Hung out to dry: choice of priority ecoregions for conserving threatened neotropical anurans depends on life-history traits

Abstract

Background: In the Neotropics, nearly 35% of amphibian species are threatened by habitat loss, habitat fragmentation, and habitat split; anuran species with different developmental modes respond to habitat disturbance in different ways. This entails broad-scale strategies for conserving biodiversity and advocates for the identification of high conservation-value regions that are significant in a global or continental context and that could underpin more detailed conservation assessments towards such areas.

Methodology/principal findings: We identified key ecoregion sets for anuran conservation using an algorithm that favors complementarity (beta-diversity) among ecoregions. Using the WWF's Wildfinder database, which encompasses 700 threatened anuran species in 119 Neotropical ecoregions, we separated species into those with aquatic larvae (AL) or terrestrial development (TD), as this life-history trait affects their response to habitat disturbance. The conservation target of 100% of species representation was attained with a set of 66 ecoregions. Among these, 30 were classified as priority both for species with AL and TD, 26 were priority exclusively for species with AL, and 10 for species with TD only. Priority ecoregions for both developmental modes are concentrated in the Andes and in Mesoamerica. Ecoregions important for conserving species with AL are widely distributed across the Neotropics. When anuran life histories were ignored, species with AL were always underrepresented in priority sets.

Conclusions/significance: The inclusion of anuran developmental modes in prioritization analyses resulted in more comprehensive coverage of priority ecoregions-especially those essential for species that require an aquatic habitat for their reproduction-when compared to usual analyses that do not consider this life-history trait. This is the first appraisal of the most important regions for conservation of threatened Neotropical anurans. It is also a first endeavor including anuran life-history traits in priority area-selection for conservation, with a clear gain in comprehensiveness of the selection process.

Figure 1. Pattern of species richness, irreplaceability and minimum ecoregion sets for representing threatened Neotropical anurans.

Spatial patterns of threatened anuran species richness across Neotropical ecoregions (A) and spatial patterns of irreplaceability estimated by the frequency of ecoregions in the 100 optimal solutions obtained with all threatened anuran species with aquatic larvae (B) and terrestrial development (C) found in the Neotropics. Map showing minimum ecoregion sets (n = 66 ecoregions) required for representation of all threatened anuran species with different developmental modes (D), both those with aquatic larvae (AL = yellow, n = 26 ecoregions) and those with terrestrial development (TD = red, n = 10 ecoregions). Ecoregions of high importance for species of both developmental modes (AL+TD, n = 50 ecoregions) are represented in orange.

Figure 2. Key ecoregion sets for threatened Neotropical anurans obtained with or without discriminating species according to their developmental modes.

(A–C) Maps showing the minimum ecoregion sets required for representation of species with different developmental modes, both those with aquatic larvae (AL = yellow) and those with terrestrial development (TD = red)-at different cutoff levels of species representation (95, 80, and 70%). Ecoregions of high priority for species of both developmental modes (AL+TD) are represented in orange. (E–G) Maps show minimum ecoregion sets required for representation of anuran species at different cutoff levels of species representation (95, 80, and 70%).

Figure 3. Conservation status of key ecoregions for the conservation of threatened Neotropical anurans.

(A) Numbers of endemic and threatened species of Neotropical anurans found in ecoregions classified as Stable/Intact, Vulnerable or Critical/Endangered, according to . (B) Distribution of the number of species found in ecoregions classified as Stable/Intact, Vulnerable or Critical/Endangered, according to . Box plots indicate the range of the data between brackets, the middle two quartiles within the box, the median value as the midline, outside (_*) and far outside (_°) values.