Hans Slabbekoorn and Ardie den Boer-Visser
Cities Change the Songs of Birds
Current Biology, Vol. 16, Iss. 23, 2006
Pages 2326- 2331
Summary
Worldwide urbanization and the ongoing rise of urban noise levels form a major
threat to living conditions in and around cities 1, 2, 3 and 4. Urban
environments typically homogenize animal communities, and this results, for
example, in the same few bird species' being found everywhere 5 and 6. Insight
into the behavioral strategies of the urban survivors may explain the
sensitivity of other species to urban selection pressures. Here, we show that
songs that are important to mate attraction and territory defense have
significantly diverged in great tits (Parus major), a very successful urban
species. Urban songs were shorter and sung faster than songs in forests, and
often concerned atypical song types. Furthermore, we found consistently higher
minimum frequencies in ten out of ten city-forest comparisons from London to
Prague and from Amsterdam to Paris. Anthropogenic noise is most likely a
dominant factor driving these dramatic changes 7, 8 and 9. These data provide
the mos
t consistent evidence supporting the acoustic-adaptation hypothesis since it
was postulated in the early seventies 10, 11 and 12. At the same time, they
reveal a behavioral plasticity that may be key to urban success and the lack of
which may explain detrimental effects on bird communities that live in noisy
urbanized areas or along highways.
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