Download Carpentarian grasswren - Northern Territory Government

Threatened Species of the Northern Territory
CARPENTARIAN GRASS-WREN
Amytornis dorotheae
Conservation status
Australia: Endangered
Northern Territory: Endangered
Photo; Graeme Chapman
Description
The Carpentarian grasswren is a medium sized
grasswren with slender body and rusty-coloured
back. The face is streaked black and white with a
white throat in both males and females. The
crown, nape and back are streaked by white
feather shafts. The tail is rusty grey and held
largely upright. Adult females differ from males
by having the colour of the flanks, thighs and
lower belly dark chestnut rather than tawny.
normally abandon burnt areas, unless substantial
unburnt pockets of spinifex
Distribution
This species is restricted to sandstone outcrops
within the Carpentarian and Adelaidean Systems
of the Gulf of Carpentaria. Sightings are
infrequent and patchy within this distribution,
but the species has occurred at Nathan River
Station (NT) in the north to Westmoreland
Station (Qld) in the southeast of the range
(Garnett et al. 2011).
Conservation reserves where reported:
Caranbirini Conservation Reserve.
Ecology
Little information is available on the ecology of
this species. It is known to live amongst mature
stands of spinifex (Triodia pungens) on sandstone
outcrops containing large boulders. Grasswrens
For more information visit www.denr.nt.gov.au
Known locations of the Carpentarian grasswren
remain (Garnett et al., 2011). The birds nest
within spinifex clumps during the wet season.
Clutch size appears to be 2 – 3 eggs and young
are fed on a variety of seeds and insects.
the seeds of this species. Annual fires therefore
reduce both food availability and habitat
suitability. Fire caused the extirpation of the
Borroloola subpopulation in the Northern
Territory, has greatly reduced two other
subpopulations and was probably responsible for
the historical separation of the species into four
specific subpopulations (Garnett et al., 2011).
Conservation objectives and management
Habitat of the Carpentarian grasswren.
Conservation assessment
In the Northern Territory, there have been two
major surveys of the distribution of this species,
by Martin and McKean (1986) in 1986 and Perry
in 2005 (Perry 2005). Martin and McKean found
that the species was patchily distributed in
sandstone ranges in the southwest of the Gulf of
Carpentaria hinterland. Perry (2005) re-sampled
eight sites where the species had previously been
reported and found grasswrens at only one of
these sites, on Wollogorang Station. This small
sub-population (across two locations) may be the
only one persisting in the Northern Territory. The
nearest other recent records are in the Lawn Hill
area in Queensland (Garnett et al. 2011). Perry
(2005) also reported that prevailing fire regimes
across most of the sandstone environments in
the region were unsuitable for this species.
The Carpentarian grasswren is considered
Endangered (under criteria B1ab) due to:



extent of occurrence estimated to be
<5000 km2;
severely fragmented population; and
continuing decline in range, habitat quality
and population size.
Research priorities are to:
(i) monitor population numbers and make a
thorough investigation of the biology of the
species.
Management priorities are to:
(ii) improve current burning practises by
reducing the extent and incidence of late
hot dry season burns, and introduce a
balanced mosaic of burns.
Compiled by
Simon Ward
John Woinarski
[updated May 2016]]
References
Garnett, S.T., Szabo, J.K. and Dutson, G. (2011). The Action
Plan for Australian Birds. 2011. (CSIRO
Publishing/Birds Australia, Melbourne.)
McKean, J.L., and Martin, K.C. (1989). Distribution and status
of the Carpentarian Grass-wren Amytornis dorotheae.
NorthernTerritory Naturalist 11, 12-19.
Perry, J. (2005). Habitat and status of the Carpentarian
grasswren (Amytornis dorotheae) in the Northern
Territory. B.App.Sci. thesis. (Charles Darwin
University, Darwin.)
Threatening processes
Fire is currently thought to be the primary factor
influencing the distribution and abundance of the
Carpentarian grasswren. Results from studies
elsewehere (M. Lewis pers. comm.) indicate
lowered seed availability from Triodia pungens
after a history of annual dry season fires. The
Carpentarian Grasswren not only uses unburnt
patches of T. pungens as habitat but also feeds on
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