Birds-The Perpetual Tune

 

The Perpetual Tune

Birds in the mountain peaks of East Africa have been singing the same songs for as long as a million years, Live Science reported.

Sunbirds in the family Nectariniidae are small, colorful, nectar-feeding avians that resemble hummingbirds and are found throughout Africa and Asia.

A research team studied different populations of the eastern double-collared sunbird found in the “sky island” mountains from Mozambique to Kenya.

The tall peaks have isolated different populations – or lineages – of this species from one another for up to a million years. Even so, many of these lineages remain indistinguishable from each other, the team noted.

For their study, researchers visited 15 sky islands and recorded the songs of 123 individual birds from six different lineages. They then came up with a statistical technique to analyze how the birds’ songs evolved.

Their findings showed that some of the isolated populations stuck to the same tune, despite these lineages having been separated for thousands of years. The team also noticed that populations that had been separated for the longest period had nearly identical songs, unlike those that were separated for a shorter time.

The results were peculiar because biologists have noted that bird songs – as well as behavior and plumage – evolve through time in different populations, so they can adapt to new environments.

The authors suggested that the lack of geological change in the mountains of East Africa meant that the sunbirds did not need to evolve different feathers or songs – and therefore could remain unchanged for eons.