Why do penguins give each other stones?
Among Adélie penguins in Antarctica, a smooth little pebble is hard currency—practically worth its weight in gold. There are no twigs or grass stems around, so they use pebbles to raise their eggs off the ground and build nests that drain well, keep out the cold, and stand up to the wind. A well-built nest can determine whether an egg hatches, so female penguins care a lot about whether a potential mate can find good stones.
When courting, male penguins present pebbles one by one—a sort of “first-meeting gift” in the penguin world. But stones aren’t just collected; they’re stolen, too. Pebbles are scarce, and males often sneak into a neighbor’s nest to pinch some while the owner is out. An even more interesting observation, published in The Auk in 1998, found that female penguins would secretly mate with single males and then carry a pebble back to their own nest. One account recorded 62 “transactions” in a single hour (we’ll spare you the many details).
So while giving stones may look romantic, it’s actually a very real investment in survival. A male is showing off not only his ability to find stones, but also his ability to hold on to them. What would you use to “propose”?
Among Adélie penguins in Antarctica, a smooth little pebble is hard currency—practically worth its weight in gold. There are no twigs or grass stems around, so they use pebbles to raise their eggs off the ground and build nests that drain well, keep out the cold, and stand up to the wind. A well-built nest can determine whether an egg hatches, so female penguins care a lot about whether a potential mate can find good stones.
When courting, male penguins present pebbles one by one—a sort of “first-meeting gift” in the penguin world. But stones aren’t just collected; they’re stolen, too. Pebbles are scarce, and males often sneak into a neighbor’s nest to pinch some while the owner is out. An even more interesting observation, published in The Auk in 1998, found that female penguins would secretly mate with single males and then carry a pebble back to their own nest. One account recorded 62 “transactions” in a single hour (we’ll spare you the many details).
So while giving stones may look romantic, it’s actually a very real investment in survival. A male is showing off not only his ability to find stones, but also his ability to hold on to them. What would you use to “propose”?