Boa Constrictors and Suffocation: New Way to Die

Victims of boa constrictors, it turns out, are neither "shot through the heart," Bon Jovi style, nor actually suffocated--as we've always thought. Their blood supply to the heart and other vital organs is cut off by the muscular snake, according to research that Dickinson University biology professor Scott Boback and other researchers recently published in The Journal of Experimental Biology.

The good thing is, victims don't die slowly by suffocation; lights go out quickly for them.

"We have been studying constriction for a number of years," says Boback, the study's lead author, whose earlier experiments measured the pressure exerted by snakes crushing dead rats and led to the discovery that snakes control constriction in response to their victims' heartbeats, a release said. 

For the recent study, Boback and other researchers needed to measure blood pressure in living, anesthetized rats as they were constricted. The lead author says that the project proposal underwent a full review by the Institutional Animal Care and Use Committee (IACUC), said the release.

The researchers inserted ECG electrodes and blood-pressure catheters into each rat's body before giving the sedated animal to a boa constrictor. The snake aimed a bite at the rodent's head and coiled its body to squeeze the animal, the release noted.

Clinicians watching the vital information stream across the computer screen saw the rat's blood circulation shut down in a few seconds. The scientists suspect that without blood flow to the brain, any animal in the snake's coils likely passes out very soon after being caught, before other critical organs begin to fail, according to the release.

"By understanding the mechanisms of how constriction kills, we gain a greater appreciation for the efficiency of this behavior and the benefit it provided early snakes," noted Boback in the release.

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