The striated grasswren (Amytornis striatus ) is a small, cryptically coloured ground-dwelling species of wren-like bird in the family Maluridae, endemic to Australia. It occupies a large discontinuous range across arid and semi-arid areas of western, central and southern Australia where it is associated with spinifex (Triodia ) grass.
The striated grasswren is one of 11 species in the genus Amytornis, commonly known as the grasswrens, found only in arid and semi-arid areas of Australia. All are small cryptic birds with long, usually cocked-tails, characterised by diagnostic distinctive interscapular gap in the feathering, an enlarged auditory bulla (tympanic chambers) and ten rectrices. The striated grasswren is a slim, long-tailed grasswren with a slender pointed bill. The plumage is highly variable across its range, suited to local soil and rock colour; birds are slightly sexually dimorphic; females have a brighter rufous flank-patch. All populations are soft red-brown above, streaked white; an orange-buff eyebrow and fore-supercilium; white throat; bold black submostachial stripe; and buffish underbody.Like other grasswrens they have short rounded wings and are unable to undertake long flights, typically flitting or hopping from perch to perch within vegetation, and run or hop when on the ground in a series of fast jerky movements. While closely related to the familiar fairy-wrens (Malurinae ) striated grasswrens are larger (17-20g c.f. 6-16g), and more sombrely coloured, with varyingly prominent white streaking on varying shades of brown, rufous and black plumage.Striated grasswrens are usually seen as pairs, but sometimes as individuals, and often in small groups of up to five birds, which are unobtrusive, shy, and typically difficult to approach, often first detected by their calls. When breeding, birds may be inquisitive of intruders of their territory.
Striated grasswrens are the most widespread of the grasswrens, with a range which extends from the through northern South Australia, across central and southwestern New South Wales, northwest Victoria and into southern and eastern South Australia. Populations of striated grasswren are strongly associated with sandplains, dunes and stony hills dominated by spinifex (Triodia ) grass, with or without an overstorey of shrubs such as grevillea, Hakea, acacia banksia or mallee eucalypts. Spinifex provides critical habitat for foraging and protective nesting and cover for this species, and most other species of grasswren. Striated grasswren have been shown to have a preference for areas with large hummocks of spinifex, 25–40 years post-fire, though birds have been found to occupy some areas 6 to 8 years after fire.
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Striated grasswrens may be active throughout the day, and in warm temperatures (over 35 °C) may be observed thermoregulatuing by holding wings partly open, but are generally more active in the early morning and late afternoon. Like other grasswrens, striated grasswrens mainly forage on the ground, sifting through leaf-litter beneath shrubs and surrounding spinifex Triodia tussocks, never far from cover. While foraging, birds move mainly by hopping, with tail help almost vertical, when moving through shrubs and dense vegetation, tail help horizontal. When disturbed in the open, move with great speed and agility from cover-to-cover with a half-bounding half-flying action reminiscent of a bouncing ball.
Striated grasswrens are insectivorous and granivorous, foraging on the ground amongst leaf-litter and open areas, and gleaning from the foliage of herbs, forbs and low shrubs for primarily beetles and ants, and seeds of spinifex (Triodia ) and other plants. Striated grasswrens have been often observed to form foraging associations with other bird species including rufous-crowned emu-wren (Stipiturus ruficeps ), willie wagtail (Rhipidura leucophyrus ) and variegated fairy-wren (Malurus lamberti ).
Clearing of large areas for agriculture in the southeast of this species range have caused the direct loss of some populations and fragmentation of remnant areas of habitat, reducing the size of these populations rendering them more vulnerable to genetic effects and change events such as fire and drought. Striated grasswrens are vulnerable to large wildfires which cause direct mortalities of these weak flying species, and remove critical habitat and protection from predators, birds show a preference for areas with large hummocks of spinifex, 25–40 years post-fire, though birds have been found to occupy some areas 6 to 8 years after fire. Grazing by introduced herbivores affects habitat structure and is likely to contribute to population declines. Predation from introduced foxes and cats, particularly where populations have already declined, or are exposed by small areas of habitat following land clearance or fire.
