ABOVE: Sparkling violetear (Colibri coruscans) and Brown violetear (Colibri delphinae) with sharp, serrated bills puff out their “ears,” feathers on either side of their necks, as part of their combat ruse.
PHOTO BY CRISTIAN IRIAN, FINCA COLIBRÍ GORRIAZUL, COLOMBIA
Males of several species of South American hummingbirds have evolved weaponized bills that better equip them for fighting off competition for food and mates, researchers reported on January 2 in Integrative Organismal Biology. High-speed video captured these feisty hummers poking and even pinching each other. Typically, hummingbirds have flexible bills with spoon-like tips that let them drink a flower’s nectar down to the last drop. The adaptations that enable their fighting—stiffer and straighter bills, sometimes with hooks and serrated edges—are trade-offs that cut into their efficiency at sucking up nectar.
