Recovering from a flood

Penguins in the Antarctic every summer are in danger of having their simple stone nests become flooded. So, the females go looking for fresh pebbles to shore up their house. Some get them by stealing, which often results in a fight. Others target the nests of unsuccessful males living at the edge of the colony. With no parental duties, these singletons are free to go on pebble-hunting sprees and amass veritable stone castles. They are also extremely desperate to spread their seed. And about a third of the females will help them spread it. Scientists say that the sex is a swift affair; many of the inexperienced males misfire and miss their target. The female then toddles back to her nest with a pilfered pebble in her beak. Some especially cunning females flirt but skip the sex part, and simply make off with a stone. One particularly effective hustler was recorded swiping 62 pebbles within an hour.