144 resultados para White-crowned Sparrows


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The White-browed Treecreeper Climacteris affinis is one of many woodland-dependent birds that are at risk from the encroachment of human-dominated land-uses into natural landscapes. The White-browed Treecreeper inhabits semi-arid woodlands in north-west Victoria, Australia, a vegetation community that has undergone extreme modification in the last century due to the expansion of agriculture in the region. Extant woodlands represent only 10% of the original woodland cover in the region, and are highly fragmented and disturbed in many districts. Thus, the survival of the White-browed Treecreeper may depend on active management. However, current knowledge of the ecology and biology of this species is virtually non-existent, and inadequate for informed and effective conservation actions. The aim of this thesis is to redress this situation and provide the ecological basis for sound conservation management of the species. The thesis consists of two parts: an investigation of habitat use at three spatial scales and a study of the social organization, nesting requirements, breeding behaviour and reproductive success of a population of White-browed Treecreepers. Fifty-six patches of remnant woodland in north-west Victoria were surveyed to determine the factors affecting the occurrence of the White-browed Treecreeper at the regional scale. It was detected in 16 patches, and was largely confined to two core districts - Yarrara and, Wyperfeld (Pine Plains). The floristic composition of the dominant tree species was an important determinant of patch occupancy, with the results providing quantitative support for the previously suspected affinity for Belah Casuarina pauper and Slender Cypress-pine Callitris gracilis — Buloke Allocasuarina luehmannii woodlands. However, the absence of the White-browed Treecreeper from several districts was due to factors other than a lack of appropriate habitat. Demographic isolation - the distance from the focal patch to the nearest population of the White-browed Treecreeper - was the most important variable in explaining variation in patch occupancy. Patches isolated from other treecreeper populations by more than 8.3 km in landscapes of non-preferred native vegetation, and 3 km in agricultural landscapes, were unlikely to support the White-browed Treecreeper. The impact of habitat loss and fragmentation on the capacity of individuals to move through the landscape (i.e. functional connectivity) is considered in relation to disruption to dispersal and migration, and the potential collapse of local metapopulations. Habitat use was then examined in a network of patches and linear strips of Belah woodland embedded in a predominantly cultivated landscape. A minimum area of 18.5 ha of Belah woodland was identified as the most important criterion for patch occupancy at the local scale. This landscape appeared to be permeable to movement by the White-browed Treecreeper, facilitated by the extensive network of linear habitat, and clusters of small to medium fragments. The third scale of habitat use investigated the frequency of use of 1-ha plots within tracts of occupied woodland. It is important to discriminate between habitat traits that operate at the population level, and those that act as proximate cues for habitat selection by individuals. Woodlands that have high tree density, extensive cover of low-stature shrubs, abundant lichen, a complex vertical structure, and relatively low cover of grass and herbs are likely to support larger populations of the White-browed Treecreeper. However, individuals appeared to be using tree dominance (positive) and tall shrub cover (negative) as proximate environmental stimuli for habitat selectivity. A relatively high cover of ground lichen, which probably reflects a ground layer with low disturbance and high structural complexity, was also a reliable indicator of habitat use. Predictive models were developed which could be used to plan vegetation management to enhance habitat for the White-browed Treecreeper. The results of the regional, landscape and patch-scale investigations emphasise that factors operating at multiple spatial scales influence the suitability of remnant vegetation as habitat for the White-browed Treecreeper. The White-browed Treecreeper is typical of many small Australian passerines in that it has high annual survival, small clutches, a long breeding season, multiple broods and relatively low reproductive rates. Reproductive effort is adjusted through the number of clutches laid rather than clutch size. They occupy relatively large, all-purpose territories throughout the year. However, unlike many group territorial birds, territory size was not related to the number of occupants. The White-browed Treecreeper nests in tree hollows. They select hollows with a southerly orientation where possible, and prefer hollows that were higher from the ground. At Yarrara, there was considerable spatial variation in hollow abundance that, in concert with territorial constraints, restricted the actual availability of hollows to less than the absolute abundance of hollows. Thus, the availability of suitable hollows may limit reproductive productivity in some territories, although the magnitude of this constraint on overall population growth is predicted to be small. However, lack of recruitment of hollow-bearing trees would increase the potential for hollow availability to limit population growth. This prospect is particularly relevant in grazed remnants and those outside the reserve system. Facultative cooperative breeding was confirmed, with groups formed through male philopatry. Consequently, natal dispersal is female-biased, although there was no skew in the sex ratio of the fledglings or the general adult population. Helpers were observed performing all activities associated with parenting except copulation and brooding. Cooperatively breeding groups enjoyed higher fledgling productivity than simple pairs, after statistically accounting for territory and parental quality. However, the difference reflected increased productivity in the 1999-breeding season only, when climatic conditions were more favourable than in 1998. Breeding commenced earlier in 1999, and all breeding units were more likely to attempt a second brood. However, only breeders with helpers were successful in fledging second brood young, and it was this difference that accounted for the overall discrepancy in productivity. The key mechanism for increased success in cooperative groups was a reduction hi the interval between first and second broods, facilitated by compensatory reductions in the level of care to the first brood. Thus, females with helpers probably achieved significant energetic savings during this period, which enabled them to re-lay sooner. Furthermore, they were able to recommence nesting when the fledglings from the first brood were younger because there were more adults to feed the dependent juveniles. The current utility, and possible evolutionary pathways, of cooperative breeding is examined from the perspective of both breeders and helpers. Breeders benefit through enhanced fledgling productivity in good breeding conditions and a reduction in the burden of parental care, which may impart significant energetic savings. Further, breeders may facilitate philopatry as a means for ensuring a minimum level of reproductive success. Helpers benefit through an increase in their inclusive fitness in the absence of opportunities for independent breeding (i.e. ecological constraints) and access to breeding vacancies in the natal or adjacent territories (i.e. benefits of philopatry). However, the majority of breeding unit-years comprised unassisted breeders, which suggests that pairs are selectively favoured under certain environmental or demographic conditions.

