Discover the mystery of the

How does the world's smallest 'diver' survive in icy waters to catch prey? A new study of water shrews in the United States surprised researchers to show that the animal quickly raised its body temperature just before plunging into cold water, according to Eurekalert.

This behavior is surprising because lower body temperatures allow mammals to dive underwater for longer, so warming doesn't make sense. This is because animals use oxygen more quickly when they are warmer.

Water shrew

The research leader, Professor Kevin Campbell of the University of Manitoba (Canada), said: 'This finding goes against the current doctrine concerning the physiology of divers. Divers, especially small divers, are always expected to try to maximize their underwater tolerance. '

Campbell added that this behavior shows that shrews are optimizing other factors, not just diving time. Considering that they are proficient aquatic predators, the purpose of increasing body temperature is probably to improve the efficiency of food search.

Large diving animals, such as seals and penguins, have been extensively studied, but new findings suggest that small diving animals are also worth considering.

Compared to other diving mammals, shrews carry the least amount of oxygen under water and use up the oxygen the fastest. Typical dives therefore last only 5 - 7 seconds. Too small also makes them lose heat quickly.

How exactly shrews warm the body is unknown. Often shrews increase their body temperature while they simply sit still at the water's edge before diving. Researchers believe that shrews are shivering or using brown fat to produce heat.

In the framework of the study, experts observed the behavior of shrews when diving into the water at different temperatures. They compared the length of shrew dives in warm and cold water, and monitored rats' body temperature before, during and after diving.