UPSC Express

Consider the following species

Bear
Snake
Bat
Ground Squirrel
Bumble Bees
Which of the given species hibernates?

a       1 and 3
b       1, 2, 3 and 4
c       1, 3, 4 and 5
d       1, 2, 3 and 5
Explanation:

Solution (c)

Hibernation is a state of inactivity and metabolic depression in endotherms. Hibernation refers to a season of heterothermy that is characterized by low body temperature, slow breathing and heart rate, and low metabolic rate. Although traditionally reserved for “deep” hibernators such as rodents, the term has been redefined to include animals such as bears and is now applied based on active metabolic suppression rather than based on absolute body temperature decline.

True hibernators like ground squirrels awaken slowly.  However, bears can awaken very easily during their denning period.  (Note to self when hiking during the winter!)

As a consequence of these distinct differences, many scientists believe that bears are NOT true hibernators.  Instead, they refer to a bear’s denning period as “winter lethargy” or “winter sleep”.  Other scientists believe that bears exhibit a special case of hibernation.

Snakes are seen just about everywhere from spring through October, and then they are presumed to hibernate. But that’s not always true. Snakes are more reactive to consistently cold weather, rather than a change of seasons. Rattlesnakes are even known to move around during extended warm periods during winter months, especially if they hole up in a stump or other location that can be warmed easily by sunshine.

Snakes do not actually hibernate, rather they become less active during cold weather. It is called “brumation.”  Brumation is an extreme slowing down of their metabolism. Snakes are awake, but just very lethargic so you don’t see them moving around.

Bats will sometimes appear in your home during the winter months. They hibernate from late fall (Oct/Nov) until spring arrives (Mar/Apr). It was previously believed bats migrated to caves or mines for hibernation, but we now know many will hibernate inside homes and buildings.

Bumble bees hibernate, honey bees do not. Although honeybees and bumble bees are very closely related, their winter behaviors are very different. A colony of honey bees will live throughout the entire winter, actively keeping the nest warm and safe. Only the queen bumble bees hibernate until spring

Ground squirrels live in colonies that can include several dozen animals in a complex of burrows. More than one squirrel can live in a burrow. … During winter months most ground squirrels hibernate, but some young can be active at this time, particularly in areas where winters aren’t severe.