Biological consequences of global change for birds.

Climate is currently changing at an unprecedented rate; so also human exploitation is rapidly changing the Earth for agriculture, forestry, fisheries and urbanization. In addition, pollution has affected even the most remote ecosystems, as has the omnipresence of humans, with consequences in particular for animals that keep a safe distance from potential predators, including human beings. Importantly, all of these changes are occurring simultaneously, with increasing intensity, and further deterioration in both the short and the long-term is predicted. While the consequences of these components of global change are relatively well studied on their own, the effects of their interactions, such as the combined effects of climate change and agriculture, or the combined effects of agriculture through nutrient leakage to freshwater and marine ecosystems and fisheries, and the effects of climate change and urbanization, are poorly understood. Here, I provide a brief overview of the effects of climate change on phenology, diversity, abundance, interspecific interactions and population dynamics of birds. I address whether these effects of changing temperatures are direct, or indirect through effects of climate change on the phenology, distribution or abundance of food, parasites and predators. Finally, I review interactions between different components of global change.