The rally call recognition in males of two hybridizing partridge species, red-legged ( Alectoris rufa) and rock ( A. graeca) partridges

Abstract

The red-legged ( Alectoris rufa) and rock ( A. graeca) partridges hybridize and produce fertile offspring along a contact zone in French Southern Alps. The rally call emitted during pair formation, could play an important role in species recognition, acting as a behavioral reproductive isolating mechanism between males and females. In the present study, the coding system of the rally call was investigated from captive males of the two species and from F1 hybrids. By playing-back natural signals, we found that the two species as well as hybrid males responded to Alectoris signals but not to another species belonging to the Phasianidae family ( Colinus virginianus). Results also indicate that red-legged and rock partridges responded stronger to conspecific calls than to heterospecific ones. However, they reacted similarly to conspecific and hybrid calls. F1 hybrids responded stronger to hybrids calls than to the two species ones. They did not distinguish the two parental species signals from each other. Although the two species showed the ability to discriminate the conspecific from the heterospecific signal, they clearly responded to the other species. This behaviour may play a role in the hybridization phenomenon.