Friday, June 23, 2017

12:00pm 1:00pm

Clark Conference Room


Dr. Daniel W. Linden

Greater Atlantic Regional Fisheries Office, NMFS, NOAA


Using spatial encounters to estimate population size of low density species

Abstract:  Population ecology centers on attempting to understand the natural processes that determine how many individuals are present, where they are located, and the mechanisms behind why. This critical and often context-specific information is a common objective of species monitoring programs designed to inform conservation and management decision-making. Wide-ranging species that occur at relatively low densities have traditionally been difficult to monitor, but non-invasive survey techniques have enabled the collection of spatial encounter data at scales meaningful to conservation and management. Spatial capture-recapture (SCR) provides a framework for explicitly linking spatial encounter data to ecological processes such as population size, animal movement, and individual space use or resource selection. At its core, SCR is a hierarchical model that combines a spatial point process for the latent distribution of individuals with a probability function for the observed encounters of those individuals. I will discuss the capabilities of SCR models and illustrate with several examples from my own terrestrial work, including the estimation of population dynamics over time (e.g., cheetahs in Kenya, black bears in Maine) and habitat selection (e.g., fisher, marten in the Northeast). I will also touch on recent marine applications including bottlenose dolphins and white sharks and discuss potential opportunities and difficulties in applying SCR models to fisheries management issues.