Out of nearly twenty-five thousand calls he recorded, only twenty-four were this whistle. Schwing believes it’s a very personal communication between one bird and another that seems to say, “I want to have close contact.” A video he took of the whistle call shows a male perched on a bench. A female lands and moves toward him to preen him, but he kicks her away. She jumps back and then whistles quietly. He immediately lowers his head and allows her to come in and preen him.
