The function of displays of male Rufous Hummingbirds

We observed 26 male Rufous Hummingbirds (Selasphorus rufus) on their breeding territories to quantify display behaviors and to interpret their functions. Territory holders responded to intruding conspecific males with aggressive chases until the intruder left the territory. Female intruders received dive displays and shuttle-flights, which we interpret as courtship behavior. Dive displays were J-shaped (concave upward) in both ascent and descent, contrary to other reports of oval-shaped displays. We present a representative sonogram of the sounds produced during these dive displays.