Spatial-temporal phenological asynchrony induced by climate change threatens the integrity of the avian migration network

Abstract

Phenological responses to climate change frequently vary among trophic levels, which can result in increasing mismatch between the peak energy requirements of consumers and the availability of resources. Migratory birds use multiple habitats with seasonal food resources along traditional migration flyways. Spatially heterogeneous climate changes could cause this phenology of food availability along the migration flyway to become mismatched. This so-called spatial-temporal phenological asynchrony could pose a challenge by reducing food intake along the migration path and consequently influencing survival and reproduction. We develop a novel graph-based approach to quantify this problem and deploy it to evaluate the risks of, and the drivers behind, the spatial-temporal phenological asynchrony for 16 migratory herbivorous waterfowl species in Asia. We show that climate change-induced spatial-temporal phenological asynchrony could cause in average 48% loss of migration network connectivity for all study species. Species that winter at a lower latitude or that have a wider migration corridor are subjected to higher risk to the integrity of their migration network. These findings highlight the susceptibility of migratory species to climate change, and our proposed methodological framework could be applied to migratory species in general and contribute to formulate targeted actions for biodiversity conservation in the face of climate-related risks.