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1.
Environ Manage ; 37(4): 451-60, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16465565

RESUMO

We examined adaptive management (AM), applied as a science with testable and falsifiable hypothesis, in the context of a large carnivore population, specifically to wolf (Canis lupus lycaon) management in Algonquin Provincial Park, Ontario, Canada. Evidence of a population decline was based upon 12 years of data on 137 different radio-collared wolves. Because human killing accounted for an average of 66% of deaths, and most killing occurred adjacent to the park, a management prescription of complete protection for wolves around the park for 30 months was initiated in January 2001. We evaluated the probability of being able to test the null hypothesis, that protecting wolves adjacent to the park for 30 months would not result in a positive population response. Using preceding variances in population change, yearling recruitment, and mortality rates, we conducted this evaluation in two ways, the former involving a power analysis, the latter involving modeling. Both approaches showed the falsifiability of the hypothesis to be low. The reason, inherent in the application of AM to issues of population biology, especially of large carnivores, was stochasticity of the ecological system and time constraints of the human system. We discuss the political background that led up to the management prescription, and ways to avoid misapplication of a scientific approach to AM in such situations. For the latter, the merit of adjusting the relative probability levels of making Type I or Type II errors are discussed, along with recommendations that in the interests of conservation, avoiding a Type II error holds precedence.


Assuntos
Conservação dos Recursos Naturais , Lobos , Determinação da Idade pelos Dentes/veterinária , Animais , Demografia , Modelos Logísticos , Modelos Biológicos , Ontário , Dinâmica Populacional , Probabilidade , Processos Estocásticos , Lobos/fisiologia
2.
Oecologia ; 126(4): 507-514, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28547235

RESUMO

Examining both spatial and temporal variation can provide insights into population limiting factors. We investigated the relative spatial and temporal changes in range use and mortality within the Red Wine Mountains caribou herd, a population that declined by approximately 75% from the 1980s to the 1990s. To extract the spatial structure of the population, we applied fuzzy cluster analysis, a method which assigns graded group membership, to space use of radio-tracked adult females, and compared these results to a hard classification based on sums-of-squares agglomerative clustering. Both approaches revealed four subpopulations. Based on the subpopulation assignments, we apportioned the number of animals, radio-days, calving events and mortalities across subpopulations before and after the decline. The results indicated that, as the herd declined, subpopulations were disproportionately affected. In general, subpopulations with the greatest range overlap with migratory caribou from the George River herd experienced comparative reductions in activity and increased mortality. The subpopulation with the least overlap exhibited the converse pattern. The infra-population imbalances were more pronounced when hard clustering was employed. Our results reiterate that refugia from other ungulates may be important in the persistence of taiga-dwelling caribou. We propose that changes across time and space are valuable assays of localised demographic change, especially where individuals exhibit spatial hyperdispersion and site fidelity.

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