نتایج جستجو برای: fishers
تعداد نتایج: 1739 فیلتر نتایج به سال:
In pursuing their livelihood, and in a variety of overlapping contexts, commercial fishers must rely on information that is often incomplete. To fish successfully requires not only careful judgement of variable weather and water conditions and the likely movement of fish, but may entail exploration of new or less well known grounds. Fishers must also weigh up the fluctuating prices on offer for...
A recent publication hypothesized that deep snowfall can limit fisher (Martes pennanti) populations, and high fisher populations limit marten populations (M. americana). These hypotheses were evaluated by comparing the historic (1919-1924) and current (1989-1994) distributions of both Martes species in California to current snowfall distributions and forest types presumed to be habitats for eac...
My goal was to describe how biological and ecological factors give shape to fishing practices that can contribute to the successful self-governance of a small-scale fishing system in the Gulf of California, Mexico. The analysis was based on a comparison of the main ecological and biological indicators that fishers claim to use to govern their day-to-day decision making about fishing and data co...
BACKGROUND Acquiring fast and accurate information on ecological patterns of fishery resources is a basic first step for their management. However, some countries may lack the technical and/or the financial means to undergo traditional scientific samplings to get such information; therefore affordable and reliable alternatives need to be sought. METHODS We compared two different approaches to...
Globally, fisheries are challenged by the combined impacts of overfishing, degradation of ecosystems and impacts of climate change, while fisheries livelihoods are further pressured by conservation policy imperatives. Fishers' adaptive responses to these pressures, such as exiting from a fishery to pursue alternative livelihoods, determine their own vulnerability, as well as the potential for r...
Natural resource users face a trade-off between present and future consumption. Using harmful methods or extracting unsustainably, lowers future consumption. Therefore, it is reasonable to posit that people with higher time preferences extract more as compared to people with lower time preferences. The present study combines experimental methods and questionnaire data in order to understand the...
Four fishers (Martes pennanti) from an insular population in the southern Sierra Nevada Mountains, California, USA died as a consequence of an infection with canine distemper virus (CDV) in 2009. Three fishers were found in close temporal and spatial relationship; the fourth fisher died 4 mo later at a 70 km distance from the initial group. Gross lesions were restricted to hyperkeratosis of per...
Understanding the role of disease in population regulation is important to the conservation of wildlife. We evaluated the prevalence of Toxoplasma gondii exposure and Sarcocystis spp. infection in 46 road-killed and accidentally trapper-killed fisher (Martes pennanti) carcasses collected and stored at -20 C by the Pennsylvania Game Commission from February 2002 to October 2008. Blood samples we...
Fishers are elusive carnivorans, with few occurrences in the fossil record. The origin and early evolution of fishers is unclear, but they likely originated in Asia. A new record of Pekania from the Rattlesnake Formation of Oregon represents the earliest known occurrence of a fisher, more than 5 million years earlier than other records in North America. This specimen has an unambiguous derived ...
Wildlife populations of conservation concern are limited in distribution, population size and persistence by various factors, including mortality. The fisher (Pekania pennanti), a North American mid-sized carnivore whose range in the western Pacific United States has retracted considerably in the past century, was proposed for threatened status protection in late 2014 under the United States En...
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