The grey grasswren (Amytornis barbatus ) is a passerine bird in the Australasian wren family, Maluridae. It is found on arid inland floodplains of Australia where it is endemic. The grey grasswren is a rarely seen elusive bird that was first sighted in 1921 but not taxonomically described until 1968. Its greyish coloration and very long tail distinguish it from all other grasswrens. While some recent research has been conducted, there still remain many gaps in the knowledge about the ecology of this cryptic bird.
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TerrestrialTerrestrial animals are animals that live predominantly or entirely on land (e.g., cats, ants, snails), as compared with aquatic animals, which liv...
Oviparous animals are female animals that lay their eggs, with little or no other embryonic development within the mother. This is the reproductive...
Nomadic animals regularly move to and from the same areas within a well-defined range. Most animals travel in groups in search of better territorie...
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Not a migrantAnimals that do not make seasonal movements and stay in their native home ranges all year round are called not migrants or residents.
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starts withThe grey grasswren is a small bird with a length ranging between 18–20 cm, a wing span of approximately 21 cm and a weight between 15 and 23 g. Its general colour is ginger-brown suffused with grey and off-white striations. Schrodde and Christidis recorded that "the face is patterned black and white with broad white superciliary stripe and black stripe from lores through eyes linked to thin black malar line around sides of throat; tail greatly attenuated with tapered rectrices, the center pair of which extend > 5mm beyond the adjacent pair; no sexual dimorphism in colour of flanks or belly". Juvenile color is duller although similar to the adults and with no distinct facial pattern. Moult is poorly understood but thought to occur annually after breeding and between October and December.
The grey grasswren occupies a restrictive area of arid inland floodplains of central Australia. Sightings have occurred at the Bulloo Overflow in the New South Wales/Queensland border area, lower Cooper Creek, along the Kallakoopah anabranch of the Diamantina River and the overflow areas of lakes Machattie, Koolivoo and Mipea on Eyre Creek in South Australia.These birds frequent mainly floodplains of the above systems which contain areas dominated by lignum and cane grass on major drainage lines between resident sand dunes. In some swampy areas, a dense understory of spike-rush, channel millet, and sedges are present. The grey grasswren has also been known to occupy open vegetative areas well beyond the lignum swamps which are less subject to inundation during flood events. It appears that in drought years the grey grasswren occupies tall dense lignum as a refuse while in normal years it prefers other habitats. Hardy recorded significantly more captures in declared drought years than in normal years.
During 2011, an extensive grey grasswren survey was conducted at Frome Swamp in New South Wales which had recently experienced substantial rainfall and resultant lignum and cane grass growth. Despite the use of exhaustive surveys using mist netting, playback, vocal and visual methods, no grey grasswrens were located. This result could suggest that the species may be nomadic, an observation previously made by Hardy arising from his surveys in 2002 and 2003 at another location.
The shape of the beak suggests that the grey grasswren's diet consists mainly of seed and an analysis of the gut content of a specimen confirmed the presence of mainly small seeds of different plants, two small ants and the remains of small Coleoptera. Hower, other researches have noted that insect larvae is the dominate food source supplemented by mature insects and water snails.
The breeding behaviour of this species has not been extensively documented but it is thought that the species breeds in July/August usually after flooding or heavy rain. However, Hardy recorded breeding during heavy drought conditions with no local surface water in the study area for at least seven years. The semi-domed nest is built in lignum or cane grass, between 30 and 75 cm above ground level. Favaloro and McEvey noted that the nest was a large well camouflaged nest, very loosely constructed from grass with a large opening on the side. Clutch size is thought to be two eggs with an average weight of 2.4 g. Egg color is dull, white speckled all over with nutmeg brown, nutmeg to reddish-brown or cinnamon brown markings. There is considerable colour variation between eggs within the nest and also between nests.The female is solely responsible for the incubation of the eggs which is estimated at 13 to 15 days. Both parents attend to the feeding of the hatchlings and no details are known of its breeding success.
The grey grasswren is listed as threatened under the national Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act ); it is listed as endangered under the Biodiversity Conservation Act 2016 in New South Wales and in Queensland under the Nature Conservation Act 1992, while the South Australian National Parks and Wildlife Act 1972 lists the species as rare. The IUCN Red List rates it as a species of least concern.
