Abstract:
Little is known about how vocal mimicry affects the behaviour of members of other species. Such effects
might, however, be especially likely in mixed-species flocks in which birds of some species directly benefit
from the behaviour of members of other species. In mixed-species flocks in Sri Lanka, the greater rackettailed
drongo, Dicrurus paradiseus, mimics the songs and contact calls of other flock participants. We hypothesized
that this mimicry attracts other species, as drongos are well known to increase their foraging
efficiency in association with other species. Consistent with the predictions of this hypothesis, we recorded
the most mimicked vocalizations during the rare occasions in which drongos were outside of flocks.
In addition, we performed a playback experiment, which showed that taped drongo vocalizations that included
song mimicry were more than twice as attractive to birds of other species as were taped vocalizations
that lacked mimicry. We suggest that mimicry is a way in which drongos manage the behaviour
of flockmates in what appears to be overall a mutualistic relationship.
