As ecosystems in coastal British Columbia disappear due to long-term browsing pressures from overabundant black-tailed deer, a new study led by UBC with Coast Salish Nations and regional research partners identifies the most effective solutions to address deer overabundance on the Southern Gulf Islands.
The research, published in People and Nature , finds Indigenous-led hunting to be the most successful and cost-effective strategy for managing hyperabundant deer when considering ecological and cultural needs. Drawing on both Indigenous and Western knowledge systems, the study also highlights the importance of honoring distinct knowledge and value systems equitably in wildlife management.
A growing ecological crisis
Following almost two decades of research led by Dr. Tara Martin from UBC's Faculty of Forestry, black-tailed deer populations on the Southern Gulf Islands are now estimated to be up to 10 times higher than they were a century ago, due to a combination of human-altered landscapes, restrictions on hunting, and the eradication of predators.
As deer populations grow unchecked, they overbrowse vegetation, prevent forests from regenerating, reduce biodiversity, and disrupt cultural connections to the land.
"For most people these islands look beautiful and natural, but they are entirely degraded," says Dr. Martin. "The change has been so slow, most people don't recognize this shift. We've found hyperabundant deer are one of the major drivers of this change."
The consequences are stark. One of B.C.'s most endangered ecosystems, the Garry Oak meadow, is now at risk of irreversible collapse due to overgrazing. Other regions across Canada and the globe are facing similar threats from hyperabundant herbivores including Haida Gwaii, Ontario, Australia, New Zealand and New Caledonia.
Inclusive approach to decision-making
Developing deer management strategies that address overpopulation and also support the well-being of people and the land—rather than focusing solely on ecology—is inherently complex.
"This study offers a roadmap to help unpack complicated problems where many values and goals compete, often leading to decision paralysis and inaction" says lead author and doctoral student Sofie McComb. "Hyperabundant deer are damaging ecosystems around the world, and we're offering a framework that gives decision-makers practical, inclusive solutions."
Working in collaboration with Coast Salish Nations and local land stewards and knowledge holders, Dr. Martin's group considered a number of strategies for successful deer management. These included Indigenous-led hunting, improving predator viability, hiring deer reduction specialists, using birth control, increasing licensed hunting, and combining approaches.
Indigenous-led hunting was the only strategy with a high likelihood of being successful and achieving ecological and cultural benefits. Compared to the status quo, Indigenous-led hunting was found to increase the likelihood of maximizing human and ecological wellbeing by almost 60 per cent, and was more than 50 per cent likely to maximize project uptake and implementation goals.
Strategies such as increased licensed hunting were cost-effective from a Western science perspective, as they are low-cost strategies with moderate feasibility, but were less likely to achieve meaningful long-term benefits (less than 30 per cent likelihood).
Cost of inaction
Experts agreed that sticking with the status quo will not improve ecosystem functions and will continue to feed the decision-making paralysis fuelled by a fear of controversy. Researchers warn that delaying action is the most harmful option.
"If we don't do something soon, the ecosystems will not be recoverable, because there will be nothing left" says Sofie McComb. "The deer are also struggling, and have turned to eating starvation foods. Inaction is action – that is the action that has been chosen and the ecosystem is suffering."
The study provides an inclusive, transparent framework for communities worldwide facing hyperabundant herbivores. By integrating multiple knowledge systems and weighing feasibility and cost alongside ecological and cultural benefits, decision-makers can chart a path toward recovery that is both effective and socially grounded.
"It's possible to find solutions to complex environmental issues that are good for people, the land and the deer" says Dr. Martin. "This work shows that restoring cultural sovereignty and ecosystem health can go hand in hand."
