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Topic

Linking Land and Sea: Patterns of Intertidal Habitat Use by Terrestrial Mammals and Birds in Barkley Sound, British Columbia

Department of Biology

Date & location

• Thursday, December 11, 2025
• 12:00 P.M.
• Virtual Defence

Examining Committee

Supervisory Committee

• Dr. Amanda Bates, Department of Biology, ӣ��Ӱ�� (Co-Supervisor)
• Dr. Sarah Dudas, Department of Biology, UVic (Co-Supervisor)
• Dr. Jason Fisher, School of Environmental Studies, UVic (Outside Member)
• Dr. Caroline Fox, Canadian Wildlife Service, Environment and Climate Change Canada (Outside Member)

External Examiner

• Dr. Joanna Burgar, Biodiversity and Ecosystems Branch, Ministry of Water, Land and Resource Stewardship

Chair of Oral Examination

• Dr. Eva Kwoll, Department of Geography, UVic

Abstract

Ecosystems are linked by the movement of organisms, nutrients, and energy across habitat boundaries. Along the coastal interface, the intertidal zone provides a unique opportunity to observe these linkages directly. This thesis investigates how terrestrial mammals and birds use intertidal habitats in Barkley Sound, British Columbia, and how their behaviours contribute to ecological connectivity between land and sea. Using an array of 39 unbaited camera traps deployed across a range of beaches, I quantified multi-species patterns of intertidal use and identified environmental drivers of black bear (Ursus americanus) foraging. Across more than 3,000 independent detection events, cameras recorded eleven mammal species and twelve bird families using intertidal habitats for both foraging and travel. Activity patterns were structured by tidal, diel, and seasonal cycles, with bears and raccoons (Procyon lotor) exploiting prey primarily at low tide, ungulates and large carnivores using the shoreline as a movement corridor, and birds exhibiting diurnal activity at higher water levels. A focused analysis of bears revealed that intertidal use was shaped by shoreline accessibility, adjacent vegetation structure, and human disturbance, indicating that both opportunity and perceived risk govern foraging decisions. Collectively, these findings demonstrate that intertidal zones function as habitats shared by a diverse guild of terrestrial and marine species, facilitating both energetic and behavioural connectivity across ecosystems. By providing rare empirical evidence of multi-species intertidal use in a temperate rainforest system, this research advances understanding of cross-realm ecology and supports the need for management approaches that explicitly integrate terrestrial and marine processes across the coastal interface.