Daytime birdsong is something we may all take for granted, forming a backdrop to our daily lives – to the extent that we may not even notice it.
However, it may surprise you to learn that some songbirds can also frequently be heard belting out melodies from their perches in trees overnight, when there is little or no natural light.
This phenomenon may sound rather strange, but there are a number of reasons why birds that are typically active in the daytime also sing in the dark.
There is no single reason that makes birds sing at night, and a range of factors may trigger night-time warblings, depending on location and time of year.
Urban light pollution is becoming increasingly confusing for some bird species, with bright lights from buildings and traffic raising natural levels of illumination to such an extent that it becomes hard for birds to tell the difference between day and night.
During the day, using song to mark a territory is common among many bird species, and it’s no different at night. If a bird is disturbed by an intruder on their patch at night, a quick blast of their ‘ownership song’ may be enough to drive away the threat and protect their territory.
Night-singing is more frequently heard ahead of and during the breeding season. Ultra-keen males of some species are known to practice their mating calls around the clock in early spring to maximize their chances of finding a mate.
At other times of year, in early spring and later into the fall, overnight birdsong may be heard between migratory birds embarking on their annual journeys to and from breeding grounds. Many species migrate at night, and song is used as a way to protect themselves from predatory species and to maintain contact with other members of their flock.
The undisputed day and night time singer, the robin.
Northern Mockingbirds are among the most talented mimics of the bird world and it’s no wonder, as they spend time perfecting their repertoire once night has fallen. Their calls can incorporate a wide range of sounds, including insect noises, mechanical alarms, human and animal noise, and songs of other bird species.
Nocturnal singing usually reaches a peak during the breeding season with males competing to impress potential mates with their elaborate and complex melodies.
Eastern whip-poor-wills are nocturnal birds with an iconic ‘whip-poor-will’ cry from which their own name derives. They are known to be particularly persistent vocalists, with one study recording 1,088 calls repeated in rapid succession without a pause.
Active at night, they spend days roosting on the forest floor and are seldom seen, thanks to their camouflaged plumage. Singing bouts are mainly concentrated after dusk and immediately prior to sunrise.
Owls are known for their haunting nocturnal hoots, screeches and calls, heard once darkness calls. Hoots are used for territorial defense, communication and attracting mates. Owls usually pair up ahead of the breeding season in late winter, so December and January are a particularly good time to listen out for them, as other nocturnal songbirds are not usually as vocal.
A well-known nocturnal songbird from across the pond, the common nightingale, is not resident in the Americas but is well represented in song and film.
American robins are well-documented to sing at night, with the lack of other birds’ song giving them an advantage of their own tuneful melodies carrying further and giving them a boost against rivals when seeking a mate.
Northern Mockingbirds are common nocturnal singers across North America
Close up of an Eastern whip-poor-will
There have been many reports of nightingales singing at all hours during the winter, which have actually turned out to be robins!
It’s impossible to discuss nocturnal songbirds in the UK without mentioning the common nightingale, perhaps the country’s best-known overnight warbler.
Their melodious night-time tunes can be heard particularly in April, May and June and they are recognized as one of nature’s finest songbirds. Elaborate song is particularly heard by males seeking mates early in the breeding season, and although nocturnal song is most common, they can also be heard to sing during the day too.
European robins sing loudly at dawn and dusk, apart from when they are molting and become more elusive and secretive. A staple of the dawn chorus and regularly heard at sunset, it’s also not unusual to hear a burst of robin song later in the night once darkness has fallen, if they are disturbed on their roosting spots.
Nightjars are migrants to the UK, arriving to breed in the spring and summer when they can be heard uttering their distinctive ‘churring’ call at night. Their cryptic plumage makes it far more common to hear one than to see one.
The territorial ‘twit-whoo’ calls of tawny owls are perhaps the most famous nocturnal bird sounds in the UK. The two-part hooting calls are made in duets by male and female pairs.
Reed warblers and sedge warblers are also notorious for singing their rhythmic, rambling phrases at night, particularly after dusk and before dawn.
Common Nightingales are perhaps one of the most famous nocturnal singers
Tawny Owl calls can be common sound in the UK at night
Some songbirds sing at night simply because they are nocturnal species, and this is when they are programmed to be active. For example, the eastern whip-poor-will is active at night and roosts during the day, so night-time singing is its norm for communication.
