Stairway to extinction? Influence of anthropogenic climate change on distribution patterns of montane Strigiformes in Mesoamerica

Abstract

. Although anthropogenic climate change (ACC) is a global phenomenon affecting all ecosystems, its effects are especially relevant in certain ecosystems, such as tropical montane forests. Responses of montane species to ACC in Mesoamerica remain unclear, limiting our ability to assess their vulnerability and the impacts on these ecosystems overall. To understand mechanisms underlying the distribution and vulnerability of montane faunas, we analyzed the influence of ACC on the geographic distribution of owls (order Strigiformes), which are a group of top avian predators distributed in montane forests. Using ecological niche models, we estimated the potential distributions of 35 species at present and under projected future climates (2050 and 2070) and analyzed changes in distributional patterns in terms of range size and altitudinal distribution for each species, as well as spatio-temporal patterns of species richness. Most of our projections (~86%) were consistent with the widely accepted hypothesis of species range shift to higher altitudes combined with reduction in distribution, as species try to track their climatic preferences. Interestingly, the mid-elevation species emerge as the most strongly affected by ACC, showing the highest rates of change. All climate scenarios produced a similar pattern of change in owl species richness, but they differed in the total number of species, a loss of 11 species and a maximum gain of seven species. Species richness remained relatively constant at mid elevations, whereas the greatest losses were in the highlands and the contiguous lowlands. Overall, our results suggest a severe impact of ACC in the coming decades for most owls of Mesoamerican montane forests.