A team of scientists at Stanford University has captured the first record of the blue whale’s heart rate, and they have gathered some interesting insights into the behavior and evolution of the large mammal,media New Atlas reported. The huge size and skin surface area of the blue whale may give the impression that placing a research label on it would be a very simple thing to do. But the nature of wild blue whales actually poses some challenges to this type of research.
They don’t move their stomachs up like other marine creatures, and skin folds like the accordion expand and contract as they eat, meaning the labels can easily loosen.
David Cade, co-author of the paper, said: “We have to put these labels on blue whales without really knowing if they will work. “The only way is to try it. So we did our best. “
Cade actually successfully placed the label on a wild whale on its first attempt, using a device equipped with sensors that use embedded electrodes to measure its heart rate. The label, which is entangled near the whale’s left fin, has been shown to be effective in capturing data about its heart activity, and researchers found a lot of interesting information in it when they retrieved the label.
“Honestly, it was a long attempt because we had to do a lot of the right things: find a blue whale, put the label in the right place for the whale, and make good contact with the whale’s skin. Of course, make sure that the labels work and record data. Jeremy Goldbogen, an assistant professor of biology at Stanford University’s School of Humanities, said.
The most surprising finding is that the blue whale’s heart rate may drop to only twice a minute. This occurs when whales start foraging, with an average of four to eight heartbeats per minute. When it started eating its prey at the bottom of the sea, its heart rate more than tripled, and then when it rose to the surface, it began to slow again. Once it reaches the surface and breathes some oxygen, the blue whale’s heart rate soars to 37 beats per minute. That almost exceeded the researchers’ expectations, but what really surprised them was the lowest heart rate, about 30 to 50 percent lower than they had expected.
With the new data, scientists believe the blue whale’s heart is at its limits. This offers a possible explanation for why the blue whale has never evolved to be larger than it is, because the heart’s power may not be able to keep up with the energy needs of the larger body.
“Animals that operate under physiological extremes can help us understand the biological limits of size,” says Goldbogen. They may also be particularly vulnerable to environmental changes, which may affect their food supply. As a result, these studies may have important implications for the conservation and management of endangered species such as blue whales. “
The team is already busy upgrading its label, hoping to add an accelerometer to see how different activities affect the blue whale’s heart rate. “A lot of what we do involves new technologies, and a lot of it depends on new ideas and new approaches, ” says Cade. We’ve been trying to push the boundaries of how to learn about these animals. “
The study was published in the Proceedings of the National Academy of Sciences.