Species Disappearing at a High Rate
The study, by Oxford University researchers, shows that birds are the best group to use to track the losses of species as many types of obscure organism in Britain are going extinct at the same rate as the birds - evidence which supports fears of a global mass extinction.
'Biodiversity loss is arguably much more serious and more permanent than climate change,' said Clive Hambler of Oxford University's Department of Zoology, lead author of the research. 'But it's impossible to know if policy targets to reduce the loss are being met without accurate measures of extinction rates. Until now, we had only crude estimates for a very few types of organism. Now we've got evidence that many groups of living things - lichens, bugs, moths, fish, plants and so on - are going extinct at a very similar rate to the birds.'
Using Britain's uniquely detailed natural history records, the researchers found that 1-5% of the region's species in many groups were lost since 1800, with higher losses in the Twentieth Century compared to the Nineteenth. Using further data from the USA and across the whole globe, the researchers show that the patterns of extinction in Britain are likely to be typical of those found on land and freshwater elsewhere.
Mr Hambler said: 'The birds are beautiful creatures, but they are also diverse, and many of them are specialised to particular habitats. This makes them sensitive to changes in their environment - such as loss of mature trees, or the drying out of swampy ground, or coastal development. And what makes them really special for monitoring extinction is that they are also exceptionally easy to study, anywhere in the world - so we can detect declines in their populations long before we notice losses of the more obscure things like slime moulds or mosses. It's no coincidence they can signal environmental change.'
'The underlying reason for the similarity of extinction rates in birds and the other living things is that habitat loss affects them in the same way. Our work supports the use of birds to indicate extinction rates in Britain, the USA and globally, and they should now be tried in places such as tropical forests where the bulk of other species will never be recorded.'
'The recorded extinctions in any region are just the tip of the iceberg, because there are not enough observers,' said Mr Hambler. For example, in March this year the British government's advisory body, Natural England, reported about 500 species lost from England since 1800. 'The losses reported by Natural England are under 0.5% per century, from England's 55,000 species,' notes Mr Hambler. 'Our research suggests that the actual losses could be over ten times this number, with about one species going extinct in England every fortnight.'