Why Do Birds Sing in the Early Morning?

It’s spring and many of us are waking up to beautiful bird song. But have you ever stopped to think about why birds sing in the early morning?

Picture of a woodpecker on the left and a nuthatch eating from someone's hand on the right.

What is the Dawn Chorus?

Scientists are still investigating the mysteries of dawn choruses. Typically, birds begin singing 30 – 90 minutes before the sunrise. Different birds will chime in at different times. Blackbirds, robins, and thrushes are among the first to begin singing. Others will soon join them and this chorus will last until the sunrise fades. The brighter light signals that it’s time for the birds to go about their daily activities. The rest of the morning and afternoon will be relatively quiet with a few songs interspersed throughout the day.

To the untrained ear, the dawn chorus can sound like beautiful chaos. But, to birders, scientists, and careful listeners, this chorus can reveal a lot about the birds in the area, including their health and their environment. You too can begin to decipher these beautiful songs with a little research, attention, and persistence. A good way to go about this is by choosing a sit-spot for daily observation.

Why Do Birds Sing in the Early Morning?

Scientists have a few different theories to explain why birds sing at dawn. Some studies have shown that dawn singing is a way for birds to resolve social dynamics. This includes what territory belongs to who.

Singing can actually be a sign of aggression. One study looked at dawn singing in banded wrens in Costa Rica. Researchers found that males would direct their morning songs at their neighbours. If they wanted to show aggressive intent, they would match their neighbour’s song. To indicate submission, the birds switched to a non-shared song.

Scientists also believe that morning singing could be a way to display strength and health to potential mates. Support for this theory lies in the fact that the chorus is most vibrant during the mating season. It is also led primarily by male birds.

As to why singing happens in the morning and not later in the day, many hypothesized that there was less atmospheric turbulence in the morning allowing bird song to reach longer distances. But, recent studies have shown that bird song travels as far in the afternoon as in the morning. Even so, morning songs are less likely to be interrupted and may be crisper.

A study published in the Journal of Behavioural Ecology looked at how birds near airports timed their morning songs so as to minimize the competition with air traffic. Also, its long been understood that city birds will modify their songs to increase their reach in noisy areas.

Pollution and Bird Song

Another interesting finding was published in the Journal of Oecologia. The study “compared the singing behaviour of male great tits (Parus major) inhabiting an area extremely polluted with heavy metals with that of males inhabiting areas of low(er) pollution.” Scientists found that the birds inhabiting more polluted areas “had a significantly smaller repertoire size than males at the other sites.”

So, the strength and vibrancy of the dawn chorus may be a helpful indicator of the health of birds and their surrounding environment.

After the Dawn Chorus

Birds may begin singing pre-dawn because there is not enough daylight to successfully forage and accomplish other daily tasks. After the dawn chorus, birds have to get back to their daily routine. Young writes, “assuming no immediate predatory threats and alarms, the specifics of this [morning activity varies] with the ecology of a given habitat; the season; the temperature and other weather conditions, such as wind, fog, and humidity; impending weather…” and other factors. In the springtime, this activity will usually involve some amount of foraging, patrolling borders, and singing together in courtship.

References

John Burt and Sandra Vehrencamp. 2005. “Dawn Chorus as an Interactive Communication Network” in Animal Communication Networks edited by P.K. McGregor.

Timothy Brown and Paul Handford. 2002. “Why Birds Sing at Dawn: The Role of Consistent Song Transmission” in International Journal of Avian Science.

Diego Gil, Mariam Honarmand, Javier Pascual, Eneider Pérez-Mena, Constantino Marcías Garcia. 2015. “Birds Living Near Airports Advance their Dawn Chorus and Reduce Overlap with Aircraft Noise” in Behavioural Ecology.

Gorissen, Snoeijs, Duyse, and Eens. 2005. “Heavy Metal Pollution Affects Dawn Singing Behaviour in a Small Passerine Bird” in Oecologia.

Jon Young. 2012. What the Robin Knows: How Birds Reveal the Secrets of the Natural World.

5 comments on “Why Do Birds Sing in the Early Morning?

  1. What is a repertoire of a bird? Do individual birds have many different songs? So why do birds in polluted area have less repertoire? What do different pitches mean? These things are so fascinating for me. There were a number of years when I detected also zero bird calling in my back yard. After COVID the chorus returned as vigorous as it used to be.

    • Hi Christina! Thanks for your questions.

      Individual birds can have lots of different songs or calls – what I’ve referred to in the article as their “repertoire.” Take the black-capped chickadee as an example – it has its familiar “chika-dee-dee-dee” alarm call. The greater the perceived danger, the more “dees” are added to the end of the call.
      Their “gargle” call is used to scare off other birds. They also have a “fee bee” song that males use as a mating call and to establish territory. That’s just a few examples, they have many more as well!

      And, yes, birds can have different pitches too! Think of pitches like human accents or dialects. Some birds are taught to sing by other birds and can develop regional differences. It’s pretty cool!

      As to why birds in areas with heavy metal pollution had less repertoire, I’m not sure that has been firmly established yet. I’ll have to look into it and see if there is any new research.

      So nice to hear that a lovely bird chorus has returned to your backyard! It’s something that I’ve heard others mention too.

  2. Thank you, Jenna for much a quick and thorough response! I appreciate it very much.Bird dialects and bird accents are so interesting. I’m noticing that the birds in my backyard are starting to sing again about 2 hours before sunset. They are not as numerous or loud compared to the morning calls they make. Nevertheless, it is lovely and very relaxing as I wind down for the night. Why I never noticed this before is mind-boggling to me, but I’d like to thank you for opening up my ears!

    • No problem! I love hearing about others’ experiences with the birds in their backyards and communities. You’re very lucky to have a nice bird chorus! I still have so much to learn about bird songs 🙂

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