Several mammal species damage trees in British Columbia. While these mammals cause significant damage to commercial trees, this activity is part of a healthy ecosystem of which the animals are valuable components.
All tree species can experience animal damage, especially as seedlings and saplings. Ungulates (hoofed animals) feed in particular on nursery stocks, which have higher nutrient content. Western redcedar is especially susceptible to browsing (grazing) by black-tailed deer and elk on the coast. Wildllfe that cause significant economic losses include the American porcupine, black-tailed deer, cattle, elk, moose, red squirrel, vole and snowshoe hare. Often it's unclear which species caused specific damage because their damage symptoms are similar.
Red squirrels damage young lodgepole pines and several other tree species. They cut and peel the lateral (side) and terminal (top) shoots, reducing growth, and remove or hollow out the buds. Strips of bark up to 1 cm wide are gnawed from the branches and main stems of saplings.
Voles clip the terminal and lateral shoots of small seedlings, and larger seedlings and saplings are debarked and often girdled. Porcupines gnaw bark from trees, which die when the lower portion of the stem (trunk) is girdled.
Cattle can browse and trample seedlings and saplings, particularly when confined or when insufficient fodder is available. Black bears strip large sections of conifer trees' bark, then feed on the exposed sapwood.
Species causing sporadic and minor losses include mountain beaver, American pika, pocket gopher, sapsucker and bushy-tailed wood rat.
Find out more about animal damage and management options available to reduce impacts on managed forests:
Trees with bark stripped by deer, elk or moose
Mortality due to stem girdling by snowshoe hares, a species that causes significant economic losses in B.C.