To attract females, male birds perform spectacular songs and dances. Studies of song have influenced our thinking about how brains adapt for vocal learning, and, because songs are a part of courtship, have taught us how gonadal hormones regulate vocal signals. However, the dances that elevate bird songs to elegant courtship displays have been neglected by scientists. Given the exciting implications of hormone regulated neuroplasticity in brain-motor systems involved in dance, it is surprising that more research has not been done in this this area. This project will use a comparative approach employing neuroanatomical and molecular techniques to determine if the complexity of neural architecture and hormone sensitivity in motor brain regions, like the cerebellum, are positively associated with dance complexity in birds. Thirteen species of the manakin family (Pipridae) that have a range of dance complexities will be compared. Males of a species with one of the most complex displays announce the breeding season with firecracker-like snaps of the wings that punctuate flips performed so fast that high-speed cameras are required to see them. Males of a species with the simplest displays perform a vocal display but have no dance. Imagine how the brains of the former and latter species must differ. The major impact of this study will be to reveal capabilities of the cerebellum and other motor regions to flexibly adapt to demands for motor complexity and to be responsive to hormones in a way not thought possible of motor brain regions. This project will train several graduate and undergraduate students and offers learning opportunities in Central and South America while involving locals in fieldwork. The project will provide tissue samples to museums, create a bank of virtual brain sections, and share DNA sequences for hormone receptors via NCBI websites.
