Edge-core effects and the effectiveness of traditional reserves in conservation: Eurasian badgers in Donana National Park

High rates of human-mediated mortality on animals are frequently reported i nside protected areas, especially near their borders, so the overall effect of reserves on animal conservation is not usually known. To determine the effect of a traditional reserve (Donana National Park southwestern Spain) o n the Eurasian badger (Meles meles), a medium sized carnivore, we studied m ortality causes and rates, with the aid of radiotelemetry, in two populatio ns inside the reserve, one closer to the border than the other. Human-relat ed mortality (poaching and road kills) was by far the most common cause of mortality (85% of deaths recorded). The average annual mortality rate due t o poaching was high (0.48 +/- 0.08) for the population close to the border of the park whereas none of the radiomarked badgers in the core of the rese rve died during the study period A logistic model that included distance fr om the border of the park, sampling effort, and the local area (i.e., edge and core populations) indicated that the difference between both sites was due to the effect of distance from the border on survival probability. On a regional scale, badger density at the core of the park was 3.16 times high er than outside. Overall, the effect of the reserve was positive, but edge effects reduced reserve effectiveness by 36%. Edge effects in close proximi ty of the border were strong, reducing badger density even below the expect ed density outside the reserve. Edge effects should be considered carefully when reserves are implemented because they can greatly reduce reserve effe ctiveness and influence the viability of the populations inside. Enlargemen t of reserves and control of human activities that promote edge effects, bo th inside and outside the reserve, are the two management actions that can most effectively mitigate edge effects.