Have you ever wondered if animals are capable of self-destruction? Is it only humans who nurse suicidal tendencies?
It is generally considered that humans are the only known beings capable ending their own lives.
But did you know that species other than our own might be driven to engage in suicidal behavior for the sake of others; this is an example of altruism in animals. Such examples have been recorded for time to time.
“In 2011, Chinese media reported that a bear held captive on a bile farm killed her son and then herself to escape from the torture of their situation. In 2012, Psychology Today blogger Marc Bekoff wrote a post about a burro who, after the death of her infant, walked into a lake and drowned herself. Last year, a friend told me a story about her dog Lucy, who stopped eating after the death of her longtime companion, Steele. Lucy died three weeks after Steele,” according to an article by Dr. Jessica Pierce in Psychology Today.
Examples exist even in the wild. Scientists have long known that some beaked whales beach themselves and die in agony after exposure to naval sonar, and now they recognize why: the giant sea mammals suffer decompression sickness, just like scuba divers.
How the oceans’ most could accomplish deep-sea diver wind up with nitrogen bubbles poisoning its veins, like a scuba novice rising too quickly to the surface?
A researcher at the Institute of Animal Health at the University of Las Palmas de Gran Canaria, Spain, says, “beaked whales — especially one kinds known as Cuvier’s get really, really scared. The stress response, in other words, overrides the diving response, which makes the animals accumulate nitrogen, it’s like adrenalin shot.”
Suicidal actions are perpetrated when the reproductive fitness of others outweighs the reproductive fitness of the individual. There are examples of animals dying in defense of their family or colony, like the case of pea aphids increasing their chances of dying as a response to parasitism. Vervet monkeys will alert others when a brute is near, consequently drawing attention to itself and enhancing their likelihood of being assaulted.
The whale is listed as “vulnerable” on the IUCN Red List of endangered species and is thought to possess a global population of 5,000 to 7,000. They can strand together – most recently, ten long-finned pilot whales became stranded on a beach near Calais, seven of which died – but a sole reason of why this happens remains a mystery. Alternatively, many diverse factors appear to be involved.
Some mass stranding is easy to unravel because the whales involved are similarly sick or injured. In these cases, they strand because they are forced inshore by currents as they ail and die. Alternatively, they head for shore because they are simply extremely ill to swim.
As a severe form of self-sacrificial behaviors evolved by kin selection in various social animals. Many animals that have the appearance of being depressed or grieving begin to exhibit self-destructive behavior that sometimes ends in death. In 1845, the Illustrated London News reported that a Newfoundland dog had been acting less lively over a period of days before being seen “to throw himself in the water and endeavor to sink by preserving perfect stillness of the legs and feet” Every time he was rescued he attempted to do this again before he finally held his head underwater until death.
Most self-sacrificial defensive mechanisms occur in response to an acute threat to the colony, but some behaviors represent preemptive actions that avert harm to the colony.