[NetBehaviour] Why birds sing up when they move to the city.

[marc]

Why birds sing up when they move to the city.

Alok Jha, science correspondent
Tuesday December 5, 2006
The Guardian.

Songbirds change their tune when they move to cities, according to new 
research. Scientists found that great tits adapted to urban living by 
singing faster, shorter songs that were at a higher frequency than their 
forest-dwelling cousins.

Rapid urbanisation around the world and the subsequent increase in 
ambient noise has proven problematic for animals which use sound to 
communicate. For birds in particular, city noises can mask the exchange 
of vital information and prevent males from attracting mates.

To see how birds reacted to increased noise, Hans Slabbekoorn of Leiden 
University recorded the songs of great tits in 10 European cities 
including London, Prague, Paris and Amsterdam. He then compared the 
songs with birds of the same species in nearby forests. The results, 
published today in the journal Current Biology, showed that songs 
important in attracting mates and defending territory were markedly 
different in the urban setting.

"The songs diverged in several parameters," said Dr Slabbekoorn. "In 10 
out of 10 comparisons we found that birds in cities use a higher minimum 
frequency. The songs in cities are faster, especially the duration of 
the first element of each of those repetitive song phrases."

more...
http://www.guardian.co.uk/science/story/0,,1964063,00.html