An endemic species of Australian wren, the striated grasswren (Amytornis striatus) is a small, cryptically colored bird in the Maluridae family. It lives mainly on spinifex in inland sand plains and mallee, as well as locally on stony hills. The Striated Grasswren is an alert and nervously active grasswren. When temperatures are warm (over 35°C), striated grasswrens may be observed thermoregulating by keeping their wings partially open, but they are generally more active in the mornings and evenings. In the spring and summer, striated grasswrens are sedentary and often band together loosely.
Birds like this forage on the ground for insects and seeds, hopping around, cock-tailed, and darting between patches of cover. There has been a direct loss of some populations and fragmentation of habitat in the southeast of this species range due to the clearing of large areas for agriculture, which has increased the vulnerability of these populations to genetic effects and climate change events like fire and drought.
This species of grasswren is an insectivore as well as a granivore, searching for food on the ground, foraging among leaf litter and open areas, and collecting seeds of herbs, forbs, and low shrubs. It feeds mostly on beetles and ants, but also on the seeds of spinifex (Triodia) and other plants. The striated grasswren forages mainly on the ground, sifting through leaf litter beneath shrubs and tussocks of Spinifex triodia, never far from cover.
In flight, the Striated Grasswren flutters low, weakly, and directly, with the tail dragging. During non-breeding seasons, pairs or family congregations might be more common, and they may range more widely over suitable habitat areas.
Other names for this species include Rufous Grasswren and Striped Grasswren. Streaked upper parts give rise to the specific name of this species, from the Latin striatus, a line, which in turn comes from the Latin stria. Approximately 145–165 mm is the length of the striated grasswren. There are 13 species of grasswrens in the genus Amytornis, commonly called grasswrens, and they only live in arid and semi-arid regions of Australia. All species of these birds are small, cryptic, have long tails, are often cocked, and are characterized by a distinctive gap between their scapular feathers.
The male is brown to rufous above, with fine black and white streaks; the tail is slender and brown, with feathers that are rufous-edged. It has a light cinnamon color below, a white throat, and gray and white streaks on its breast. A black malar stripe runs from bill to brow and down to the base of the remiges. The eye color is brown. The bill and feet are black to blue-grey, depending on the region. Female: Each side of the lower breast has a chestnut patch. The immature bird marks are blurry as adults.
Striated grasswrens can distinguish between three different call types: the contact call, the song call, and the alarm call. StriatedGrasswrens sing reedy chirps, tseees, in contact, and sharp, burred tchrots in alarm. The song of a bird is sweet up-and-down trilled warbling. In addition to being diagnostic, the song can be heard from up to forty meters away and is much louder than the contact call. When birds are flushed from cover, they release an alarm call consisting of short, loud, harsh notes, called jit-jit or tchiritt.
Breeding and nesting seasons last from August to December; later in the summer, rainy regions. When rainfall is sufficient, however, breeding may occur outside of the usual period, especially in central and northern Australia. Breeding pairs defend territories by singing from vantage points near nests in low trees and shrubs. Females build nests, incubate, and brood the young alone, but both parents nurture the young, usually rearing one brood at a time.
Porcupine grass is combined with shredded bark to create a domed-shaped nest. Porcupine grass is often clumped in the top of the nest, lining it with plant down, grass seeds, and fur. White eggs speckled with red-browns and greys are hatched by Striated Grasswrens usually in pairs, sometimes in threes.
The eggs are sometimes more swollen at the larger end; they are oval-shaped, about 20 mm x 15 mm. It takes about two weeks for the female to incubate. It takes 11–12 days for the young to fledge. Chicks fledge at 12–14 days and remain hidden in dense cover close to the nest for 3–4 days, taking three to four weeks to become fully independent. There are three species of cuckoos known to parasitize striated grasswren nests: Horsfield’s bronze cuckoo (Chrysococcyx basalis), black-eared cuckoo (Chrysococcyx osculans) and fan-tailed cuckoo (Cacomantis flabelliformis).
Spinifex on stony hills in Pilbara and Flinders Range, WA, and Pilbara, SA, is where the Striated Grasswren can be found; Mallee and sandplain spinifex in the inland eastern and midwestern mainland. A large discontinuous range of its habitat includes arid and semi-arid areas of western, central, and southern Australia, where it is associated with spinifex (Triodia).
An endemic species of Australian wren, the striated grasswren (Amytornis striatus) is a small, cryptically colored bird in the Maluridae family. Source: WikipediaIt lives mainly on spinifex in inland sand plains and mallee, as well as locally on stony hills. Photo credit: Tony Morris
