Heterospecific rival recognition in Black Redstart Phoenicurus ochruros

Abstract

It has long been hypothesized that birds learn to recognize heterospecific competitors and for that reason males behave more aggressively against intruders in areas of local sympatry. Recently, it has been confirmed that individuals of one species are able to learn species-specific visual and acoustic characteristics of heterospecific rivals and that they are able to remember these associations. Here, we test hypotheses about the importance of learning in interspecific interactions, long-term memory of species-specific traits and early timing of this learning to the post-fledging period in the Black Redstart (Phoenicurus ochruros). We show that Black Redstart males respond to playbacks of Redstart (P. phoenicurus) only in the areas where the two species come into close contact. This result demonstrates that Black Redstart males learn individually to recognize the rival species in areas of local coexistence. Black Redstart males responded in heterospecific experiments before the arrival of Redstarts from wintering grounds. This means that birds are able to retain the memory of specific traits of heterospecific competitors to the next breeding season. Moreover, yearling and older males, which differ in plumage colouration, responded in heterospecific experiments with the same frequency and intensity. This result indicates that young males learn to recognize Redstarts in the post-fledging period before a first contact with heterospecific rivals in a territorial context.