It sounds crazy, but suicidal reproduction – also known as semelparity – is common in nature. There are a surprising number of animals that immediately die after having sex or not long after the mating season. The males especially are forced to live fast and die really, really young – often only surviving for about a year.
Why is this a thing? Scientists aren’t 100 percent sure, but it could have something to do with adaptation and survival. Males that die right after mating aren’t sticking around to eat all the food and take up space. Another theory? It’s just a freak thing: a “quirk” of nature that locks these poor creatures in a hellish cycle. Regardless of the exact reason, there are some really fascinating facts about animals that die after sex.
Furcifer Labordi Chameleons mate in January, “a nasty, often violent business of males fighting males, females fighting males, and all of them wishing they were somewhere else,” according to Natalie Angier, writing for the New York Times. If they don’t kill each other while trying to mate, hormone overdoses due to high levels of aggression might kill them. Regardless, the males and females both die after successfully mating and laying eggs, and then just “drop from the trees with the papery grace of autumn leaves.” This particular species of chameleon spends two-thirds of it existence as an egg buried in the sand and “16 to 20 weeks” post-shell, its entire lifespan over in barely a year.
The males in all 12 species of the marsupial mammal antechinus die after their first time successfully breeding, typically from stressing themselves out. Seriously: the stress of the breeding season destroys their immune system, leading to liver infections and parasites of the blood and intestine. While some females live to breed for another season, all the males are sure to die. That’s not the only place males get the short end of the stick: as babies they’re denied adequate milk by their mothers, who prefer to wean the females. At least they get to end their pathetic, year-long lives trying to mate with as many females as they can, “in violent, frenetic encounters that can each last up to 14 hours.”
Some female praying mantises bite their much smaller mate’s head off after or even during fertilization. That’s cold-blooded, for sure, but to make matters worse, the poor sap gets seduced by pheromones and a courtship dance beforehand. What’s the advantage of biting your mate’s head clean off like it’s a Teddy Graham? Believe it or not, research shows “the male appears to thrust more vigorously” once beheaded and the cannibalism may lead to more successful mating.
Unlike the mammals and lizards on this list who get sick or just die of natural causes after mating, male Australian Redback Spiders commit sexual suicide. Like their American cousin the black widow spider female Redbacks devour males post-coitus if they make themselves available. Males who choose to sacrifice themselves “sire proportionately more offspring than do the partners that the female spiders choose not to chew.” That’s not the only motivation: a male Redback’s lifespan is so woefully short, he will likely die or get eaten by a predator before making it to another female’s web anyway, so why not take the plunge?
The male Australian phascogale is the largest known mammal to kick the bucket after sex for reasons similar to the antechinus and other marsupial mammals. Around the age of 11 month to 12 months, the male phascogale – if fortunate enough to be chosen by the dominant female – breeds in early winter. He expends so much energy trying to seal the deal it fries his own immune system. All three species of phascogale fall prey to stress-induced diseases and die, or they fall prey to prey and are eaten by owls, foxes, and cats. Either way, they’re bound to die after their first and only breeding season.
The males in the Dasykaluta rosamondae or “Little Red Kaluta” species is one of four marsupial mammal species where the dudes are doomed to go out with a bang. Like the antechinus and phascogale, males die soon after their first mating period after reaching sexual maturity at about 10 months old. The Little Red Kaluta, however, is the only one of these marsupials to live in the grasslands of Australia. The rest of these unlucky guys dwell in the forest. Interestingly, in laboratory settings, the males kept alive after mating become “reproductively senile,” which, no, doesn’t mean they keeps losing their keys during sex – it means they’re too old to effectively mate … at the ripe old age of one.
Australian marsupial mammals known as dibblers living on Boullanger Island off the coast of Western Australia die shortly after breeding. Unlike their related species, dibblers not on the island survive for multiple mating seasons. Researchers think the lack of nesting seabirds on Boullanger Island means less nutrient-rich soil, which means fewer insects. Since dibblers live on insects, having a poor quality food source may keep them from lasting through the mating season. It’s a shame, too, because their copulation lasts “a few hours,” preceded by “up to 15 days” of “chases” – both male- and female-driven – and frequent “attempted mountings.” Now that’s foreplay.
Call it a “Romeo and Juliet” lifecycle if Juliet got knocked up: male Brazilian Slender Opossums die off shortly after mating, while females die shortly after giving birth. This means no individual opossum ever lives through more than one mating season. Symptoms before dying off include “fur loss in the rump and parasite infestation,” indicating a weakening of the immune system similar to Australian marsupials that croak after they poke.
Unique on this list, the male Trans Volcanic bunchgrass lizards of Mexico actually outlive the females by seven months, but both are destined to die after mating successfully. It isn’t a dramatic death – they just simply die of “natural causes” after they’ve lived long enough to mate once. They reach sexual maturation within five months; after that, they spend the rest of their short lives – regardless of what season it is – trying to mate. Once it happens, females only have two months or so to live, while males can linger on for another ten or so.
Perhaps the saddest creature on this list is the male Dark Fishing Spider, who dies instantly following a “sperm transfer.” The female doesn’t do the killing, and the spider doesn’t get sick: it’s just doomed to die, like the flick of a switch. Why? It has to do with an irreversible rise in blood pressure, a by-product of the mating process. The female eats the male after, which may offer reproductive benefits, so the poor schmuck didn’t die in vain.