As our high streets are becoming increasingly deserted by humans, it's becoming apparent that we aren't the only creatures roaming our cities. Birds are still chirping away out there. A city is not a natural place for a bird, but some species manage to thrive. Intelligence was once thought to be the deciding factor, but maybe that's not the whole story, as put forward by new research in Nature Ecology and Evolution. Melanie Jans-Singh found out more from UCL's Alexander Pigot... Like this podcast? Please help us by supporting the Naked Scientists