Observations of Biotic Response in Wild Species to Current Climate Change

Climate is a driver of biotic systems at all levels of biological organization. It affects individual fitness, population dynamics, distribution and abundance of species, and ecosystem structure and function. Regional variation in climate creates selective pressures for the evolution of locally-adapted physiologies, morphological adaptations (e.g. color patterns, surface textures, body shapes and sizes), and behavioral adaptations (e.g. foraging strategies and breeding systems). Biologists have usually studied influences of climate in terms of mean values (often monthly), largely due to availability of data, rather than because of its specific biological relevance. Although many biological patterns correlate well with mean climatological values, we argue that, mechanistically, the stronger drivers are likely to involve extreme weather. By understanding such inter-relationships, impacts of future extremes may be predicted more reliably.