Climate change and habitat loss or fragmentation are two major threats to biodiversity. Montane amphibians are particularly sensitive to these threats. Colombia, a megadiverse country, is home to the world’s second largest number of amphibians. The Sierra Nevada de Santa Marta (SNSM), an isolated mountain range, houses 48 amphibian species of which 17 are endemic. We aimed to address climate vulnerability of the amphibian community in the SNSM and prioritize amphibian species at risk and conservation actions. We conducted three visual encounter surveys from, 800 – 3,600 m, during September 2017 – July 2018. In order to assess species vulnerability, we completed two independent spatial analyses. First, we calculated the Area of Habitat of each species, defined as habitat available to a species. Area of Habitat was refined (from the original IUCN EOO maps) for the majority of amphibian species, averaging a reduction in available suitable habitat by 71%. We then examined the breadth of climatic space occupied by 16 species and how this space is predicted to shift under predicted climate scenarios (RCP scenarios 4.5 and 8.5) for 2050. Our analysis reveals a large reduction in climatic space under both 2050 RCP 4.5 and 8.5 scenarios. We combined these two analyses with trait data related to adaptive capacity, obtained from previous research, to create a combined (correlative-trait) climate change vulnerability assessment (CCVA) for 19 focal species (16 endemic). Our vulnerability assessment identified eight high priority species, including all three Atelopus spp and five within the Pristimantis complex. Given its isolation, the SNSM and endemic species are particularly susceptible to changing climates. The information provided from the CCVA offers a platform to develop regional strategies for climate change adaptation and conservation.

Amphibian visual encounter surveys (Heyer et al. 1994) were conducted on the north-western slope of the SNSM, in the department of Magdalena (Fig. 1). Surveys were conducted at 35 transects across three elevational bands (Low: 800 – 1,200 m; Mid: 1,200 – 2,000 m; and High: 2,000 – 3,700 m), and five land cover types. To assess current and future climate space of species within the SNSM, we used hypervolumes (Blonder et al. 2014) to quantify a coarse measure of species’ overlap with climatic space in the SNSM. We further determined how this overlap shifts under two climate scenarios. We used species occurrence data from GBIF (doi:10.15468/dl.ihs3es, doi:10.15468/dl.hcqkns) to supplement the records collected from our visual encounter surveys and generate a minimum of five observations for most of our species (Proosdij et al. 2016). We removed duplicate localities, those with georeferencing uncertainty above 1 km, samples outside of a species’ known elevation range, and samples with taxonomic uncertainty. We defined our geographic extent for analyses as the entire range of the SNSM, which would encompass all available habitats from sea level to 5,775 m with a one-degree buffer around the SNSM to include potential low elevation, non-montane climates.

Missing values are indicated by n/a.. Data are useful for subsequent development of ecological niche models or species distribution modeling.