998 resultados para Birds - Australia, Southeastern


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Faunal atlases are landscape-level survey collections that can be used for describing spatial and temporal patterns of distribution and densities. They can also serve as a basis for quantitative analysis of factors that may influence the distributions of species. We used a subset of Birds Australia’s Atlas of Australian Birds data (January 1998 to December 2002) to examine the spatio-temporal distribution patterns of 280 selected species in eastern Australia (17–37°S and 136–152°E). Using geographical information systems, this dataset was converted into point coverage and overlaid with a vegetation polygon layer and a half-degree grid. The exploratory data analysis involved calculating species-specific reporting rates spatially, per grid and per vegetation unit, and also temporally, by month and year. We found high spatio-temporal variability in the sampling effort. Using generalised linear models on unaggregated point data, the influences of four factors – survey method and month, geographical location and habitat type – were analysed for each species. When counts of point data were attributed to grid-cells, the total number of species correlated with the total number of surveys, while the number of records per species was highly variable. Surveys had high interannual location fidelity. The predictive values of each of the four factors were species-dependent. Location and habitat were correlated and highly predictive for species with restricted distribution and strong habitat preference. Month was only of importance for migratory species. The proportion of incidental sightings was important for extremely common or extremely rare species. In conclusion, behaviour of species differed sufficiently to require building a customized model for each species to predict distribution. Simple models were effective for habitat specialists with restricted ranges, but for generalists with wide distributions even complex models gave poor predictions.

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Bird life occurring along the Murray River was distinctly different from surrounding much drier vegetation. It was found that the presence of the Murray River, with it's associated moist Red Gum forests, provide a corridor whereby birds typically of cool climates can expand their range and occur in an arid landscape.

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Locust outbreaks provide an abundant, but unpredictable food source for many native species in Australia. For economic reasons, locust control is unavoidable and can affect a considerable area in Eastern Australia. Depending on the pesticide applied, locust control operations may affect birds in treated areas, either directly through intoxication of the predator, or indirectly, through elimination of its prey. As a preliminary step in identifying the potential impact of these operations on native species, the co-occurrence of birds and locust control operations was assessed using GIS mapping techniques. Data from the Birds of Australia New Atlas provided information about species' distribution between latitudes 17 and 37 degree S, and longitudes 136 and 152 degree E. Of the 834 species present in this region, 292 were chosen on the basis of their geographical distribution and occurrence west of the Great Dividing Range. Sightings for each species were mapped using reporting rates and number of observations per half-degree grid cells. Birds were categorised by habitat, distribution, movement and feeding habits and those species reported to consume Orthopterans were noted. APLC locust survey (1987–2000) and spraying data (1977–2002) were analysed and overlapped with soil and vegetation maps obtained from Geoscience Australia and Environment Australia to find significant hotspots for locust occurrence. These maps were then overlayed with bird distributions to identify the species most likely to be in areas of locust presence and spraying operations.

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This layer is a georeferenced raster image of the historic paper map entitled: Map of the discoveries in Australia : copied from the latest M.S. surveys in the Colonial Office, by permission dedicated to the Right Hon.ble Viscount Goderich, H.M. principal Secretary of State for the Colonies, and President of the Royal Geographical Society, by his Lordships obliged servant J. Arrowsmith. It was published by Pubd. by J. Arrowsmith, 35 Essex St., Strand in Feb. 15 1834. Scale [ca. 1:3,041,280]. Covers southeastern Australia with additions to the east of the Gulf of St. Vincent and Granite Island inserted in Encounter Bay.The image inside the map neatline is georeferenced to the surface of the earth and fit to the Asia South Lambert Conformal Conic coordinate system. All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as drainage, cities and other human settlements, territorial boundaries, shoreline features, and more. Relief shown by hachures and spot heights. Major explorations shown. Includes also notes and insets: The Colony of Western Australia ... -- [Map of Australia in Asia].This layer is part of a selection of digitally scanned and georeferenced historic maps from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of originators, ground condition dates, scales, and map purposes.

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Spatial and temporal variation in the breeding of Masked Lapwings (Vanellus miles) in Australia were examined using data from Birds Australia’s Nest Record Scheme (NRS; 1957–2002), the Atlas of Australian Birds (1998–2006), and climatic data (1952–2006). Breeding in north-western Australia was concentrated in summer, while in other regions the peak of breeding occurred during spring. Breeding success varied between regions and years but was generally highest in Tasmania. Clutch-size (mean 3.57 eggs ± 0.033 s.e., n = 549 clutches) did not vary regionally or temporally. In the north-east, breeding became earlier over time (~1.9 days per year, NRS), while in the south-east, breeding became later (~0.9 days per year); in other regions temporal trends were not evident. Only Tasmania showed a significant temporal change in breeding success (decrease of ~1.5% per year). All regions experienced warming climates, and annual rainfall increased in north-western regions and decreased in eastern regions. There were weak or no relationships between the amount or success of breeding, clutch-size and the climatic variables considered (with the possible exception of Tasmania), suggesting either that data limitations precluded us from detecting subtle effects or that Masked Lapwings have been little influenced or are resilient to changes in climate over most of their range.

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An abundant, low diversity cool-water macroinvertebrate fauna from the Middle Permian Broughton Formation in the Sydney Basin, eastern Australia, was investigated. The fauna was described and identified, which assisted in regional and global correlation of the Broughton Formation, as well as palaeogeographical and palaeontological research.

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This PhD determines the reproductive biology of five stingaree species caught as bycatch from south-eastern Australian commercial fisheries for fisheries stock assessments, ecological risk assessments, and species extinction risk evaluations.

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Locusts and grasshoppers cause considerable economic damage to agriculture worldwide. The Australian Plague Locust Commission uses multiple pesticides to control locusts in eastern Australia. Avian exposure to agricultural pesticides is of conservation concern, especially in the case of rare and threatened species. The aim of this study was to evaluate the probability of pesticide exposure of native avian species during operational locust control based on knowledge of species occurrence in areas and times of application. Using presence-absence data provided by the Birds Australia Atlas for 1998 to 2002, we developed a series of generalized linear models to predict avian occurrences on a monthly basis in 0.5 degrees grid cells for 280 species over 2 million km2 in eastern Australia. We constructed species-specific models relating occupancy patterns to survey date and location, rainfall, and derived habitat preference. Model complexity depended on the number of observations available. Model output was the probability of occurrence for each species at times and locations of past locust control operations within the 5-year study period. Given the high spatiotemporal variability of locust control events, the variability in predicted bird species presence was high, with 108 of the total 280 species being included at least once in the top 20 predicted species for individual space-time events. The models were evaluated using field surveys collected between 2000 and 2005, at sites with and without locust outbreaks. Model strength varied among species. Some species were under- or over-predicted as times and locations of interest typically did not correspond to those in the prediction data set and certain species were likely attracted to locusts as a food source. Field surveys demonstrated the utility of the spatially explicit species lists derived from the models but also identified the presence of a number of previously unanticipated species. These results also emphasize the need for special consideration of rare and threatened species that are poorly predicted by presence-absence models. This modeling exercise was a useful a priori approach in species risk assessments to identify species present at times and locations of locust control applications, and to discover gaps in our knowledge and need for further focused data collection.