Why Do Robins Sing at Night? Street Lights and Noise

A normal robin’s singing day

To understand night song, it helps to know when robins normally sing. In the breeding season a European robin usually starts singing about an hour before sunrise, making it one of the first voices in the dawn chorus. It sings on and off through the day and usually stops around half an hour after sunset.

Robins have relatively large eyes for their size, which lets them see and feed in dim light. That is one reason they start early and finish late. The leap from singing at dusk to singing in the dark is shorter for a robin than for most songbirds.

Unlike most European birds, robins also sing all year. In autumn and winter both males and females defend separate feeding territories, and both sexes sing. So a robin singing on a December night may be a female as well as a male.

The noise theory

The best-known study of night-singing robins was carried out in Sheffield, England, and published in 2007 by Richard Fuller, Philip Warren and Kevin Gaston. The researchers mapped where robins sang at night and measured both light and daytime noise levels at those places.

They found that robins were much more likely to sing at night where it was noisy during the day. Daytime noise turned out to be a stronger predictor of night singing than how brightly the area was lit at night. The explanation is simple: song only works if others can hear it. Along busy roads, low-pitched traffic rumble masks bird song for much of the day, so robins shift part of their singing into the quieter hours of darkness.

Other studies of urban birds support the same idea. City birds of several species sing louder, at a higher pitch or at different times than their country cousins, all ways of getting a message through the noise.

The street light theory

Artificial light is still part of the story. Bright street lights, floodlights and illuminated buildings can make a robin’s surroundings look like early dawn or late dusk all night long. Studies of European songbirds, including robins, have found that birds living near artificial light tend to start their dawn song earlier than birds in dark areas.

In practice, noise and light usually go together: the busiest streets are also the brightest. Many night-singing robins are found perched near a lamp post, in a lit car park or by a floodlit building, close to the roads that make their days so loud.

Robin or nightingale?

Many people who hear a bird singing at night assume it must be a nightingale. In most of Britain, and in almost all towns, it is a robin.

Nightingales are summer visitors that spend the winter in Africa, and they have declined sharply in Britain. They live in thick, tangled scrub and are rare in built-up areas. A bird singing outside a city window in winter or early spring is almost certainly a robin. Even the famous wartime song “A Nightingale Sang in Berkeley Square” is often joked about by birdwatchers, since a bird singing in central London was far more likely to be a robin.

Other birds that sing at night

Robins are not the only night singers. In Europe, blackbirds and song thrushes sometimes sing under street lights, and reed and sedge warblers often sing through the night in wetlands. In North America the northern mockingbird is famous for singing all night, especially unpaired males in spring, and American robins occasionally sing in the dark near bright lights.

Does night singing harm robins?

There is no clear evidence that night singing on its own harms robins. Singing costs energy, and light at night can upset birds’ natural daily rhythms, so scientists are interested in the long-term effects of light and noise pollution on urban wildlife. So far, robin numbers in Britain have risen strongly since the 1960s, and robins remain one of the most common garden birds.

If you hear a robin singing at night, you are hearing a small bird adjusting to life in a noisy, lit world. Its daytime equivalent, the dawn chorus, is explained in why do birds sing in the morning?.