How flying birds became extinct

BIRDS had to discover flight all over again after the asteroid strike that killed off the dinosaurs, scientists believe. The cataclysm 66million years ago not only wiped out Tyrannosaurus rex and its relatives, but also tree-living flying birds.

As forests burned around the world, only flightless species that lived on the ground survived. Every bird today is descended from them, the scientists say.

Dr Regan Dunn, one of the team from the Field Museum in Chicago, said: ‘There are multiple lines of evidence suggesting the forest canopies collapsed. Perching birds went extinct because there were no more perches.’

Dr Daniel Field from the University of Bath, co-author of the study reported in Current Biology, said: ‘The ancestors of modern tree-dwelling birds did not move into trees until the forests recovered.’