The underground sex life of the Guatemalan Spike-thumb Frog (Plectrohyla guatemalensis)

Two populations of Plectrohyla guatemalensis from two different sites in Sacatepéquez, Guatemala, were monitored for three consecutive rainy seasons, and noteworthy reproductive behavior was observed. The objective of the surveys was to assess the impact of nearby high-tension power lines, but additional information could be obtained. Our observations that male vocalizations to attract females occurred in the crevices of rocks in streams, inside which females lay eggs, suggest that the species' reproduction is closely linked to the presence of such crevices. Any clutches were then guarded by the male until hatching. We inferred the existence of male-male competition for gaining control of these reproduction sites building upon previous observations, remarks about the genus and other species with similar patterns, and evidence of such aggression, although we did not directly observe any. Also, with the help of local wardens, we recorded vocalizations in mid-January, extending the previously reported reproductive period for this species. We therefore consider the conservation and restoration of rocky streams with adequate forest coverage to be an important conservation action for this species.