Animals falsify death for long periods of time to escape predators

Animals falsify death for long periods of time to escape predators

European antlion (Euroleon nostras) at its back plays dead. Credit: Nigel R. Franks

Many animals conjure up death to try to escape from their predators, and some individuals of prey species remain motionless, when in danger, for a long time.

Charles Darwin recorded a beetle standing still for 23 minutes – the University of Bristol, however, documented that individual antlion larvae pretended to be dead for 61 minutes. Equally important is the amount of time an individual remains immobile, not only long, but also unpredictable. This means that a predator cannot predict when a potential prey item will move again, attract attention and become a meal.

Predators are hungry and cannot wait indefinitely. Similarly, prey can lose opportunities to get on with their lives if they remain motionless for too long. Thus, the death penalty can best be seen as part of a deadly game of hide and seek in which prey can earn the most by thwarting death if alternative victims are available.

The study, published today in the scientific journal Biology letters, which was involved in evaluating the benefits of death conviction in terms of a predator visiting small populations of conspicuous prey. Researchers have used computer simulations that use the statement of marginal value, a classical model for optimization.

Lead author of the paper, Professor Nigel R. Franks, of the University of Bristol’s School of Biological Sciences, said: “Imagine you are in a garden full of identical soft fruit bushes. You are going to the first forest. fruit is quickly collected and consumed, and easily, but as you strip the syrup, more fruit becomes more difficult and time consuming.

“At some point you have to decide to go to another forest and start again. You are greedy and want to eat as much fruit as quickly as possible. The marginal value statement will tell you how long you should spend in each forest. given the time will also be lost to the next forest.

“We use this approach to look at a small bird visiting patches of conspicuous antelion pits and show that antlion larvae that waste the time of the predator, by ‘playing dead’ when they fall, significantly change the game. In a certain sense encourages them to look elsewhere. ‘

The modeling suggests that antlion larvae will not earn significantly if they move even longer than they actually do. This suggests that in this arms race between predators and prey, the death toll has been prolonged to such an extent that it can hardly be improved.

Professor Franks added: “Death play is therefore rather like magic. Wizards divert an audience’s attention from seeing their sleights by encouraging them to go elsewhere. Similarly with the antlion larvae that play death – the predator looks elsewhere. Playing death seems like it seems to be a very good way to stay alive. ”


How long do you have to play dead to stay alive?


More information:
Hiding strategies and immobility after contact, Biology letters (2021). royalsocietypublishing.org/doi… .1098 / rsbl.2020.0892

Provided by the University of Bristol

Quotation: Animals Fake Death for Long Periods to Escape from Predators (2021, March 2) Retrieved March 3, 2021 from https://phys.org/news/2021-03-animals-fake-death-periods-predators.html

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