Turtles - ZS

Turtles are ectothermic animals that control their body temperature by moving into or out of warm or cool places. Many marine turtles can only survive in warmer waters, however their activities help to regulate their body temperature.

Behavioural Adaptations

 * Aquatic turtles often leave the water in lower temperatures, in order to expose themselves to the sun on logs, rocks or along the banks of lakes to warm their bodies.
 * In winter, some turtles that live in seasonal climates enter a dormant state similar to hibernation so that they can preserve the energy that they need for body temperature regulation; in this state (known as torpor), the turtle stops feeding and its oxygen requirement is very low.
 * Aquatic turtles usually stay underwater during this time in winter and obtain the oxygen they need from water through their skin, throat linings and sacks within the cloaca.
 * On the other hand, land-living turtles burrow into the soil or find a sheltered area where their environment helps to regulate their body temperature.
 * Eastern box turtles may spend the winter in shallow burrows; these turtles have adapted to be able to survive partial freezing of their body fluids for several days.
 * Young painted turtles usually spend their first winter in an underground nest and they are able to survive sub-freezing temperatures for several days.

Leatherback Sea Turtles
The leatherback turtle is an interesting case as it is strangely well adapted to its cold environment unlike other turtles: These behaviours mean that the leatherback turtle can survive in a wider range of temperatures and maintain a fairly constant core body temperature.
 * it has a low surface area to volume ratio and a high core body temperature which changes at a slower rate.
 * in cold water they have adapted by increasing their flipper stroke frequency - more heat is produced which raises the body temperature.
 * the blood flow to extremities in the body is also decreased; instead the heat is retained in the core by the blood vessels.
 * they also have a layer of brown adipose tissue which is an insulating fat layer, decreasing heat loss.
 * in high temperatures, the turtle decreases the frequency of flipper strokes and blood flows to extremities rather than being transferred to the core.