Predicting local and non-local effects of resources on animal space use using a mechanistic step selection model
Article first published online: 17 JAN 2014
© 2013 The Authors. Methods in Ecology and Evolution published by John Wiley & Sons Ltd on behalf of British Ecological Society
This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.
Methods in Ecology and Evolution
Volume 5, Issue 3, pages 253–262, March 2014
How to Cite
Potts, J. R., Bastille-Rousseau, G., Murray, D. L., Schaefer, J. A., Lewis, M. A. (2014), Predicting local and non-local effects of resources on animal space use using a mechanistic step selection model. Methods in Ecology and Evolution, 5: 253–262. doi: 10.1111/2041-210X.12150
- Issue published online: 11 MAR 2014
- Article first published online: 17 JAN 2014
- Accepted manuscript online: 12 DEC 2013 12:48PM EST
- Manuscript Accepted: 2 DEC 2013
- Manuscript Received: 18 MAY 2013
- NSERC Discovery and Acceleration
- Canada Research Chair and a Killam Research Fellowship
- Institute for Biodiversity, Ecosystem Science & Sustainability
- Sustainable Development & Strategic Science Division of the Newfoundland & Labrador Department of Environment & Conservation
- Newfoundland and Labrador Department of Environment and Conservation
- animal movement;
- caribou (Rangifer tarandus);
- master equation;
- mechanistic models;
- resource selection analysis;
- step selection functions
- Predicting space use patterns of animals from their interactions with the environment is fundamental for understanding the effect of habitat changes on ecosystem functioning. Recent attempts to address this problem have sought to unify resource selection analysis, where animal space use is derived from available habitat quality, and mechanistic movement models, where detailed movement processes of an animal are used to predict its emergent utilization distribution. Such models bias the animal's movement towards patches that are easily available and resource-rich, and the result is a predicted probability density at a given position being a function of the habitat quality at that position. However, in reality, the probability that an animal will use a patch of the terrain tends to be a function of the resource quality in both that patch and the surrounding habitat.
- We propose a mechanistic model where this non-local effect of resources naturally emerges from the local movement processes, by taking into account the relative utility of both the habitat where the animal currently resides and that of where it is moving. We give statistical techniques to parametrize the model from location data and demonstrate application of these techniques to GPS location data of caribou (Rangifer tarandus) in Newfoundland.
- Steady-state animal probability distributions arising from the model have complex patterns that cannot be expressed simply as a function of the local quality of the habitat. In particular, large areas of good habitat are used more intensively than smaller patches of equal quality habitat, whereas isolated patches are used less frequently. Both of these are real aspects of animal space use missing from previous mechanistic resource selection models.
- Whilst we focus on habitats in this study, our modelling framework can be readily used with any environmental covariates and therefore represents a unification of mechanistic modelling and step selection approaches to understanding animal space use.