Avian Atlas: Unveiling the Diversity Divide in Desert Realms between Tropics

Abstract

Understanding diversity gradients across global deserts remains a significant challenge. The unique characteristics of deserts complicate conservation efforts for these biomes, which are highly affected by climate change. Here, we conduct a comprehensive study of ecological traits to determine the behavior and uniqueness of avian communities in ten major tropical deserts, using crowd-sourced avian diversity data from GBIF.org as a key analytical tool. Our results reveal significant variations in bird diversity among tropical deserts, with heightened diversity in deserts near the Tropic of Cancer (TCan) compared to those near the Tropic of Capricorn (TCap). The analysis of ecological traits indicates that, unlike TCap deserts, TCan deserts have a higher prevalence of migratory species. This is facilitated by a broader niche breadth among sedentary bird species, which reduces niche competition and allows the influx of migratory invertivores. This study is the first to identify a differential avian diversity gradient within tropical deserts, demonstrating that avian species richness in deserts is more closely linked to tropical locations than to realm classifications. Recognizing the vulnerability of TCap deserts and the diverse trophic roles played by avian species, our analysis underscores the need for targeted conservation strategies. Protecting the unique avian diversity in TCan deserts and mitigating extinction risks in TCap deserts are essential steps to ensure the resilience and sustainability of these critical ecosystems.