There are a few theories about the reasons why birds wake up so early.
Birds’ body clocks prompt them to get up about an hour before sunrise, when it is starting to get light. The actual time of sunrise and the amount of light will vary from season to season.
Birds’ eyes are able to see ultraviolet light and so they detect the sun’s rays before humans are able to. This makes it seem like they wake up extra early.
Like human eyes, though, diurnal birds’ eyes do not function in the day so they sleep at night and need the daylight to move around.
When birds perceive it to be daytime, they begin their activities. Sitting around snoozing or doing nothing doesn’t fit with their schedule.
When birds are stationary and asleep they are vulnerable to predators. So it’s important for them to begin their day of foraging and finding mates.
Why are birds so loud at 5am?
Birds begin singing even before dawn to announce their presence to others.
There are a few theories about why this singing, known as the dawn chorus, is so intense at this time. Scientists are still investigating these different hypotheses.
Which makes most sense to you when you think about the birds you see and hear?
Birds sing at dawn because sound travels further early in the day
In the period before dawn, it is not only quiet but the air conditions mean that sound will travel further. The air is usually still and colder than later in the day when the sun has risen.
For a long time it was thought that this cooler air is more dense and will carry sound further. This is ideal for the bird because its purpose in singing is to communicate the location of its territory and to attract a mate.
In this case, singing as early as possible, when acoustics are best, would be the most effective way for a bird to deliver its message.
Some studies show, however, that the sound can be carried just as far later in the day as in the early morning.
Birds want to communicate to as many other birds as possible
The further the song travels, the more other birds are likely to hear it - including great numbers of potential mates.
If the song is heard over a wider area, the bird is effectively broadening its territory. This deters competitors for the food sources it has found there.
The variations of each singer stand out better early in the morning
Birdsong be heard from a longer distance at this time. Plus the variations and distinctiveness of an individual’s song are more readily detected.
And if a bird can make its voice heard more clearly and distinctly in the quietest time before any other competition pipes up, even better!
Singing before breakfast shows you’re tough
The majority of the birds singing in the dawn chorus are the males. They are trying to attract the females in the area. The females will be seeking a strong mate that can defend its territory against rivals.
Vociferous singing takes strength and impressive command of its breathing and beak dexterity. The morning is a time when birds’ energy is generally low because they haven’t eaten all night.
One theory is that it is a sign of vitality and eligibility if a male bird can make its presence known in the earliest time of the day. It's strong enough to sing before it’s had the opportunity to fuel up on food.
Birds are giving themselves a pep talk
For some birds, their song has been shown to affect their behavior and hormone levels.
Perhaps birds are singing for themselves as much as for others, warming themselves up for interacting with other birds once daylight arrives.
Birds sing as soon as they wake up because it’s too dark to do anything else
By singing before dawn, birds are also making the most of the time when they are not able to do much else.
Before the sun has risen enough for their eyes to see, they cannot yet go foraging for food. Insects are not yet flying about to be caught as prey.
Diurnal birds, whose eyes work best in the daytime like ours, cannot fly around without being able to see properly. So in the time before the sun rises, they sing instead.
Sounds seem louder to humans at this time
The volume of the bird song may seem louder to humans at this time because there are no other sounds to distract from it.
As other human activities begin, there is more noise and it is less easy to hear the birds. Our ears become desensitized to the more delicate sound of the birdsong.
Are birds waking up earlier?
Birds usually wake up around an hour before dawn. They can be heard starting their day by singing.
We have learnt about the reasons why birds sing at this time, but sometimes it seems like the traditional dawn chorus is getting earlier.
Some studies suggest that birds are waking up more than one hour before dawn, and starting to sing even earlier in the day than they used to.
Let’s look at the factors that influence what time birds wake up.
Changes in season and climate cause birds to wake up earlier
When the sun rises earlier in the spring and summer months, the birds start their dawn chorus accordingly.
Though this is due in part to the increase in light earlier in the day, the temperature also plays a part in waking them up.
In warmer climates, birds will wake up earlier as the temperature rises sooner. They tend to start their day later in cooler seasons.
The warmer weather of spring also coincides with the start of the breeding season. At this time, male birds will be keen to sing to attract a mate. They may start singing earlier in the day to get a head start on the competition.
Light pollution disturbs birds’ natural sleep patterns
Human-created sources of artificial light disrupt birds, whose body clocks are programmed to fall asleep when it’s dark.
Light pollution from traffic or street lights can awaken the birds earlier than their usual time. The brighter the lights, the more exaggerated the effect on the birds’ wake-up time, with their dawn chorus beginning even earlier.
Scientists have suggested that it is possible that because the birds are starting to sing earlier, it increases their chances at attracting a mate and reproducing successfully.
Different birds wake up at different times
How early a bird wakes up depends on its species.
Bird watchers in the US are likely to hear the blackbird and the American robin as some of the first birds in the morning. Warblers and red-eyed vireo, for instance, start their vocalizations later.
Noise pollution affects when birds wake up
As well as being sensitive to artificial light, birds are affected by unnatural noises. Noise wakes them up earlier in the day.
Investigators tested their theories by playing traffic noise to sleeping birds to see if it would cause them to wake up earlier than usual. They found that even birds like sparrows who were already well adapted to an urban environment woke up at an earlier time.
In addition to making birds wake up earlier, noise pollution can make their mating songs or alarm calls inaudible, which could adversely affect their population numbers.
The extra noise caused by traffic and other human activity causes the birds to try to adapt. Some birds may begin to sing at an earlier hour, before the noise begins.
In some cases birds increase their volume, or even alter the pitch and hold the notes for longer, which can make the song more audible over the low-frequency urban noises.
Some ingenious birds have tried to overcome this early-morning noise disturbance by singing at night instead.
Why do birds wake up simultaneously?
Often birds will sleep very close together, roosting communally in trees or even squeezed in with others in small gaps or holes in trees. Their close sleeping arrangements mean that once a few of the groups are awake, it is more likely that all of them will get disturbed too.
If you are keen to get out and make the most of different times of the day, feel free to check the suggestions that we have included in this article offering Birding binoculars tips: how to see the most birds
We have started to discuss the theories behind birdsong, but scientists are starting to question the traditional perception that it is always the male birds singing. The same goes for nest building - is it usually the female that builds the nest or are there exceptions?
- 1 Why are birds so loud at 5am?
- 1.1 Birds sing at dawn because sound travels further early in the day
- 1.2 Birds want to communicate to as many other birds as possible
- 1.3 The variations of each singer stand out better early in the morning
- 1.4 Singing before breakfast shows you’re tough
- 1.5 Birds are giving themselves a pep talk
- 1.6 Birds sing as soon as they wake up because it’s too dark to do anything else
- 1.7 Sounds seem louder to humans at this time
- 2 Are birds waking up earlier?
- 3 Why do birds wake up simultaneously?
- 4 What's next?