Reptiles are well known for many of their quirky traits, and they’re so different from most of the animals we learn about in school. Not only are all reptiles cold-blooded ectotherms, but their skin is covered in scales! Reptiles aren’t covered in anything like fur or feathers.
So, why don’t reptiles have fur?
The reason that reptiles don’t have fur is that they are cold-blooded. Cold-blooded animals rely on external factors like the sun to warm up, unlike mammals that produce heat internally and stay at a constant temperature. With fur, most reptiles would quickly overheat anytime they were in the sun!
In this article, we’ll discuss exactly why you won’t ever see a furry reptile. Then, we’ll talk more about fur and what other adaptations you might see on a reptile’s skin.
Why Don’t Reptiles Have Fur?
Reptiles are cold-blooded animals. Also referred to as ectotherms, the heat produced internally through metabolic processes is almost nonexistent. Ectotherms must use outside sources to change their body temperatures.
Because of the way their bodies function, reptiles have plenty of adaptations to make sure that they stay at the right temperature all day long. On sunny days, reptiles can often be found on a rock or basking in the sun. They’ll try to heat up and stay warm as much as they can. If it gets too hot, they’ll have to find shade or some cool water to lie in. At night, reptiles must take cover in a den or burrow on cold nights or risk freezing to death.
If reptiles had fur, it would be really difficult for them to cool down. The main purpose of fur for an animal is to provide insulation and trap heat or reflect sunlight. Reptiles don’t benefit from either of these things. If a reptile had fur it would overheat easily and wouldn’t be able to cool down well at all.
Do All Reptiles Have Scales?
All reptiles do have scales! Interestingly, scales are made of the same material that fur is made of, keratin.
Scales are just another adaptation that reptiles use for protection against the elements. Because reptiles need to move around and be exposed to stay warm, they also need tough skin!
Reptiles will shed their skin routinely to reveal a newer layer of scales. Even though scales are incredibly tough, they can also feel soft and smooth.
Why Do Animals Have Fur?
So, if reptiles don’t have fur, why did so many of the animals that we know and love today evolve to have fur?
Most of the animals that have fur are mammals. Mammals are warm-blooded animals that are also called endotherms. Endothermic animals produce heat internally through metabolic processes. And while some of their heat is still exchanged externally, much of it is created through biological processes within.
For endotherms, fur is a necessary trait for survival. Fur helps animals trap and retain heat that they would otherwise lose as soon as they left a warm area. It also helps them to stay cool in extremely hot temperatures. The extra insulation of fur basically just makes temperature fluctuations less extreme than they normally would be.
How Is Heat Exchanged Between Animals And Their Environments?
If you’re still wondering why some animals have scales, some have fur, and others have feathers, keep reading. There are four main ways that animals exchange heat with their environment. Obviously, reptiles utilize these strategies far more often than mammals do to survive.
Radiation is one of the ways that reptiles exchange heat with their environment.
The sun’s rays produce radiative heat that can be absorbed by all living beings. Radiation can also be reflected or transmitted depending on the wavelength and on the object receiving the radiation. Not all radiation is good, but the sun sure does a lot for keeping reptiles warm without any fur!
Evaporation is a process where water turns to gas and cools the area that it leaves in the process.
Sweating is a trait that helps humans to cool down through evaporation. Reptiles can use evaporation to cool down by jumping into a body of water and then drying off. Soaking is one way that your pet reptile might like to cool down in captivity. With fur, evaporation isn’t as effective and might actually make the wearer too cold if drenched in liquid!
Even though conduction sounds complicated, it explains the process of heat always moving from something warm to something cool.
Reptiles use conduction to either warm up or cool down as needed. Reptiles can lay on warm rocks during the evening to stay warm overnight. Or, if a reptile needs to cool down, it can find a cold shady spot of ground where the heat from its body will spread out evenly over the cool floor.
Again, conduction works with fur but not as efficiently. Just think of how much faster heat transfers between bare skin as opposed to between people dressed in puffy jackets!
Convection is very similar to conduction except instead of solids, convection has to do with gasses! Convection is an effective method of heat transfer for just about anything, ask your oven! Reptiles take advantage of warm days by receiving heat through the warm air and might cool down in the breeze.
Since fur sort of gets in the way of these processes, it makes sense that reptiles don’t have any. They need to be able to correct their body temperatures by taking advantage of all of these methods of heat transfer.
Do Any Reptiles Have Fur?
There aren’t any reptiles in existence that have fur on their bodies, however, there is one special adaptation that looks a lot like hair.
Setae can be found on gecko’s toes and explain why geckos can scale walls like Spiderman. Setae are thin keratinous structures that help geckos stick to smooth surfaces. They aren’t fur but are considered tiny hairs!
This video gives a good visual of what we’re talking about.
Even though setae aren’t fur and aren’t used to keep the animal warm, they are hair. Geckos still use the same behavioral adaptations to stay warm, but use hairs to climb up walls and trees!
Reptiles just aren’t furry or fuzzy animals, and sadly, they never will be.
Fur would be a big setback for an animal that needs to be able to cool down and warm up very quickly. But even though reptiles aren’t fuzzy, they can still be adorable pets and make great scaly friends.