Can Boa Constrictors Breathe While They Constrict?

A new study reveals how boa constrictors avoid suffocating themselves while constricting their prey.

Transcript

00:00When boa constrictors squeeze the life out of their prey, how do they avoid suffocating

00:04themselves in the process?

00:10A new study published in the Journal of Experimental Biology solves this mystery.

00:15It turns out that boa constrictors can rapidly adjust which section of their rib cage they

00:19use to breathe.

00:21So if one portion of the snake is, say, busy constricting a squirrel, a different portion

00:25can take over and allow air to continue moving in and out of their lungs.

00:29Researchers figured this out by placing blood pressure cuffs on boa constrictors to restrict

00:33the movement of their ribs.

00:35They then used a special technique called X-ROM to track how the snake's ribs were moving

00:40in real time.

00:41The team also used various techniques to measure air flow in and out of the snake's lungs and

00:45the electrical activity of different muscles.

00:48Unlike humans, snakes don't have a diaphragm to help pull air into their lungs and then

00:52push it back out.

00:54Instead, the animals completely rely on muscles attached to their ribs to alter the volume

00:58of their rib cage and thus allow their lungs to expand and compress.

01:02In these video clips, you can see how when one section of the rib cage is constricted by

01:05the blood pressure cuff, another section takes over to ventilate the lungs.

01:10Even when only the back of the lung, towards the snake's tail, can inflate, air still travels

01:14through the rest of the lung, allowing oxygen to pass into the bloodstream and waste products

01:18to pass back out.

01:20Study author John Capano told me that the development of this form of lung ventilation

01:24was likely a key step in the evolution of snakes as we know them today.

01:28He said, what we postulate in this paper is that this sort of modular lung ventilation

01:33mechanism is a big part of how snakes evolved to be what they are today.

01:37It doesn't seem like you could evolve constriction to kill really big things if you're compromising

01:42lung ventilation.

01:43So if you ever see a boa constricting a cute, fuzzy animal, don't worry.

01:48The boa can breathe just fine.