photographic noise

theguardian.com
Cities should be studied as evolutionary hotspots, says biologist
Animals and birds evolve more quickly in urban environments than in remote habitats, Cheltenham science festival is told
By Hannah Devlin

Foxes loitering around rubbish bins and pigeons roosting in train stations: urban animals are widely regarded as the dregs of the natural world.

However, according to biologist Simon Watt, cities represent some of the world’s hotspots for evolution and behavioural adaptation. Speaking at the Cheltenham science festival, Watt, who is founder of the Ugly Animal Preservation Society, said: “The ice caps are melting, the rainforest is shrinking, the one environment that is growing is cities. If we’re going to look for evolutionary shifts right now in our world, the place to look is cities.”

In his talk, Watt cited a host of examples of how the urban environment is prompting new genetic shifts and unexpected behaviours. A proportion of black cap warblers, which used to migrate to Morocco or southern Spain, have shifted their route to Britain where urban heat islands and garden bird feeders allow them to survive at more northerly latitudes than was previously possible.

“The ones that come to Britain are starting to get shorter wings – better for manoeuvrability, worse for long flights – and longer beaks, which are better to get through the wee bars of garden bird feeders, although worse for things like fruits and berries.”

Birds in cities often sing at a higher pitch, perhaps to be better heard against higher levels of background noise. Photograph: Sue Tranter RSPB Images/PA Wire