In this context, we study the endocrine, molecular, and neurobiological mechanisms of innate and learned vocalizations for various bird species in a natural setting. Birds, in particular songbirds display a large variety of gender-specific singing behaviour. In most bird species, male singing behaviour plays a role in direct or indirect competition for females, and female mate choice is based on vocal performances of the males.
In songbirds, songs consist of genetically determined and learned components. Further, learning changes female preferences for male songs. Thus, learning is crucial for both the production of sexual signals and the response to sexual signals, i.e. learning is central for vocalization-based sexual selection in songbirds. The acquisition of auditory memories, the transformation of auditory memories into motor memories, and the subsequent use of motor memories is influenced by the physiological, endocrine conditions and/or the socio-sexual experience of an individual. Thus, song development and production is sensitive to sex steroid hormones (androgens and estrogens) and other endocrine systems (e.g. melatonin) that signal environmental changes.
The anatomical and functional distinctness of the vocal control system of songbirds as well as the large data base on natural behaviour of songbirds makes the vocal system suitable for investigating the genetic and environmental causes of neural sex differences and their consequences for sexual behaviour. Further, we study other bird models that show distinct sex-specific vocal behaviours such as crowing behaviours of chicken. The projects are multidisciplinary and integrate works on the level of gene expression, endocrinology, neuroanatomy, electrophysiology and behaviour in semi-natural and natural conditions.