Birds sing to mark their territories, to attract potential mates, and to broadcast their needs, but what makes this communication system extraordinary is its innate artistry and elevated learning process. The next time you hear birds singing outside your window, listen carefully. What you’re hearing is a complex arrangement of sounds meant to communicate very specific messages to other birds. Bird songs and calls vary from species to species, and even within species depending on the location. Learning to vocalize is a unique trait that both humans and some types of birds share.
Only songbirds, parrots, and hummingbirds are able to change their vocalizations through learning. And because learning vocalizations tends to be a skill that’s passed down from adults to juveniles, birds of the same species learn the "language" of their adult tutors.
The ability to sing is biological. Birds have a vocal organ called a syrinx which allows them to make a wide variety of noises. All singing birds have a special part of the brain that has evolved to help them learn and even improve their singing skills. But the actual songs that birds learn come mostly from listening to others of their species.
Some bird species are known as “closed-ended learners,” meaning they have one short period of time in their youth when they are able to learn to sing. Other species are “open-ended” learners and can continue to learn new songs throughout their lives.
Bird song plays an important role in selecting a mate. Starting with Darwin’s theory of sexual selection, bird song has typically been attributed to males of the species. However, research published in Nature Communications suggests that females sing in as many as 71% of bird species, and there is increasing interest in research that studies how female birds use song. Different bird species have distinctive songs so they know whether they’re communicating with a potential mate. During the breeding season, males sing to attract females. Much of the research supports the idea that females select males with better songs if no other features, like how complex the male’s plumage is, are at play. Because female birds will choose mates based heavily on their singing prowess, it’s important for male birds to distinguish themselves from the competition both in and out of their species. Birds also want to make sure that any mating competitors of the same species know that they’re not welcome in certain areas.
Birds use specific alarm calls to defend their territory from predators. These calls tend to be less complex and louder than songs, depending on how big the territory is. Some birds have even learned to use specific vocalizations to warn their neighbors of different types of predators.
One Japanese species can not only change the types of notes it uses depending on the predator, but it can even alter how quickly it sends out the calls to tell other birds if the predator is a snake, mammal, or even another bird. Birds may also use calls to defend their territory from potential mating competition or even from other birds who might be trying to take away their resources.Both males and females can use calls to defend a territory and resources during non-mating seasons.
Singing may not be just for serious business. According to a study published in the journal Current Biology, birds may sing for their own enjoyment as well. In the study, "feel good" chemicals were injected into female birds and researchers found that their singing increased. In addition, birds have been observed singing when they were not trying to attract a mate or defend territory, but more research is needed to know if they really can derive pleasure from singing.
A bird song is made up of a sequence of different musical features like rhythm and pitch. Songs are complex and differ in length and content depending on what the song is being used for. Different sound sequences can even be combined to create longer and more elaborate songs.
Bird calls are often used to communicate very specific messages and are often shorter, less complex, and more “speech-like” than songs. If you hear quick chirps, you are most likely hearing a call. The main goals of bird calls are: