Contrasting Population Trends at Two Razorbill Colonies in Atlantic Canada: Additive Effects of Fox Predation and Hunting Mortality?

摘要: We developed a stochastic, stage-based, matrix-projection population model to assess population viability and estimate the impact of mortality caused by hunting, illegal incidental the murre (Uria sp.) hunt, fox (Alopex lagopus) predation on Razorbill (Alca torda) populations breeding on Gannet Islands, Labrador, "affected" population, Machias Seal Island, New Brunswick, the "unaffected" population. estimated potential growth rate in absence anthropogenic mortality sources using juvenile survival estimates from relatively unaffected Island Razorbill used data collected Islands 1978–2009 to estimate change productivity as result presence. The intrinsic (l) stochastic matrix based vital rates was 0.957±0.008 1.058±0.005 for Seal Island. Hunting reduced predicted 0.033, while fox predation 0.017. These combined baseline population growth 0.050. According our model, Island appears to be growing rapidly. In contrast, may decline, likely because hunting. However, oceanographic differences between two areas uncertainty regarding dispersal behavior in this species also contribute disparity populations. Based findings, we make several recommendations conservation management Razorbills Atlantic Canada.