Australia has the greatest diversity of avian life

THREE GROUPS OF BIRDS FOUND WIDELY WORLDWIDE, PARROTS, PIGEONS AND SONGBIRDS, EVOLVED IN AUSTRALIA. THE FIRST

TWO ARE ABUNDANT HERE.

LONDON: Long ecologically adrift as an island continent, Australia benefited through the evolution of a remarkable diversity of fascinating, colourful, noisy, clever, innovative species of bird. Australia is home to about 830 species.

Australia is lucky to have two of the world’s largest and heaviest birds. Three groups of birds found widely worldwide— parrots, pigeons and songbirds — evolved in Australia, which explains why the former two are so diverse and abundant here.

Parrots, with their cacophonously noisy calls, immediately stand out to first-time visitors to Australia. They are so species-rich in Australia that as biologist Tim Low notes in his book Where Song Began, the songbirds are an enormous group of living birds, comprising about 5,000 species, such as the robins, mockingbirds, jays and thrushes of the northern hemisphere, and the magpies, bowerbirds and lyrebirds of Australia.

Throughout the 20th century ornithologists believed many bird groups evolved in the north, only later spreading to Australia. It was an extension of the idea promulgated by 19th century naturalists that Australia was an empty land, waiting to be filled with good stuff from the north. Finding fossils in Australia is relatively challenging compared with many other parts of the world, and the fossil record of birds is particularly poor because they have small, light bones, perfectly adapted for flight but unlikely to be preserved. But songbird fossils were eventually found here that were up to 54m years old— much older than those found elsewhere in the world. Research in the 1980s also started to show that the greatest genetic diversity of songbirds was found in Australia. The idea that songbirds first appeared in Australia took a long time to be accepted overseas, but a huge study of 100 species from 25 countries left little doubt when it was published in the journal Nature Communications in 2016. That work suggested songbirds had begun to diversify in Australia 33m years ago but did not begin to spread beyond our shores for another 10m years —a period during which Australia was replete with birdsong, but much of the rest of the world was silent to its beauty.