1000 resultados para Owls - Ecology - Victoria


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Relatively little is known about the biology and ecology of the world’s largest (heaviest) bony fish, the ocean sunfish Mola mola, despite its worldwide occurrence in temperate and tropical seas. Studies are now emerging that require many common perceptions about sunfish behaviour and ecology to be re-examined. Indeed, the long-held view that ocean sunfish are an inactive, passively drifting species seems to be entirely misplaced. Technological advances in marine telemetry are revealing distinct behavioural patterns and protracted seasonal movements. Extensive forays by ocean sunfish into the deep ocean have been documented and broad-scale surveys, together with molecular and laboratory based techniques, are addressing the connectivity and trophic role of these animals. These emerging molecular and movement studies suggest that local distinct populations may be prone to depletion through bycatch in commercial fisheries. Rising interest in ocean sunfish, highlighted by the increase in recent publications, warrants a thorough review of the biology and ecology of this species. Here we review the taxonomy, morphology, geography, diet, locomotion, vision, movements, foraging ecology, reproduction and species interactions of M. mola. We present a summary of current conservation issues and suggest methods for addressing fundamental gaps in our knowledge.

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This paper’s research question concerns how the ecological creativity of the Volcanic Plains region of Western Victoria may be transformed into an ecology of well-being of benefit to the local community. Drawing on the philosophies of Spinoza and Gilles Deleuze, we argue that community well-being results from the richness of connections and relationships made within a place. The case study for our investigation is ‘Flows & Catchments’, which is an ongoing, collaborative, creative-arts research project auspiced by Deakin University. Its modus operandi is Practice-Based Research (PBR), and its aim is to promote community well-being in Western Victoria. However, while the whole metier of the creative arts is to make the novel connections and relationships that should bring about community wellbeing, the various artists of ‘Flows & Catchments’ have proved slightly reluctant to make connections outside of their individual or small-group sub-projects. In this way, ecological creativity has not reached its full potential as an ecology of well-being because the rich connections and relationships essential to this well-being have not yet been fully realised. This paper explores the potential of using the NVivo qualitative analysis software package to bring together the creative-arts sub-projects of ‘Flows & Catchments’, as a way of fostering an ecology of well-being out of a currently dispersed ecological creativity.

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Landscape transformation associated with urbanization is one of the most damaging and pervasive impacts humans have on natural ecosystems. The response of species to increasing urbanization has become a major focus of research globally. Powerful owls ( Ninox strenua) are a top-order predator the have been shown to reside in urban environments, but increasing urbanization has also been demonstrated to significantly reduce available habitat. In this paper we use species distribution models established for key food and nesting resources of powerful owls across an urban-forest gradient to constrain habitat predictions from a previously developed powerful owl species distribution model. This multi-criteria decision analysis (MCDA) approach allowed us to investigate the impacts of urbanization on potential powerful owl habitat when challenged with food and nesting requirements. As powerful owls only use tree cavities for nesting we propose that the cue for settlement in an area is associated with the presence of habitat and food and as such breeding requirements may be disconnected from settlement requirements.Our results demonstrate that incorporation of a general prey resource (at least one group of arboreal marsupials) as a cue for settlement does not reduce the amount of available habitat for powerful owls substantially. Further constraining the model with a tree cavity resource, however, leads to a substantial reduction in powerful owl habitat in the urban and urban fringe environments. If a diverse prey resource (two or more groups of arboreal marsupials) is used as the cue for settlement, this sees a substantial reduction in available habitat in urban environments. Incorporation of tree cavities into this model does not reduce the available habitat for powerful owls substantially.We propose that powerful owls do not need a diverse prey base for survival, and that breeding resources are unlikely to be a cue for settlement. As such, we argue in this paper that increasing urbanization has the potential to create an ecological trap for powerful owls as there is a significant difference between habitat capable of supporting powerful owls, and habitat in which owls can breed.Management of powerful owls in urban environments will be difficult, but this research highlights the potential for the use of nest boxes to enhance the breeding activities in increasingly urbanized environments. Replacement of this critical resource may be able to reverse any potential ecological trap that is occurring. © 2014 Elsevier Ltd.

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Coronary heart disease (CHD) is a major problem for firefighters, even when considering the healthy worker effect (HWE). Although volunteer firefighters outnumber paid personnel, previous research has focused on paid US firefighters. By contrast, no CHD data for Australian firefighters exist. Risk factor data were collected from 2,943 Australian volunteer firefighters and CHD risk was compared with reference "low-risk" and Australian population data. Predicted CHD risk for male and female firefighter was 19.2% and 5.1%, respectively. Female firefighters high blood pressure and fasting glucose was significantly lower than the general population, whereas all other risk factors was similar to the general population. Firefighters' CHD risk was greater than other volunteer and paid emergency services, but the prevalence for most risk factors was similar to the general population. Therefore, Australian volunteer firefighters may not benefit from the HWE.

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This study assessed the sustainability of utilising groundwater systems to manage an aluminium smelters fluoridated trade wastewater stream. Replacing ocean discharge of the wastewater with land irrigation is one option. Using a groundwater model (developed using MODFLOW incorporating parameter estimation software (PEST-ASP)), we found that most of the groundwater flow takes place through surface sands. Fluoride is adsorbed in these sands during the drier summer months, but desorption is rapid when winter rain flushes the aquifer. Underlying clays and other layers prevent significant contamination of the deeper aquifer.

