How songbirds produce their beautiful melodies: Avians can control SOME vocal fibers, giving them an incredibly fine control over their tunes
- Songbirds can control some vocal muscle fibers, researchers in Denmark discovered
- This ability gives them an incredibly fine control over their melodic tunes
- Important because women use it to decide if they are attracted to a man
- But like humans, songbirds have to learn their song from a teacher through imitation
Their beautiful melodies make for the perfect early morning wake-up call, but how do songbirds do that?
It turns out that their secret is being able to control some vocal muscle fibers, researchers in Denmark have discovered, giving them an incredibly fine control over their tunes.
Such control is important because women detect and use these small changes to decide whether or not they are attracted to a man.
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Melodies: Songbirds like the zebra finch (pictured) can control individual vocal muscle fibers, researchers in Denmark have found, giving them incredibly fine control over their tunes
TOP 10 MOST SPOTTED SONGBIRDS IN THE UK
Blue tits are often seen in British gardens
- house sparrow
- blue tit
- wood pigeon
- great tit
- long tailed tit
Songbirds produce their sounds using a special vocal organ unique to birds, the syrinx. It is surrounded by muscles that contract at super-fast speed about 100 times faster than human leg muscles.
“We found that songbirds have an incredibly fine control over their song, including frequency regulation below one Hertz,” said Iris Adam, lead author of the study and assistant professor at the University of Southern Denmark.
A motor unit is the basic contraction unit of muscles and consists of a motor neuron and the number of muscle fibers it connects to and activates.
By combining tissue samples for counting muscle and nerve fibers with mathematical models, the researchers were able to show that a large proportion of the motor units must be very small and even as small as a single muscle fiber.
“Motor units range in size from a few hundred or thousands of muscle fibers in our leg muscles to just 5-10 in the muscles that control eye position and the muscles in the larynx,” says Dr. Coen Elemans, senior author of the study and head of the Sound Communication and Behavior group at the University of Southern Denmark.
‘In the song muscles of zebra finches, our models predicted that 13-17 percent of motor neurons innervate a single muscle fiber.’
Songbirds produce their sounds using a vocal organ unique to birds, the syrinx (shown)
To understand the effect such small motor units have on singing, researchers also measured the amount of stress the muscles can cause and how such stress changes the frequency of the sound.
“We found that songbirds’ vocal muscles have the lowest stress measured in all vertebrates,” Adam added.
“They are among the fastest muscles we know, and now we show that they are also the weakest with the highest possible control.”
Songbirds evolved about 40 million years ago and quickly diversified into the group of birds we know today. Singing is crucial for females to find and judge males and can even encourage the creation of new and different species.
However, like humans, songbirds must learn their song from a tutor through imitation, researchers have found.
“We think that in addition to a special syrinx and their amazing ability to imitate sounds, the fine gradation of song characteristics, such as pitch, increased the amount of different sounds a bird can make,” Adam said.
In April this year, the RSPB warned that nearly 80 percent of Britain’s most popular songbirds are in decline.
The world’s largest wildlife survey, Big Garden Birdwatch, found that 16 of the 20 most spotted garden birds faced a decline in numbers from the previous year.
More species are currently facing decline than in 2020, when half of the birds in the top 20 saw numbers plummet, the conservation charity said.
More than a million wildlife enthusiasts counted 17 million birds in their yard in one hour on the last weekend of January — double the number of people who took part in the charity’s massive birdwatching event last year.
The study found that the house sparrow remained number one, but 16 of the top 20 bird species showed a decline in average counts from last year.
Thrush has declined by a whopping 78 percent over the past four decades, despite a marginal increase this year.
Only robins, blackbirds, carrion crows and song thrush saw an increase in 2020, with loss of habitat and food, which is why most bird species have seen their numbers decline since birdwatching began 42 years ago.
BIRDS USE SONG TO COMMUNICATE WITH OTHER BIRDS
Birds use their voice to communicate with other birds.
Sharp tunes are an efficient way to communicate over long distances, especially if you’re small and live in dense habitats like rainforests.
Most bird species use specific calls to identify themselves and communicate a nearby threat.
Birdsong is a special type of call used by many species to help them mate.
Almost exclusively a male activity, birdsong helps the warbler to signal that he is fit, healthy and ready to breed.