Date: June 12, 2019
When a male or female white-browed sparrow-weaver begins its song, its partner joins in at a certain time. They duet with each other by singing in turn and precisely in tune. A team led by researchers from the Max Planck Institute for Ornithology in Seewiesen used mobile transmitters to simultaneously record neural and acoustic signals from pairs of birds singing duets in their natural habitat. They found that the nerve cell activity in the brain of the singing bird changes and synchronizes with its partner when the partner begins to sing. The brains of both animals then essentially function as one, which leads to the perfect duet.
White-browed sparrow-weavers (Plocepasser mahali) live together in small groups in trees in southern and eastern Africa. Each bird has a roosting nest with an entrance and an exit. The dominant pair will have a breeding nest which is easily recognisable by the fact that one passage is closed to prevent eggs from falling out. In addition to the dominant pair, there are up to eight other birds in the group that help build nests and raise the young. All group members defend their territory against rival groups through duets of the dominant pair and choruses together with the helpers.
White-browed sparrow-weavers are one of the few bird species that sing in duet. It was assumed that some cognitive coordination between individuals was required to synchronise the syllables in the duet, however the underlying neuronal mechanisms of such coordination were unknown.