The Eyrean grasswren (Amytornis goyderi ) is a small grasswren from the Passerine family Maluridae. This is a cryptically plumaged and uncommon bird endemic to arid regions of Central Australia. The species was discovered by F.W. Andrews in 1874 around the Macumba River at Lake Eyre, and named after the South Australian Surveyor General George Woodroffe Goyder.
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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...
A territory is a sociographical area that which an animal consistently defends against the conspecific competition (or, occasionally, against anima...
Monogamy is a form of relationship in which both the male and the female has only one partner. This pair may cohabitate in an area or territory for...
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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 withAt 14–16.5 cm in length, Amytornis goyderi is the smallest grasswren. It has a deep, finch-like bill. There are some minor differences between sexes, and between populations across the distribution.
A. goyderi has a patchy, restricted distribution, found only in dune fields of the Simpson and Strzelecki deserts of Central Australia. These deserts are located in the Birdsville Structural Basin, an enormous drainage basin centring on Lake Eyre. Most populations are found in South Australia from north of Cameron Corner to Witjira National Park; with some in SW Queensland and the Northern Territory. It is likely that populations are plastic, being most abundant when canegrass is plentiful and withdrawing to refuges during drought.
The Eyrean grasswren habitat consists of sandhill canegrass (Zygochloa paradoxa ) tussocks on large, loosely sanded dune crests and slopes; as well as in speargrass (Aristida holathera ), spinifex (Triodia spp.) and dune pea (Swainsona rigida ) where it grows among Z. paradoxa. Typical landscapes consist of tussocks ranging from 1-4m high and 2-3m in diameter, spaced well apart and with bare ground between them. The birds rarely stray from dune slopes; but are sometimes observed in swales.
No extensive surveys of Eyrean grasswren behaviour have been undertaken, but it is thought to be sedentary. They are usually found in singles and pairs, or small groups of up to ten. It is cryptic, remaining hidden within Z. paradoxa tussocks, and is difficult to flush. Flight is rare, but when flushed the birds bound with wings half spread between tussock clumps or fly short distances of up to 10m with the tail trailing. They use a distinctive "half running, half flying" movement low to the ground, bounding and flying for short distances of 40–220 cm. Movements are quick and furtive with the tail usually held cocked. They sometimes perch low (c. 1 m) on grevillea branches, canegrass or other shrubs.
Prey consists of about equal amounts of vegetation and invertebrates. Specimen stomach contents include seeds from grasses Z. paradoxa and Aristida holathera, as well as remnants of numerous invertebrate species. Individuals move with small hops while foraging between clumps of spinifex (Triodia spp.) and within clumps of dune pea (Swainsona rigida ). It will sometimes skip backwards and shuffle the feet to uncover food items in the sand.
Very little is known about the mating habits of A. goyderi. No information exists on laying or incubation durations. Nests containing nestlings and eggs have been located from July to September and dependent fledglings from May to September. Clutches are 2-3 broadly oval eggs with slight variations in shape. It is assumed to be monogamous and to breed throughout the range.
Females are responsible for nest construction, which takes about one week to complete. Nests are wedged into tussock stems close to the ground (usually <1m height) in clumps of Z. paradoxa and Australian boxthorn (Lychan austral ). The nest consists of a truncated cup or dome of varying dimensions made from grasses such as A. holathera with Z. paradoxa strands woven in to the base, while an inner cup consists of finer grass and sometimes downy plant material or spider silk. Nests are well spaced but may be more densely aggregated in patches of good habitat.
A. goyderi was listed by the IUCN as threatened in 1988, and as special concern by the Royal Australian Ornithologist's Union in 1992 as further research was required. The IUCN currently lists it as least concern since the species is not thought to be declining and probably fluctuates due to seasonal cycles.
Threats include any species or processes affecting the quality of sandhill canegrass habitat such as erosion driven by grazing rabbits, camels and livestock.
