In our community, just ten years can bring about countless new music trends. In contrast, some bird species prefer to sing the same ‘tune’ repeatedly for thousands to millions of years.
This is part of a study conducted by scientists from the University of California, Berkeley (USA) after a long period of observing isolated populations of nectar-feeding birds living in the highlands of East Africa.
One of many species of nectar-feeding birds in East Africa studied – (Photo: UC Berkeley).
Previously, scientists believed that bird songs were highly variable over time, as they are passed down orally, leading to numerous variations.
However, the research team from the University of California, Berkeley argues that this is only true for migratory bird species, especially in the Northern Hemisphere. In contrast, isolated bird populations, such as those found in the mountain regions of East Africa, including Mount Kenya and the “Roof of Africa,” Kilimanjaro, show different patterns.
The research team visited 15 mountain peaks in East Africa over many years, starting in 2007, documenting the songs of 123 birds from various nectar-feeding species.
The results showed that despite the passage of many generations (nectar-feeding birds can live from 7 to 22 years), the researchers found that the songs sung by these birds each day showed almost no differences.
Even among nectar-feeding species that are relatively distantly related, their songs were still very similar.
Based on methods of measuring differences, the team concluded that these birds have transmitted their songs nearly intact for thousands to millions of years.
Professor Rauri Bowie from the University of California, Berkeley, the lead researcher, stated that the key lies in the birds’ isolated living environment that has remained unchanged for thousands of years.
Professor Rauri further explained that this is somewhat similar to human communities. If you live in isolation within a community for hundreds of years, you are likely to retain the dialect and cultural traits of that community.
