Local Extinction in a Small and Declining Population: Wild Dogs in the Serengeti

摘要: Altered assumptions about how different ecological factors limit population numbers may lead to conclusions the causes of decline and ultimate extinction a small population. Here, alternative hypotheses for local disappearance Serengeti plains study African wild dogs (Lycaon pictus) are examined in light observations density dependence, deterministic frequent rapid fluctuations number. After crash from 60 individuals 1975 30 1976, fluctuated around mean value 22 16 years before occurred. Variation was extreme, with inter-annual reductions size at least 40% occurring three times. Several explanations consistent observed trends including outbreaks various epizootics competition other predators. Monte Carlo simulation, parameters set reflect fluctuations, demonstrate that likely chance alone. In declining populations, which precise data controls unavailable, determining cause(s) usually will be impossible.