For many other species, including the northern mockingbird, a quieter overnight environment can prove to be advantageous to many nocturnal singers. With a reduced amount of ambient noise, their own songs can be heard more clearly, which in turn increases their chances of successfully attracting a mate.
Urban environments are increasingly brighter in the evenings and artificial light can disorient birds, leading to changes to their natural patterns and behavior. This has gradually led to an adaptation in habits and lifestyle over time, with night-time song evolving to be a typical trait.
Another notorious nighttime singer, the American Robin
Although often beautiful, melodic and enchanting to listen to, it’s undeniable that to some, being woken night after night by nocturnal songbirds may prove to be something of an annoyance. The disruption to human sleep may feel eternal, but it will usually be short-lived, and ease off once the mating season is over.
Nocturnal bird song is incorporated into many cultural aspects of life, including literature and national identity. John Keats’ poem “Ode to a Nightingale” was inspired by the evening warblings of nightingales and reminds people to appreciate nature and mortality. Nightingales are the official national birds of Ukraine and Iran, where they symbolize happiness, hope and optimism.
Humans also must own some of the responsibility for the increase in nocturnal birdsong, with urban sprawl and a presence of increased ambient light once darkness falls. Street lamps, traffic headlights and illuminated homes all project light into their surrounding areas, shortening hours of quality darkness and inviting birds to sing longer and later than they might if it was pitch black.
Bird perched on a lamp post at night
Urban sprawl and light pollution are two worrying factors that can potentially impact. With more homes being built and the growth of suburban areas, comes the issue of extra artificial lighting from residential areas, which may lead to birds having their natural rhythms of day and night disturbed.
Light pollution, from vehicles, street lamps, factory lights, airplanes and artificial structures has the potential to create longer periods of lighter skies, which can confuse and unsettle birds, causing their natural patterns to become out of sync.
Dusk is perhaps the most fruitful time to listen out for nocturnal bird song, with a peak of activity in the period before and immediately after sunset each evening.
In urban areas with particularly polluted skies, bird song may continue long into the evening. Some species will sing for the duration of the hours of darkness, with the dawn chorus beginning each day between an hour and 30 minutes before the sun rises.
When using technology to record birds at night, it is strongly advised to minimize any bright torch or flashlight beams and definitely avoid shining lights directly into a bird’s face.
Where possible use night vision binoculars so as to cause as little disturbance as possible, Sound recording apps are a useful way of saving any sounds you may encounter, but resist the temptation to play back your recordings until you are safely inside.
When observing nocturnal birds and listening out for their nightly song sessions, you need to cause as little disruption to the natural after dark environment.
Wearing dark clothes, making as little noise as possible and keeping a respectful distance from nest sites are always recommended. Turning your phone to silent will prevent any unwanted or unsettling disturbances.
Always remember that you are entering the birds’ natural habitat and should minimize any intrusion, so as not to spook or alarm roosting or singing birds.
Bluethroat singing whilst perched on a branch
Although a potential disturbance to your sleep, night-time birdsong is a fascinating phenomenon and is usually only heard for a relatively short-lived period. These nocturnal serenades are a perfect reminder of the natural world’s ability to adapt and thrive amid changing conditions.
Birds use song at night for three main reasons: to attract a mate, to warn of danger or to mark a territory. One reason you may suddenly notice intensified bouts of singing after dark is the arrival of the breeding season, with males instinctively using their voices to attempt to attract a mate regardless of the daylight conditions.
In areas where light pollution increases, or for example, during an extra bright full moon, the illumination of their habitat is greater than usual, which may lead to more night-time warblings.
Listening carefully, you may be able to recognize tuneful patterns usually associated with daytime birdsong, as birds do not usually alter their melodies according to the amount of light.
American robins will occasionally sing louder and more elaborate versions of their daytime songs, taking advantage of the surrounding quietness to allow their tunes to carry further and maximize chances of attracting a mate.
When using outdoor lights in a garden or yard, it is sensible to fit them as low to the ground as possible, and add hoods to minimize upward-shining lights, adding to any light pollution in the sky.
Switch off any lights that are not needed, to try and provide as natural an environment as possible. Neighborhood schemes that offer part-night lighting are helpful in reducing the impact of unnecessary street lighting, rather than remaining illuminated for the entire night.
Mimicry is common in nocturnal songbirds, and piercing calls that sound like alarms are not unusual. The main culprits might include northern mockingbirds and steller’s jays, both known to be particularly loud and persistent noise-makers at night, with the realistic ‘alarm’ sound a favorite party piece.
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