| Autor: |
Sinsch U; Institute of Integrated Sciences, Department of Biology, University of Koblenz-Landau, D-56070 Koblenz, Germany., Hecht K; Institute of Integrated Sciences, Department of Biology, University of Koblenz-Landau, D-56070 Koblenz, Germany., Kost S; Institute of Integrated Sciences, Department of Biology, University of Koblenz-Landau, D-56070 Koblenz, Germany., Grenat PR; Ecología, Departamento de Ciencias Naturales, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Ruta Nacional N° 36-km 601, Río Cuarto X5804BYA, Argentina.; Instituto de Ciencias de la Tierra, Biodiversidad y Sustentabilidad Ambiental (ICBIA), Universidad Nacional de Río Cuarto-CONICET, Río Cuarto X5804BYA, Argentina., Martino AL; Ecología, Departamento de Ciencias Naturales, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Ruta Nacional N° 36-km 601, Río Cuarto X5804BYA, Argentina.; Instituto de Ciencias de la Tierra, Biodiversidad y Sustentabilidad Ambiental (ICBIA), Universidad Nacional de Río Cuarto-CONICET, Río Cuarto X5804BYA, Argentina. |
| Abstrakt: |
Mate choice is the attempt of an individual to gain higher reproductive fitness by preferring to mate with some individuals and not with others. We studied the role of mate choice in the mating system of the neotropical toad Rhinella arenarum by assessing male reproductive tactics for mate acquisition and the contribution of female choice for pair formation. In a shallow pond in central Argentina, we estimated male mating success and the corresponding reproductive tactics by focal observation. The variation of phenotypic and genotypic traits (size and shape, longevity, vocalization features, heterozygosity) was related to the observed mating success in 110 males. The phonotactic response of 21 reproductive females to conspecific advertisement call features was tested in arena experiments. Mating success was limited to 32 males, pair formation was size-assortative. The dominant reproductive tactics were advertising from call positions near suitable breeding sites and pre-mating fights with intruding males, whereas the interception of amplectant pairs and the displacement of mated males were never observed. Female phonotaxis was directed to conspecific choruses but complex and simple call structures were not distinguished. We conclude that the mating system is a lek combining pre-mating fights among males and female choice of slightly smaller males. Fights interfere with female choice, undermining size-assortative mating. This is a unique system in the R. marina species group, in which interception behavior dominates reproduction. |
