|Research Focus Tits, noise and urban bioacoustics

Humans, particularly in cities, are noisy. Researchers are only just beginning to identify the implications of an increase in noise for species that communicate acousti-cally. In a recent paper, Slabbekoorn and Peet show, for the first time, that some birds can respond to anthropo-genically elevated noise levels by altering the frequency structure of their songs. Cities are fruitful grounds for research on the evolution of animal communication systems, with broader implications for conservation in human-altered environments. An ever-increasing number of humans now live in cities, and one aspect of the urban environment that we all complain about is the increase in noise. This noise extends ever more often beyond city borders and into natural habitats. Few researchers, however, have addressed th