Boa constrictors are known for their efficiency. The snakes don’t take more than just a few seconds to kill their prey, but the scientific community has long debated whether these reptiles suffocate the animals they feed on or whether they give them heart attacks.
The widely spread belief is that boa snakes suffocate their prey, however a new study has shown that the second scenario is the real one. Boa constrictors cut off the blood flow and give prey circulatory arrest.
Scott Boback, associate professor of biology over at Dickinson College (Pennsylvania) and lead researcher, gave a statement informing that “This is such an efficient behavior, and it allows us to realize that this behavior was really important in snake evolution”.
But while professor Boback may have been the scientists who offered proof and set the record straight in an official manner, he is not the only one to ponder the notion that the boa’s tight coils don’t suffocate the snake’s prey. One early study can be tracked back to 1928, while another one was written a little closer to the present, back in 1994.
The 1994 study was conducted by Dr. Hardy, a snake expert and anesthesiologist, who commented on how quickly boa snakes manage to subdue and kill other animals. He noted that if the boa’s prey was dieing from suffocation, the process should have taken several minutes, whereas the snake’s meal doesn’t take more than a few seconds to die.
In fact, the boa’s prey can only last 60 seconds at most, a finding that lands itself to the belief that boa snakes cause heart attacks.
To prove these findings, Professor Boback and his colleagues conducted a series of experiments involving rats and boa snakes. The first step was to implant rats with electrocardiogram electrodes so that the researchers could measure the rats’ heart rates. But they also implanted the rats with two blood pressure catheters, one inside a major artery and one inside a major vein.
The team gave a statement explaining that they need to use an artery as well a vein because they were interested in observing “both sides of the circulatory system”.
Last but not least, the field experts also implanted the rats with pressure probes and collected blood samples before giving the rodents anesthetics and throwing them to the boa snakes in order to see how their bodies respond to constrictions.
The researchers quickly collected the rats after they died. Because they didn’t allow the snakes to feed on their defeated prey, they rewarded them with some other dead rats.
The team then took a second set of blood samples from the freshly killed rodents. What the test results of these samples and the data provided by the implanted sensors revealed was that the snakes shut down the rats’ blood circulation in just a few short seconds after they began their attack.
The rats’ arterial pressure also dropped, which indicated that oxygenated blood was not circulating throughout the rodents’ bodies, and their venous pressures rose, meaning that there wasn’t any blood returning back to the heart.
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