Culture in Songbirds and Its Contribution to the Evolution of New Species

Abstract

No discussion of culture would be complete without considering learned behaviors in non-human animals. This chapter gives a brief overview of cultural phenomena in a variety of vertebrates, focusing on songbirds. Because they are amenable to both observation and experiment, songbirds provide excellent systems for studying culture. There is abundant evidence that variation in song is influenced by both genes and learning, and that song can play an important role in mate choice. Various forms of greenish warbler (Phylloscopus trochiloides) provide an example in which cultural evolution may have contributed to the evolution of two species from one. It is shown that: song structure differs greatly between two northern forms, which do not interbreed where they co-occur; song structure changes gradually around a ring to the south that connects the northern forms; singing behavior is relatively simple in the south but becomes increasingly complex to the north; and song varies along independent axes of complexity in the western and eastern south-north clines. This pattern was produced through an interaction between cultural and genetic evolution in response to changing levels of sexual selection.