Climate change projections suggest severe decreases in the geographic ranges of bird species restricted to Mexican humid mountain forests

Abstract

Climate change-driven modifications in thermal and precipitation patterns can result in shifts in species distributions. Avian species in humid mountain forests (HMF) are among the most vulnerable to these atmospheric changes. In this study, we assessed the extent to which climate change could cause distribution shifts in 34 bird species spatially restricted to HMF ecosystems in Mexico. In addition, we analyzed the representation of the species in protected areas (PAs) and the extension these areas covered in the entire range of each species. Species distribution models (SDMs) were generated using Maxent algorithm. Future SDM scenarios were considered using two scenarios: The Interdisciplinary Climate Research Model (MIROC5) and The Community Climate System Model (CCSM4) with a single representative concentration pathway (RCP6.0). We found that by 2050, under MIROC5, modeled species distributions showed an average reduction of 34%, and under CCSM4, a decrease of 40%. By 2070, MIROC5 showed an average a reduction of 51% and under CCSM4 of 54%. SDMs for 20 species overlapped with protected areas (PA), although nine species would reduce their presence in the PAs by 2050 under MIROC5 and 11 under CCSM4. By 2070, 11 and 12 species respectively for both scenarios, would reduce their distribution range in the PAs. More than 94% of the bird species considered, have less than 10% of their distribution in PAs in the current and future scenarios. The species distribution models of 14 species, particularly those of small range, showed no overlap with any PA under the current or future scenarios. To ensure that HMF endemic bird species are represented in different protected areas in the future, conservation schemes such as protected social and community areas and biological corridors could be valuable in ensuring the conservation of endemic birds in the long-term, especially in those regions underrepresented by PAs.