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On the African prairie, how can you escape if you come across a lion? Fall to the ground and play dead, hold your breath, or run wild? Scientists have come up with an unexpected way: draw eyes on your ass!

It sounds like an Arabian Night. after all, the lion is so fierce and a predator, how can he be afraid of a pair of false eyes? However, scientists have confirmed this through experiments on cattle. What is the principle of this?

Cattle: first of all, I didn't bother anyone in Africa. Most herdsmen raise cattle by grazing, let them move freely during the day, and rush back to the pasture at night, although this way allows cattle to grow better and more freely in line with their original characteristics. But the disadvantage is that when they move freely, they are easily targeted by predators such as lions and become their lunches. According to incomplete statistics, thousands of cattle lose their lives every year, causing innumerable property losses. Therefore, in order to resolve these conflicts and protect the property of large predators and herdsmen, the Government of Botswana wants to find a way to reduce lion hunting.

(photo Source Botswana Predator Conservation) scientists from Botswana and Australia in Africa conducted a study in Botswana in 2016 under the theme of "painting things on cow buttocks to observe how cattle are hunted by predators". The researchers selected 2061 cattle from 14 pastures and divided them into three groups: one group drew two eyes on the back of the cow's ass, with a number of 683; the second group drew two "X" numbers on the back of the cow's ass, the number was 543; the third group did not give any treatment to the cattle, the number was 835. Then, according to the normal grazing time, count the number of cattle in each group every night to observe the number of cattle killed by lions and other animals.

Whether to say it or not, I was scared when I read it. | reference [1] after 4 years of observation, the researchers published a research paper in the journal Communications Biology in 2020. the data are as follows: the killing rate of cattle without any processing is 1.8%, that of cattle with "X" is 0.73%, and that of cattle with two eyes is 0. In other words, it is feasible to draw eyes on the back of the cow's ass to prevent predators from killing the cow! Even if you don't draw eyes, you can draw something casually to a certain extent.

Why on earth can drawing eyes prevent cattle from being hunted? It also starts with the biological evolution of animals to prevent natural predators.

Many butterflies have eye spots on their wings, such as this big-eyed brown-brown butterfly (Mycalesis patnia). | Wiki after tens of thousands of years, animals have evolved many ways to avoid being eaten by predators, such as camouflage color, warning color, and mimicry to reduce the risk of predation. A typical example is the Eyespot on the wings of moths or butterflies. For example, there are many pairs of threatening large eyes on the anterior ventral segment of the moth larvae. When they are frightened, they will retract their head and chest into their bodies, revealing eye points to frighten predators. The butterfly has a pair of eye spots on its front and back wings, which match the lines of the body. Whenever the wings of the butterfly are flat, it looks like the face of an owl from behind, scaring away some small birds with poor eyesight.

Who would have thought? It turned out to be the back of a dwarf owl, which seemed to say, "I've found you!" At present, there is still a lot of debate in academic circles about the specific principle and influence of eye-like pattern formation, but the research team said in the paper that their findings provide proof for the following three hypotheses, namely: detection hypothesis, predator mimicry hypothesis and conspicuous hypothesis.

The detection hypothesis suggests that eye-like lines in animals may make predators think they have been discovered and then abandon the attack or divert the target. The eye spot on the nape of the necks of small raptors such as the natural dwarf owl (Glaucidium spp.) and the American kestrel (Falco sparverius) is a similar function, preventing ambush attacks by other birds of prey.

Lions and leopards are ambush hunters who rely on bushes to hide themselves and attack immediately only at certain moments. So this hypothesis is widely used in animals like lions, who like to sneak attacks. once they are aware that they have been noticed by their prey, they are easy to give up the attack.

The predator mimicry hypothesis holds that the eye-like lines on the animal will make the predator think that other predators are present, or that the predator's own natural predators appear, and then give up predation. The researchers believe that although the eye symbols painted on cattle in the experiment are too large and inaccurate, it may be difficult to deceive lions, cheetahs and other animals, but they can still make these animals think that this is a new species they have never seen before. and give up the attack.

The conspicuous hypothesis holds that the similar eye lines on the animal make the animal a strange creature that the predator is unable to judge and then give up the attack. The researchers believe that the X mark on cattle should have a similar function to limit the number of deaths of cattle with X marks to 4.

It's really hard to tell which is the fish's eye, it's too cunning! | other Wiki-related hypotheses include the deflection hypothesis, which holds that eye spots allow predators to shift targets from the brain areas of animals with eye spots to other non-lethal areas of their bodies, reducing the risk of death. After all, it is better to lose the tail than to be bitten off.

For example, the four-eyed butterfly fish (Chaetodon capistratus) has large and conspicuous eye spots on both sides of the body near the tail, while the real eyes are pierced by a black vertical line above the head, making it difficult for predators to tell where the fish's Achilles' heel is.

As to whether the same method is applicable to humans, no one has ever tried it.

Reference:

[1] Radford, C., McNutt, J.W., Rogers, T. Et al. Artificial eyespots on cattle reduce predation by large carnivores. Commun Biol 3430 (2020). Https://doi.org/10.1038/s42003-020-01156-0

[2] https://en.wikipedia.org/wiki/Eyespot_(mimicry)

This article is from the official Wechat account: bring Science Home (ID:steamforkids), author: everything Magazine

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