According to lead scientist on the project and Miller Postdoctoral Fellow at UC Berkeley Alejandro Rico-Guevara, physical traits observed in male hummingbirds in the tropics of Central and South America could not be explained through adaptations to feeding strategies.

Alexander Stubbs of the University of California, Berkeley, and Fernando Montealegre-Z of the University of Lincoln in England studied a recording of the sounds made by diplomats and published by The Associated Press.

Using high-speed video cameras, the researchers have for the first time captured hummingbird fencing and feeding strategies in slow motion to document the various ways the birds use their bills to fight and the trade-offs they accept when choosing fighting over feeding prowess.