A Bird’s Stinky Egg Is Actually a Humblebrag
Female hoopoes will paint their eggs with a brownish goo, in a bid for greater male attention.
In preparation for birth, some expectant human parents will build IKEA cribs or down prenatal vitamins. Female hoopoes douse their eggs in a pungent postcoital goo.
Shortly after laying their eggs, these delightfully zebra-striped birds will begin to paint the clutch with their beak. The pigment they use is made in-house—a brown, oily substance secreted by the uropygial gland, located at the base of the female’s tail. The eggshells start out cerulean, but with each coat of fluid, they transform into a mucked-up greenish-gray. Though subtle in appearance, the secretions are rank: Thanks to the bonanza of bacteria within, they reek like “a very strong and smelly cheese,” tinged with a putrid , Juan José Soler, a biologist at
