Every birder has enjoyed a beautiful sunrise accompanied by a medley of energetic birdsong, but why do birds create this dawn chorus? This phenomenon is not restricted to one type of bird or one geographic location, but despite its variety, these singing morning birds are always a unique and amazing behavior to observe.
Why Birds Sing in the Morning
Birds may sing at any time of day, but songs are often more energetic, louder, and more frequent in the early morning hours. This concert may start as early as 4 a.m. and extend several hours until the sun has risen and temperatures begin to warm. This harmonious time period is known as the dawn chorus, and singing at this time gives birds several benefits.
- Advertising Fitness: It takes great energy to sing so loudly and powerfully. Showing off one's vocal prowess very early in the morning demonstrates that the singer was strong and healthy enough to survive a night of dipping temperatures, no feeding, and active predators. This can help attract a potential mate, whether the singer is courting a female or renewing bonds with an existing mate.
- Less Ambient Noise: Other competing sounds such as insect buzzes or artificial noises like traffic or construction are less common in the early morning hours and a bird's song is not as likely to be drowned out. This gives strong singers in the dawn chorus the advantage of having more effect with their songs because they are easier to hear.
- Traveling Sound: Lower morning air temperatures and less active air currents may permit a bird's dawn chorus song to travel further without as much interference or losing strength. This gives the bird an advantage for using its song to claim or defend a territory or advertise its presence to prospective mates in a wider area.
- No Other Activities: Early morning light levels are too low for effective foraging, air currents are not as conducive for migrating, and insects are not yet active for feeding. With fewer other activities to choose from, this time of day is an excellent opportunity for birds to sing.
The dawn chorus is strongest and most obvious in spring, exactly the time when birds are seeking mates and establishing territories. It does continue to a lesser degree through the entire breeding season, giving birders plenty of opportunities to enjoy this avian symphony.
Which Birds Are Singing
Nearly all passerines will join in the dawn chorus to varying degrees, though the exact birds that can be heard will depend on many factors, including:
- Range: Birds are more likely to join the dawn chorus as they reach their breeding ranges and seek to claim territories. Year-round residents will also join the chorus as they renew pair bonds and feel breeding urges.
- Habitat: The birds joining in the chorus varies by habitat, and birders are unlikely to hear vagrant or unusual species in the overwhelming medley of resident birds. More common species are most likely to be heard in the chorus as they compete for mates and territories, but savvy birders can often pick out the tunes and tones of even more unusual birds as well.
- Time: Different birds join each morning's chorus at different times. Larger birds such as thrushes and doves are among the earliest singers because they are more active earlier in the day, while smaller species often join an hour or two later. Through the course of a morning, the composition of singers can change several times.
In North America, the American robin is one of the most audible and common participants in the dawn chorus, with many warblers joining in later in the concert. The European robin and other thrushes are equally active singers in Europe. With their widespread ranges and bold voices, other thrushes throughout the world are often the most recognizable singers each morning.
Using the Dawn Chorus
The early hours of the day are perfect for practicing birding by ear. Not only are birds actively singing near sunrise, but they often do so from exposed, visible perches, offering exceptional views and photography opportunities in the morning light. Because the chorus is most prevalent in spring, many of the singers are also in their bright breeding plumage, making identification even easier. Birders who want to experience this early morning phenomenon should take proper steps to stay safe and follow appropriate bird recording ethics to avoid stressing or distracting the birds.
Quieting the Dawn Chorus
Getting up to enjoy the dawn chorus can be an experience many birders eagerly anticipate. Even the most dedicated birders, however, rarely enjoy the cacophony of sound beginning in the wee hours for weeks, particularly when backyard birds join in right outside bedroom windows. To minimize the disruptive effects of the chorus:
- Close windows to block as much sound as possible, and opt for double-paned windows whenever possible to make them more insulating.
- Use white noise such as fans or sound machines in bedrooms, and position the machines near windows to cover as much birdsong as possible.
- Trim trees and shrubs to remove the exposed perches birds use for morning songs, encouraging them to move elsewhere for their part in the chorus.
- Remove bird feeders in the late afternoon or early evening to encourage birds to find evening roosts further away so they are not nearby when they begin to sing the next morning.
The dawn chorus is an amazing auditory phenomenon that many birders enjoy. Understanding why birds sing so close to sunrise can help every birder better appreciate this time of day for enjoying the birdsong.