The mating ritual of a rainforest tinamou, Tinamus major

Abstract

The mating systems of many tropical birds remain poorly understood, especially those that elude observation in dense rainforest understories. Here we dissect mating behaviors between two Great Tinamous, Tinamus major (Tinamidae), a secretive species with a wide range across the lowland Central and South American tropics. Despite anecdotal preconceptions that males court the females, we observed courtship displays solely from the putative female tinamou. In this mating ritual recorded in their natural habitat, we observed clucking and soft-rolling songs along with a suite of courtship displays, such as neck-elongation, tail-raising, crouching, and feather-fluffing performed by the putative female. In contrast, the putative male watched while standing still, approached, walked away, and carried out a few mounting attempts. The clucking and soft-rolling songs sung by the putative female were of lower frequency, energy, and amplitude, but higher entropy than the common morning territorial songs recorded in the vicinity. The clucking song by the putative female was not previously described but we repeatedly observed this song type immediately before the soft-rolling songs during the behavioral displays. Clucking was of lower frequency and energy, and around ten times shorter than the soft-rolling songs. This behavioral auditory analysis enriches understanding of rainforest tinamou mating rituals and motivates scrutiny of the partition of courtship roles between sexes in a male parental-care mating system with little sexual dichromatism and reversed sexual size dimorphism.