Early detection of declining populations using floor and ceiling models
1. Within Caughley’s (1994) declining population paradigm for conservation, we develop a realistic method of detecting population changes using floor and ceiling population models. 2. A theoretical framework for detecting declining populations is presented and applied to four ungulate species from Kruger National Park, South Africa. 3. Census data are fitted to a non-linear autoregressive population model. Based on this model two auxiliary models, called the floor and ceiling models, are derived. These models predict the upper and lower threshold