Evolution of vocalizations in a frog family: are torrent ranid advertisement calls adaptive?. Sandra Goutte Muséum National dHistoire Naturelle Paris

Título: Evolution of vocalizations in a frog family: are torrent ranid advertisement calls adaptive?

Ponente: Sandra Goutte, Muséum National d'Histoire Naturelle, Paris

Resumen:

Signals used in intra-specific communication and crucial for reproductive success may be under environmental selective pressures and are thus potentially adaptive. Male anurans use acoustic signals to advertise their presence to potential mates. During their transmission, these signals are attenuated and distorted by the physical environment and this degradation depends on both the sound and the environment’s physical properties. Torrent dwelling anurans have to cope with the loud noise produced by the fast flowing waters, which may mask their calls. In these frogs, vocalizations minimizing masking by noise may thus have been selected.

We investigated the presumptive adaptive nature of vocalizations in torrent dwelling frogs in the family Ranidae. We first defined a torrent dwelling frog guild using fine scale habitat measurements, and built a molecular phylogeny of the study group with five molecular markers in order to frame the study in a phylogenetic context. We then used Ancestral State Reconstruction methods to track evolutionary changes in calling site preferences and vocalization characteristics in these frogs. Finally, we tested the Acoustic Adaptation Hypothesis (AAH) on vocalization and calling site characteristics and accounting for potential confounding factors (body size, temperature and phylogenetic relatedness) with comparative methods. We show that several kinds of advertisement calls evolved in torrents and find support for the AAH in some vocalization characteristics and reject it for others.