Amazing Nature

Social Distancing in Nature

Jun 2020
Author: Green Power
Trees that grow at an appropriate distance
Invisible borders are formed among tree crowns.
© Dag Peak @ Wikipedia

While social distancing becomes a new norm worldwide during the COVID-19 pandemic, do you know that in the world of animals and plants, social distancing is not so uncommon?

Distance for Shyness

You may see an interesting phenomenon if you look up to the canopy of a tropical rainforest: no matter how dense it is, the tree crowns seem to have an invisible borderline where they keep a distance from each other and allow sunlight to penetrate. This phenomenon was coined "crown shyness" in the early 19th century by the scientific community. One possible explanation is similar to why we are avoiding shaking hands in the coronavirus pandemic—to minimise the spread of pathogens through contact, although the trees are avoiding insects that feed on their leaves, along with bacteria and fungus. There are other postulations too: to avoid shading from neighbouring trees to gain more access to sunlight, or to limit tree branch growth that may lead to excessive abrasion in windy conditions, etc. Yet to date, scientists have not reached any conclusive explanation for the phenomenon.

Two cats fighting for territory
Cats often keep distance from one another, for territorial protection.
Photo from Pixabay

Distance for Territory

Some animals are highly territorial, to safeguard resources for their survival (such as food) and reproduction. Cats and dogs, the human pets, are naturally territorial too. They mark their territories with their excretions or gland secretions to warn potential intruders. If other unwelcome guests enter their territories, they will show warnings. If the intruders still do not go away, they will launch an attack and hostilely expel them.

Female elephant family members
When a male elephant reaches puberty, it will keep a distance from its original close female family members.
© Elaine Yuen

Distance for Growth

Males or females of many social animals leave their original families upon growing up. Elephants, for example, live in matriarchal societies led by a female head. The calves follow their grandmas, mothers and sisters when they are young. But after learning all the essential survival skills and entering puberty, the males gradually keep a distance from their original families. Instead, they join groups of males, and eventually become independent from their original families.

While a male elephant may meet its original family members in its search for a mate, scientists have discovered that elephants will reduce the chance of inbreeding—and hence potential genetic diseases—by using sound and smell to avoid mating with their kin. The "distancing" of elephants from their family members enhances the fitness of the offspring in evolutionary terms.