Development of sexual signals in bowerbirds (Ref: 4235)

Male bowerbirds are famous for their complex courtship displays that incorporate a bower decorated with coloured objects, vocalisations, and vigorous display movements. Despite the variety of signals that males produce when courting females, little is known about how the male constructs his bower, how his physical display movements interact with the bower display, and whether males adjust bower appearance or courtship displays in response to social and environmental changes. This project will quantify the female perspective of male displays to address novel questions about construction behaviour, multi-component courtship displays, perception, and female choice, in the great bowerbird Chlamydera nuchalis. This project will increase our understanding of movement-based courtship displays and their interaction with an extended phenotype by addressing the following questions: 1. How do males build bowers? Males build a new bower every year, and bower size and composition appear to vary across individuals. By quantifying how males construct and decorate their bowers, we will investigate variation in building behaviour and explore parallels with nest building behaviour more broadly. 2. Are courtship displays indicators of skill? When displaying to females, males pick up, shake and toss a variety of coloured objects, interspersed with presentations of their pink crest. By videoing the male's display from the female's point of view from within the bower and using markerless object tracking software, we will quantify how the motion of both the male and the objects he displays are perceived by the female, how males vary in their displays, and whether females prefer males that produce more skilful or vigorous displays. 3. What effect does urbanisation have on male displays? We will quantify court objects in urban and rural areas to determine how anthropogenic pollution can affect traits involved in sexual signalling.