Featuring more than 1,300 maps describing patterns of distribution for nearly 300 bird species, the new British Trust for Ornithology (BTO) Bird Atlas 2007-11 has recently been released to the public. This comprehensive study of bird distribution trends in Britain and Ireland was compiled from data gathered by more than 40,000 volunteers over a period of four summers and four winters. The information was analyzed by scientists and authors Simon Gillings, Dawn Balmer, Brian Caffrey, Bob Swann, Rob Fuller and Iain Downie and compiled into a treasure trove of information for all who are interested in the birdlife of this region.
Among the wealth of interesting information presented in the Bird Atlas is the fact that as many as forty exotic species have taken up residence in Britain and Ireland. These include the white-cheeked turaco from Ethiopia and Sudan; the red-rumped parrot of Australia; the pin-tailed whydah of sub-Saharan Africa; and the Alexandrine parakeet from Sri Lanka and India, as well as zebra finches and Chinese pheasants. While these are most likely originally escapees from private owners, they have adapted to their surroundings and many have started breeding. So, although they are not indigenous to Britain and Ireland, it appears that they are there to stay and should therefore be monitored along with local populations.
This monitoring becomes even more important when exotic species start posing a threat to native birds, as appears to be the case with the ring-necked parakeet from Delhi. These birds were first reported in the wild in Britain in 1971, having escaped from aviaries. The survey notes that there are now more than 30,000 ring-necked parakeets resident across southern Britain and they appear to be moving northwards. As they use holes in trees to lay their eggs, they are encroaching on the nesting territory of the nuthatch and other birds – and are not shy about taking over.
Observations regarding native birds include the disheartening fact that nightingales, yellowhammers and woodcocks numbers are declining. On the other hand it’s been noted that the little egret and avocet is experiencing an increase in numbers. In addition to listing statistics, the Bird Atlas provides explanations regarding changes that have taken place. For example, the decline in Dartford warbler breeding pairs from 3,214 pairs in 2006, to 600 pairs in 2010 is attributed to the harsh winters experienced in two successive years. It’s not all doom and gloom for Dartford warblers though, as the Bird Atlas notes that they have the capacity to recover and expand their range.
For more information on the new British Trust for Ornithology Bird Atlas 2007-11, visit the BTO Website.
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