Here we present an acoustic approach for reliable sexing in four whistling duck species from the genus Dendrocygna and compare it with molecular and cloacal inspection techniques. In the four examined species, the White-faced Whistling Duck D. viduata, Fulvous Whistling Duck D. bicolor, Cuban Whistling Duck D. arborea and Red-billed Whistling Duck D. autumnalis, sexes are indistinguishable by appearance. However all the four species show strong sexual differences in the structure of their species-specific loud whistles. For 59 examined birds, an acoustic-based sexing showed 100% accordance to the DNA PCR analysis, while the cloacal inspection showed only 89.8% accuracy. The results demonstrate that acoustic sexing represents a feasible alternative to the two traditional methods as a nonabrasive tool for the distant sexing of the four whistling duck species both in captivity and in the wild.
sexual dimorphism, call, vocalization, DNA PCR analysis, cloacal inspection, Dendrocygna, Anatidae