Preacherman
July 17, 2003, 12:01 AM
From the Telegraph, London (http://www.telegraph.co.uk/news/main.jhtml;$sessionid$POIJ3NS5QILRRQFIQMGSFF4AVCBQWIV0?xml=/news/2003/07/17/wtweet17.xml&sSheet=/news/2003/07/17/ixworld.html) - and yes, there really IS a bird in England called the "great tit"!
Song birds must hit higher notes to survive in the city
By Roger Highfield, Science Editor
(Filed: 17/07/2003)
Urban song birds are raising the pitch of their voices to make themselves heard above the background roar of the city, scientists report today.
But the sounds of city life may be harming the chaffinch, dunnock and other birds whose vocal range is unable to soar above the din.
Loud and low noise sources such as cars, planes, and machinery are placing new selection pressure on wildlife that rely on sound to attract mates and define territories.
This has been observed for the first time in great tits (Parus major), which have been found to sing higher notes near major roads and busy intersections, a ploy that could allow these urban birds to ensure that their mating calls are heard above the racket.
Birds in quieter spots such as residential neighbourhoods, on the other hand, more often dip to the bottom of their vocal register, a Dutch team reports today in Nature.
City-dwelling birds seem to be tailoring their songs to ensure maximum success with the opposite sex against a background of low-frequency urban rumblings, according to Drs Hans Slabbekoorn and Margriet Peet of Leiden University.
The team base their findings on recordings in and around Leiden but have now extended their work to other major European cities, including London.
Dr Slabbekoorn said: "Data from London have not been analysed yet but there is no reason to think they are different."
Any bird species that produces songs within the frequency range of urban pollution and lack the ability to adapt their songs so they are heard, may find it difficult to breed in built-up areas.
"Birds like the crested lark and golden oriole are disappearing or have disappeared from Dutch cities and, among several other factors (loss of habitat, lack of food sources, loss of nesting sites) masking of their advertisement song by ambient noise may have played a role," Dr Slabbekoorn said.
Song birds must hit higher notes to survive in the city
By Roger Highfield, Science Editor
(Filed: 17/07/2003)
Urban song birds are raising the pitch of their voices to make themselves heard above the background roar of the city, scientists report today.
But the sounds of city life may be harming the chaffinch, dunnock and other birds whose vocal range is unable to soar above the din.
Loud and low noise sources such as cars, planes, and machinery are placing new selection pressure on wildlife that rely on sound to attract mates and define territories.
This has been observed for the first time in great tits (Parus major), which have been found to sing higher notes near major roads and busy intersections, a ploy that could allow these urban birds to ensure that their mating calls are heard above the racket.
Birds in quieter spots such as residential neighbourhoods, on the other hand, more often dip to the bottom of their vocal register, a Dutch team reports today in Nature.
City-dwelling birds seem to be tailoring their songs to ensure maximum success with the opposite sex against a background of low-frequency urban rumblings, according to Drs Hans Slabbekoorn and Margriet Peet of Leiden University.
The team base their findings on recordings in and around Leiden but have now extended their work to other major European cities, including London.
Dr Slabbekoorn said: "Data from London have not been analysed yet but there is no reason to think they are different."
Any bird species that produces songs within the frequency range of urban pollution and lack the ability to adapt their songs so they are heard, may find it difficult to breed in built-up areas.
"Birds like the crested lark and golden oriole are disappearing or have disappeared from Dutch cities and, among several other factors (loss of habitat, lack of food sources, loss of nesting sites) masking of their advertisement song by ambient noise may have played a role," Dr Slabbekoorn said.