This work involved acoustic analysis of the song of individual colour-ringed males and assessment of breeding success, including molecular paternity analysis. In addition to this work I have continued to examine the selection pressures influencing avian tail shape. This research involves the use of novel stereo-video techniques to reconstruct the flight paths of birds in 3 dimensions. Using experimental manipulations it is then possible to test the role of tail morphology for a variety of flight parameters. Current research From Jan 2001 I will be involved in a project examining the role of early developmental stress on song production by adult birds.
Female birds use male song to make mate choice decisions in a range of common bird species.
Furthermore, we know that both the amount of song and the song structure are important to females. Theoretical models examining the evolution of sexual signals suggest that such signals must be costly to produce or maintain to remain evolutionary stable. We assume that males which sing for a long time are honestly advertising their quality as the time spent singing might reflect physiological condition, ability to evade predators or resource possession, for example. We have recently demonstrated that parasitized male sedge warblers have simpler repertoires than uninfected males, suggesting that the complexity of song which a male can produce may also be condition-dependent. A large body of work exists documenting the early development of the brain nuclei controlling song learning and production.