Sex That Kills
Male antechinus mate so intensively — up to 14 hours at a time — that every single male dies within weeks of the mating season.
The brown antechinus, a small Australian marsupial, has one of the most extreme mating strategies in nature: males literally mate themselves to death.
During the 2-3 week breeding season, male antechinus engage in marathon mating sessions lasting up to 14 hours at a time. They mate with as many females as possible, barely stopping to eat or sleep.
The physical toll is catastrophic: - Stress hormones flood their bodies - Fur falls out in patches - Internal organs begin to fail - Immune systems collapse - They develop ulcers and infections
Within 2-3 weeks of the breeding season starting, every single male is dead. Not some of them — all of them.
Why evolve such a self-destructive strategy? It's called semelparity — reproducing once then dying. The theory is that by putting every ounce of energy into one mating season, males maximize their reproductive success even at the cost of their lives.
The females, meanwhile, live on to raise the young. They typically survive 2-3 breeding seasons.
This "suicidal reproduction" is rare in mammals but evolved independently in several antechinus species across Australia. The intensity of competition — all breeding happening in a short window — drove this extreme adaptation.