Why do many birds sing only 'one song' for millions of years?

This is part of a study by scientists from the University of California, Berkeley (USA) after a long time observing populations of honeybirds living in isolation in the high mountains of East Africa.

One of the many East African honeybirds in the study

Previously, scientists believed that bird songs are easy to change over time, because they are transmitted orally, many variations will arise.

However, the team from the University of California, Berkeley believes this is only true for birds with migratory habits, especially in the northern hemisphere. Meanwhile, isolated bird populations such as in the mountains of East Africa such as the top of Kenya or the "roof" of Africa Kilimanjaro are the opposite.

The team traveled to 15 mountain peaks in East Africa over the years, starting in 2007, recording the songs of 123 birds of different species of nectar.

As a result, despite many lives (honeybirds can live from 7-22 years), the team still found that there was almost no difference between the songs the bird used to hum every day.

Even among the nectarines that are relatively distantly related, the songs of the birds are quite similar.

Based on differentiating methods, the team suggests that songs have been transmitted almost entirely orally by these birds over the past thousands to a million years.

Professor Rauri Bowie from the University of California, Berkeley, who led the study, said the key point lies in the birds' isolated habitats, which have remained unchanged over thousands of years.

Professor Rauri further explains this is similar to the human community. If you live in isolation in a community for hundreds of years, it is easier for you to maintain the voice or identity of that community.