A new study on the North American lark has shown that birds living in irregular weather conditions can sing more flexibly.
To test this idea, researchers at the Australian National University and the National Center for Evolution analyzed the voice recordings of more than 400 male birds of 44 North American larks. This dataset includes golden birds, howling birds, warblers, sparrows, sparrows, sparrows …
The researchers used computer software to convert each of these recordings into spectral images, according to Science Daily. Like a musical scoreboard, intricate lines and stripes in a spectral image help scientists visually see and analyze each sound segment.
For each bird species in this data set, they measured vocal characteristics such as length, highest and lowest notes, number of notes, and distance between notes.
When they combined this data with records of temperature, precipitation, and other information such as habitat and range, they found a surprising trend: Males experience conditions.
“They can sing really low or very high notes, or they can adjust their intensity or speed,” said study co-author Clinton Francis of the National Center for Evolution.
In addition to the seasonal variations of the weather, experts also study geographic differences and find a similar trend. Species that live in areas with large differences in precipitation will sing more complex melodies. “Precipitation is closely related to the abundance of trees in the habitat,” explained co-author Iliana Medina of the Australian National University.
In other words, changing trees means changing the sound environment.
Another group of researchers recorded a similar environmental link to birdsong in 2009, but this is the first to show a common pattern of birds.
