4,633 research outputs found
Effects of landscape transformation on bird colonization and extinction patterns in a large-scale, long-term natural experiment
No full textContrasting effects of pine plantations on two skinks: results from a large-scale "natural experiment' in Australia
No full textExperimental evaluation shows limited influence of pine plantations on the connectivity of highly fragmented bird populations
No full textPasture height and crop direction influence reptile movement in an agricultural matrix
No full textTackling the global threat of habitat fragmentation on biodiversity requires knowledge of how species move within agricultural landscapes. However, the specific mechanisms influencing dispersal within such landscapes remain poorly understood. The objective of our study was to assess how matrix type (improved pasture, native pasture or crop) and structure (grass height) influence fine-scale reptile movement, as well as influences of crop sowing direction and setting-sun position. In an agricultural region of south-eastern Australia, we first released 20 individuals of an arboreal gecko (Christinus marmoratus) at set distances from trees to determine the distance at which they could perceive their tree habitat (perceptual range). We then translocated 36 individuals into six matrix environments within their perceptual range of isolated trees to examine how gecko movement was modified by the type and structure of the matrix. We also recorded crop sowing direction and setting-sun position and examined all recorded tracks using angular statistics. We found that geckos exhibited a perceptual range of 40-80m. Short matrix environments promoted direct movements towards trees, irrespective of matrix type. Furthermore, movements were significantly affected by crop sowing direction with individuals following the planted lines. Our study has three significant implications: (i) restoring mature tree spacing to 80 m apart will assist gecko movements, (ii) targeted management for low pasture height, such as by maintaining directional narrow strips of low vegetation among taller pastures, might assist movement and facilitate increased' connectivity, (iii) directional sowing of crops between habitat patches presents a simple but potentially effective tool for reconnecting fragmented landscapes. (C) 2016 Elsevier B.V. All rights reserved
Evaluating the effectiveness of overstory cover as a surrogate for bird community diversity and population trends
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Marsupial response to matrix conversion: Results of a large-scale long-term 'natural experiment' in Australia
No full textClimate change adaptation strategies for Australian birds
No full textAbstract
In the first continental analysis of the effects of climate change on a faunal group, we identified that the climate space of 101 Australian terrestrial and inland water bird taxa is likely to be entirely gone by 2085, 16 marine taxa have breeding sites that are predicted to be at least 10% less productive than today, and 55 terrestrial taxa are likely to be exposed to more frequent or intense fires.
Birds confined to Cape York Peninsula, the Wet Tropics, the Top End of the Northern Territory (particularly the Tiwi Islands), the arid zone, King Island and southern South Australia (particularly Kangaroo Island) are most likely to lose climate space. There was some variation in the predictions of the 18 climate models deployed, but all predicted that the rainforest avifauna of Cape York Peninsula is likely to face the strongest challenge from climate change, particularly taxa currently confined to the Iron and McIlwraith Ranges. For marine birds, those nesting on Lord Howe and Norfolk Islands, the Great Barrier Reef and the Houtman Abrolhos are likely to face the greatest declines in local marine productivity. Changes in local marine productivity may also affect the endemic terrestrial birds of these islands, for which no climate modelling was possible. A small group of beach-nesting and saltmarsh birds may be affected by sea level rise.
Many taxa, and particularly seabirds, are potentially highly sensitive to climate change based on a set of ecological and morphological metrics. Small island taxa were most likely to be both exposed and sensitive to climate change, followed by marine and shoreline taxa. While threatened birds were more likely than non-threatened taxa to be exposed or sensitive to climate change, or both, a substantial proportion was neither.
A key action that needs to be undertaken immediately is fine scale modelling of regions identified as having numerous highly exposed bird taxa, in order to identify climatic refugia within the landscape. Such refugia can then be secured and managed appropriately for the future. The most urgent ongoing action is monitoring, with support for the Atlas of Australian Birds seen as a particularly cost-effective investment. In the future, the most expensive actions will be management of refugia, and captive breeding should all other approaches to conservation in the wild fail. However, most of those for which captive breeding is recommended as a last resort are subspecies of species that are widespread, either in Australia or in New Guinea.
For in situ management, the most important actions will be those that are already important – fire management, weed and feral animal control and, for marine taxa, controls on fishing. A small number of species-specific actions are suggested, and there appears to be no urgent requirement for corridors for the maintenance of taxa likely to be threatened with extinction – those few taxa not already living in areas where there are likely to be refugia will require assistance to colonise new climate space.
The cost of management over the next 50 years for persistence in the face of climate change of the 396 bird taxa that are very highly exposed, sensitive or both is estimated at 47,700 per year for each taxon. The biggest ongoing costs are monitoring and direct species management but refugia management and captive breeding may eventually be needed, and will be much more expensive.
