To trill or not to trill? Territorial response to a heterospecific vocal trait in male collared doves, Streptopelia decaocto

Responding of individuals outside the conspecific range has been largely explained by biases in sensory or cognitive systemstoward particular traits or trait values. More recently, it has been shown that such responses might occur if individuals stillrespond to signal traits that have been lost over time.

Jean Secondi et al, Behavioral Ecology Vol. 14 No. 5: 694-701