That's why Boback plans to repeat the study with lizards or frogs. That said, Boback and his team only looked at how boa constrictors kill rats that are about 25 percent of their size, so there's still a possibility that this result is only relevant for mammals, or mammals of a certain size. The study provides a "more detailed explanation than ever before of how constriction subdues even large and strong prey so quickly and effectively," Moon says. "Constrictors stop the flow of blood in their prey, and that's causing death," Boback explains. The researchers found that when boa constrictors kill a rat, they squeeze hard enough to interfere with the animal's blood pressure, blood gases, blood ion balance, and heart function. Eventually the snake would strike, and the experiment began. "All of these wound together in a bunch of these wires and tubes coming out of the rat," Boback says.
![anaconda vs boa vs python anaconda vs boa vs python](https://www.nhm.ac.uk/content/dam/nhmwww/discover/giant-snakes/reticulated-python-full-width.jpg)
The snake itself was also equipped with a device that can detect the pressure that the snake is generating around the rat. Vascular catheters measured the blood pressure inside the circulatory system, while electrodes measured the electrical activity of the animal's heart. First, they inserted a number of electronic sensors inside anesthetized rats, to see what happens when a boa starts to squeeze. Researchers used boa constrictors and rats to find out how these snakes kill their prey. So all things considered, circulatory arrest is much deadlier. "But if you stop the flow of blood then you absolutely cannot deliver oxygen to the tissue," says Scott Boback, an animal ecologist at Dickinson College and a co-author of the study. Because of that, animals continue to benefit from what little oxygen is stored in the blood, at least for a short while. So when an animal gets asphyxiated, that doesn't interfere with the heart, which continues to pump. That's why today's paper is important it might finally put a nail in the coffin of scientists' previous, breathtaking assumption.Īsphyxiation, by definition, is absence of ventilation. Stopping the flow of blood means you can't deliver oxygen to the tissue But most of the literature over the last century actually hypothesized that prey died from suffocation, says Brad Moon, a snake researcher at the University of Louisiana-Lafayette, who didn't work on the study. A few researchers suggested in the '80s and '90s that circulatory arrest - stopping the flow of blood - was the correct method by which constrictors killed prey. Until now, researchers had never actually directly tested how constrictors kill their prey. The finding, published in the Journal of Experimental Biology, likely means that many a biology textbook will need to be revised.
![anaconda vs boa vs python anaconda vs boa vs python](https://study.com/cimages/multimages/16/reticulated_python.jpg)
That approach is so efficient that animals don't survive long enough to die from asphyxiation - the method that most scientists thought was the correct "cause of death" in constricted prey. Researchers have demonstrated for the first time that constrictor snakes kill by stopping the flow of blood inside their prey.