Failure to address many of the difficulties inherent in the analysis of carnivore faeces has hitherto limited the value of this technique in comparing carnivore diets or quantifying carnivore food consumption. In this review, major problems are discussed, and improved procedures designed to overcome them are recommended. The principal improvements recommended for laboratory procedures address the microscopic fraction of faeces, which cannot be analysed visually. This fraction may be derived from a variety of sources, leading to bias in previous techniques, particularly with regard to the importance of earthworms and birds. Attention to the microscopic fraction is necessary for correct comparison or quantitative determination of diet. Particular attention is given to statistical procedures which quantify the errors that arise in collection of samples, or during analysis. Clear statement of such errors will lead to greater comparability between studies. The procedures recommended here define the limits to accuracy in relation to sample size, total faecal production, and laboratory methods. In conjunction with adequate pilot studies, these techniques will allow more effective design of ecological studies relating to carnivore diet and food consumption.
Wildlife management in modern environments has to contend with an inheritance of faunal and landscape changes caused by humans which affect the relationships between predatory and prey species. In both game management for harvesting, and in species preservation, this leads to difficult decisions about whether and how to manage predation. Predator control by humans is as old as livestock husbandry. The deliberate, often organized, destruction of many mammalian predator species has been a feature of human development in Europe ‐ and later in countries to which Europeans spread ‐ for centuries. Destruction to the point of extinction was practised for a number of reasons (self‐protection, protection of domestic stock, protection of wild game, fur, adventure, sport) which were rarely distinguished. Reduction of predator numbers specifically to allow an increased harvest of some game species was mainly a nineteenth century development, while the adoption of predator control to benefit endangered species for their own sake belongs to recent decades. We review scientific literature relevant to predator control in game management and in conservation. Understanding of the role of predation in prey population dynamics has changed considerably during the last 20 years, and predation is now credited with a much more powerful role than in the past. Increasingly it becomes possible not merely to understand what predator control achieves, but to predict when it might be valuable in management, and what strategy will best achieve the aims. Examples of conservation problems involving predation illustrate the complexity of decision‐making in management. Because of habitat loss, habitat degradation, altered predator communities, or altered predator‐prey ratios, predation losses often have increased significance in modern environments. Novel approaches potentially offer non‐lethal ways to manage mammalian predators. However, most are still in an exploratory phase and there have been no unqualified successes. The best tested approach, excluding predators from small areas by fencing, is discussed. In Britain, predator control to benefit small game populations and allow harvesting has been practised for nearly 200 years, and has undoubtedly played a role in shaping the present‐day fauna. Although earlier gamekeeping severely reduced the geographical range of several mammalian (and avian) predator species, nowadays predator control is subject to legal restrictions based on species' conservation status and humaneness. However, illegal persecution of species protected by law remains a persistent and significant conservation problem. The predator species legitimately targeted are successful, common and increasing in the modem environment, while wild populations of gamebirds and many other ground‐nesting birds are declining seriously in most areas.
JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org.. British Ecological Society is collaborating with JSTOR to digitize, preserve and extend access to Journal of Animal Ecology. SUMMARY(1) Details of the replacement are revealed by a series of twenty-two annual distribution maps (1960-81).(2) Colonization of the region by invading grey squirrels was patchy, and pioneer populations were often detached from the main distribution of the species. Similarly, the red squirrel in decline was reduced to scattered 'island' populations.(3) Interaction between the two species could at the most provide a partial explanation of red squirrel decline: in many cases red squirrels became locally extinct before establishment of grey squirrels in the same area. In other cases, coexistence occurred for up to 16 years, or continued in 1982. Grey squirrel presence per se did not enhance the probability of red squirrel extinction. However, the more plausible possibilities of density-dependent interaction could not be tested in this extensive approach.(4) The loss of local red squirrel populations showed no temporal or spatial grouping. (5) A viral disease caused high death-rates locally in red squirrel populations, sometimes resulting in local extinction, but was not recorded in grey squirrels. Outbreaks frequently arose outside the current geographical range of the grey squirrel, weakening the hypothesis of the latter species as an immune vector. Outbreaks showed no temporal grouping.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.