Traffic noise driving songbirds to the limit in cities

The rising level of noise in urban areas may be preventing some species of songbirds from setting up home in developed areas, a study has concluded.

Canadian researchers found that noisy surroundings masked the lower frequencies of bird songs, affecting the way some species communicated.

Unable to hear all elements of a song, females could perceive singing males as ill-suited mates, they added.

The findings have been published in the Global Change Biology journal.

"There has been a growing interest in preserving or increasing the biodiversity of songbirds in urban areas," explained co-author Darren Proppe.

"At the same time we know that these areas have pretty high levels of anthropogenic noise.

Dr Proppe, now based at Calvin College, US, but carried out the study while based at the University of Alberta, added: "We sometimes find areas within cities that have what seems like suitable habitat, yet we get lower diversity (of songbirds).

"So we wanted to investigate the hypothesis that there was link between bird diversity and noise levels."