Unlike warm blooded mammals, reptiles are often referred to as being cold blooded creatures. This is not strictly true since they would not exist if their body temperatures were not maintained within certain limits.

The main difference is that, reptiles, since they have no mechanism for generating or maintaining their own internal body heat rely totally on external sources of heat from the environment. This is referred to as being ectothermic, and thus the term cold blooded has been coined.

Paradoxically, different to mammals, the reptile will increase its activities in warmer environments, and slow down in cooler places. But to experience environmental temperatures greater than 36º C, and less than 4º C can prove fatal for the reptile.

Reptiles do not possess any hair or feathers so suffer heat loss through their skins, but equally are adapted to absorbing environmental heat through their skin, either by radiation from the sun, or direct transfer from sandy surfaces and warm rocks.

Dark objects absorb heat more readily than lighter colored objects, and is probably the reason that reptiles located in cooler environments have evolved darker skin colors. Indeed it has been noticed that some species of reptile become even a darker color when pregnant, to gain extra energy from the additional heat being absorbed.

Many reptiles become totally dormant during prolonged spells of coldness. They literally switch off, and all metabolic activity stops, some species can still remain alive when being frozen.

This can only be due to the fact that their bodies contain some kind of anti-freeze like glycerol which prevents the inner body tissue from freezing. Despite this property many reptiles do die if frozen.

Tagged with: • • • • • • •

Filed under: Arts And Culture

Like this post? Subscribe to my RSS feed and get loads more!