Azure-winged Magpies on the way out?

Researchers have predicted that Azure-winged Magpies could lose up to 95 percent of their already tightly restricted range in Europe because of global warming. Surprisingly, some bird-lovers would welcome a significant drop in their numbers - though there is certainly no sign of it yet.

The Azure-winged Magpie is one of the Algarve's most distinctive birds. For visiting birdwatchers who haven't already see one, it is high on their tick list. Few will be disappointed because there are plenty of Azure-wings around and they are usually both highly visible and noisy.

The species takes its name from the colour of its wings and tail, but this may not be the first colour you notice. The velvet black forehead, crown and nape contrast with the white throat and the pale underparts. The back is a warm ash brown next to the cool blue of the long wing and even longer tail feathers.

This flamboyant colouration together with its boisterous habits and peculiar global distribution make this an intriguing species. The smallest member of the crow family, in Europe it is confined to southern Portugal and Spain. Elsewhere it only found across the other side of the world, in China, Mongolia, Korea, and Japan. But they do not migrate between these two vastly separated locations. They are distinct resident populations.

Estimates put the number of breeding pairs in southern Iberia at well over a quarter of a million, but that could change drastically over the next 50 years if the predictions of a major study published in the journal Nature in 2004 are to be believed. The report concluded that a quarter of all land and plant species in the world may be driven to extinction if greenhouse gas emissions are not drastically reduced.

Researches in Britain and the Netherlands, including ornithologists from the RSPB, named the Azure-winged Magpie as one of the top ten climatically threatened bird species in Europe. They anticipated a loss of between 50% and 95% in its range, depending on its ability to disperse and occupy new suitable areas in response to habitat changes brought about by global warming.

Fortunately for the Azure-wings, they are not at all fussy about their diet. They enjoy soft fruits, acorns, pine nuts, berries, insects, grubs and other invertebrates. Even when surrounded by plentiful supplies of naturally available food in cork or holm oak woods, they can be easily tempted into the garden by kitchen scraps, even bread crumbs on bird tables. They are especially partial to cat biscuits. A band of azure-wings will come silently raiding with SAS precision for left-overs in pets' bowls close to the house.

The gregarious and energetic character of these birds is most noticeable in the winter when they dash around in foraging groups, usually numbering a few dozen but sometimes 100 or more, vigorously flapping and gliding, jabbering in an excited wheezy sort of way. They often squabble among themselves, but they are also remarkably sociable and co-operative when it comes to breeding.

Each pair bonds monogamously for life and both immature and adult birds within a non-territorial breeding colony help their fellow Azure-wings in a highly flexible way with nest building, supplying food to incubating females, feeding the young and even removing faecal sacs from nests.

They are brainy too, among the brightest in the bird world. Along with other members of the crow family (Corvids), azure-wings have a brain-to-body ratio equal to that of the great apes and cetaceans (whales, dolphins and porpoises). It is only slightly lower than ours. Experiments show that Corvids can out-performs cats and dogs if given clues about the whereabouts of food. They are believed to have a well-developed memory and a capacity for imagination.

The trouble with Azure-winged Magpies, says Dr Colin Key, a resident authority on birds in southern Portugal, is that there are “far too many of them now - the population here must have trebled in the past ten years.”

Colin (who took the three Azure-wing photos) has personally witnessed a group of ten or so attack and kill a Song Thrush for no apparent reason. They will also take eggs and young from the nests of other birds. “Their aggressive behaviour is having a detrimental effect on the populations of garden breeders such as Blackcaps, Serins,Woodchat Shrikes, Blackbirds and Golden Orioles,” says Colin.

If Azure-wing numbers continue to increase at the current rate, he thinks “a controlled cull might be in order to halt the decimation of our passerine population".