1000 resultados para gamete conservation


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In some wilderness areas, wildlife encounter vehicles disrupt their behaviour and habitat use. Changing driver behaviour has been proposed where bans on vehicle use are politically unpalatable, but the efficacy of vehicle setbacks and reduced speeds remains largely untested. We characterised bird-vehicle encounters in terms of driver behaviour and the disturbance caused to birds, and tested whether spatial buffers or lower speeds reduced bird escape responses on open beaches. Focal observations showed that: i) most drivers did not create sizeable buffers between their vehicles and birds; ii) bird disturbance was frequent; and iii) predictors of probability of flushing (escape) were setback distance and vehicle type (buses flushed birds at higher rates than cars). Experiments demonstrated that substantial reductions in bird escape responses required buffers to be wide (> 25 m) and vehicle speeds to be slow (< 30 km h-1). Setback distances can reduce impacts on wildlife, provided that they are carefully designed and derived from empirical evidence. No speed or distance combination we tested, however, eliminated bird responses. Thus, while buffers reduce response rates, they are likely to be much less effective than vehicle-free zones (i.e. beach closures), and rely on changes to current driver behaviour

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Over the past 3 decades, the status of sea turtles and the need for their protection to aid population recovery have increasingly captured the interest of government agencies, non-governmental organisations (NGOs) and the general public worldwide. This interest has been matched by increased research attention, focusing on a wide variety of topics relating to sea turtle biology and ecology, together with the interrelations of sea turtles with the physical and natural environments. Although sea turtles have been better studied than most other marine fauna, management actions and their evaluation are often hindered by the lack of data on turtle biology, human–turtle interactions, turtle population status and threats. In an effort to inform effective sea turtle conservation a list of priority research questions was assembled based on the opinions of 35 sea turtle researchers from 13 nations working in fields related to turtle biology and/or conservation. The combined experience of the contributing researchers spanned the globe as well as many relevant disciplines involved in conservation research. An initial list of more than 200 questions gathered from respondents was condensed into 20 metaquestions and classified under 5 categories: reproductive biology, biogeography, population ecology, threats and conservation strategies.

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The implementation of appropriate protection measures for endangered species in protected areas requires knowledge of their fine-scale habitat use. In May and June of 2006 and 2007, we used GPS loggers (some linked to the Argos system) and a conventional Argos transmitter to track male and female loggerhead turtles Caretta caretta in the vicinity of the breeding area of Laganas Bay within the National Marine Park of Zakynthos, Greece. We obtained (1) 9681 useable locations (mean: 1383 locations ind.–1; range: 519 to 2198 locations) from Tracktag GPS loggers attached to 7 females for a mean duration of 34 d (range: 17 to 52 d); (2) 1245 useable locations (mean: 311 locations ind.–1; range: 38 to 1110 locations) from 4 males fitted with Fastloc Argos tags for a mean duration of 29 d (range: 3 to 51 d) and (3) 100 locations from 1 male fitted with a conventional Argos satellite tag tracked for 128 d. GPS data indicated that before the onset of nesting, both males and females primarily used an area within 500 m of the shore along a core 9 km stretch of coastline, where existing protective legislation requires strengthening. Our observations suggest that a 76.7% female-biased operational sex ratio, measured previously from in-water surveys, may represent a realistic sex ratio estimate in the period before nesting starts. In the first month following the onset of nesting, female spatial distribution remained similar, whereas most males departed for distant areas presumably to forage. Our study provides quantitative evidence of the need to improve the management planning and conservation measures to protect sea turtles in a coastal breeding area, and new insights on male turtle migration.

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Despite decades of conservation efforts on the nesting beaches, the critical status of leatherback turtles shows that their survival predominantly depends on our ability to reduce at-sea mortality. Although areas where leatherbacks meet fisheries have been identified during the long distance movements between 2 consecutive nesting seasons, hot-spots of lethal interactions are still poorly defined within the nesting season, when individuals concentrate close to land. Here we report movements of satellite-tracked gravid leatherback turtles during the nesting season in Western Central Africa, South America and the Caribbean Sea, which account for about 70% of the world population. We show that during and at the end of the nesting season, leatherback turtles have the propensity to remain over the continental shelf, yet sometimes perform extended movements and may even nest in neighbouring countries. Leatherbacks exploit coastal commercial fishing grounds and face substantial accidental capture by regional coastal fisheries (e.g. at least 10% in French Guiana). This emphasises the need for regional conservation strategies to be developed at the ocean scale—both at sea and on land—to ensure the survival of the last leatherback turtles.

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Mining started in South Australia in the early 1840s with the discovery of silver-lead ore at Glen Osmond in 1841 and later copper in Kapunda in 1842 and Burra in 1845; all these discoveries greatly contributed to South Australia's economic development. South Australia entered the mining era at the time when the Cornish engine was at the peak of its development, and the horizontal engine was beginning its rise in popularity. These South Australian historic mining sites contain extensive extant evidence of technology, innovation and human endeavours that previously went into the mining activity. This paper seeks to critically review items for inclusion on the South Australian State Heritage Register, the character of mining heritage places, enforcement by legislation, interpretation of the heritage assessment and how these practices could guide Malaysia in recognizing industrial heritage as a significant part of its cultural heritage that needs to be conserved, restored and managed as a legacy for present and future generations.

