In recent decades, scientists have produced countless studies on the effects of one environmental factor or another — climate change, deforestation or pollution, for example — on wildlife and habitats around the world. But few have examined the interplay and overlap among multiple factors at the same time in the same location.
But understanding how such threats work together, and whether certain factors intensify or mitigate others, will be crucial for protecting plant and animal species in a rapidly changing world.
A new UCLA-led study takes that approach, analyzing how warming temperatures and fragmenting habitats — areas of wilderness that have been separated by agriculture and other human development — are affecting 24 species of tropical birds in the Usambara Mountains of East Africa, one of the most species-rich regions on the planet.
Over the course of the 34 years the researchers analyzed, from 1987 to 2020, nine of the 24 species were affected by both factors. But warming temperatures were the bigger threat, negatively affecting 14 of the species. In the hottest year during the study, population growth rates declined 20%, even in the largest habitat fragment, which was 5.84 square miles.
Read more at University of California - Los Angeles
Image: Male collared sunbird perched on a flower (Credit: Charles J. Sharp/Wikimedia Commons)