Monday, October 13, 2008

Wildlife Trees

Wildlife Trees
December 2005

Wildlife tree or firewood? Long known as snags (and we’re not talking not new age sensitive guys!), dead or partially dead standing trees have traditionally been sought after as nicely cured firewood or considered “eyesores” that require prompt removal. However, scientists, naturalists and our provincial government have realized that these seemingly lifeless trees are, in fact, biological “hotspots” that contribute enormously to the diversity of a forest and the BC Wildlife Act has provided protection to them in some cases.
Many reasons contribute to the death of a tree but a common cause is from a wound that becomes infected with bacteria and fungi, which in turn attracts insects who encourage the softening of the heartwood, making it more easily excavated by woodpeckers. As diseased and dying trees progress they provide food, nesting, roosting and denning sites and hunting perches to over 80 species of wildlife, many of which completely depend on them for some portion of their life. The larger the circumference and height of the tree, the more ecologically valuable it becomes. Old, mature Douglas-firs with strong, thick branches are preferred sites for bald eagle nests, larger diameter alders find favour with pileated woodpeckers and outsized, hollow trees can offer den sites for bears and river otters. Characteristics of valuable wildlife trees include sizeable diameter and height, thick branches, loose bark, broken tops, heart rot and other decay. To determine if your tree is a wildlife tree or if it is in use currently, look for nests, signs of feeding (owl pellets, feathers, fur), denning holes, wood chips around base, claw marks or fur on bark, food caches or bat guano around or beneath loose bark.
Just as “no man is an island”, a wildlife tree is more ecologically productive with a naturally vegetated buffer to protect the tree during storm and high wind events as well as provide a more viable environment for the wildlife that use the tree.
In the Pacific Northwest, some trees will remain standing for decades to hundreds of years after their death so careful consideration should be given before they are cut down as a “dangerous” hazard. Even after they come to their final resting place on the ground, downed logs continue to provide homes and food for smaller mammals, lizards, amphibians and insects, supply travel routes through the forest, act a “nurse” logs to young seedlings and finally contribute as nourishment to the soil.
If you are concerned about a wildlife tree for safety reasons, you can consider modifying them so that they retain some natural value. Remove the worrisome limbs or cut off the top (leave it as tall as possible) and if it is determined that the tree should be felled, leave it as a downed log rather than remove it entirely. If it is too obtrusive an eyesore, move the log into a forested area to decay.
WiTS or Wildlife Tree Stewards is a stewardship program of the Vancouver Island Region of the Federation of BC Naturalists (FBCN). The goal is to create, coordinate and assist a network of community stewards committed to conserving coastal wildlife tree habitats through volunteer monitoring, landowner agreements, and community education along the Strait of Georgia. If you are interested in their program, contact Gwen Greenwood – 250-652-2876,
Save the firewood cutting for smaller diameter trees, they’re easier to haul and chop anyways. Enjoy your wildlife trees, find a hidden spot from which you can watch the daily and seasonal wildlife dramas that make rural living so much a part of a Metchosin experience.

The Life Cycle of a Wildlife Tree:
live, healthy tree
• provides nesting, roosting and perching opportunities
live unhealthy tree with decay or growth deformities
• provides nesting, roosting and habitat for strong primary excavators (woodpeckers, sapsuckers, nuthatches, chickadees) and nesting platforms for bald eagles, etc
dead tree with strong heartwood
• provides habitat for bats, brown creepers and insects under loose bark and in cracks
dead tree with soft heartwood
• provides homes for cavity nesters: many birds, small mammals and amphibians
fallen dead tree
• provides territory for small mammals, insects, reptiles and amphibians; provides travel routes for small creatures; nourishes and replenishes soil
BC Wildlife Act
Currently, Section 34(b) of the BC Wildlife Act extends year-round protection to a select group of birds’ nests that include those of Bald Eagles, Ospreys, and Great Blue Herons. For other bird species, the federal Migratory Birds Convention Act and provincial Wildlife Act protects nests only when they are occupied by adult birds, their young and/or eggs. For these species, the nest tree is vulnerable to removal when occupation by birds or their eggs is unknown.

Section 34 of the BC Wildlife Act states:
34 A person commits an offence if the person, except as provided by regulation, possesses, takes, injures, molests or destroys
(a) a bird or its egg,
(b) the nest of an eagle, peregrine falcon, gyrfalcon, osprey, heron or burrowing owl, or
(c) the nest of a bird not referred to in paragraph (b) when the nest is occupied by a bird or its egg.

WiTS information website:
Online Wildlife Tree Atlas:
Wildlife Tree or Dangerous Tree?

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