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Koolunga, Australia

Black A.,South Australian Museum | Carpenter G.,24 Dryden Rd. | Pedler L.,PO Box 58
South Australian Ornithologist | Year: 2011

The Thick-billed Grasswren Amytornis modestus occurs widely but discontinuously in inland South Australia in four populations: west of Lake Eyre and Lake Torrens (North West), around the margins of the North Flinders Ranges (Flinders), north-east of Lake Eyre (Eyre) and south-west of Lake Frome (Frome). In field surveys conducted during 2007 and 2008 the species was found at 52 (72%) of 72 sites of previous observations made between 1913 and 2008, in low shrublands dominated by chenopods, the key features of which are a cover of Blackbush, Oodnadatta Saltbush, spiny shrubs and taller shrubs. Occupied habitats vary nonetheless among the four populations. Typical habitats for the North West population are Oodnadatta Saltbush and Cotton-bush low shrublands and less commonly Blackbush low shrubland, whereas the last is the predominant habitat for Flinders and Frome populations. Total shrub cover averaged 21.2 +/-8.5%, and was sparsest in the North West region (14.5 +/-5.6%). Habitats for this species differ from those of the Western Grasswren A. textilis myall in being sparser, lower and less dense, and in the make-up of shrub species; this difference is most marked for the North West population that is geographically closest to A. t. myall. The gap in distribution between the two species is largely due to lack of suitable habitat for either; but other unknown factors are involved in determining the broad distributional limits of each. Breeding is documented, indicating year-round reproduction with a peak in spring. Like A. t. myall, A. modestus occurs today in areas within South Australian pastoral lands that are unprotected almost in their entirety. Pastoral land management that ensures the long-term maintenance of perennial chenopod shrub cover is therefore critical for the survival of the species. Source

Black A.,South Australian Museum | Carpenter G.,Black Forest | Pedler R.,SA Arid Lands NRM Board | Pedler L.,PO Box 58 | Langdon P.,PO Box 3114
Corella | Year: 2012

Grey grasswrens amytornis barbatus were first described in swamps at the termination of the bulloo river and that population and nominate subspecies is now considered threatened. A second subspecies is found to the north in wetlands of the diamantina/goyder lagoon/warburton system. we found the species at 54 sites within the goyder lagoon/warburton floodplain and conclude that that population appears secure. Grey grasswrens were found chiefly in lignum (dominant at 57%, present at 88%) and old-man saltbush (dominant at 19%, present at 43%) with average vegetation cover of 32.5 per cent but ranging from seven per cent to 81 per cent. While the species occurs above goyder lagoon, in both the georgina/eyre and diamantina catchments, Connectivity between these localities has not been demonstrated. The Grey Grasswren occurs in a third catchment, Cooper Creek, where its relationship with other populations, including its subspecific status is unproven. The species is best known from dense shrublands of Lignum Muehlenbeckia florulenta and Swamp Canegrass Eragrostis australasica but we have shown that it occupies and may breed in more open shrublands such as Old-man Saltbush Atriplex nummularia ssp. nummularia. Our findings question the relative reliance of Grey Grasswrens on these two rather disparate habitats; whether they occupy the more open habitats when forced from deeply inundated Lignum swamps and whether the former serve to aid dispersal between what otherwise appear to be isolated populations. Source

Martin T.,PO Box 58
Health Physics | Year: 2011

The Hanford nuclear site in Washington State had a major role in the production of nuclear weapons materials during the Manhattan Project in World War II and during the Cold War that followed. The production of weapons-grade radionuclides produced a large amount of radioactive byproducts that have been stored since the mid-1900s at the Hanford Site. These by-product radionuclides have leaked from containment facilities into the groundwater, contaminated buildings used for radionuclide processing, and also contaminated the nuclear reactors used to produce weapons-grade uranium and plutonium. This issue has been a major concern to Hanford stakeholders for several decades, and the U.S. Department of Energy, the U.S. Environmental Protection Agency, and the Washington State Department of Ecology established a Tri-Party Agreement in 1989, at which time Hanford ceased production of nuclear weapons materials and began a major effort to clean up and remediate the Hanford Site's contaminated groundwater, soil, and facilities. This paper describes the concerns of stakeholders in the production of nuclear weapons, the secrecy of Hanford operations, and the potential impacts to public health and the environment from the unintended releases of weapons-grade materials and by-products associated with their production at the Hanford Site. It also describes the involvement of public stakeholders in the development and oversight by the Hanford Advisory Board of the steps that have been taken in cleanup activities at the Hanford Site that began as a major effort about two decades ago. The importance of involvement of the general public and public interest organizations in developing and implementing the Hanford cleanup strategy are described in detail. Copyright © 2011 Health Physics Society. Source

Black A.,South Australian Museum | Carpenter G.,24 Dryden Road | Jaensch R.,11 Glen Frew Street | Pedler L.,PO Box 58 | Pedler R.,Natural Resources SA Arid Lands
Corella | Year: 2015

Two subspecies of the Grey Grasswren occupy terminal swamps of separate inland rivers, Amytornis barbatus barbatus on the Bulloo River and A. b. diamantina in Goyder Lagoon on the Diamantina. There have been sporadic reports from three other discrete areas; the Eyre Creek, Diamantina River and Cooper Creek floodplains. In a survey of those outlying populations, Grey Grasswrens were sparsely and unevenly distributed, being found at eleven localities (including one within 20 kilometres of Goyder Lagoon) but undetected at 16 where they had been observed previously, in some cases over several years. All five populations appear to be isolated from one another by distances of between 50 and 150 kilometres over which suitable habitat appears to be absent. Grasswrens from Eyre Creek belong to the same subspecies as those in Goyder Lagoon where Eyre Creek terminates, suggesting that in relatively recent times those two populations at least have been in reproductive contact, but the subspecific status of the other two outlying populations remains unknown. Our findings indicate that the outlying populations are small and that one or more might be declining towards local extinction. On the other hand we infer that Grey Grasswrens may be more able to disperse during exceptional seasonal conditions than is widely assumed to apply to grasswren species. Factors that might explain why the outlying populations are small and/or declining are discussed. Source

Austin J.J.,University of Adelaide | Joseph L.,CSIRO | Pedler L.P.,PO Box 58 | Black A.B.,South Australian Museum
Conservation Genetics | Year: 2013

The Western and Thick-billed Grasswrens (Aves: Passeriformes: Maluridae: Amytornis textilis and Amytornis modestus, respectively) exemplify issues surrounding the evolution, biogeography and conservation of Australia's arid and semi-arid zone fauna. The two species together have historically occurred across much of southern Australia. They showed high intraspecific taxonomic diversity and short range endemism but suffered high rates of recent anthropogenic extinction. Of 11 named and 1 un-named subspecies, 5 are extinct and 3 are vulnerable or critically endangered. To clarify taxonomic issues, and to understand their pre-extinction phylogeography and identify extant populations and taxa of conservation value, we sequenced ~1,000 bp of the mtDNA ND2 gene from all extant populations and all but one extinct population. We confirmed reciprocal monophyly of A. modestus and A. textilis and identified strong phylogeographic structure associated with morphological divergence within each species. Populations of A. t. myall at the western edge of their range in South Australia may preserve "ghost" lineages of extinct subspecies from Western Australia as a result of ancient gene flow. Our results support recent taxonomic revisions, and highlight the critical importance of including samples of extirpated populations and extinct species to fully understand and interpret extant diversity. Conservation and management plans should recognise and seek to preserve the unique evolutionary diversity present in surviving populations. © 2013 Springer Science+Business Media Dordrecht. Source

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