杏吧原创

Red goshawks 鈥� unusual, strikingly colorful birds of prey endemic to Australia 鈥� have been rapidly vanishing from the continent for decades.

The species, which is already considered Australia鈥檚 rarest raptor, has gone extinct in more than one-third of its historical range over the last four decades, and is barely present in another 30 per cent. The birds may be substantially more imperilled than previously thought.

Red goshawks (Erythrotriorchis radiatus) are powerful predators that inhabit open woodlands in a band of coastal territory in northern and eastern Australia. They specialise in hunting other birds, such as kookaburras and parrots. Many female birds of prey are bigger than their male counterparts, but at nearly twice the males鈥� size, female red goshawks are among the most extreme examples of this pattern, says at the University of Queensland in Australia.

Their rarity, combined with their rich, ochre plumage, has made them revered by bird watchers.

鈥淧eople had anecdotally reported that the species was in decline. For example, bird watchers were no longer getting their occasional glimpses of this hawk across whole regions,鈥� says MacColl. But no one had yet quantified this.

MacColl and his colleagues developed a database of nearly 1700 red goshawk sightings across Australia from 1978 to 2020, pulled from numerous survey efforts and citizen science reports. The team analysed this information to reveal trends in where and how often the goshawks were turning up.

In eastern Australia, records of red goshawks have dropped off precipitously since the 1980s. The last records of goshawks in New South Wales were about a decade ago, and the team thinks that regional population is extinct. Just in the last decade, the birds have disappeared from about half of Queensland.

Red goshawks have been considered 鈥渧ulnerable鈥� to extinction by the Australian government since 1992. But the International Union for Conservation of Nature classified the species as 鈥渆ndangered鈥� in 2022, and the researchers argue that this classification should now be mirrored in Australian law, given the findings.

Clearing and developing of the goshawks鈥� habitat might be behind their decline. In developed regions, natural fire cycles are disrupted, which can leave the woodland habitats the birds prefer overgrown with vegetation, says MacColl.

With regards to raptors across the world, at the Spanish National Research Council鈥檚 Do帽ana Biological Station says he is 鈥渁fraid we will be seeing more and more of these鈥� steep and 鈥榤ysterious鈥� declines in the decades to come鈥�.

Sergio, who wasn鈥檛 involved with the research, describes a 鈥渃ocktail鈥� of threats to raptors, from habitat loss, to being killed by humans, to climate change.

The red goshawk isn鈥檛 the first raptor to experience swift declines, he says. For instance, several vulture species in Africa and India have recently suffered population collapse from food sources contaminated with poisonous drugs.

Now missing from 34 per cent of its former range, red goshawks appear limited to Australia鈥檚 far north. The region鈥檚 tropical savanna and woodlands are largely intact and undeveloped, and are now critical to this species鈥� persistence, says MacColl.