Drivers of vulnerability to extinction of Brazilian amphibians: insights for conservation

Abstract

(1) To evaluate which biological characteristics and environmental factors tend to make amphibian species vulnerable to extinction. (2) With this knowledge, we can provide suggestions for improving conservation planning and actions. Working Plan: Although extinction risk assessments are an important step in biodiversity conservation by providing valuable information on vulnerabilities and threats (Stuart et al., 2004; Martins & Molina, 2008; Böhm et al, 2013; ICMBio-MMA, 2018; IUCN, 2020), they are not able to produce a broad assessment of the biological characteristics of species that make them vulnerable to extinction (e. g., Bielby et al., 2006; Böhm et al., 2016). Several intrinsic and extrinsic characteristics can predispose species to extinction, either by natural causes or by the impacts that mankind causes in their habitats, and the knowledge of these characteristics is very useful in conservation because it subsidizes planning and allow improvements in action plans (Cardillo et al., 2004; Böhm et al., 2016). This project aims to assess which biological characteristics and environmental factors factors tend to make amphibian species vulnerable to extinction and, with this knowledge, provide suggestions for the improvement of planning and conservation actions. Methodology: The variable used to indicate vulnerability to extinction will be the IUCN threat status (2012) of each Brazilian amphibian species on the current list of threatened species (ICMBio-MMA, 2018), with a scale of five levels: from value 1 for Least Concern (LC) to value 5 for Critically Endangered (CR; e. g., Cardillo et al., 2004). Distribution maps will be produced for all species (Extent of occurrence, IUCN, 2012), based on the occurrence data used in the amphibian conservation status assessments. conservation status of amphibians by RAN-ICMBio, as well as additional data not yet accessed during the assessments, which will be sought in a systematized way (see, e. g., Birskis-Barros et al., 2019).The following characteristics will be tested regarding vulnerability to extinction (predictive variables): degree of habitat specialization (number of occupied habitats), ability to maintain populations in altered areas (with input from experts), body size (maximum CRC), fecundity, and reproductive mode. The environmental predictor variables will include annual rainfall, average rainfall for the wettest quarter, average annual temperature, average temperature for the hottest quarter, altitude (Hijmans et al., 2005), and primary productivity (Imhoff et al., 2004). Human influence (CIESIN, 2005b) will also be tested as a predictor variable. All environmental predictor variables will be extracted along the distribution of each species using geographic information system software (e.g., ArcGIS, QGIS). The most recent and complete amphibian phylogenies (e.g., Frost et al., 2006; Pyron & Wiens, 2011) will be used in the analyses to eliminate the effect of species relationships (Freckleton et al., 2002). Phylogenetic generalized linear models (Orme et al., 2012) will be used in the analyses, implemented in the R environment (R Core Team, 2020). (AU)