994 resultados para Royal South Yarra Club
Resumo:
The Rufous Bristlebird (Dasyornis broadbenti) is a sedentary, ground-dwelling passerine of southern Australia, which is listed as nationally vulnerable, and as near-threatened (lower risk) in Victoria. The species inhabits a variety of vegetation, including shrub thickets in coastal gullies to heathlands on limestone cliffs. This study aimed to assess the size, distribution and habitat use of a population of the subspecies D. b. broadbenti at Portland in south-western Victoria. Monthly surveys (2002–03) were conducted on foot for 1 h after official sunrise and 1 h before official sunset, and presence of Bristlebirds recorded using vocalisations and sightings. Observations outside of the survey times were also recorded to estimate the size of territories and core area of occupancy. To quantify habitat preferences, vegetation composition and structure were measured in areas where Bristlebirds were present, as well as surrounding areas where they were not detected. The population in the survey areas was estimated at between 70 and 86 individuals in the 170-ha survey area. The estimated size of territories of eight selected pairs of Bristlebirds ranged from 0.5 to 3 ha, with core areas of occupancy ranging from 0.2 to 0.6 ha. During the nesting season (August November) Bristlebirds were detected at greater frequencies in the core area of occupancy within each territory. Significant associations were found between the presence of Bristlebirds and floristic associations dominated by the native environmental weeds Acacia sophorae and Leptospermum laevigatum. Bristlebird presence was significantly positively correlated with increasing vegetation density in the mid-canopy level (80–120 cm) indicating that vegetation structure is a key factor in habitat use.
Resumo:
Dietary samples from four Sooty Owl Tyto tenebricosa roost-sites within one territory in the Royal National Park, Sydney, New South Wales, were collected in December 2005. A total of 144 dietary items was identified, representing eight mammal species and at least one bird species. The samples were compared with those collected during a study 10 years earlier (in 1994-96) that included samples from the same roost-sites. Ten years later, the diet of the Sooty Owl in this territory appears little changed, except that the Sugar Glider Petaurus breviceps is now taken more frequently. The Common Ringtail Possum Pseudocheirus peregrinus continued to be the principal prey species taken by the Owls at this location. The Long-nosed Bandicoot Perameles nasuta may have declined in the Sooty Owl's diet during this period, but this trend was not significant statistically. This study showed that Sooty Owl diet at a single location is relatively stable, despite the occurrence of a major disturbance to habitat caused by a severe wildfire 12 years previously.
Resumo:
Recent sediment samples recovered from the mid-latitude South West Shelf (SWS) of Western Australia (23°- 32° S) by a scientific team aboard the RV Franklin have produced large numbers of free-living, lunulitiform bryozoans. Among these are three undescribed species, Otionellina boneae sp. nov., Selenaria kayae sp. nov., and Selenaria meganae sp. nov. The Australasian lunulite fauna is both diverse and abundant and the new species bring the total of described taxa to sixty (P. Cook unpub.). Twelve lunulite species have been recorded from the SWS. These findings have extended the known geographical range of several lunulite species.
Resumo:
In highlighting the relationship between the production of knowledge, the administration of government and the formation of subject–citizens in colonial systems, post-colonialism has arguably found its most fertile field of inquiry and revision in South Asia. The reasons for this are complex and relate, in part, to the nature of both colonial administration and the colonised civilisations to be found in the region, as well as to the nature of the different independence movements—many of these persisting well beyond the formal grants of independence in the late 1940s. Also important is the emerging post-colonial middle class, its transnational interconnections comprising inter alia extensive participation in knowledge/information economies, and its ‘organic intellectuals’ (Gramsci 1971) whose work represents the interests of their class. In other words, the tremendous insights offered by post-colonial theory into the nature of latent or implicit power relations to be found in forms of knowledge reveal the ongoing complicity of scholarship in government. Post-colonialism, thus, raises the issue of how the nexus of knowledge and power translates into contemporary situations—the post-colonial predicament (Breckenridge and van der Veer 1993).