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Analyses the interaction between white and indigenous cultures, specifically the impact of the white practices of Christianisation, bureaucracy and commercialisation on indigenous women's cultural and religious practices, values and cosmology (Tjukurrpa), and argues that indigenous women's gynocentric cultural initiatives should be better resourced.

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This study looks at indigenous child removal in Western Australia as a case of genocide. The key figure in the process of child removal in Western Australia was the Chief Protector, A.O. Neville. The intention was complete biological absorption through forced child removal and controlled procreation of Aboriginal women.

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This research project was a response to the outbreak of white blister rust disease and its spread to Brassica oleracea crops in Australia. Disease management strategies based on the understanding of the Albugo - Brassica pathosystem, epidemiology, and the use of chemical control measures were developed for the Australian Brassica industry.

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This thesis explores criticism of racial exclusion and prejudice in Australia during the late nineteenth and early twentieth centuries. It argues that resistance to White Australia was more sustained and significant than previously understood and examines the complexities of racial thinking in relation to contemporary understandings of racism and anti-racism.

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Explores the spirituality of some white, rural, Australian women, and includes their experience of ceremony as part of their shared spiritual practice. The women's self-identification, relationship with divinity, the land and their bodies are documented, together with their experience of ceremony and its power.

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Argues that the most influential landscape poetry deals with landscape as an aesthetic concept, and also with the politics of land ownership. Several "landscape poets". Aboriginal and non-Aboriginal, have given voice to some of the most compelling social currents in society, and their work has an important place in contemporary political debate.

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Allegations of body parts trafficking implicating the West have been surfacing persistently in the media of many non Western countries for almost 20 years. Western media has responded to the allegations with denials and denunciations. This thesis considers the competing accounts and places them in a framework for analysis.

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‘The good editor,’ suggests Thomas McCormack in his Fiction Editor, the Novel and the Novelist, ‘reads, and … responds aptly’ to the writer’s work, ‘where “aptly” means “as the ideal appropriate reader would”.’ McCormack develops an argument that encompasses the dual ideas of sensibility and craft as essential characteristics of the fiction editor. But at an historical juncture that has seen increasing interest in the publication of Indigenous writing, and when Indigenous writers themselves may envisage a multiplicity of readers (writing, for instance, for family and community, and to educate a wider white audience), who is the ‘ideal appropriate reader’ for the literary works of the current generation of Australian Indigenous writers? And what should the work of this ‘good editor’ be when engaging with the text of an Indigenous writer? This paper examines such questions using the work of Margaret McDonell and Jennifer Jones, among others, to explore ways in which non-Indigenous editors may apply aspects of McCormack’s ‘apt response’ to the editing of Indigenous texts.

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The taxation of aboriginal/native title payments gives rise to a number of complex and difficult legal and policy issues. Reform measures announced on 13 February 1998 by the then Federal Treasurer and Attorney-General did not address the possible capital gains tax (‘CGT’) implications and even those relating to ordinary income under s 6-5 Income Tax Assessment Act 1997 (Cth) remain unimplemented. The much anticipated Report of the Native Title Payments Working group (6 February 2009), while primarily focusing on non-taxation issues, also recognises the need for taxation reform and makes some recommendations in regard to such. Most recently, on 18 May the Assistant Treasurer, Senator Nick Sherry, the Minister for Families, Housing, Community Services and Indigenous Affairs, Jenny Macklin, and the Attorney General, Robert McClelland, announced the commencement of a national consultation on the tax treatment of native title, including the interaction of native title, Indigenous economic development and the tax system. The Assistant Treasurer recognised the need for “greater clarity and increased certainty for native title holders on how the tax system and native title interact.” At the same time, they released a paper entitled Native Title, Indigenous Economic Development and Tax to guide the national consultation. The proposed measures considered in the paper, including exempting Native title payments and/or creating a new tax exempt Indigenous Community Fund, provide a welcome step towards reform in this area. This article is part of a broader research project that explores the CGT implications of aboriginal/native title. While these provisions impact on both Indigenous traditional owners and relevant payers, such as mining companies, the focus in the project is particularly on the CGT implications for the traditional owners. This first part of the project examines the status of aboriginal/native title and incidental/ ancillary rights as CGT assets. The broader research project will then build on this analysis in the context of relevant CGT events. As the preliminary findings in this article evidence the CGT implications of aboriginal/native title are far from certain. The application of CGT to aboriginal/native title raises more issues than it answers. The key reason is that the current law is entirely unsuitable to communally held inalienable aboriginal/native title. Nevertheless, it will be seen that it is arguable that aboriginal/native title and/or incidental rights are post-CGT assets and acts in relation to such could trigger a CGT event with tax implications for the traditional owners. It will be suggested that these current tax provisions provide a very pertinent example where the law operates as a blunt tool that does not appropriately promote justice and reconciliation. To tax Indigenous communities as a result of acts that extinguish or impair their traditional ownership is incongruous. A specific provision(s) should be included in the capital gains provisions to ensure any such payments are exempt from taxation. This is not only fair given the history of uncompensated extinguishment of aboriginal title Australia, but also promotes the ability of Indigenous communities to optimise the financial benefits stemming from aboriginal/native title agreements.