Joey Clarke, Senior Science Communicator
A casual mention of the word “grasswren” will have any nearby birdwatchers clutching for their binoculars quicker than you can say “oh wait, it’s hopped away”. Grasswrens are the ultimate birdwatcher’s birds: diverse, charismatic, and in many cases posing a real challenge to detect and identify. What’s more, they live in some of the remotest corners of the country, requiring a high level of enthusiasm and perseverance from those wishing to make a grasswren their next ‘tick’.
Usually, it’s the call that gives them away first. Their high-pitched contact calls sound similar to fairy-wrens, but the loud, complex, metallic song produced by some of the larger grasswren species stands out. Hopping sneakily between rocks or dense vegetation, these birds easily slip away into their surroundings. Their plumage matches their habitat: various shades of fawn, umber and rusty brown, finely streaked white to help them fit in amongst broken lines of spinifex, canegrass or lignum. Some grasswrens have contrasting bars of black and white to break up their outline, adding to the subterfuge. Grasswrens spend most of their time close to the ground, moving in pairs or small groups to hunt for insects and forage for seeds. Nesting near ground-level and having limited capability for flight has made them vulnerable to introduced predators like cats and foxes, as well as changes to vegetation caused by introduced grazing animals and poor fire management.
The relationships between different populations has been a major focus of recent research, and most ornithologists now agree there are at least 13 distinct species of grasswrens – between them they cover most parts of arid Australia.
Several species of grasswrens are found across Australian Wildlife Conservancy sanctuaries and partnership sites, including some threatened species of high conservation concern.
Striated Grasswren (Amytornis striatus howei) – Endangered
The Striated Grasswren was once considered the most widespread of the group, but in the current classification only isolated populations in the Central West region of New South Wales and the Murray Mallee are ascribed to this species. Scotia Wildlife Sanctuary and the adjoining property Tarawi constitute one of just two sites where this species has been recorded recently in NSW. It’s likely that the 8,000-hectare fenced safe haven at Scotia has helped the grasswrens persist at the sanctuary, while so many other populations have suffered dramatic declines and local extinction.
Dusky Grasswren (Amytornis purnelli)
A denizen of the Central Australian ranges, the Dusky Grasswren can be spotted at several accessible sites close to Alice Springs. It is also resident at Newhaven Wildlife Sanctuary, where small groups occur on the rocky scree and boulder slopes of the ancient quartzite range Wardikinpirri, as well as on other nearby ranges. Wardikinpirri sits entirely within AWC’s 9,450-hectare feral predator-free safe haven, providing a barrier which protects the grasswrens against the additional pressure of cat and fox predation.
Eyrean Grasswren (Amytornis goyderi)
This is the smallest grasswren, at 14-16 centimetres (only slightly bigger than a Superb Fairy-wren). The Eyrean Grasswren has a thick, finch-like bill, possibly an adaptation to feeding on the seeds of canegrass (Zygochloa) which form part of its diet. Unlike the other grasswrens profiled here, this species is not closely associated with spinifex hummocks. Instead, it prefers to hop and scurry around clumps of canegrass on the slopes of well vegetated dunes in the Simpson and Strzelecki deserts. After the first specimens known to Europeans were shot for museum collections in the 1870’s in the area around Kalamurina, there were no verified sightings of the Eyrean Grasswren by scientists for nearly a century.
Black Grasswren (Amytornis housei)
The Black Grasswren is among the largest, loudest and most visually striking of the grasswrens – males have a black head and belly, finely streaked with white, while females are rich orange-brown underneath. The most extensive ecological study of this species was conducted at Charnley River-Artesian Range Wildlife Sanctuary in the north-west Kimberley in 2013 and 2014. Unlike the two other large grasswrens in tropical Australia which have declined dramatically due to damaging fire patterns, the Black Grasswren appears to have a stronghold in the complex, rocky range country of the north Kimberley. It is relatively abundant at Artesian Range, and also occurs on Dambimangari Country.
Carpentarian Grasswren (Amytornis dorotheae) – Vulnerable
One of the first projects initiated by AWC under a partnership with North Australia Pastoral Company (NAPCo) is to identify potential populations of Carpentarian Grasswrens on NAPCo properties in the Gulf of Carpentaria. In late 2022, AWC wildlife ecologist Dr Rich Seaton deployed an array of acoustic recorders across two NAPCo properties in the Gulf region of north-west Queensland. The devices are programmed to record continuous audio from before dawn to after dusk, while the grasswrens are active. Analysis of the recordings may reveal previously unreported populations of this threatened species.