Modelling Killer Whale Feeding Behaviour Using a Spatially Adaptive Complex Region Spatial Smoother (CReSS) and Generalised Estimating Equations (GEEs)

  • Lindesay A. S. Scott-Hayward
  • Monique L. Mackenzie
  • Erin Ashe
  • Rob Williams
Article

DOI: 10.1007/s13253-015-0209-2

Cite this article as:
Scott-Hayward, L.A.S., Mackenzie, M.L., Ashe, E. et al. JABES (2015) 20: 305. doi:10.1007/s13253-015-0209-2

Abstract

To develop appropriate spatial conservation planning for individual species, it is important to understand their habitat requirements and in particular to identify areas where critical life-history process such as breeding, weaning or feeding take place. The process of defining critical habitat often ignores behavioural aspects of animal distribution, which for highly migratory species like baleen whales whose feeding and breeding grounds are clearly demarcated and widely separated is not a problem. However, for other species like the endangered ‘Eastern North Pacific southern resident’ killer whale stock, critical life-history processes occur in the same waters. This killer whale stock lives in a topographically complex region (many islands) off the west coast of Canada/USA, which makes accurate mapping of densities or behaviours difficult using traditional generalised additive models. We present results on the spatial distribution of southern resident killer whale feeding grounds in 2006, using a binomial, complex region spatial smoothing model within a generalised estimating equation framework, which allows for both complex topography and correlated residuals. The model performs well and suggests a region to the south of San Juan Island as an area with a high probability of feeding, which could not have been as accurately established from a more traditional presence–absence model. We also calculate estimates of precision, which other studies did not include, enabling more informed management decisions for spatial conservation planning. A vignette containing the code along with an R workspace and function file is provided to allow the user to fit the models presented in this paper.

Supplementary materials accompanying this paper appear on-line.

Keywords

Spatial modelling Habitat conservation Marine mammal Generalised additive model Residual correlation 

Supplementary material

13253_2015_209_MOESM1_ESM.html (1 mb)
Supplementary material 1 (html 1056 KB)

Copyright information

© International Biometric Society 2015

Authors and Affiliations

  • Lindesay A. S. Scott-Hayward
    • 1
  • Monique L. Mackenzie
    • 1
  • Erin Ashe
    • 2
  • Rob Williams
    • 2
  1. 1.Centre for Research into Ecological and Environmental Modelling (CREEM), School of Mathematics and StatisticsUniversity of St. AndrewsSt. AndrewsUK
  2. 2.Sea Mammal Research Unit (SMRU), School of BiologyUniversity of St. AndrewsSt. AndrewsUK

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