BACKGROUND & SCOPE: 

Habitat loss continues to erode biodiversity in the tropics while climate change poses an insidious threat with impacts that can be difficult to detect. Assessing the ecological effects of these synergistic stressors ideally requires long-term monitoring data which are especially scarce in the tropics. A fruitful alternative is to revisit transects originally surveyed in decades past and compare assemblages between now and then. These “resurveys” can reveal changes in species distributions, decreases in abundance, and even mountaintop extinctions, but they hinge upon suitable baseline data. For birds, extensive surveys during the 20th century provide ample opportunity for resurveys in the present day.



GOALS & OBJECTIVES: This symposium aims to 1) disseminate findings from recent bird resurveys in the tropics, 2) share methods for comparing historical and modern survey data often gathered in very different ways, and 3) encourage local ornithologists to conduct more resurveys in regions of the tropics lacking historical-modern comparisons, particularly if historical data exists. Together, we want to sketch out a pipeline that enables scientists to identify suitable baseline data, undertake coordinated field resurveys, collate and analyze the data, discover the broad-scale changes in tropical birds, and inform subsequent conservation action. 



IMPORTANCE: Habitat loss and climate change are imperiling biodiversity throughout the tropics and resurveys provide an invaluable opportunity to detect changes in ecological communities that could not be detected otherwise. These systems are critical epicenters of diversity and endemism, particularly along elevational gradients where species turnover is highest. Here, even protected areas cannot fully prevent the cryptic effects of global warming, and resurveys are needed to assess the potential for resilience and adaptation in the face of change. Not only must we share the insights gained from existing resurveys, but we must empower more ecologists to look for changes in their own bird communities. Critically, modern resurveys offer a way to increase equity and inclusivity when conducted by local scientists.