Some Iowa Turtles Can Breathe from Their Butt… Seriously

In this latest instalment of fact is truly stranger than fiction, we'll look at our state's turtle population and their penchant for breathing from, you guessed it by the title, their buttholes. No this isn't a joke or prank; this is real science people!

Now that video (above) had me in stitches last night, but the fact that some of our Iowa turtles can in actually breathe underwater using what is scientifically known as "cloacal respiration" is not only wild, but highly necessary for their survival.

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Before you start picturing turtles literally gulping air with their rear ends, let me explain how this works. Firstly, a turtle’s cloaca is a multipurpose opening used for both reproduction and waste. Secondly, inside of it are thin-walled sacs called cloacal bursae. Thirdly, these sacs contain loads of blood vessels and can absorb small amounts of oxygen from water when it moves in and out of the cloaca.

In cold environments like our great state of Iowa, this ability becomes incredibly important during winter. Many of our freshwater turtles spend months at the bottom of ponds, lakes, and slow rivers when ice seals them in. They can't come up for air, so what can they do? Well, turtles slow their metabolism down in the cold water, meaning they need less air to stay alive. That being said, they can absorb limited oxygen through the skin, tissues in the mouth and throat, and yes, the cloaca. Think of it like underwater hibernation; which in the turtle world is known as brumation.

Even with this unusual breathing trick, survival isn't guaranteed. Oxygen levels in winter water can get extremely low. Some species like the Painted Turtle are expert survivalists. They can survive periods with almost no oxygen by switching to a state of anaerobic metabolism. Their shells help buffer the buildup of lactic acid that would be deadly to almost any other animal. So, while “butt breathing” sounds like the setup to a punchline (or a 90's rock band), it’s actually a clever survival skill that helps turtles make it through our harsh winters.

Iowa turtles known to use cloacal respiration

• Painted Turtle
• Common Snapping Turtle
• Spiny Softshell Turtle
• Smooth Softshell Turtle
• False Map Turtle
• Ouachita Map Turtle

Next time you spot a turtle basking on a log, just remember: when winter rolls around, it might be relying on one of the strangest breathing tricks in the animal kingdom. Nature is weird, and amazing, isn't it?