Electrocuted! Amphibian deaths caused by electric discharge

Several studies have mapped the causes responsible for amphibian declines. Although habitat loss and overutilization have been pinpointed as the main motivators of this declines, others biological and anthropic factors have impacted amphibian communities such as the use of road salt, catastrophic events and fires. We described an episode of anuran deaths caused by eletric discharge in the wild. On 07 November 2016 a group of dead mature frogs was found in a temporary pond located at Universidade Federal do Rio Grande, Rio Grande municipality, Rio Grande do Sul state, Brazil (-32.0754 S -52.1689, 7 m a.s.l.). All of them were found in a ca. 2-meter radius between a lamppost and electric energy font, both flooded partially. Diurnal vertebrates were not affected by electric discharge once that electric flow was interrupted by a photocell light-sensitive module during daylight. We used a Minipa Et- 3110 Digital Clamp Multimeter to measure voltage in the water and recorded a current of 34.8 volts. A total of 15 dead individuals were recorded: Elachistocleis bicolor (2 males and 2 females), Leptodactylus latrans (1 male and 5 females), one male of Pseudopaludicola falcipes, one male of Rhinella arenarum, and three undentified individuals. The number of deaths by electric discharge was underestimated, seeing as some individuals were consumed by native birds. Dead specimens were deposited at the Herpetological Collection of FURG (CHFURG 5258-5269). Our concern regarding anuran mortality caused by dissipated electricity is the synchronism between the formation of temporary ponds and anuran aggregation for reproduction. Such a confluence of events should be highlighted in our study area, since it is the preferred breeding habitat for most species. Additionally, this scenario may impact tadpoles that develop at that same pond. Up our knowledge, there are no previous studies reporting amphibian mortality caused by incidental electric discharge.