Biol. Lett. doi:10.1098/rsbl.2010.0165 (2010)

In Darwin's finches, males learn to sing from their fathers. Song types can persist from one generation to the next, but for how long?

Eben Goodale and Jeffrey Podos at the University of Massachusetts, Amherst, compared song recordings from medium ground finches (Geospiza fortis) on Santa Cruz Island in the Galapagos made in 1961 and 1999. They found that, despite copy errors and other modifications, several song types persisted over almost four decades with remarkable fidelity. Certain parameters, such as trill rate, number of notes and song duration remained unchanged.

Male offspring that fail to reliably copy their father's song might be less successful at mating, the researchers suggest.