Literaturdatenbank
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Boarman, W. I. Reducing predation by common ravens on desert tortoises in the mojave and colorado deserts. Bureau of Land Management, U.S. Department of the Interior, US Geologicals Survey and Western Ecological Research Center.
Added by: Admin (25 Aug 2008 22:06:33 UTC) |
| Resource type: Book BibTeX citation key: Boarman View all bibliographic details  |
Categories: General Keywords: Fressfeinde = predators, Gopherus, Gopherus agassizii, Habitat = habitat, Nordamerika = North America, Schildkröten = turtles + tortoises, Testudinidae Creators: Boarman Publisher: Bureau of Land Management, U.S. Department of the Interior, US Geologicals Survey and Western Ecological Research Center |
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| Abstract |
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Tesdinidae Gopherus agassizii Conflicts between humans and natural populations often result from habitat fragmentation and degradation that accompanies human activities. Common raven populations in the Mojave Desert have benefited by human-provided resources; they.ve expanded precipitously in recent years. Because ravens prey on juveniles of the threatened desert tortoise, they have become the focus of management concerns to help recover dwindling tortoise populations. I have outlined herein a series of management recommendations designed to reduce raven predation on desert tortoises thereby facilitating juvenile tortoise recruitment into the population of reproductive adults. The recommendations are based on the best available scientific information and are intended to provide a basis for a long-term reduction in raven impacts. The recommendations fall into four basic categories. (1) Modify anthropogenic sources of food, water, and nesting substrates to reduce their use by ravens. This includes modifying landfill operations, septage containment practices, livestock management, and other commercial and private practices that help facilitate raven survival and dispersal by providing food and water. Most of these measures are long-term actions designed to reduce the carrying capacity of the desert for ravens. This action is critical and must be done over very large areas. (2) Lethal removal of ravens by shooting or euthanizing following live trapping. Specific ravens known to prey on tortoises would be targeted as well as all ravens found foraging within specific high-priority desert tortoise management zones (e.g., Desert Tortoise Natural Area, DTNA). These actions would primarily be deployed on a short-term emergency basis to give specific tortoises populations a necessary boost until other measures become fully implemented and achieve their goals. (3) Conduct research on raven ecology, raven behavior, and methods to reduce raven predation on tortoises. Results of these studies would be used to design future phases of the raven management program. (4) All actions should be approached within an adaptive management framework. As such monitor, actions should be designed as experiments so that monitoring of actions will yield reliable and scientifically sound results. Coordinating and oversight teams should be convened to facilitate cooperation and coordination among agencies and to ensure that the actions are being implemented effectively.
Added by: Admin |