2 resultados para Charles Albert, King of Italy, 1844-1900.

em Avian Conservation and Ecology - Eletronic Cientific Hournal - Écologie et conservation des oiseaux:


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The Ivory-billed Woodpecker has long held a special place in the psyche of North American conservation, eliciting unusually colorful prose, even from scientists, as an icon of the wild. The reverence in which it was held did little to slow the habitat loss that led to its apparent extinction 60 years ago. A consequence of the emotion and attention associated with the amazing rediscovery of this species is that conservation biologists will be under considerable pressure to make good on this “second chance.” This poses a challenge to conservation paradigms that has important political consequences. First, the decline of the species is due to habitat loss, recovery from which has been much more seldom achieved than recovery from declines due to impacts on vital rates. This challenge is exacerbated by the enormous area requirements of the species. Second, the species at best exists as a critically small population. It will be difficult to make the case that a viable population can be established without undermining the small population paradigm that underlies conservation strategies for many other species. This has already resulted in some political backlash. Conservation of this species is best based on the one point of clear scientific consensus, that habitat is limiting, but this may result in additional political backlash because of conflicts with other land uses.

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We used ground surveys to identify breeding habitat for Whimbrel (Numenius phaeopus) in the outer Mackenzie Delta, Northwest Territories, and to test the value of high-resolution IKONOS imagery for mapping additional breeding habitat in the Delta. During ground surveys, we found Whimbrel nests (n = 28) in extensive areas of wet-sedge low-centered polygon (LCP) habitat on two islands in the Delta (Taglu and Fish islands) in 2006 and 2007. Supervised classification using spectral analysis of IKONOS imagery successfully identified additional areas of wet-sedge habitat in the region. However, ground surveys to test this classification found that many areas of wet-sedge habitat had dense shrubs, no standing water, and/or lacked polygon structure and did not support breeding Whimbrel. Visual examination of the IKONOS imagery was necessary to determine which areas exhibited LCP structure. Much lower densities of nesting Whimbrel were also found in upland habitats near wetlands. We used habitat maps developed from a combination of methods, to perform scenario analyses to estimate the potential effects of the Mackenzie Gas Project on Whimbrel habitat. Assuming effective complete habitat loss within 20 m, 50 m, or 250 m of any infrastructure or pipeline, the currently proposed pipeline development would result in loss of 8%, 12%, or 30% of existing Whimbrel habitat. If subsidence were to occur, most Whimbrel habitat could become unsuitable. If the facility is developed, follow-up surveys will be required to test these models.