Sleep is a luxury. Many of us snooze our alarms in the morning, forgoing breakfast for a few extra hours of rest. The same is true in the animal kingdom. Koalas sleep for up to twenty-two hours per day! Another marsupial, however, does precisely the opposite. Male dusky antechinuses, mouse-like marsupials native to Australia, sacrifice sleep for sex to make the most of their short lifespan. They live for only one year—a single reproductive cycle—and have thus evolved a fascinating strategy to ensure the species’ survival: having as much sex as possible in three weeks.
In a study that tracked dusky antechinuses over several years, researchers observed that males competed with one another for access to females during mating season. An intense courting process involving consecutive couplings with multiple partners favored animals who could shrug off exhaustion to sire more offspring. Therefore, natural selection results in the prevalence of males able to sustain an inordinately high “activity level” and reduce sleep time by at least three hours per night.
However, sleep deprivation is not without its consequences. This is true even for antechinuses, who have adapted to a state of minimal rest by taking tiny “naps” throughout the day. At the end of a mating season, male antechinuses die en masse for reasons not yet entirely understood. Living short yet eventful lives, these marsupials embody the motto of pleasure-seekers worldwide: “We’re here for a good time, not a long time.”