Critically endangered plains-wanderer found in unfamiliar territory

Researchers from the University of Adelaide have found a critically endangered bird known as the ‘Goldilocks’ of the grasslands in a previously unrecorded habitat niche in South Australia.

The Plains-wanderer is a ground-dwelling bird, so evolutionarily unique that it is often referred to as a living fossil.

It was believed to rely exclusively on sparce native grasslands, but new research, published in Ecology and Evolution, suggests its habitat preference may be more flexible than previously thought.

Saskia Gerhardy, a PhD candidate with the University of Adelaide, was part of a team of researchers that discovered the 272 Plains-wanderers in South Australia living at the edge of their current known range.

“It was a surprise to find one Plains-wanderer, let alone 272,” says Saskia.

“South Australia has historically been considered marginal habitat for the species, with fewer than 90 recorded sightings over the past 100 years before we began this project.

“We were immediately interested in understanding why there were so many birds living in habitat that had not been described as suitable for the species.”

To better understand this unexpected habitat, the research team turned to new ecotechnologies, fitting the birds with tiny GPS trackers worn like miniature backpacks.

“They’re lightweight and designed to sit comfortably between the birds’ wings, almost like a little hiking pack. This allowed us to follow their movements across the landscape without disturbing their natural behaviour," says Saskia.

“What we found really surprised us. Plains-wanderers are known to be an extremely picky grassland specialist, but our data revealed that the birds were selecting low, open shrublands dominated by low-growing and prickly Sclerolaena.”

Saskia says this behaviour challenges long-established knowledge of Plains-wanderer habitat use.

“While grassed regions were within our study region, we found the birds were avoiding these areas as they were too dense and did not provide enough open habitat,” Saskia says.

“The fact the birds picked habitat that had specific composition, rather than specific species, suggests that vegetation structure, rather than plant species alone, is the key factor in habitat selection for the Plains-wanderer.

“Our findings suggest a shift in how we understand the species – that Plains-wanderers may be better described as compositional specialists than purely grassland specialists."

This subtle distinction may open up new conservation possibilities for the critically endangered species.

“As the habitat we identified in this study is common throughout much of South Australia’s arid and semi-arid interior, it is possible that there are more hidden Plains-wanderer populations existing throughout this region,” Saskia says.

This discovery highlights the conservation value in studying peripheral populations of endangered animals.

“Peripheral populations are often overlooked, but they can be essential for a species’ long-term survival,” Saskia says.

“These groups might have unique genetic traits, show distinct behavioural adaptations, or act as a buffer if conditions in the core range decline.

“This research shows how even the most surprising findings can help shape a more hopeful future for endangered species.”

The research was carried out on the Bush Heritage Australia-managed Boolcoomatta Station Reserve, Adnyamathanha and Wilyakali Country, 100km west of Broken Hill.

Graeme Finlayson, Bush Heritage Australia's SA Arid Rangelands Healthy Landscapes Manager said the finding were an exciting win in the fight against biodiversity loss.

“Bush Heritage began managing Boolcoomatta as a conservation reserve in 2006," Graeme says.

"Before this research project commenced, we were only detecting Plains-wanderer on the property in ones and twos, so this is a game changer in terms of how we think about the concept of a core range for this species and the likely importance of the Reserve for Plains-wanderer conservation efforts.

“Back in 2019, I spotted three Plains-wanderers in this location whilst out collecting data related to our monitoring of the species, and at the time we really hoped it was a breeding pair.

"To think that now, just a few short years later, we have found more than 250 Plains-wanderers on the reserve is just incredible."