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.More info and transcript at BirdNote.org. Want more BirdNote? Subscribe to our weekly newsletter. Sign up for BirdNote+ to get ad-free listening and other perks. BirdNote is a nonprofit. Your tax-deductible gift makes these shows possible.