It might be a little irritating when people tell you to fit more sleep into your already overloaded schedule, but they're not wrong — all across the animal kingdom, less sleep means worse performance. With one rather large, sex-mad exception.
The pectoral sandpiper spends most of its time far down in the Southern Hemisphere, then migrates all the way to the Alaskan tundra for the breeding season. Their breeding season is in May and June, when the Arctic Circle experiences near constant sunlight. And, as anyone who has seen either the Stellan Skarsgard or Christopher Nolan version of Insomnia, that isn't necessarily the best time and place to get a good night's sleep.
As it turns out, some of the male sandpipers eschew sleep almost entirely, spending all their permanently sunlit hours mating with as many females as possible. All previous research into animal sleep patterns would suggest this strategy would backfire on the insomniac sandpipers, with the more rested males proving the better maters in the long run. And yet, as Dr. Niels Rattenborg of the Avian Sleep Group explained to BBC News, the truth is the exact opposite:
"[Colleage Professor Bart Kempenaers] discovered that these male pectoral sandpipers were being incredibly active throughout the 24-hour period. We used a variety of methods to gain insight into what was actually going on up there. What were these sandpipers doing? We put transmitters on their back that could measure when they were moving. So we could record patterns throughout 24 hours, over a period of several week. We collected every egg on the study site, incubated them, hatched them and then got DNA from each of the chicks, so we could tell how many chicks a given male sired. Then we returned the chicks to the mothers out in the field."
In fact, the birds who slept the least — some were awake for as much as 95% of the day for weeks on end — were by far the most successful during the mating season. As Dr. Rattenborg explains, this flies in the face of everything we thought we knew about animals' sleep requirements. Somehow, these pectoral sandpipers have adapted to live on almost zero sleep. We do know that it's almost certainly a byproduct of their polygynous mating habits, which mean males try to breed with as many females as possible. The males of other sandpiper species that focus on just one potential mate showed far greater willingness to get a good night's sleep before resuming their mating activities.
One final point to keep in mind is that these pectoral sandpipers throw themselves into their sleepless sex marathon immediately after migrating thousands of miles. I'm tempted to say these sandpipers are the most virile things on the planet, but it might be wise to first know just what the female pectoral sandpipers think of the males', uh, unorthodox approach to mating season.