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Round-leaf Pomaderris Pomaderris vacciniifolia F. Muell. ex Reissek (Rhamnaceae) is a Victorian endemic shrub listed as threatened under the Flora and Fauna Guarantee Act 1988 and critically endangeredunder the Environment Protection and Biodiversity Conservation Act 1999. A review of the available literature for P. vacciniifolia indicated most information is anecdotal or found in unpublished works. Better understanding of the ecology of P. vacciniifolia may help explain why it is vulnerable, and enhance future management. Future research should focus towards better understanding of P. vacciniifolia habitat, reproductive ecology, seed dispersal mechanisms and competitive ability and how these compare with more common sympatric congeners, to determine whether any differences could explain the relative success of these species. Targeted searches for this species on public and private land are warranted to reveal additional populations and fully appreciate the distribution of this species. (The Victorian Naturalist 131 (2) 2014, 44-51).

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The use of public spaces can promote social cohesion and facilitate interpersonal interactions within the community. However, the ways racial and ethnic groups interact in public spaces can also reflect and influence informal segregation in the wider community. The present study aimed to examine patterns of intergroup contact within public spaces in Victoria, Australia through short-term observation in four localities. Data were collected on within-group, intergroup and absence of contact for people from minority and majority groups. A total of 974 contacts were observed. Findings indicate that in the observed public spaces, people from visible minority groups tended to have no contact with others or to interact with people from other ethnic/racial groups. In contrast, those from the majority group tended to interact predominately with other majority group members. This suggests that majority group members are more likely to ‘self-segregate’ in public spaces than those from minority groups.

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A dieta e a ecologia alimentar de juvenis de Lutjanus jocu foram verificadas em 92 espécimes coletados em quatro canais de maré do estuário do rio Curuçá, Norte do Brasil, entre setembro de 2003 e julho de 2004. O comprimento total dos peixes coletados não apresentou diferenças significativas entre os meses amostrados. A intensidade alimentar foi elevada conforme indicado pelos altos valores do índice de repleção estomacal e os baixos valores do índice de vacuidade. A presa mais importante foi Penaeidae, seguida por Grapsidae e Porcellanidae. A dieta de juvenis de L. jocu apresentou diferenças sazonais evidentes. Os espécimes da estação seca (setembro e novembro) e transição seca/chuvosa (janeiro) foram considerados especialistas alimentando-se exclusivamente de Penaeidae. No entanto, os espécimes da estação chuvosa (março e maio) e da transição chuvosa/seca (julho), que alimentaram-se principalmente de Grapsidae, Penaeidae e Porcellanidae, foram considerados generalistas. Esta mudança sazonal na dieta poderia estar relacionada com a disponibilidade do alimento.

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Beginning in the late 1980s, large groups of previously unidentified killer whales (Orcinus orca) were sighted off the west coast of Vancouver Island and in the Queen Charlotte Islands, British Columbia. Scientists working in this region produced two killer whale photo-identification catalogues that included both transient (mammal-eating) whales and 65 individual whales that investigators believed represented a distinct killer whale community (Ford et al. 1992, Heise et al. 1993). It was thought that these killer whales maintained a generally offshore distribution and were provisionally termed “offshores”; a term that has since been used as a population identifier for the eastern temperate North Pacific offshore killer whale population. Then in September 1992, 75 unidentified whales entered the Strait of Juan de Fuca just south and east of Victoria, British Columbia (Walters et al. 1992). Although most of these whales had not been seen before, two were matched to killer whales in the Queen Charlotte photo-identification catalogue (Ford et al. 1992, Heise et al. 1993) and were thus listed as “offshore” killer whales. During a similar time period, other large groups of killer whales, previously unidentified, were also being sighted off Alaska and California (Dahlheim et al. 1997; Nancy Black and Alisa Schulman- Janiger, unpublished data, respectively).

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Colour polymorphisms have fascinated evolutionary ecologists for a long time. Yet, knowledge on the mechanisms that allow their persistence is restricted to a handful of well-studied cases. We studied two species of Lake Victoria cichlid fish, Neochromis omnicaeruleus and Neochromis greenwoodi, exhibiting very similar sex-linked colour polymorphisms. The ecology and behaviour of one of these species is well studied, with colour-based mating and aggression preferences. Here, we ask whether the selection potentially resulting from female and male mating preferences and aggression biases reduces gene flow between the colour morphs and permits differentiation in traits other than colour. Over the past 14 years, the frequencies of colour morphs have somewhat oscillated, but there is no evidence for directional change, suggesting the colour polymorphism is persistent on an ecological timescale. We find limited evidence of ecomorphological differentiation between sympatric ancestral (plain) and derived (blotched) colour morphs. We also find significantly nonrandom genotypic assignment and an excess of linkage disequilibrium in the plain morph, which together with previous information on mating preferences suggests nonrandom mating between colour morphs. This, together with negative frequency-dependent sexual selection, found in previous studies, may facilitate maintenance of these polymorphisms in sympatry