Integrating individual movement processes into population models

Speaker: Beth Gardner, University of Washington

Abstract: Understanding of the ecological processes that drive populations requires knowledge not only of demographic rates (e.g., abundance, survival, reproduction) but also of how animals use space through resource selection and movement. For example, individual movement is a key driver of population dynamics for recolonizing species. To incorporate both demographic and movement processes requires a flexible framework, one that can integrate data from multiple streams, such as an integrated population model. In this presentation, I’ll demonstrate approaches to incorporating individual movement into spatial capture recapture models and integrated population models. I’ll present a case study on recolonizing grey wolves (Canis lupus) in Washington, USA. We developed a model for grey wolf recolonization that has two main components: [1] an age- and state-structured population model that governs the population state process, and [2] an individual-based spatial model describing the dispersal of individuals and colonization of sites. We also considered different movement models to incorporate uncertainty in how dispersing wolves select new territories, an essential but unobservable process. All forms of the model resulted in showing gray wolves have a >99% probability of colonizing all of Washington State’s recovery regions by 2030. This case study, along with the other models presented, highlights how incorporating movement processes into population models and propagating uncertainty throughout the model can help us to address ecological questions related to habitat use, selection, and population dynamics.