Habitat selection and connectivity of mountain lions (Puma concolor) across anthropogenic barriers on the Olympic Peninsula: a multi-method comparison

Author

Thomas R. Barbee, University of Montana, MissoulaFollow

Year of Award

2024

Document Type

Thesis

Degree Type

Master of Science (MS)

Degree Name

Wildlife Biology

Department or School/College

Wildlife Biology

Committee Chair

Hugh Robinson

Committee Co-chair

Mark Hebblewhite

Commitee Members

Sarah Sells, Mark Elbroch

Keywords

connectivity, step-selection, occupancy, mountain lion, cougar, puma

Publisher

University of Montana

Subject Categories

Behavior and Ethology | Other Ecology and Evolutionary Biology | Terrestrial and Aquatic Ecology

Abstract

Designing and maintaining effective wildlife corridors is an increasingly important conservation challenge in today’s fragmenting landscapes. GPS-based resource selection functions and camera-based occupancy models are both well-established staples of wildlife connectivity analyses and corridor planning, but each have notable trade-offs in cost and data resolution. Wildlife organizations worldwide rely heavily on camera-based occupancy modelling to plan wildlife corridors, especially where resource limitations or ethical concerns prohibit the use of GPS tags. If spatial connectivity maps from occupancy models could be shown to capture the essential elements of animal movement well enough to identify functionally equivalent corridors to those identified in more nuanced GPS analyses, this could support the wider application of remote cameras and similar data types to predict large-scale movement-based connectivity. However, though both methods are widespread, few studies have actually compared inferences from the two approaches, and concurrent datasets from both sources for comparison are rare. In Chapter 1, I developed a connectivity surface for mountain lions on the Olympic Peninsula by simulating movements from a population-level integrated step selection function (iSSF) applied to GPS locations from 82 individuals tracked between 2010 and 2023. Individuals varied widely in their responses to different landscape attributes, but a population- level model with individual random slopes captured the variation well even across demographic categories. Simulated step counts aligned well with a previous least-cost paths corridor analysis for the same region and two successful crossings by tagged mountain lions during the study. In Chapter 2, I developed a stacked single-species, single-season occupancy model and a current density connectivity surface for mountain lions using detections from 1,210 camera stations deployed between 2013 and 2022 and compared them with the iSSF surface from Chapter 1 and an existing expert-based probability of use surface. I found that all models except for the expert-based model predicted withheld mountain lion GPS locations well. Model predictions of probability of use were only moderately correlated across the landscape (0.12 - 0.26) but were strongly correlated in the areas of greatest human disturbance essential for corridor planning. All agreed reasonably well with previously identified least-cost linkages and observed mountain lion highway crossings. I conclude that any of these methods can be useful for planning wildlife corridors given that the limitations and assumptions of each are recognized. Though the step selection models perform best, occupancy models appear to offer a good compromise between cost and utility, and these findings support their continued use for corridor planning.

Recommended Citation

Barbee, Thomas R., "Habitat selection and connectivity of mountain lions (Puma concolor) across anthropogenic barriers on the Olympic Peninsula: a multi-method comparison" (2024). Graduate Student Theses, Dissertations, & Professional Papers. 12302.
https://scholarworks.umt.edu/etd/12302