Sensitivity Analyses of a Population Projection Model of Ring-Necked Pheasants

Abstract A large literature exists on population dynamics of ring-necked pheasant (Phasianus colchicus) in North America, but there has not been an attempt to formulate a matrix model nor a sensitivity analysis of the relationships between vital rates and population finite growth rate (λ) that can be used to guide management. We summarized demographic data available from a 5-year field study in Iowa, USA, collected in Kossuth County (low composition of perennial habitat) and Palo Alto County (high composition of perennial habitat) into a 2-stage (young and adult) matrix projection model. We estimated λ1 (the dominant eigenvalue of the deterministic matrix), the stable age distribution (w), relative reproductive value vector (v), other demographic parameters, and λiid, a bootstrap estimate of growth that includes interannual variation in life history parameters. We analyzed the relative importance of vital rates on population growth rate using sensitivity and elasticity of both matrix elements and lower-le...