Deer, Odocoileus spp.,/ Elk, Cervus spp./ Moose,
Alces alces
Distribution: Throughout
B.C.
Tree Species Attacked: Conifers
-
All tree species are susceptible. Western redcedar is particularly susceptible to browsing by black-tailed deer and elk on the coast, especially for deer on islands that lack predators, such as the Queen Charlottes and Texada. Elk and deer damage also occurs in the interior, but is not as serious as browse damage on the coast. Moose browsing is most common in the interior. Nursery stocks have high nutrient content and are particularly sought after.
Broadleaves -
All species are attacked, especially bigleaf maple, trembling aspen, and hybrid poplar.
What To Look For: Patches of damaged bark, ragged browse patterns, stunted small trees, large droppings.
Signs & Symptoms: Terminal and lateral shoots are removed from seedlings and saplings during browsing activities. Browsed ends are squarely cut and have a ragged appearance. Feeding deer sometimes uproot seedlings entirely. Young bark may be peeled from sapling stems, leaving vertical toothmarks approximately 4 to 6 mm wide in the exposed sapwood. Bark is also stripped from the branches and trunk of saplings during antler polishing in the fall. Shredded bark clings to these injured areas. All the preceding injuries are confined to the lower 1.5 m of the tree for deer browse, higher for elk, and up to 2.3 m for moose. Stunted, bushy growth is seen on seedlings and saplings that have been repeatedly browsed. The distribution of browsed trees in a plantation is often clumped. Droppings are usually found. Numerous trails can be seen when the ungulate population is high in the local area.
Ungulates damage trees in two main ways: by browsing seedlings, suckers, saplings, and foliage; and by rubbing antlers on saplings and larger trees. Browsing normally occurs in late summer and autumn, and in winter where deer or elk concentrate. Browsed trees produce more stems that are concentrated and stunted in appearance due to repeated terminal and lateral shoot removal. Ungulate browsing appears ragged and splintered as a result of pulling and gnawing with the teeth; seedlings may be inadvertently uprooted or have their tops broken off. Bark may also be removed with lower incisors, leaving vertical grooves on the trunk and branches. Tooth marks are approximately 4 mm (deer), 6 mm (elk), or 6 to 9 mm wide (moose). Bark is worn by antler rubbing in late summer and autumn and can appear shredded, hanging in strips from the tree. Broken branches also indicate antler rubbing. Ungulates also trample young seedlings.To determine the source of the damage, signs of the ungulate such as droppings and prints may be located near the damaged tree. Moose damage may reach higher up the tree than deer or elk. Moose are known to pull down trees of 3 m or greater and snap the top off while browsing. Local knowledge of mammal populations may also assist in identifying the source of damage.
Damage: Occasionally, seedlings are killed when pulled from the ground. More commonly, browsing on terminal and lateral shoots causes growth loss and deformation in seedlings and saplings. Repeated browsing results in severe height suppression over extensive portions of affected plantations. Most damage occurs in the spring during bud flush. Elk are herding animals, and may trample trees.
Effects on young trees include decreased growth, stem deformation, and multiple stems. Open wounds provide entry sites for decay. Regenerating areas, widely-spaced plantations, and areas of high ungulate populations, risk permanent damage. Moose are known to decimate 1 or 2-year-old sucker stands by browsing tops and leaving only a few feet of the sucker behind.
Similar Damage: Distinguishing between the different browsing ungulates is difficult. The height of the browsing can be a clue; for example, large moose may browse as high as 2.3 m, while deer browse below 1.5 m. Local population knowledge, dropping size, and track size will also help distinguish the animal.
Voles, rabbits, and hares also gnaw on the bark of trees; however, the teeth marks in the cambium are tiny (about 1.5 to 2 mm wide) and not uniformly vertical. Rodents and rabbits cleanly clip branches, whereas ungulates leave a ragged edge. Cattle damage can appear similar, but cattle droppings and prints can be distinguished from wild ungulates.
|