Please cite this report as:
Garnett, S, Franklin, D, Ehmke, G, VanDerWal, J, Hodgson, L, Pavey, C, Reside, A, Welbergen, J, Butchart, S, Perkins, G, Williams, S 2013 Climate change adaptation strategies for Australian birds, National Climate Change Adaptation Research Facility, Gold Coast. pp.109.
In the first continental analysis of the effects of climate change on a faunal group, we identified that the climate space of 101 Australian terrestrial and inland water bird taxa is likely to be entirely gone by 2085, 16 marine taxa have breeding sites that are predicted to be at least 10% less productive than today, and 55 terrestrial taxa are likely to be exposed to more frequent or intense fires.
Birds confined to Cape York Peninsula, the Wet Tropics, the Top End of the Northern Territory (particularly the Tiwi Islands), the arid zone, King Island and southern South Australia (particularly Kangaroo Island) are most likely to lose climate space. There was some variation in the predictions of the 18 climate models deployed, but all predicted that the rainforest avifauna of Cape York Peninsula is likely to face the strongest challenge from climate change, particularly taxa currently confined to the Iron and McIlwraith Ranges. For marine birds, those nesting on Lord Howe and Norfolk Islands, the Great Barrier Reef and the Houtman Abrolhos are likely to face the greatest declines in local marine productivity. Changes in local marine productivity may also affect the endemic terrestrial birds of these islands, for which no climate modelling was possible. A small group of beach-nesting and saltmarsh birds may be affected by sea level rise.
Many taxa, and particularly seabirds, are potentially highly sensitive to climate change based on a set of ecological and morphological metrics. Small island taxa were most likely to be both exposed and sensitive to climate change, followed by marine and shoreline taxa. While threatened birds were more likely than non-threatened taxa to be exposed or sensitive to climate change, or both, a substantial proportion was neither.
A key action that needs to be undertaken immediately is fine scale modelling of regions identified as having numerous highly exposed bird taxa, in order to identify climatic refugia within the landscape. Such refugia can then be secured and managed appropriately for the future. The most urgent ongoing action is monitoring, with support for the Atlas of Australian Birds seen as a particularly cost-effective investment. In the future, the most expensive actions will be management of refugia, and captive breeding should all other approaches to conservation in the wild fail. However, most of those for which captive breeding is recommended as a last resort are subspecies of species that are widespread, either in Australia or in New Guinea.
For in situ management, the most important actions will be those that are already important – fire management, weed and feral animal control and, for marine taxa, controls on fishing. A small number of species-specific actions are suggested, and there appears to be no urgent requirement for corridors for the maintenance of taxa likely to be threatened with extinction – those few taxa not already living in areas where there are likely to be refugia will require assistance to colonise new climate space.
The cost of management over the next 50 years for persistence in the face of climate change of the 396 bird taxa that are very highly exposed, sensitive or both is estimated at 47,700 per year for each taxon. The biggest ongoing costs are monitoring and direct species management but refugia management and captive breeding may eventually be needed, and will be much more expensive
Effects of past and present livestock grazing on herpetofauna in a landscape-scale experiment
No full textLivestock grazing is the most widespread land use on Earth and can have negative effects on biodiversity. Yet, many of the mechanisms by which grazing leads to changes in biodiversity remain unresolved. One reason is that conventional grazing studies often target broad treatments rather than specific parameters of grazing (e.g., intensity, duration, and frequency) or fail to account for historical grazing effects. We conducted a landscape-scale replicated grazing experiment (15,000 km(2), 97 sites) to examine the impact of past grazing management and current grazing regimes (intensity, duration, and frequency) on a community of ground-dwelling herpetofauna (39 species). We analyzed community variables (species richness and composition) for all species and built multiseason patch-occupancy models to predict local colonization and extinction for the 7 most abundant species. Past grazing practices did not influence community richness but did affect community composition and patch colonization and extinction for 4 of 7 species. Present grazing parameters did not influence community richness or composition, but 6 of the 7 target species were affected by at least one grazing parameter. Grazing frequency had the most consistent influence, positively affecting 3 of 7 species (increased colonization or decreased extinction). Past grazing practice affected community composition and population dynamics in some species in different ways, which suggests that conservation planners should examine the different grazing histories of an area. Species responded differently to specific current grazing practices; thus, incentive programs that apply a diversity of approaches rather than focusing on a change such as reduced grazing intensity should be considered. Based on our findings, we suggest that determining fine-scale grazing attributes is essential for advancing grazing as a conservation strategy
Surviving with a resident despot: do revegetated patches act as refuges from the effects of the noisy miner (Manorina melanocephala) in a highly fragmented landscape?
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