Estivation or Aestivation

Estivation or Aestivation

Context: Animals often tend to show some physiological adaptation to survive in challenging environments. This adaptation varies depending on factors like when and why they are occurring and what kind of animals are adopting it.

Physiological adaptations are mainly of three types:

  1. Hibernation
  2. Brumation
  3. Estivation or Aestivation

Further Migration can also be considered as an adaptation technique where species relocate themselves to avoid harsh weather.


  • Hibernation is a physiological adaptation practised by some animals. It is a state of inactivity and dormancy that enables some animals to survive in cold environments with reduced food availability during the winter months.
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  • Hibernation is mostly done by the endotherms or warm-blooded animals
  • A variety of animals can hibernate, including bats, bears, rodents, and some species of birds and reptiles.


  • Brumation is known as the hibernation for cold-blooded animals. In a nutshell, brumation is to reptiles what hibernation is to mammals.
image 41

Hibernating animals need to eat in order to have enough food storage to last them through their hibernation period as their metabolism while decreased is still active.

Brumating animals stop eating before entering inactivity as their metabolic rate drops so low that they are unable to fully digest their meal until outside temperatures increase.

Estivation or Aestivation

  • It is a physiological adaptation whereby the animal enters a long period of dormancy or inactivity in response to high temperatures or maybe even drought-like conditions. 
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Similarities Between Hibernation, Brumation and Aestivation:

  1. Metabolic Slowdown: In all strategies, animals experience a significant reduction in their metabolic rate while in a dormant state.
  2. Reduced Activity: Processes involve a decrease in activity levels, which serves to conserve energy.
  3. Water Conservation Adaptations: Animals have developed specific adaptations to minimize water loss, such as creating protective mucus layers or sealing themselves within cocoons.
  4. Prolonged Dormancy: Processes can endure for extended periods, enabling animals to survive challenging environmental conditions until more favourable circumstances return.

PYQ – 2014

Q. Consider the following:

1. Bats

2. Bears

3. Rodents

The phenomenon of hibernation can be observed in which of the above kinds of animals?

(a) 1 and 2 only

(b) 2 only

(c) 1, 2 and 3

(d) Hibernation cannot be observed in any of the above 

Ans. (c)

Practice MCQ

Q. Consider the following statements:

1. Brumation is a physiological adaptation which is practised by warm-blooded animals.

2. Estivation is a state of inactivity and dormancy that enables some animals to survive in cold environments.

Which of the statements given above is/are correct?

(a) 1 only

(b) 2 only

(c) Both 1 and 2

(d) Neither 1 nor 2

Ans. (d)

Source: The Hindu

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