TY - JOUR

T1 - Bilateral Song Convergence in a Passerine Hybrid Zone

T2 - Genetics Contribute in One Species Only

AU - Secondi, Jean

AU - Bordas, Paul

AU - Hipsley, Christy A.

AU - Bensch, Staffan

PY - 2011

Y1 - 2011

N2 - Hybridization can drive the convergence of territorial and sexual signals. However, non-genetic processes such as competition, environment matching, or cultural transmission, also generate this pattern. We investigated the effect of hybridization on song convergence between two interspecifically territorial warblers in a moving hybrid zone. We confirmed song convergence in each species. Using an AFLP-based genetic index, we detected an effect of genetics on song convergence in Hippolais polyglotta, the expanding species. Evidence was weaker for H. icterina, the receding species. In moving zones, introgression is expected to be larger in the expanding species than in the receding. Thus, the asymmetric contribution of the genetic index to convergence was consistent with expectations for genetically determined traits in moving hybrid zones, and the observed introgression pattern of AFLP markers. However, the geographical location of individuals had an effect on song variation too when genetics was accounted for, suggesting that convergence also has non-genetic explanations. We examine the possible role of alternative processes to that of hybridization and discuss their conflicting effects on reinforcement and hybrid zone dynamics.

AB - Hybridization can drive the convergence of territorial and sexual signals. However, non-genetic processes such as competition, environment matching, or cultural transmission, also generate this pattern. We investigated the effect of hybridization on song convergence between two interspecifically territorial warblers in a moving hybrid zone. We confirmed song convergence in each species. Using an AFLP-based genetic index, we detected an effect of genetics on song convergence in Hippolais polyglotta, the expanding species. Evidence was weaker for H. icterina, the receding species. In moving zones, introgression is expected to be larger in the expanding species than in the receding. Thus, the asymmetric contribution of the genetic index to convergence was consistent with expectations for genetically determined traits in moving hybrid zones, and the observed introgression pattern of AFLP markers. However, the geographical location of individuals had an effect on song variation too when genetics was accounted for, suggesting that convergence also has non-genetic explanations. We examine the possible role of alternative processes to that of hybridization and discuss their conflicting effects on reinforcement and hybrid zone dynamics.

KW - Competition

KW - Cultural transmission

KW - Hippolais icterina

KW - Hippolais polyglotta

KW - Hybridization

KW - Interspecific territoriality

U2 - 10.1007/s11692-011-9133-8

DO - 10.1007/s11692-011-9133-8

M3 - Journal article

AN - SCOPUS:81255160903

VL - 38

SP - 441

EP - 452

JO - Evolutionary Biology

JF - Evolutionary Biology

SN - 0071-3260

IS - 4

ER -