Red-Eared Sliders

Breeding

Red-eared sliders reach sexual maturity at 2-5 years of age, however young males may practice courtship before they fully mature. The courtship display is relatively simple with a male swimming backwards while facing the female with front legs outstretched towards her. Females will produce and lay eggs even in the absence of males. Females can lay up to 20 eggs per clutch and between 1-4 clutches per season. Like many reptiles RES do not incubate their eggs themselves, instead choosing to lay their eggs in warm sandy areas where the heat of the environment incubates the eggs. Captive RES are also provided with the opportunity to lay eggs. If a suitable location is not provided the females may retain the eggs causing them to become egg bound leading to a range of serious diseases. Nesting areas are made primarily of sand with a small proportion of soil and organic matter.

RES are considered one of the 100 most invasive species in the world and have devastated ecosystems in India and Australia. They have been classified as a pest in a Northland, Auckland and the Bay of Plenty where they have been found to reproduce in the wild. Populations have not yet established in Hawke’s Bay as it is considered to be too cold for the eggs to successfully incubate, however this may change with climate change increasing summer temperatures.

Typical Behaviour

Red-eared sliders are ectothermic meaning they do not regulate their temperature through internal processes but instead exchange heat with the surrounding environment. To increase their body temperature and associated metabolic processes RES spend a large portion of their day basking in the sun. Another benefit is the absorption of UV rays essential for the production of vitamin D3. Sufficient basking areas should be provided for all RES and if the turtles are seen to be stacking on top of one another more should be provided. Large flat stones are considered the best basking platform as they absorb the suns heat and can warm the RES from below, however partially submerged logs can be used to provide the RES a variety of options.

During periods of prolonged cold RES undergo brumation a process similar to mammalian hibernation. Brumation usually begins when temperatures fall below 10°C and is characterised by periods of inactivity. Whilst brumating turtles remain almost motionless at the bottom of ponds and forgo feeding or defecating. During brumation RES only rise to the surface to breath and may go days between breaths. They are able to survive between breaths by generating energy via glycolysis rather than cellular respiration. The lactic acid produce as a by-product of glycolysis is offset using the calcium in their bodies, to ensure RES do not become deficient in calcium a supplement or extra provision of cuttlefish should be provided in autumn.

Fun Facts

• The popular crime fighting comic-book heroes the teenage mutant ninja turtles are red eared slider turtles.
• The sex of red-eared sliders is determined by the temperature at which the eggs are incubated. Males develop when incubated at cooler temperatures (27°C) while females develop at warmer temperatures (30°C).