City birds struggle to make themselves heard

My first ever feature article has just been published in this week's issue of New Scientist. It's about the ways in which songbirds are coping with the noisy din of cities. Low-frequency urban noises mask the calls that they use to attract mates, defend territories and compete with rivals. The race to adapt to this new soundscape has already seen some losers being forced out and some winners developing some intriguing strategies to cope with the clamour. Robins have started to sing at night when it's quieter, while nightingales just belt out their tunes more loudly (breaking noise safety regulations while they're at it). Several species including great tits and song sparrows have started to sing at higher frequencies that are less likely to be masked. Song is a sexual trait, and over time the different strategies used by urban and country birds could lead to a single species splitting ...