Song sparrows use threatening signals against territorial threats
Washington, February 13 : Territorial song sparrows have a hierarchical warning scheme in place when they need to ward off trespassing rivals, according to a new study.
First an early warning that matches the intruder's song, then wing waving - a bird's version of "flipping the bird" - as the dispute heats up, and finally, if all other signals have failed, attack.
"This is one of the most complicated communication systems outside of human language," said lead author Çaglar Akcay, who did the study as a UW graduate student. He is now a postdoctoral researcher at Cornell University.
"Here we find that if a sparrow matches the intruder's song as the intruder invades his territory, this almost always predicts that he will eventually attack the intruder," Akcay said.
The study is the first evidence that song-matching is used as an early warning signal.
The finding have been published in the Proceedings of the Royal Society B.