Thanatosis, or playing dead, is a defense mechanism used by many animals. They have adapted this technique as a way to avoid being eaten and to scare off prey. The Eastern Hognose Snake, Mallard Duck, Virginia Opossum, European Rabbit, and Lemon Sharks are animals that use playing dead to their advantage.
Read on to find out about these fascinating animals.
Eastern Hognose Snake
This North American snake gets its name from the upturned scales around its snout. The Eastern Hognose Snake, also known as the Puff Adder, is a small nonvenomous snake that likes to blend into its background.
They live, along with other wildlife, in the Eastern half of the United States, from the Great Lakes to Southern Florida, eating mostly eat frogs, salamanders, small mammals, and birds.
When they feel threatened, they flatten their heads and necks. Then, they hiss and strike. They do not often bite, but this threat is meant to scare off potential predators. If this doesn’t work, they go to plan B. This is when the snake rolls over onto its back. Its mouth gapes open, tongue lolls. It writhes a few times before settling into a dramatic, fake death.
According to research conducted on the behaviors of death-feigning snakes, they innately become immobile. They enter a natural state of paralysis similar to hypnosis called tonic immobility. In this state, their heart rate slows. Their bodies may twitch, but they are unresponsive to external stimuli. This defense mechanism helps to make the snake appear less appetizing to a potential predator.
The duration of the thanatosis varies depending on the type of predator.
Mallard Duck
Mallard Ducks have a characteristic green, glossy head and white collar. They are one of the most abundant duck breeds in the world. They live in marshes, wooded swamps, ponds, rivers, lakes, bays, and city parks.
According to a 1975 study by Alan B. Sergeant and Lester E. Eberhardt, 50 ducks of varying species, including the Mallard, were observed faking their death when red foxes attacked. They would become completely immobile when they were first seized and would remain motionless until there was an opportunity for escape.
In this study, 29 out of the 50 ducks survived using this tactic. So, Mallards have adopted the skill of “playing dead” as a means to increase their survival rate when captured by predators.
Virginia Opossum
The most commonly known animal that plays dead, the Virginia Opossum, is the only marsupial living north of Mexico. They are so well-known for playing dead that the action is sometimes called “playing opossum.”
They live throughout the US and Canada in a variety of habitats. They are about 16 inches long with an 11.6-inch tail and weigh around 4.6-6.2 pounds.
When an opossum feels threatened, it will lie flat on its back and appear dead. Scientists believe that this action is involuntary. The opossum is so overcome with fear that it goes into shock, similar to the way a person faints. Then, the creature releases a bad odor.
This behavior is beneficial to the opossum because a predator looks and smells the animal, assuming it is dead. Opossums can also appear to have rabies. They hiss and drool, yet these animals rarely contract the disease. This bluff also keeps predators, and humans, away.
European Rabbit
European rabbits are common, grayish-brown mammals that inhabit every continent in the world, except Asia and Antarctica. It is even considered invasive in some areas. These rabbits are prey to a large number of predators, including carnivores and birds of prey, so it is no surprise that they have adapted to escape and evade animals that want to eat them.
Playing dead is risky. If the predator is a scavenger, it will eat the animal whether it appears dead or not. However, it can help make animals who prefer fresh kills less likely to attack. In the case of European rabbits, they will lie down on the ground with their eyes closed, remaining motionless and silent. If the predator goes away, the rabbit can make its escape.
Lemon Shark
Lemon Sharks have olive to yellow-brown skin, giving them their name. They have a blunt snout and a narrow mouth. They live no deeper than 188 feet, remaining in reefs, bays, mangroves, and docks in the Gulf of Mexico, West Indies, and the Caribbean. However, attacks by these sharks are rare.
These sharks’ main threat is humans. Some humans use the Lemon Shark for food, medicine, and research. When a human handles or entraps this shark in a way that causes it to flip over, a Lemon Shark demonstrates a tonic immobility response, according to research conducted in 1990.
When a Lemon Shark plays dead, its dorsal fin straightens, its muscles relax, and its breathing becomes slower.
Conclusion
Many prey animals use every means at their disposal to ward off predators. Thanatosis, or playing dead, is one of many defense mechanisms that animals have adapted to protect themselves from harm. These animals use their extreme shock to help escape tricky situations, increasing their likelihood of survival.
