Overabundant populations of large herbivores are both a wildlife resource and a threat to the integrity of the ecosystems they occupy. At high densities, deer can damage forests and jeopardize their regeneration. Anticosti Island (Québec, Canada) offers a natural outdoor laboratory for testing forest and deer management methods adapted to the overabundance of deer. The high density of white-tailed deer (Odocoileus virginianus) on the island has greatly altered the composition, structure and regeneration of its forests. The habitat degradation caused by this overabundance can also affect deer hunting, which is the principal economic activity on the island. For more than 20 years, the main objective of our research has been to develop forest and wildlife management methods adapted to high deer densities. We are interested in identifying and understanding the mechanisms by which deer alter ecosystem integrity, particularly through their habitat use behaviour. From a perspective of sustainable management of forest resources, we are testing different silvicultural treatments adapted to high deer densities. Overall, our work will support the development of management tools to reconcile forest regeneration and the valorization of white-tailed deer.