Long-term dynamics of rodent populations in arid Australia: the influence of rainfall

摘要: Populations of rodents were studied for periods 7−9 years at each three sites in arid Australia. All species fluctuated dramatically abundance, being absent or low numbers during droughts but erupting after significant rainfall. Strong correlations obtained between capture rates and cumulative monthly rainfall residuals, with time lags, that had been modified by an exponential decay function to model the post-rain depletion resources. The introduced Mus domesticus erupted within only two months exceptional one site, whereas native Notomys alexis, Pseudomys hermannsburgensis P. desertor generally responded 3Œ10 rain. faster response M. reflects its high reproductive potential compared rodents, perhaps greater immigration. Differences magnitudes delays among due probably differences initial population sizes times available and, desertor, between-site quality quantity food Population declines all dry followed resource shortages. Despite usually strong linkage dynamics, rain failed trigger responses prolonged sites, was not clearly associated eruption third. lack a site attributed predation, events other remain unexplained. We conclude long-term studies should play important role describing temporal changes rodent populations Australia field experiments, evaluating how factors combine effect changes.