An Animal Movement Model Incorporating Resource Selection and Home Range

• Activity Number: 173
• Type: Invited
• Date/Time: Tuesday, August 10, 2004 : 8:30 AM to 10:20 AM
• Sponsor: Section on Statistics and the Environment
• Author(s): Jay M. Ver Hoef*+ and Aaron M. Christ
• Companies: Alaska Department of Fish and Game and Alaska Department of Fish and Game
• Keywords: Bayesian methods ; hierarchical model ; MCMC ; utilization distribution ; vector autoregression ; simulation

Abstract

How an animal uses space and how it uses the habitat resources within that space are two common questions in biology. One major factor influencing the path an animal follows is the need for certain resources along that path. These resources may fill requirements for nutrition, shelter, reproduction, etc. We develop a unified model that accounts for both movement and the use of habitat implied by that movement. A vector autoregressive model is developed and subsequently modified by a habitat-indexed multiplicative constant such that the likelihood depends on a home-range distribution, a movement distribution, a habitat distribution. The resulting utilization distribution incorporates preference for and aversion to the various habitat types. Model parameters are estimated using Bayesian methods and MCMC. The method is generalized to multiple animals using a hierarchical framework. A simulation study shows that the current method outperforms previous resource selection methods. The method is applied to brown bear data from Southeast Alaska. We find that for these data, distance to stream is the most important covariate, while vegetation classes are also important.