Every species on earth reproduces. They do it in different ways, with different levels of success, but it’s the only strategy to ensure that the genes from one generation are passed to the next.
This makes reproduction about life, but for some animals, sex is also about death. As they try to pass their genes on, some prospective parents die. Here are some of the deadliest mating rituals in the animal kingdom.
- 9 deadly, brutal females that lure males to their death: For these unlucky male animals mating is a lethal business
- Death by sex: The animals that die during or after mating
Deadliest mating rituals
Antechinuses
The brown antechinus lives fast and dies young. Males of this small marsupial mouse, which live in the woodlands of eastern Australia, become sexually mature at around ten months old. After that, they have one thing on their mind.
Males engage in a two-week-long sex marathon with as many females as they can find. Each frenzied encounter can last up to 14 hours. As soon as he’s done with one female, he moves on to another, leaving himself no time to eat, sleep or recharge his batteries.
As his levels of stress hormones rocket, his immune system plummets. The male exhausts himself so thoroughly that his body falls apart. His fur goes patchy, he develops gastric ulcers and he becomes unable to fight off infections. Then he dies. Male brown antechinuses never make it past their first birthday. They shag themselves to death and die at the end of their first and only breeding season.
Anglerfish
When the words ‘sexual’ and ‘parasitism’ are used in the same breath, you know it’s not going to be pretty. Sexual parasitism is a reproductive strategy where one organism uses the body of another to reproduce, often by physically attaching to them.
In the case of the anglerfish, small shrimpy males bite the bellies of big, bulbous females, and then hang on. In a plot worthy of a David Cronenberg film, the male’s body then fuses with the female’s body. Across weeks to months, their blood vessels merge. This enables the male to poach nutrients and oxygen from the female, whilst he provides her with sperm. The body parts he no longer uses, such as eyes, fins and most internal organs, wither away, until the male is little more than a sperm-filled bag.
This macabre arrangement can last for decades. The females live in an environment where males are scare, so it’s thought the strategy evolved to provide them with a continuous supply of sperm. And although the male doesn’t exactly die, it’s not much of a life either.
Honeybees
Honeybee society is structured into three different roles. There are queens who lay eggs. There are non-reproductive workers, who are female. And there are drones, who are male. Drones only have one purpose, which is to mate with a queen, but what seems like a privilege is in fact, a poisoned chalice.
Drones have a penis-like organ called an endophallus, which as the name suggests, is usually located inside his body. During mating, however, the organ is forcefully and explosively turned inside out, as it penetrates the queen.
The act is so violent, it creates a popping sound which is audible to the human ear and rips the drone’s phallus from his body. Intercourse occurs on the wing and lasts less than five seconds. Afterwards, unsurprisingly, the drone dies… but at least he goes out with a bang.
Yellow garden spiders
Male spiders don’t have penises, but they do have arm-like appendages called pedipalps, which they use to transfer sperm into a female’s body. Yellow garden spiders (Argiope aurantia) are a type of orb weaver spider found in North and Central America. When they deliver their sperm, they do it one pedipalp at a time. The first package is delivered without issue, but when the male inserts the second pedipalp, it all goes pear-shaped. His heart stops, his legs curl up and within 15 minutes he is dead.
The female doesn’t trigger this ‘spontaneous death.’ Instead, it is programmed into the male. After he dies, the male’s pedipalp remains wedged inside the female for a further 20 minutes or so. During this time, she is unable to mate with other males, so in a strange way, the suicidal strategy benefits the male because it makes his sperm more likely to fertilize her eggs.
Praying mantis
Sexual cannibalism does ‘what it says on the tin.’ The strategy, where one mate eats the other either before, during or after sex, has been spotted in insects, spiders, crustaceans and even some snakes.
Usually, it’s the female that eats the male. Take the praying mantis. In this species, it’s well known that females bite the male’s head off during sex. He sacrifices himself and she gets extra nutrition from eating his body.
What’s less well known however, is that sometimes headless, dead males continue to mate with the females after they’ve been beheaded. Call it muscle memory. Biologist Mike Maxwell, from the National University at La Jolla, California, has found that around half the decapitated males do this. He calls them the “headless horsemen!”
Black widow spider
Although hundreds of species practice sexual cannibalism, very few proactively offer themselves to their partner for consumption. The Australian black widow or redback spider is one of them.
After the male has inserted his first sperm-laden pedipalp into the female, he executes a unique 180-degree somersault, which positions his abdomen right in front of her mouthparts. Whilst she starts to devour him, he then has a second go at mating with the other pedipalp. It’s a ballsy move that doesn’t end well. Two-thirds of these males are eaten alive, whilst those who escape die soon after from their injuries.
Some males do manage to survive sex, however, by mating with immature females, who are less likely to cannibalize them. The females then retain the sperm and use it to produce offspring later.
Common European frog
Most of the time, when an animal dies during sex, it is the male of the species who succumbs. In the common European frog, however, females are at risk.
The frogs mate in springtime, when huge numbers congregate in ponds and lakes. Males vastly outnumber females, leading to fierce competition. Groups of up to eight or more males pile onto a single female, to create a dense ‘mating ball’ of frogs.
This is dangerous for the female at the center of the ruckus, but she has a few tricks up her sleeve. Females try to escape by squirming and mimicking the ‘release call’ that males make when they want to be left alone. If that fails, females pretend to be dead. But if that fails, the females can end up dead, either by suffocation or by drowning.
Bed bugs
Bed bug sex is brutal. Males practice ‘traumatic insemination’. They have a sharp, spear-like penis, which they use to stab through the female’s abdominal wall and inject sperm directly into her body cavity. The sperm then disperses through the female’s body in her hemolymph (insect blood), and ends up in the ovaries, where fertilization occurs.
Unsurprisingly, this is not good for her health. It creates an open wound, which leads to water loss and makes the female vulnerable to infection. Although the encounter doesn’t kill her immediately, it does significantly shorten her lifespan. Over the next five months, bedbugs that have been traumatically inseminated are twice as likely to die than similarly-aged females that manage to avoid it.
