A Song That Has Survived for Thousands of Years

Sometimes, a species’ song changes over the course of a few decades. But a bird that lives in the mountains of eastern Africa, the Forest Double-collared Sunbird, appears to have kept the same song for at least 500,000 years. That’s the amount of time that two populations of the species split up into two separate mountain ranges. Despite a lack of contact between those populations, they sing a nearly identical song, suggesting that it’s very similar to the one their ancestors sang long ago.

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A Song That Has Survived for Thousands of Years

Written by Conor Gearin

Michael Stein: This is BirdNote.

Sometimes birds change their tune. For example, White-throated Sparrows in many areas have shortened their songs in just a few decades.

[White-throated Sparrow “doublet” song]

But there are also songs that appear to have stayed the same over millennia.

[Forest Double-collared Sunbird song]

Several related species of sunbirds in Eastern Africa live on isolated mountaintops, also known as sky islands. Their mountaintop habitats led them to become distinct populations and in some cases evolve into different species.

[Moreau’s Sunbird song]

But researchers found that two populations of one species, the Forest Double-collared Sunbird, still have nearly identical songs, despite having separated into different mountains at least 500,000 years ago. That suggests the song that these sunbirds sing today is probably very similar to that of their long-lost ancestors.

[Forest Double-collared Sunbird song]

The findings show that there are good reasons for a species to keep singing the same old song. Having a unique and stable song helps birds recognize members of their own species, even if their ancestors split up long ago.

So if a tune works, don’t change it. For BirdNote, I’m Michael Stein.

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Senior Producer: John Kessler
Producer: Mark Bramhill
Managing Editor: Jazzi Johnson
Managing Producer: Conor Gearin
Content Director: Jonese Franklin
Bird sounds provided by The Macaulay Library of Natural Sounds at the Cornell Lab of Ornithology, Ithaca, New York. White-throated Sparrow ML59381331 recorded by Jeff Dyck, and Forest Double-collared Sunbird song ML101233 recorded by David Moyer.
Moreau’s Sunbird song Xeno Canto 430079 recorded by Frank Lambert.
BirdNote’s theme was composed and played by Nancy Rumbel and John Kessler.
© 2023 BirdNote August 2023
Narrator: Michael Stein

ID# song-18-2023-08-21 song-18

References
https://phys.org/news/2022-01-birds-song-hundreds-thousands-years.html
https://royalsocietypublishing.org/doi/10.1098/rspb.2021.2062#