Increased exposure of Colombian birds to rapidly expanding human footprint

Understanding and mapping anthropogenic threats on species distributions is a crucial task in conservation science to identify priority areas and propose appropriate conservation strategies. Yet, there is a big challenge to quantify how these threats are associated with species distribution patterns at multiple temporal scales. For birds, existing national and global analyses have mostly focused on forest specialists and they tend to consider only one time period. Here, we evaluated spatial and temporal changes in human footprint within the distributions of Colombian birds from 1970 to 2018, and projected them into 2030. We show that widespread increases in human footprint were common within the distribution of terrestrial birds. Endemic and threatened birds have been disproportionately affected by past increases in human footprint within their distribution, and this trend will continue into the future. Several areas harboring high diversity of forest-specialists remained relatively intact up to 2018. However, our predictions show significantly higher and faster (>2% annual change) levels of transformation within these areas by 2030. Importantly, our results suggest that non-forest birds could be experiencing habitat quality declines that are just as significant as those shown for forest birds. Our results show that mitigating negative anthropogenic effects on bird habitats in Colombia requires an array of conservation strategies that range from strict habitat protection to mixed management. These analyses can serve as inputs in conservation decision tools that consider spatiotemporal variation of anthropic threats under multiple scenarios of change.