Print PageSexually dimorphic traits are used for mate selection either by female choice (intersexual selection) or male – male competition (intrasexual selection). In anurans, past evidence has shown that either type of selection mechanism, although more commonly intersexual selection, will generally favor large males. In bufonids, however, male size does not seem to be a factor in mate selection. Very little is known about the mating preferences of the endangered Houston Toad (Bufo houstonensis). Studies examining the breeding dynamics of B. houstonensis were conducted during the early 1980’s, however, results were conflicting. To further examine mate selection, 329 Houston toads were collected from Bastrop State Park, Texas and the snout-urostyle length (SUL) measured. We used a t-test to assess a difference in SUL between male and female toads and a 2 factor ANOVA to asses if the SUL of males was significantly different between two breeding ponds (ponds 9 and 10) or significantly different among amplexus status (in amplexus or not in amplexus).
Results/Conclusions
There was no significant difference in size for males found in amplexus and those not in amplexus and pond location was not a factor, therefore females are not selecting larger males. Current Houston Toad populations and consequent breeding pond densities may not be large enough to be an effective sample size for studying mate selection and reproductive ecology. This provides both an increased impetus for analyses of historical data and highlights the crucial nature of long term, high quality curation of endangered species datasets. Future research should involve evaluations focusing on pond densities, call variables, time spent at breeding sites, and arrival times to breeding sites in order to further understand the nature of mate selection among Houston Toads.
