Reply To: Global warming threatens biodiversity

he State of the UK’s Birds 2006 report shows that the wintering populations of some species are declining, principally, it is suggested, because of climate change.

The report, which examines bird population trends, has also highlighted a doubling of the overall numbers of 39 species of waterfowl spending the winter in the UK in the last three decades.

Every winter the UK receives over five million ducks, geese, swans and wading birds, from northern Europe, Greenland, Siberia and Arctic Canada. These birds are attracted to spend the winter in Britain and Ireland because of the relatively mild climate and ice-free conditions.

According to the State of the UK’s Birds 2006, the populations of some species, notably wading birds including the black-tailed godwit and the avocet, have increased markedly since the late 1970s. This is largely as a result of conservation action.

However, concerns are growing over the decline in the populations of other regular visitors, including the Greenland European populations of white-fronted geese, shelduck, mallard, pochard, ringed plover, dunlin and turnstone.
Milder winters

The precise reasons for the decline of each species vary, but a common theme appears to be climate change. As winters become milder both in the UK and elsewhere, it appears that some birds are not flying as far as the UK to find suitable conditions: this trend has been particularly noted in Northern Ireland with declines of pochard and Bewick’s swan.

Similar changes perhaps underway here in east Asia, too: indeed, apparent climate change effects evident at Beidaihe, east China, even by late 1980s.
Last winter, Dalmatian Pelicans didn’t make it south as far as Hong Kong, maybe as relatively warm.