Method of sex determination of whistling ducks by their loud whistles
White-faced, Fulvous, Cuban and Red-billed whistling ducks are among favorite species in zoo animal collections. In this summer, all the four species can be seen on ponds of Moscow Zoo. In contrast to many other ducks, male and female whistling ducks are undistinguishable as twins. The superficial resemblance is extended also on equality in their parental obligations toward their offsprings. Paired males and females built a nest together and sit on eggs in turn. When ducklings are hatched, a mother and a father together guide them to a pool, with one parent walking and another flying over the family and observing whether any danger is nearby.
Up to currently, zoo keepers used for sexing whistling ducks either cloacal or DNA analysis. Both the methods need capturing and unpleasant for birds procedures of eversion of the cloaca or taking feathers for further DNA extraction for analysis. No method of distant sexing was available. Now researchers of Moscow Zoo and of Tierpark Berlin proposed a new bioacoustical approach, not demanding capturing and handling (article), that is applied both in zoos and in nature. This method is based on the acoustic analysis of the loud whistles, with which the ducks themselves report their sex to an observer. The acoustic recordings of the loud whistles of all the four species are free available for listening and downloading in the Animal Sounds Gallery on web-site of Moscow Zoo.
Photo – a male and a female Fulvous whistling ducks