The beautiful birdsong of the Australasian magpie may be perceived as a sign of competition for territory or a way for males to attract a mate. However, birdsong is not always a one-dimensional display of competition. In some species, birdsong plays a role in promoting social cooperation and cohesion within populations.
For example, in the highly social zebra finch, the song of males has been found to help coordinate nest building, mating, and reproduction when food is abundant for their young. Therefore, when listening to birdsong, it's important to remember that nature also encompasses cooperation and harmony within species and bonding between males and females.
Studying the Zebra Finches
Zebra finches are a highly social bird species that travels in large flocks through Australia's arid interior, searching for seeds. They are known for their ability to learn new songs and are one of the most studied birds in Australia due to their ease of being kept in captivity, as added by Ebird.org.To study their behavior in the wild, researchers had to travel to a remote study area near Broken Hill.
They installed over 20 microphones and recorded the birds' songs from dawn to dusk every four days for a year. The researchers chose to study the Zebra finches because the males have individually distinctive songs and sing relatively quietly compared to other bird species. This is important because when birds sing softly, it indicates that the song is not a warning about territory.
The songs can only be heard by birds within a few meters and are often sung when birds perch together in the same bush. The researchers believe that the birds singing their unique songs allows others in the group to figure out who is singing and gauge how many males are nearby.
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Song of Friendship
When researchers play the song of one male zebra finch to another male, it does not provoke an aggressive response as it would in other territorial and less social species. Instead, it has the opposite effect and draws other males closer to share the same space. This is why you often hear multiple males singing together in the same bush. In a study conducted by the researchers, even during one of the worst droughts in the last 100 years in 2019, zebra finches could be heard singing every day; they observed that no finches even attempted to breed.
When the climate shifted from drought to rains and floods, the finches could sense the change in food availability and began mating. As the drought broke, the researchers noticed an increase in the males' singing, peaking around the time the female birds laid their eggs. This suggests that the zebra finch song is part of an ongoing "discussion" between a female and her partner, which helps synchronize their activity.
The song is likely related to how birds feel; birds feel better and sing more when food is abundant. When individual finches hear a lot of singing in the area, it gives them greater confidence in the decision to start breeding. Contrary to popular belief, Scientific American notes that zebra finch males do not sing to claim territory or to show off to prospective mates.
Song of the Songbirds
They tend to sing after they have found a partner, singing to her while perching next to her on a branch, and they will regularly sing, even daily, throughout their relationship. Unlike most singing species, female zebra finches do not sing, but researchers believe that the serenading of the female zebra finch by her partner may serve a similar social function as the commonplace song duets of other Australian songbirds. For example, magpie-lark couples sing a duet while performing synchronized wing spreading, shoulder raising, and body flicking movements.
The synchronized songs and visual displays of these duets help strengthen the pair's bond and coordinate their behavior. It also serves as a warning to territory intruders. For zebra finches, the male's constant song may be sufficient to keep the pair well-bonded. Australia is well-known for its diverse bird population, including raucous cockatoos and melodious songbirds.
Birdsong evolved in Australia first and spread to the rest of the world. The discovery that zebra finches use a song as a form of social bonding allows researchers to look for similar behavior in other species worldwide. It is expected that many other gregarious species will use the song in ways more complex than marking territory or attracting mates. Birdsong is an animal sound that humans encounter regularly and is a part of the background of one's lives, but for birds, it is far beyond just a melody; it is fundamental to how they live and their existence as a species.
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