Behaviour 2019
High Intensity Mating Displays at Close Range in White Bellbirds
Jeff Podos1, Mario Cohn-Haft2. 1Univ. Massachusetts, Amherst, MA, United States; 2Inst. Nac. Pesq. Amazonia, Manaus, AM, Brazil

Courtship rituals often involve stereotyped display sequences that provide animals multiple opportunities for mutual assessment. As courtship rituals proceed, animals often come into increasingly close proximity, and transition their mating displays from high- to low-intensity. We here describe a blaring exception to this pattern, in one of the world’s loudest birds, the white bellbird (Procnias albus). We observed that courtship is initiated when a female alights on a tree in which a male is singing. The female then approaches the male in a series of short hops and flights. As this happens the male stays silent and swivels in place so as to maintain his back to the female. When the female arrives directly alongside the male, he inflates his throat, sings the first note of a song while facing away, and then swivels abruptly to sing the rest of his song facing the female. In this close-range context, we found that males always chose to sing the louder of two song types. Females always fluttered backwards as males swiveled, seemingly to evade the male's acoustic onslaught. It is unclear why males choose to apply a close-range courtship maneuver that females seem to find startling.