Ecological and anthropogenic drivers of local extinction and colonization of giant pandas over the past 30 years

Abstract

Understanding the patterns and drivers of species range shifts is essential to disentangle mechanisms driving species' responses to global change. Here, we quantified local extinction and colonization dynamics of giant pandas (Ailuropoda melanoleuca) using occurrence data collected by harnessing the labor of >1000 workers and >60,000 worker days for each of the three periods (TP1: 1985–1988, TP2: 1998–2002, and TP3: 2011–2014), and evaluated how these patterns were associated with (1) protected area, (2) local rarity/abundance, and (3) abiotic factors (i.e., climate, land-use, and topography). We documented a decreased rate (from 0.433 during TP1–TP2 to 0.317 during TP2–TP3) of local extinction and a relatively stable rate (from 0.060 during TP1–TP2 to 0.056 during TP2–TP3) of local colonization through time. Furthermore, the occupancy gains have exceeded losses by a ratio of approximately 1.5 to 1, illustrating an expansion of panda's range at a rate of 1408.3 km²/decade. We also found that pandas were more likely to become locally extinct outside of protected areas, when locally rare in surrounding areas, and when certain biotic conditions were not met (e.g., increased forest cover). Local colonization was less likely in areas with high local rarity, challenging biotic conditions and unprotected area status. As the network of panda reserves expanded and the forest matured, the relative importance of other factors such as climate, biotic factors, and land-use became more influential in determining patterns of local extinction and colonization. Our findings provide insights into the factors governing the expansion of panda's range and illustrate how the relative influence of biotic and abiotic factors can change over time, indicating that effective conservation intervention may be able to mitigate some of the negative impacts of climate change and habitat degradation. This insight extends beyond pandas and highlights the role of conservation interventions can play in building resilience under a changing climate.