Resumo:
We investigated the home-range size and habitat use of eight Sooty Owls (Tyto tenebricosa tenebricosa) in coastal forests in East Gippsland, Victoria, Australia, between November 2006 and January 2008. The size of home-ranges varied widely; based on 95% adaptive kernel estimates, the average size of home-ranges of males was 3025ha (±1194s.d., n=3), whereas that of females was 994ha (±654s.d., n=5). Sooty Owls utilised a broad range of ecological vegetation classes and topographical features for roosting and foraging at a greater scale than previously assumed. There was minimal selection for habitat types based on floristic composition, primarily only avoiding heathlands (for foraging and roosting) and selecting particular dense foliage (rainforest and riparian scrub) for foliage roosting. Two Owls maintained home-ranges close to logged areas, with logging regrowth (<45 years old) being strongly avoided by both individuals. We recommend that the size of individual reserves for Sooty Owls in commercial forests should be increased to more closely resemble the core spatial resource requirements needed by a pair. Reserves should be largest where they feed predominantly on hollow-dependent prey. Most importantly, rather than conservation measures just focussing on the spatial requirements of Sooty Owls, efforts should be directed towards retaining high densities of crucial resources, such as hollow-bearing trees and mammalian prey species throughout the landscape.
Resumo:
The Macquarie perch (Macquaria australasica) is a threatened fish species that inhabits rivers and impoundments in south-eastern Australia. Previous studies have shown that Macquarie perch in impoundments exhibit synchronised upstream spawning migrations to shallow, fast-flowing habitats in the lower reaches of inflowing streams. There has been little study of movement behaviours of entirely riverine populations of Macquarie perch despite this being the species’ natural habitat. Here, radio-telemetry is used to test the hypothesis that riverine populations exhibit synchronised migrations during the spawning season. Thirty Macquarie perch in the Yarra River, Victoria, a translocated population outside of the species’ natural range, were radio-tagged before the late spring–early summer spawning season and their movements followed over a 10-month period (May 2011 to February 2012). Tagged fish typically occupied restricted reaches of stream (<450 m). Sixteen of the fish undertook occasional upstream or downstream movements (~250–1000 m) away from their usual locations, particularly associated with large flow variations during the spawning season. There was no evidence of synchronised migratory behaviour or movement of multiple fish to specific locations or habitats during the spawning season. Whilst further research over more years is needed to comprehensively document the spawning-related behaviours of riverine Macquarie perch, our study demonstrates that management of riverine populations of this threatened species cannot necessarily be based on the model of spawning behaviour developed for lacustrine populations.
Resumo:
This pilot study uses concentrations of metals in maternal and cord blood at delivery, in seven selected geographical areas of South Africa, to determine prenatal environmental exposure to toxic metals. Samples of maternal and cord whole blood were analysed for levels of cadmium, mercury, lead, manganese, cobalt, copper, zinc, arsenic and selenium. Levels of some measured metals differed by site, indicating different environmental pollution levels in the regions selected for the study. Mercury levels were elevated in two coastal populations studied (Atlantic and Indian Ocean sites) with mothers from the Atlantic site having the highest median concentration of 1.78 mu g/L ranging from 0.44 to 8.82 mu g/L, which was found to be highly significant (p < 0.001) when compared to other sites, except the Indian Ocean site. The highest concentration of cadmium was measured in maternal blood from the Atlantic site with a median value of 0.25 mu g/L (range 0.05-0.89 mu g/L), and statistical significance of p < 0.032, when compared to all other sites studied, and p < 0.001 and p < 0.004 when compared to rural and industrial sites respectively, confounding factor for elevated cadmium levels was found to be cigarette smoking. Levels of lead were highest in the urban site, with a median value of 32.9 mu g/L (range 16-81.5 mu g/L), and statistically significant when compared with other sites (p < 0.003). Levels of selenium were highest in the Atlantic site reaching statistical significance (p < 0.001). All analysed metals were detected in umbilical cord blood samples and differed between sites, with mercury being highest in the Atlantic site (p < 0.001), lead being highest in the urban site (p < 0.004) and selenium in the Atlantic site (p < 0.001). To the best of our knowledge this pilot investigation is the first study performed in South Africa that measured multiple metals in delivering mothers and umbilical cord blood samples. These results will inform the selection of the geographical sites requiring further investigation in the main study.
Resumo:
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)