Hundreds of Critically Endangered Plains-wanderers found thriving in unexpected habitat
In a ground-breaking discovery, researchers found more than 250 Plains-wanderers thriving in habitat nobody expected the species to use.
The Plains-wanderer (Pedionomus torquatus) is a critically endangered(1) bird found in the native grasslands of south-eastern Australia. It's the only species in the family Pedionomidae and is considered one of the world’s most evolutionarily distinct birds. Less than 1,000 individuals have been estimated to remain in the wild.(2)
This small, ground-dwelling bird resembles a quail with lankier legs and a finer bill, but it’s actually a closer relative of gulls and shore birds. The South American Seedsnipe – a plant-eating shorebird – is its closest relative and it’s thought the bird’s evolution could trace back 60 million years to when Australia was connected to South America and Antarctica! (3)
Standing about 12-15 cm tall and weighing 40 to 95 grams, Plains-wanderers are small fawn coloured birds that blend in seamlessly with the plains of arid Australia. Their dappled feathers include white and blackish marks, with spots and streaks on the head and neck.
Adult males are light brown and have fawn-white underparts with black crescents. Females are larger and sport a distinctive white-spotted black collar around the neck and reddish brown chest.
Image Information
A female Plains-wanderer with white-spotted black collar around the neck and reddish brown chest. Photo Graeme Finlayson.
Where do Plains-wanderers live?
Once found from Victoria through to Queensland, small fragmented populations are holding on in western Victoria, eastern South Australia and in the western riverina region of NSW.
Habitat structure is thought to be very important. Their preference is for semi-arid, native grasslands with a diversity of plant species, which usually occur on red-brown soils. Good habitat has been described as around 50% bare ground, 40% herbs, forbs and grasses (mostly under 5 cm but with some tussocks for concealment) and 10% fallen vegetation litter in which they’ll forage for seeds, leaves and insects.(4)
Most recorded sightings in the last 30 years had been in the western riverina of NSW, but surveys across 5,000km2 of this area in the 1990s found even in this stronghold, only about 5% of the land was suitable habitat, shrinking to 1% or 2% in very hot or wet years when grasslands became too dense or were grazed too low. (4)
Plains-wanderer behaviour
In suitable conditions, Plains-wanders are largely sedentary, although they may be more active during droughts.
Each bird would have an average home range of around 12 hectares. Males and females with overlapping ranges form breeding pairs, with the larger females defending their territories and mating with several birds in a season while the males incubate eggs and raise the young.
In suitable conditions females can lay multiple clutches of two to five eggs a year.
Plains-wanderer threats
Plains-wanderers are easy prey for foxes. If disturbed their first instinct is to run. While not entirely flightless, they tend to fly low and poorly, relying on camouflage to avoid being seen.
The main reason for the bird’s dramatic decline since European settlement has been the conversion of native grasslands for agriculture or dense pastural use.
It's listed as Critically Endangered under Australia’s Environment Protection and Biodiversity Conservation Act 1999.(1)
Image Information
Plains-wanderer at Boolcoomatta. Photo Andrea Tschirner.
What’s Bush Heritage doing?
When we bought Boolcoomatta Reserve in South Australia’s arid rangelands back in 2006, it was to secure a landscape under-represented in Australia’s National Reserve System. At the time there had only been a few records of Plains-wanderers on the property.
With sweeping plains of saltbush shrublands and grasslands, Boolcoomatta has enjoyed more than a decade of conservation management and has also benefitted from effective goat and fox control through the state government’s Bounceback baiting program.
Enter science intern Emily Matthews who spent three months at Boolcoomatta in 2017. We can only imagine her surprise when a Plains-wanderer ran in front of her as she was driving across the property. Slamming on the brakes to let it pass, Emily counted herself lucky to have seen the rare bird at all. But then, just a few hundred metres further down the road, she spotted a second.
– Emily Mathews, Science intern“Our first thought was, ‘What’s happening here? We couldn’t believe it. One night we found a female and then we found a male nearby, so we assume they're a pair. We also found an active nest with eggs.”
Overall, Emily recorded eight Plains-wanderers during her three months! This led us to working with the National Plains-wanderer Recovery Team to implement a new monitoring program. Thirty acoustic ‘Song Meters’ were deployed across the reserve and on neighbouring properties in suitable habitat. Sound recordings from each device were analysed by a call-recognition software program.
Plains-wanderer research
272 found at Boolcoomatta
Since then, against all expectations, we've found 272 Plains-wanderers thriving at Boolcoomatta Reserve.(6)
Usually associated with native grasslands in Victoria and NSW, South Australia has historically been considered marginal habitat (with less than 90 birds found in the past 100 years).
The project by researchers at the University of Adelaide, working with Bush Heritage staff, has changed how we think about the ‘core range’ for this species and the likely importance of Boolcoomatta for Plains-wanderer conservation efforts.
Research at Boolcoomatta found that this population of Plains-wanderers consistently chose open shrublands dominated by a low-growing woody herb, Sclerolaena.(7) As it's often thought of as a grassland specialist, this research suggesting a preference for shrublands opens new possibilities for the discovery of more hidden populations and for the improved protection of this threatened species.
References
- Australian Government: Plains-wanderer
- IUCN Red List: Plains-wanderer
- Victorian Dept of Sustainability & Environment – Plains-wanderer
- NSW Office of Environment & Heritage – Plains-wanderer Profile
- The Conversation: We tracked one of Australia’s most endangered birds into strange new habitat
- Ecology and Evolution: Contrasting Habitat Use at the Range Edge of an Endangered Grassland Specialist: Insights Into Plains-Wanderer (Pedionomus torquatus) Habitat Use in a Periphery Population
Image Information
Plains-wanderer. Photo Graeme Finlayson.
How you can support Plains-wanderer conservation
To lose such an ancient and unique species would be devastating. Donate today to help us continue to monitor and protect Plains-wanderers, along with other vital conservation work around Australia.
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