Spatial variation in morphology of the White-browed Laughingthrush ( Garrulax sannio ) and its relationship with climate conditions in southern China

Geographic heterogeneity and climatic conditions are credited for shaping contemporary patterns of avian biodiversity as populations respond differently to landscape-level changes in the environment. Southern China is a globally recognized region characterized by geographic heterogeneity and avian diversity. We analyzed geographic variation in the morphology of the White-browed Laughingthrush ( Garrulax sannio ) throughout southern China, and examined the relationship between spatial morphological variation and current climate conditions. White-browed Laughingthrushes in the southwest mountain region of China were characterized by larger body component and foraging components, but smaller maneuverability component in relation to their eastern or northeastern conspecifics. The annual temperature component was correlated positively with foraging component, but negatively with maneuverability component and skull length. Wet season precipitation was correlated positively with maneuverability, but negatively with cranial component. These results suggest the local adaptation of G. sannio with climate conditions in southern China and provide a better understanding of the factors shaping contemporary biogeographic patterns of avian morphology, allowing for the prediction of potential responses of species to future climate changes.