Wildlife moves to stay cool in a warmer world

Salmon swim north into Arctic seas, locusts plague northern Italy and two heat-loving bee-eater birds nest in a hedge in Britain. Signs of global warming fed by greenhouse gases produced by human activity, or just summertime oddities? In the United States, some warblers are flying north to Canada. In Costa Rica, toucans are moving higher up into the mountains, apparently because of rising temperatures. In July, a Norwegian man fishing in a fjord had a shock when he landed a John Dory, a fish more usually found in temperate waters off southern Europe or Africa.