Fake death, thanatosis or tonic immobility, which is the most widely accepted term in scientific literature, refer to a behavior or state of inactivity that certain animals have in order to appear dead. They do this mainly when they are detected by a predator and there is no possibility of escape, so they use this mechanism to see if it is possible that the attacker, believing that the prey has died, does not carry out a violent action that actually takes away the prey. life and, thus, there is the possibility that interest in the prey will be lost or the opportunity arises for it to escape.
It has been documented that tonic immobility involves certain physiological changes in animals, such as decreased heart and respiratory rates, it also includes keeping the eyes open, the tongue sticking out and, in certain cases, emitting fluids. Other reasons for playing dead may be more for hunting or breeding purposes. Keep reading this article on our site and meet the animals that play dead
Virginia opossum (Didelphis virginiana)
One of the most iconic animals that play dead to survive is the Virginia or North American opossum. When located by a predator, this animal, if it has a chance, will try to escape, but if not, it will try to persuade an attack by showing its teeth, making certain sounds and appearing to be larger. If this does not deter the attacker, the marsupial enters a state of tonic immobility, feigning death, which can last up to several hours.
The ability to play dead is so real that there's even a common phrase “playing possum” to refer to faking death. This occurs mainly in young animals, since adults tend to have a greater ability to evade predators.
Learn more about these incredible animals in this other article: "Types of opossums".
European Rabbit (Oryctolagus cuniculus)
Another mammal that uses thanatosis to try to distract its predator and give it a chance to escape is the European rabbit. Although adult specimens that develop good sizes are very agile and quick both to escape and to take refuge in burrows, they are not always exempt from a predator getting close enough, as in younger and weaker individuals, so Imitating the state of death is a strategy for survival
Tree frog (Phyllomedusa burmeisteri)
Within the anurans there are also examples of animals that play dead, and one of them is found in this frog native to Brazil. It is common for some amphibians to have the possibility of secreting toxic substances that affect their predators, but in certain cases these are not enough, so they use the tonic immobility to persuade their attackerEven if a person grabs this frog with his hand, he will think that the animal is dead.
Collared snake (Natrix natrix)
Among reptiles we also find examples of animals that play dead to defend themselves and survive. One case is this snake native to Asia and Europe, also known as the grass snake, which is a non-venomous species, but uses variousdefense strategies when she feels threatened, such as expelling blood, moving into an attack position and making certain sounds. If this does not work, it goes into a state of immobility, leaving its body limp, which gives the idea of being dead.
However, this is not the only species with this strategy, as there are several snakes that play dead, such as:
- Black-tailed creeper snake (Drymarchon melanurus erebennus)
- Eastern Hognose Snake (Heterodon platirhinos)
- Mediterranean collared snake (Natrix astreptophora)
Maquech (Zopherus chilensis)
In the group of insects, there are also species that use this strategy to try to protect themselves against predators. Thus, we find this small beetle endemic to Mexico, which, when faced with an unusual physical contact that suggests danger, proceeds to fold its legs and antennae down the body, staying that way from a few minutes to longer periods. The body of the insect will remain rigid and with the extremities covered as much as possible while the potential danger lasts.
Striped beetle (Agriotes lineatus)
Another type of beetle that carries out thanatosis to survive is this species, however, unlike the previous one, immobility has been determined in the larval stageof the animal, that is, when it is shaped like a worm, which is when it is most susceptible to being preyed upon, for example, by birds. Within the different species of the genus, A. lineatus is the one that has shown the longest period of tonic immobility.
Fire Ant (Solenopsis invicta)
The young workers of this species of ant, faced with the possible attack of other neighbors, choose to play dead and avoid a confrontation This gives them a better chance of living because they can lose in combat. Now, adult individuals do tend to confront each other and do not use the immobility strategy.
Do you want to know more Curiosities about ants? Don't miss this other article!
Nursery Web Spider (Pisaura mirabilis)
Thanatosis, in addition to being used to avoid predation, is also used by some species in order to mate, and an example we have it in this kind of chandelier. It is usual for the females to seek to prey on the males, so that they prepare some food, such as an insect, which they tie to their body and pretend to be dead. The female approaches and drags the hook that the male has set, thus, while she enjoys the food, he becomes active and tries to copulate. The process gives a high result of reproduction occurring in these animals.
Livingston's cichlid (Nimbochromis livingstonii)
In contrast to avoiding predation, tonic immobility is also used for huntingAn example of this is this freshwater fish, also known as kalingono, which means "sleeper". Thus, this fish is placed on the substrate at the bottom of the water and pretends to be dead. When other fish it feeds on come close, it quickly attacks and devours them.
Ducks
Birds do not escape the group of animals that play dead to survive and the different types of ducks are a clear example. It is documented how various species of ducks, when caught by foxes, enter a state of thanatosis. In this state, if the canine is not experienced enough and leaves the bird alive to feed later, will be able to escape Now, the older foxes that have Having learned this escape strategy from their prey, they kill the duck immediately after catching it.
Other animals that play dead
Animals that play dead are not few, on the contrary, it is a more common strategy than we think. If you still want to know more examples of animals that carry out thanatosis, here we present some more:
- Gazella (Gazella gazella)
- Brown snake (Storeria dekayi)
- Grasshopper (Emsleyfolium diasae)
- White-tailed jackrabbit (Lepus townsendi)
- Kroyer's Dwarf Frog (Physalaemus kroyeri)
- Brazilian seahorse (Hippocampus reidi)
- Mountain Cottontail Rabbit (Sylvilagus nuttalli)
- Moorland Peddler (dragonfly) (Aeshna juncea)
