Australian populations of threatened bird species fall 60% in past 40 years

The gang-gang cockatoo is one of the species monitored by the threatened bird index. Photograph: William Robinson/Alamy

Australia’s populations of threatened and near-threatened bird species have declined by 60% on average in the past 40 years, new research shows.

The threatened bird index, which is produced by scientists working with the University of Queensland, reveals some of the largest declines were among species found in South Australia and Queensland.