DECRYPTION – British and Hungarian scientists have analyzed the plumages of 4,500 species of passerines.
Are the birds more colorful in the tropics than in our temperate regions? This intuition formulated more than a century ago by Charles Darwin, and shared by many travellers, is nonetheless still debated by biologists. The scientific research carried out on this subject is indeed contradictory, and observation biases linked to the abundance of species around the equator could explain the impression that butterflies, insects, plants and fish are more colorful there.
In a study published on April 4 in the journal Nature Ecology & Evolution, British and Hungarian scientists are again looking into the hypothesis. These researchers from the universities of Sheffield and Debrecen analyzed the plumages of 4,500 species of passerines – an order that brings together more than half of the birds living on earth, including sparrows, crows, swallows or finches. “Studying such a huge sample allows us to test whether there is a rule at large…