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

The red-legged (Alectoris rufa) and rock (A. graeca) partridges hybridize a nd 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 mecha nism 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 f rom Fl hybrids. By playing-back natural signals, we found that the two spec ies as well as hybrid males responded to Alectopis signals but not to anoth er species belonging to the Phasianidae family (Colinus virginianus). Resul ts also indicate that red-legged and rock partridges responded stronger to conspecific calls than to heterospecific ones. However, they reacted simila rly to conspecific and hybrid calls. Fl hybrids responded stronger to hybri ds calls than to the two species ones. They did not distinguish the two par ental species signals from each other. Although the two species showed the ability to discriminate the conspecific from the heterospecific signal, the y clearly responded to the other species. This behaviour may play a role in the hybridization phenomenon. (C) 2001 Published by Elsevier Science B.V. All rights reserved.