Demographic models of the northern spotted owl (Strix occidentalis caurina)

摘要: Calassical demographic methods applied to life history data on the northern spotted owl yield and estimate of annual geometric rate increase for population λ=0.96±0.03, which is not significantly different from that a stable (λ=1.00). Sensitivity analysis indicates adult survivorship has by far largest influence λ, followed probability juveniles survive dispersal, fecundity. Substantial temporal fluctuations in parameters have little effect long-run growth because long expectancy. A model dispersal territory occupancy assumes equilibrium evaluated using amount old forest habitat remaining Pacific Northwest current this owls. This employed predict future loss fragmentation population, implying extinction will result if reduced less than proportion 0.21±0.02 total area large region. The estimated minimum requirement greater allowed management plants USDA Forest Service.