Defensive behavior of Melanophryniscus genus, unken reflex. © Luis Fernando Marin da Fonte

Our work was initially motivated by curiosity about the true geographic range and abundance of the Admirable Red Belly Toad (ARBT), which grew into a sense of conservation urgency, due to the very small size of the very threatened known population. The known site is embedded in a small forest fragment surrounded by a heavily deforested agro-industrial landscape. A nearby tourist facility and upstream pesticide use expose the site to direct and indirect human threats. Until 2014, there was also a plan to build a small hydroelectric power plant upstream of the site. Through a combination of institutional networking and support from the state public prosecutor’s office, we managed to revert the government authorization to build the plant and, in the process, upgrade the risk category of ARBT to “Critically Endangered” in the IUCN, Brazil, and Rio Grande do Sul red lists.

The work proposed here aims to strengthen conservation action with an efficient observation system that will improve knowledge of the ARBT population and facilitate in-site protection actions. The main contributions of the monitoring work will be population assessment and projection. If we succeed in identifying environmental triggers of reproductive events, our results will contribute a substantial improvement in monitoring efficiency. During 70 days of field monitoring, from October 2010 to the present, 90% of individual toad captures took place in just one third of the days. This is a consequence of the unpredictability of ARBT reproductive events, which last two to five days and result in many captures when the toads are reproducing but hardly any when they are not. In this project, we propose to set up a web-connected camera surveillance system, working seven days a week, which will achieve a sevenfold increase in our ability to detect reproductive events. Relatively precise abundance estimates will also improve our ability to measure variation in population size, which is a key component of stochastic population growth models that assess extinction risk into the future.

Finally, the analysis of how weather and river flow may trigger reproductive events will allow us to better anticipate (not just respond to) the onset of toad activity. With this knowledge, we can improve timing of conservation actions and sampling efficiency, not just at our site but at other locations were the species may be present but yet unknown.