Recent research came across an unsuspected discovery. In birds, tropical varieties are considerably more colorful than their polar relatives. Birds near the equator are more colorful. Why?
Many of us have seen pictures of bustling rainforests. There we see brightly colored macaws, colorful frogs, and many other striking animals. It may seem common sense to suggest that these are places with more color than others. But for scientists, the colorfulness of tropical species has been surprisingly difficult to quantify.
Latitude and coloring
They now decided to take some 140,000 photographs of approximately 24,000 birds. The outstanding results are those concerning passerines. They are better known as songbirds. In this species, birds near the equator are more colorful, gradually increasing.
The new research used the extensive bird collection of the British Natural History Museum. It was a surprise even to the researchers themselves. They did not even expect to find such a strong association between latitude and coloring.
Dr. Chris Cooney, of the University of Sheffield, is lead author of the study. He says in a statement, “This work reveals the general pattern that bird species tend to be 30% more colorful towards the equator. And it identifies some general explanations for why this pattern might occur. This is exciting. It helps us better understand the factors that promote and maintain biodiversity.” The results have been published in the journal Nature Ecology & Evolution.
It’s not so simple to answer why this happens. Cooney and his team have suggested a couple of different reasons. The dark nature of rain forest interiors would influence, (it would be better to have bright colors there). Also structural complexity of these environments leading to structural color complexity.
But the exact reasons are still unknown. Moreover, further studies will be required to unravel the many interactions at play.