Sparring Hummingbirds (IMAGE) University of California - Berkeley Caption Sparkling violetear (Colibri coruscans) and Brown violetear (Colibri delphinae) displaying their neck-side feathers, so called "ears", trying to dissuade each other from using their bill weapons: strongly serrated bill edges and dagger-like tips. Credit Photo by Cristian Irian, Finca Colibrí Gorriazul, Colombia. Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.