Snakes don't have cold blood. It's more correct to say that they can't regulate their body temperature by generating their own body heat (ectothermic). Snakes achieve the desired body temperature by basking in the sun--after which a snake can be as warm as a mammal!--and cooling off in the shade or underground. A snake has specialised nerve endings all over its body to detect small changes in temperature. Most snakes do best at 25-32 degrees C, but many thrive in cooler climates with long cold winters.
Advantages of being ectothermic: Don't need to eat constantly. A snake has a low metabolic rate because it doesn't have to constantly burn fuel to maintain body temperature. A "warm-blooded" animal must eat 10 times more. This is even though they have fur and feathers to prevent heat loss. A snake can pig out when food is plentifulAnd can shut down its body during food-scarce periods living off stored fat for 6 months to 1 year. Some large snakes can go 2 years between meals, but young snakes need to eat more regularly. This allows them to survive in habitats with low or irregular food supplies where "warm-blooded" animals would starve. See how do snakes swallow for more on how snakes have an even greater advantage because they can eat a huge meal in one sitting.
Being "cold-blooded" also means that snakes can be long and narrow, a shape which leads to greater loss of body heat because the surface area is much larger than the volume of their body. See why snakes are long for more on why this is a good thing.
Disadvantage of being ectothermic: They can't keep up active movements for long as they don't generate internal energy. This affects many aspects of snake behaviour. Many snake predators take advantage of this to get the better of snakes.
More about snakes
- What are snakes?
- Are snakes cold?
- Why are snakes long?
- What do snakes eat? Do they drink?
- How do snakes swallow?
- How do snakes hunt?
- Why and how do snakes kill?
Snake predators and how do snakes protect themselves?
Snake mating, eggs and babies
Where are snakes found?
Fascinating snake adaptations to various habitats
Snake bites and first aid
Snakes in danger: role and conservation and snakes in human culture
Snake records: biggest, smallest, deadliest and more
- More snakes
- More animals
- General snake links and references
Further informations in german can be found here!