See text The thick-billed grasswren (Amytornis modestus) is a species of bird in the family Maluridae.

[2] Seven subspecies have been identified in recent studies (Black 2011, 2016; Austin et al. 2013):[3][4][5] The thick-billed grasswren has dull brown underparts, a long dark-brown tail and noticeable white streaking on the head.

The white streaks across the chin to the forehead and along the wings and rump, contrast with the red-brown to grey colours of the feathers.

[6][7] It is also speculated to still occur in fragmented populations in the Grey Range of Sturt National Park.

Chenopod scrublands (consisting largely of saltbush), sandhill cane-grass and flood debris in dry, sandy watercourses.

Thick-billed grasswrens are usually sedentary, with these elusive birds seen running, hopping or rarely flying, between vegetative cover to remain undetected.

The thick bill allows for tougher seeds and other food niches to be accessed, compared with the smaller fairy wren species.

If disturbed, individuals take refuge in any existing cover – usually vegetation or piles of old flood debris along dry sandy watercourses and even down rabbit burrows.

Sources vary, but mating pairs maintain between five, and 20 to 40 hectare territories year-round and rarely, possibly never, band with their neighbours outside the breeding season.

The thick-billed grasswren eats mainly insects and other small invertebrates, as well as plant seeds and berries.

The main threat to thick-billed grasswrens is loss of habitat through clearing and overgrazing by hard-hooved animals, such as sheep and goats that trample the vegetation.

Higher frequency of fires disrupts the life-cycle processes of the thick-billed grasswren, as well as the plants and macroinvertebrates that they depend on.

Changes in expected environmental conditions will also challenge tolerance ranges and exacerbate the impacts of existing threats to the species.

[9] The subspecies Amytornis modestus obscurior (north-west NSW) is listed as critically endangered by both the New South Wales and Commonwealth Governments.

Thick-billed Grasswren (eastern subspecies) Amytornis textilis modestus (North, 1902) Recovery Plan.