Plains-wanderers Show Unexpected Habitat Flexibility at the Edge of Their Range
New research finds Critically Endangered species thriving in semi-arid chenopod shrublands, challenging long-held views of their grassland-only preference
Plains-wanderer discovery in South Australia broadens habitat definition
Once thought to be strict grassland specialists, Plains-wanderers (Pedionomus torquatus) have now been documented using low forb-like chenopod shrublands at the western edge of their range. The two-year study, conducted at Boolcoomatta Station Reserve in South Australia, tracked 29 individuals and recorded 272 sightings, revealing a strong preference for open Sclerolaena-dominated vegetation. This community averaged 55% cover, with plants around 11 cm high and interspersed with 40% bare ground – conditions strikingly similar in structure to grasslands in the species’ core range, but botanically distinct.
These findings, published in *Ecology and Evolution*, expand the recognised habitat tolerance of the species and suggest that peripheral populations may be more adaptable than previously assumed. Lead author Saskia Gerhardy noted that “height and structure appear more important than plant species composition,” meaning that low, open vegetation types beyond traditional grasslands can support viable populations.
High encounter rates and stable home ranges
Despite assumptions that range-edge birds might be scarce and nomadic, the study recorded more individuals than expected – potentially indicating a robust local population. Home ranges averaged 53.6 ha, comparable to those in core populations, suggesting resource availability is not limiting. Notably, 35 of 36 nests were located in Sclerolaena divaricata communities, reinforcing their importance for breeding.
Tracking data showed males often remained within small territories during incubation while females ranged further afield, sometimes up to 1 km from the nest. The avoidance of dense chenopods and tall grasses, along with selection for open structure, mirrors patterns documented in the east, despite differences in vegetation composition.
Conservation implications for range-edge populations
The study underscores the value of peripheral habitats in species recovery plans. Such populations can act as genetic reservoirs and may harbour adaptations to different environmental pressures. By overlooking these areas, conservation strategies risk missing opportunities for resilience and range expansion.
Given that similar chenopod shrublands occur elsewhere in the species’ historical range, researchers recommend expanding survey and monitoring efforts beyond recognised grassland strongholds. They also call for further genetic studies to determine whether habitat use at the range edge reflects behavioural flexibility or emerging divergence from core populations.
From specialist to structural opportunist?
The Plains-wanderer remains one of Australia’s most distinctive and threatened birds, but this research suggests it may be less ecologically rigid than its ‘grassland specialist’ label implies. Recognising its capacity to thrive in alternative open-plain habitats could help safeguard its future in a changing landscape.
August 2025
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