Birds and climate change

Climate is warming and precipitation regimes are changing. Birds are responding to climate change and these changes concern distributional ranges, migration patterns, life history traits and species interactions. Many bird species are spreading north or northwest, or in elevation. Migratory birds either stay longer on their breeding grounds, or overwinter there, or, else migrate to new places. Warmer springs lead many species to breed earlier, but evidence for an effect of global warming on fecundity is still unclear. Milder winters reduce winter mortality of many resident species. Long-distance migratory birds experience strong declines probably because of a lower winter survival due to drier conditions in the wintering grounds. Most of these changes are phenotypic responses, but adaptive changes of migratory systems have been proved. Species loss would probably affect communities in a profound way.