Did you know that most lizards can’t run and breathe at the same time? You’ve probably even observed this in real life, but just didn’t quite put it together.
Picture this: You’re out hiking and you come across a small lizard. The small lizard darts about ten feet away from you, then stops and heaves heavily. If you continue walking towards the lizards, it will dart off again before pausing and heaving again.
You may think to yourself, well that’s a little odd. Why wouldn’t it just run away all at once?
That’s because most species of lizards use the same muscles to breathe as they do to run. They have to contract their chest muscles, one after the other, to run. And when you’re running fast, and constantly compressing your chest muscles, there’s no room left for new air.
If you watch a lizard move, you can see what I’m talking about. Lizards move their bodies pretty dramatically from side to side as they walk and run. They don’t just move in a straight line like a cat or dog. This side-to-side movement is what is constantly forcing the air out of their lungs—well, actually, it’s more like back and forth between their lungs. Until they pause to catch their breath, they’re really just swapping the old stale air back and forth between the available lung space. This is a phenomenon known as carrier’s constraint.
Essentially, most lizards are sprinters, not marathon runners. They have to pause to catch their breath after a hard sprint. This is why I like to tell people that I’m a lizard runner, because I too must pause and catch my breath after a very brief run. They don’t usually get the joke.
Obviously, not being able to run long distances without stopping can be a huge disadvantage to a lizard who has caught the attention of a predator. A lizard who is in pursuit and fears for its life, may even run so much that it passes out from a lack of air. This is also why I tell my kids to leave little lizards alone. I don’t like the idea of my kids scaring lizards half to death.
The exception to this rule is monitor lizards. Think like the Komodo Dragon, Savannah monitor, Nile monitor, etc. These monitor lizards are able to breathe effectively while running due to their large, muscular throats which are able to still pump air into their lungs even during a hot pursuit. A huge advantage over other lizards and the reason why monitor lizards tend to be bigger and more aggressive hunters.
There are a few other lizards that don’t perfectly follow this rule, but in general you can pretty much expect that a non-monitor lizard will be a lizard you observe sprinting and a monitor lizard is one that you observe running long distances.
So there you have it. Can lizards run while breathing is part myth, part fact.
Did you already know this or is this something you just learned today? Let me know in the comments below!
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