Analysis of Population Monitoring Data

M onitoring is a system for detecting trends over a period of time in areas such as habitat, water, and more. Herein we focus on animal populations and evaluate common quantitative methods for monitoring wildlife species. Animal distribution, abundance, survival, and productivity are examples of important biological parameters that can show trends based on ecosystem condition. Although there are different monitoring types (Morrison and Marcot 1995), monitoring is at its best with targeted ( or focused) monitoring (Nichols and Williams 2006), when specific goals and objectives are identified and evaluated under rigorous sampling designs. Here in we focus on targeted monitoring. The process of defining goals and objectives, sampling, evaluating population response, and directing further monitoring and/or management actions should be classified as scientific research (Morrison et al. 2008). We first distinguish between the biological versus sampled population, as these are seldom the same entity. Since it is rare to census all individuals in a population, the sampled population usually represents a subset of the biological population, but processes in the former may not fully reflect those in the latter (Morrison 2012). The related biological and sampled populations are a result of a hierarchical framework of processes (see Chapter 10): the true underlying ecological process (state process) and the observation process (sampling process) (Fig. 8.1). A biological population consists of all individuals of the same species that occur in the same area at a specific time and is characterized by births, deaths, emigration, and immigration. A community (or assemblage) of species consists of multiple populations of different species that occur in the same area at a specific time. The current state of a community is characterized by number of species (species richness), species composition, number of species and relative abundance of each species (diversity), and local species extinction and colonization. A robust monitoring data set requires careful planning and adequate support to ensure durability. Researchers and managers should