Mating season in the animal kingdom can be dramatic, and sometimes violent. As an example, take deer clashing their antlers during the rut – nostrils flaring, hooves hammering the ground, grass flying everywhere, and that eerie silence before the thunderous collision. The winning buck gets access to the harem, while the loser must find other females to fight for.
Many other animals also have formidable weapons. They range from rhinoceros beetles’ pointy horns to fiddler crabs’ proportionally gigantic claws and the long tusks of walruses and narwhals.
Birds also need to compete for their mates, which often involves fiercely defending a territory. But most birds don’t sport impressive weapons; we know them better for their colors, dances and songs. As evolutionary biologists primarily interested in birds and weapons, respectively, we couldn’t help but wonder: Why do most birds lack their own version of antlers? The answer, which we present in a recent study, likely lies in a trade-off between flying and fighting.