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There is a long-standing debate concerning the suitability of European or ‘western’ approaches to the conservation of cultural heritage in other parts of world. The Cultural Charter for Africa (1976), The Burra Charter (1979) and Nara Document on Authenticity (1994) are notable manifestations of such concerns. These debates are particularly vibrant in Asia today. This article highlights a number of charters, declarations and publications that have been conceived to recalibrate the international field of heritage governance in ways that address the perceived inadequacies of documents underpinning today’s global conservation movement, such as the 1964 Venice Charter. But as Venice has come to stand as a metonym for a ‘western’ conservation approach, intriguing questions arise concerning what is driving these assertions of geographic, national or civilisational difference in Asia. To address such questions, the article moves between a number of explanatory frameworks. It argues declarations about Asia’s culture, its landscapes, and its inherited pasts are, in fact, the combined manifestations of post-colonial subjectivities, a desire for prestige on the global stage of cultural heritage governance and the practical challenges of actually doing conservation in the region.

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The ongoing evolution of the global heritage movement has been marked by a move away from fabric-centred understandings of heritage, towards a language of ‘place’, ‘values’ and ‘stakeholders’. Recent initiatives like the ‘Vienna Memorandum on Historic Urban Landscapes’ and the ‘Seoul Declaration on Heritage and the Metropolis in Asia and the Pacific’ represent important steps in such directions for managing the heritage of urban environments. This paper examines these developments in the context of Srinagar, the capital city of Indian administered Kashmir. With the conflict in the region enduring for more than fifteen years, the city - regarded as one of the most important pre-modern urban landscapes in South Asia - has suffered extensive physical damage. Nonetheless, the city remains the cultural and political heart of a wider collective identity rooted in the Kashmir Valley. As such, Srinagar presents a rich example of a city that would strongly benefit from the insights gained from Seoul and Vienna; an approach that recognises how a sense of ‘place’ arises through an intimate dialogue between the built environment and the socio-cultural context within which it sits. However, as we shall see, a framework oriented around ‘values’ and ‘context’ opens up unfamiliar and difficult questions and challenges. If a city like Srinagar is to be discussed in more holistic, less fabric-based terms, the interfaces between heritage and its wider social values, such as cultural sovereignty, multi-culturalism or democracy require far greater attention than they have received to date.

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Change has engulfed the coastal fringe of Australia. In balancing the built and natural environment, community needs, cultural significance and economic sustainability, planners aim to improve quality of life and create vibrant communities. Yet managing place change, particularly in coastal areas, is fraught with tensions. Most planning discussions about the rapidity of change, the impact of the Sea Change process and increased development have focused upon the extensiveness of residential expansion and the housing styles that challenge the essence of the character of these coastal towns. Character and sense of place qualities are the very reasons that sea changers desire to engage with and reside within these communities. One aspect missing from this discussion and analysis is the impact that large-scale transformations of iconic buildings are having upon these places. This paper examines the consequences that major commercial development projects have upon the communities of Sorrento and Queenscliff. It considers changes (proposed or realised) to four landmark historic hotels: The Koonya and Continental in Sorrento; and the Ozone and Vue Grand in Queenscliff. This paper focuses on issues of planning, social engagement and community debate.

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Conservation projects occur under many types of uncertainty. Where this uncertainty can affect achievement of a project's objectives, there is risk. Understanding risks to project success should influence a range of strategic and tactical decisions in conservation, and yet, formal risk assessment rarely features in the guidance or practice of conservation planning. We describe how subjective risk analysis tools can be framed to facilitate the rapid identification and assessment of risks to conservation projects, and how this information should influence conservation planning. Our approach is illustrated with an assessment of risks to conservation success as part of a conservation plan for the work of The Nature Conservancy in northern Australia. Risks can be both internal and external to a project, and occur across environmental, social, economic and political systems. Based on the relative importance of a risk and the level of certainty in its assessment we propose a series of appropriate, project level responses including research, monitoring, and active amelioration. Explicit identification, prioritization, and where possible, management of risks are important elements of using conservation resources in an informed and accountable manner

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1. Identifying landscape patterns that allow native fauna to coexist with human land use is a global challenge. Riparian vegetation often persists in anthropogenic environments as strips of natural or semi-natural vegetation that provide habitat for many terrestrial species. Its relative contribution to landscape-scale conservation is likely to change as environments become increasingly modified. We used a ‘whole of landscape’ approach to test the hypothesis that riparian vegetation offers disproportionate benefits, relative to non-riparian vegetation, for the conservation of woodland birds in highly modified agricultural landscapes. 2. We selected 24 landscapes, each 100 km2, along a gradient of landscape change represented by decreasing cover of native vegetation (from 60% to <2%), in an agricultural region in SE Australia. Bird species were systematically surveyed at three riparian and seven non-riparian sites in wooded vegetation in each landscape. 3. Riparian sites supported a greater richness of woodland-dependent species, a group of conservation concern, than did non-riparian sites. The composition of assemblages also differed between site types. 4. At the landscape scale, the pooled richness of bird assemblages at riparian and non-riparian sites, respectively, decreased with overall loss of tree cover despite constant sampling effort. Within landscapes, the β-diversity of woodland species among non-riparian sites increased (composition became less similar) as landscape tree cover declined. In contrast, riparian assemblages were relatively stable with no change in β-diversity. Importantly, as landscape tree cover declined, the proportion of woodland species uniquely present at riparian sites increased and made a greater contribution to overall landscape diversity. 5. Synthesis and applications. Landscape-scale richness of woodland species declines as landscape tree cover is lost. In highly depleted landscapes, riparian vegetation retains a relatively rich, stable assemblage compared with that in heterogeneous remnants of non-riparian vegetation and consequently contributes disproportionately to landscape-scale diversity. These observations, together with the diverse benefits of riparian vegetation for aquatic ecosystems, mean that protection and restoration of riparian vegetation is a high priority in anthropogenic environments. Importantly, such actions are directly amenable to individual land managers, and the benefits will accumulate to enhance the persistence and conservation of species at landscape and regional scales.