As reported last Sunday, in The Guardian by Hannah Devlin, biologist Simon Watt says cities represent hotspots for evolution and behavioural adaption. Speaking at the Cheltenham, UK. Science Festival, Watt said "The ice caps are melting, the rainforest is shrinking, the one environment that is growing is cities." Watt cited a host of examples of how urban environment is provoking new genetic shifts and unexpected behaviours. Some Black-capped Warblers (see photo above) which used to migrate to Morocco or southern Spain, have changed their route to Britain's urban heat islands and where garden bird feeders allow them to survive in more northerly latitudes. Birds coming to Britain are starting to have shorter wings (better for manoeuvrability) and longer beaks for access to small openings in garden bird feeders. Birds have also changed vocalizations, perhaps by acclimatisation rather than evolution. Watt says: "They (birds) tend to sing at higher pitch...use fewer notes...and sing faster". "They have their own urban music. This happens across all the species, they sing at different times - at night because they've got street lights. They are not quite sure when its bedtime. It does mean some of these birds are stressed out". It's adaptable omnivores, relatively intelligent and scavengers by nature, that seem to be thriving in urban settings.
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