this article, then by all means, allow the red-eared slider turtles time outdoors.
A cattle tank, such as a 300-gallon Rubbermaid tub, makes an adequate outdoor home for even the largest red-eared slider turtles. When half-filled with water, it can hold two female red-eared sliders and two male red-eared slider turtles comfortably. Depending on owner preference, these tanks can be fitted with drain valves and standpipes that allow water to be maintained at a certain level.
Of course, basking sites, such as anchored logs or concrete blocks, can also be used. Do not use cinder blocks with large holes because red-eared slider turtles can get lodged inside them and drown. Also, the rough surface on some rocks and concrete materials may cause red-eared slider shell abrasions, and this factor should be carefully monitored. Shell abrasions can allow bacteria to enter and cause infections. An abrasion on a red-eared slider turtle shell is really no different than a cut to someone’s skin.
Red-eared slider turtles can also be kept outdoors in sunken, plastic-lined garden ponds. Appropriate fencing to keep red-eared slider turtles from wandering off can be constructed with aluminum flashing at least 2 feet tall, or hardware cloth of the same height but with the top bent over to form a lip, which prevents red-eared slider turtles from climbing out.
Outdoor red-eared slider turtle enclosures should be circular rather than square or rectangular because this tends to discourage red-eared slider turtles from climbing out at the corners. Raccoons and other predators might prey on red-eared slider turtles in cattle tanks or other outdoor, aboveground containers, so it is vital that wire-mesh lids be placed over outdoor red-eared slider turtle tanks to prevent catastrophes.
Varied Diet Best
Not finicky feeders, red-eared slider turtles eat a variety of meat and vegetables, but remember that red-eared sliders prefer a carnivorous diet if presented with both meats and vegetables at the same time.
Thus varying the two food groups between feedings is advisable. Aquatic plants, such as elodea, and leafy vegetables, such as romaine lettuce, can be left in the enclosure for casual grazing. Meat items, such as live crickets, earthworms and shrimp, should only be provided in small amounts, and remove uneaten food from the red-eared slider’s tank. Commercial turtle chow, such as Mazuri freshwater turtle chow or ReptoMin, which I use, provide most of the needed vitamins and nutrients, so use them in conjunction with natural foods.
Many turtlekeepers feed their red-eared slider turtles in separate plastic bins to minimize wastes discharged into the regular aquarium. Because red-eared sliders are not particularly sensitive to disturbance and adapt to their owners, this method usually works well.
It’s a Commitment
Red-eared slider turtles are one of the easiest and enjoyable turtles to keep in captivity. Perfect for budding herpetologists, red-eared sliders help develop an appreciation and fascination for turtles. However, that does not mean red-eared slider turtles do not require responsible care.
For many of us over age 40, a red-eared slider turtle was one of the first pets we had as children, and I can still recall my first hatchling red-eared slider in its little plastic bowl with a plastic palm tree in the center. Back in the day, millions of hatchling red-eared sliders were sold in pet stores, and most did not survive for very long. Our knowledge about captive husbandry was minimal, and recognition that red-eared slider turtle care was a long-term commitment was also sorely lacking.
Red-eared slider turtles are long-lived animals. With proper care red-eared sliders can live more than 40 years. That’s at least twice as long as a beloved dog or cat. Always consider this factor before taking on the responsibility of caring for a pet red-eared slider turtle.
If a turtlekeeper eventually faces circumstances in which caring for the red-eared slider turtle is no longer possible, an adoptive home should be found. Pet red-eared slider turtles should not be released into the wild. Although the red-eared slider can survive in unusual and out-of-range places, that does not mean that it should be released into those areas. Doing so could create serious negative consequences. For example, outside Albuquerque, N.M., red-eared sliders have been released into the Rio Grande. That river is the sole home to the Big Bend slider turtle (Trachemys gaigeae), and the long-term conservation concern is that T. gaigeae could become genetically swamped out of existence due to hybridization with red-eared sliders. Competition with native species also has been suggested as a possible concern. Some European herpetologists have suggested that red-eared sliders may have negative effects on native European pond turtles (Emys orbicularis) where the red-eared sliders have been released into ecosystems.
The red-eared slider turtle is one species that clearly deserves our respect for its adaptability, but it also needs to be carefully managed. For those of us who enjoy these colorful turtles, it is our responsibility to take care of them and their environments.
KURT A. BUHLMANN, a research scientist with the Savannah River Ecology Laboratory near Aiken, S.C., has an M.S. in wildlife sciences and a Ph.D. in ecology. He helped establish Asian-turtle assurance colonies with the Turtle Survival Alliance, and he has worked with Partners in Amphibian and Reptile Conservation. He has written a number of aquatic turtle articles for REPTILES magazine.