ONE MILLION many years ago, soundtrack famous about the mountain entitled L Islandsuffering in East Africa, probably very similar to what it is today.
That’s because a group of tiny, colorful birds have been singing the exact same tune for more than 500,000 years, maybe even a million, according to a new study.
Sunbirds in the family Nectariniidae are colorful, small-bodied nectar-eating birds that resemble hummingbirds and are common throughout Africa and Asia.
“These birds are the ‘little gems’ that appear before you,” wrote senior author Rauri Bowie, who is also professor of integrative biology at the University of California, Berkeley, USA, and curator at the Museum of Vertebrate Zoology.
Double collared sunbird east (fairy, reported Voice Editor from Live Science, Friday, January 14, 2022, also known as the ‘sky island sunbird’, lives on the tops of high mountains in East Africa, from Mozambique to Kenya.
The tops of these skyscrapers have isolated the various populations, or lineages of these species from each other for tens of thousands to a million years.
However, despite not interacting at all, many populations of sky island sunbirds are indistinguishable from one another.
Bowie and his team wondered if bird song had also remained unchanged for thousands of years. To answer this question, the researchers visited 15 separate sky islands in East Africa in 2007 and 2011.
They recorded songs from 123 individual birds from six different sunbird lineages. Then, they developed statistical techniques to analyze how sunbird song evolved.
Apparently, some of these isolated bird populations still sing the same song.
This indicates that these songs did not develop much in thousands of years, as these lineages had split.
The researchers also found, through analysis of genetic differences between populations, that the two populations of the species that had been separated the longest had nearly identical songs.
The other two populations were separated for a shorter time. has a very different song, according to the statement.
The team’s findings were surprising, as biologists typically expect bird song to evolve, and change over time, in different populations.
“The idea that bird song evolved rapidly, likely stems from studying birds in the Northern Hemisphere, where environmental conditions have changed several times over tens of thousands of years,” Bowie said.
Northern Hemisphere Birds
The species is thought to have developed new colors, songs, and behaviors to better adapt to new environments, such as the presence or absence of glaciers.
However, the mountains of East Africa have undergone little geological change, suggesting that sunbirds had no reason to develop distinct feathers or song.
The researchers concluded that birds, and their songs, could remain unchanged for millions of years, until environmental changes caused them to evolve rapidly, according to the statement and accompanying video.
“If you isolate people, the dialect changes quite often; You can tell after a while where someone is from. And, the song has been interpreted in the same way,” said Bowie.
“What our paper shows is that it doesn’t always hold true for birds. Even in traits that are supposed to be very volatile, like singing or feathering, where you can be in a static state for a long time.”
Now, scientists are continuing research in East Africa to find out why some birds develop new songs, and others don’t.
The findings were published on November 17, 2021 in the Journal Prosiding Royal Society B.***
Source: Live Science