title: Female Sexual Preferences Toward Conspecific and Hybrid Male Mating Calls in Two Species of Polygynous Deer,Cervus elaphus andC. nippon.
abstract: The behavioral processes at the basis of hybridization and introgression are understudied in terrestrial mammals. We use a unique model to test the role of sexual signals as a reproductive barrier to introgression by investigating behavioral responses to male sexual calls in estrous females of two naturally allopatric but reproductively compatible deer species, red deer and sika deer. Previous studies demonstrated asymmetries in acoustic species discrimination between these species: most but not all female red deer prefer conspecific over sika deer male calls while female sika deer exhibit no preference differences. Here, we extend this examination of acoustic species discrimination to the role of male sexual calls in introgression between parent species and hybrids. Using two-speaker playback experiments, we compared the preference responses of estrous female red and sika deer to male sexual calls from conspecifics versus red × sika hybrids. These playbacks simulate early secondary contact between previously allopatric species after hybridization has occurred. Based on previous conspecific versus heterospecific playbacks, we predicted that most female red deer would prefer conspecific calls while female sika deer would show no difference in their preference behaviors toward conspecific and hybrid calls. However, results show that previous asymmetries did not persist as neither species exhibited more preferences for conspecific over hybrid calls. Thus, vocal behavior is not likely to deter introgression between these species during the early stages of sympatry. On a wider scale, weak discrimination against hybrid sexual signals could substantially contribute to this important evolutionary process in mammals and other taxa.
authors.affiliation: Mammal Vocal Communication and Cognition Research, School of Psychology, University of Sussex, Falmer, BN1 9QH UK ; Department of Wildlife, Fish and Conservation Biology, University of California, 1331 Academic Surge Building, One Shields Ave., Davis, CA 95616 USA.
authors.forename: Megan T
authors.initials: MT
authors.lastname: Wyman
authors.affiliation: Muséum National d'Histoire Naturelle, Réserve de la Haute Touche, 36290 Obterre, France.
authors.forename: Yann
authors.initials: Y
authors.lastname: Locatelli
authors.affiliation: School of Biology and Environmental Science, University College Dublin, Belfield, Dublin 4, Ireland.
authors.forename: Benjamin D
authors.initials: BD
authors.lastname: Charlton
authors.affiliation: Mammal Vocal Communication and Cognition Research, School of Psychology, University of Sussex, Falmer, BN1 9QH UK.
authors.forename: David
authors.initials: D
authors.lastname: Reby
keywords: Deer; Hybridization; Introgression; Mating; Sexual communication; Sexual preference; Species discrimination; Vocalization