fast facts

Climate change experts predict that many parts of the world will not only get warmer, but that they will get drier too. This drying trend, is expected to be particularly severe for the wetlands of the plains states of Canada and the US, the Mediter-ranean Basin of Europe, and the drier parts of southern Africa. All these regions harbor critical bird sites. Many duck species use the Prairie Pothole Wetlands for breeding (half of all North American ducks breed in them) or for migration stopovers. These wetlands often disappear in dry years, and populations of ducks such as Mallard, Pintail, American Widgeon and Northern Shoveler can be severely affected.

Scientists believe that at least two internationally important wetland sites--the Great Salt Lake (Utah) and the Stillwater-Lahontan Valley Wetlands (Nevada) --may be among the most vulnerable to global warming. Birds under threat at the Great Salt Lake include huge migratory populations of Wilson's Phalarope and American Avocet, as well as internationally important breeding colonies of California Gull, White-faced Ibis and the American White Pelican. The effects of climate change will be exacerbated by the over-use of scarce water resources as a result of agricultural development. The effects of severe drought were recorded at yet another threatened wetland, Cheyenne Bottoms, in central Kansas, when the rains failed in the spring of 1988. That year, the Dowitchers, Baird's Sandpipers, Black-bellied Plovers and Semipalmated Sand-pipers that stopped there were unable to put on enough weight to take them even half way to their destination in the Canadian Arctic.

The drying trend is expected to cause problems in Europe as well. For many migrants, the Mediterranean wetlands present their last chance to feed before crossing the desolate wastes of the Sahara in one long and dangerous flight. Many Mediterranean wetlands, including the Coto Donana in Spain, the Camargue in France, and Lake Ichkeul in Tunisia, are under dual attack from global warming and coastal development. The birds that depend on them, such as Greylag Geese, Black-tailed Godwits and Wood Sandpipers may be the biggest losers. Drying out of reed-beds in the Mediterranean and along the west coast of Africa would affect migratory birds such as Reed, Great Reed and Sedge Warblers, as well as several species of Drake and Rail. Further north, in the UK, loss of marsh and bog habitat would threaten the Bittern, Snipe, Dunlin and Curlew.

Habitat loss will affect coastal stopover sites as well as breeding areas. Perhaps of greatest concern are impacts to Arctic tundra, the preferred summer habitat of many shorebirds such as Sanderling, Knot and Baird's Sandpiper, and geese such as the Snow Goose. Global warming is expected to have its greatest impacts near the poles, and warming will cause melting of permafrost and a massive loss of Arctic tundra as the treeline pushes northward. Some evidence for these changes can already be seen in Northern Canada and Alaska. The Western Arctic has experienced a warming trend in the last century, and spring seems to be coming earlier there too. European populations of migratory species such as the Brant and Barnacle Goose breed in the high Arctic and winter in Scotland's Solway Firth and the Wadden Sea coast of Germany and the Netherlands. Their summer home is threatened by warming of tundra habitat, and their wintering sites are highly vulnerable to flooding and loss due to sea-level rise. For the Knot, the bird that perhaps symbolizes best the threat to migratory birds, climate change probably even threatens it at wintering sites in the far south, in Tierra del Fuego, on the Cape of South Africa, and in southern Australia. For some birds, no matter how hard they fly, there may be no escaping global warming.