Encouraging Wildlife

Aldo Leopold, A Sand County Almanac

A healthy wildlife population has value in its own right – it belongs in the ecosystem and each species plays an important role. Stuart Hill, a McGill University entomologist and organic agriculture advocate, makes the point that 99% of all organisms are benign from a `pest’ point of view. When we encourage monocultures, we inevitably succumb to pesticide dependencies. Pesticides kill many non-target organisms. Each time we kill a non-target organism, we inherit its job in the system. We don’t even recognize what most of these jobs are and even when we do, we don’t perform them very well.

Insects, soil-dwelling organisms, invertebrates, fungi, etc. help break down decaying matter and make nutrients available for plants; birds help control the insects that can harm plants (a study in Washington State estimates that given the amount of spruce budworms eaten by evening grosbeaks, it would cost at least $1,820 per square km (.6 square miles) per year over a 100-year rotation to spray with insecticides to produce the same mortality); squirrels and birds play important roles in spreading seed; animals are very quick composters, turning plants into nutrients that are readily available to growing plants, which produce more food.

The point here is that natural systems are complex and involve vast numbers of interactions. Chris Maser describes a good example of such an interaction in The Redesigned Forest. He looked at just one role that northern flying squirrels play in Oregon’s old growth forests. These squirrels nest in the canopy of large trees and come down to the forest floor at night to feed. In the squirrel’s fecal pellets, Maser found spores of mycorrhizal fungi (the `seeds’ for new fungus), nitrogen-fixing bacteria (that will grow in the new fungi and fix atmospheric nitrogen for the tree) and yeast (a nutrient source that stimulates growth and nitrogen-fixing in the bacteria). These pellets are perfect inoculants to improve tree growth. As the squirrel travels along the forest floor, it litters the area with these pellets. Mycorrhizal fungi infect tree roots and become part of the cellular structure. Infected trees are much healthier than those not infected. We have no idea if this exact relationship exists here but no doubt many similar relationships do. The common chanterelle mushrooms are mycorrhizal and northern flying squirrels live in our forests. This is just one example of how complex the ecosystem is and how little we know about the effects of our intervention.

What do we gain from healthy forest communities? A resilient forest with a wide range of species can translate directly into dollars from forest products, purify ground water, store carbon and provide a natural classroom where ecology can be taught and studied. Exciting, ever-changing areas allow us to observe the native flora and fauna of our Island – a natural landscaped garden that requires little maintenance. Forests also provide opportunities for tourism, recreation and spiritual pursuits.

What you can do:

• Create walking/skiing trails through your forests so you and others can enjoy your woodlands at all times of the year. Learn what lives in the forest and how they relate to each other. Becoming more aware of the forest’s inhabitants will give you valuable insights into how to harvest wood products and still maintain the integrity of the forest.
• Leave slash (treetops and branches from the selective harvesting) for nesting sites and cover for many animals. Burning removes this habitat, releases carbon dioxide into the air (a contributor to global warming) and wastes valuable nutrients. Three logs placed together will provide a shaded, moist environment for salamanders.
• Rodenticides used to protect seedlings from damage by mice can also be detrimental to hawks, owls, foxes that eat those rodents and non-target birds and mammals that eat the poisoned grain. Control weed competition around the seedlings, especially late in the fall, by mowing or mulching to remove shelter and food for rodents. Wrap fine wire mesh, tarpaper or plastic tree guards around the trunk to prevent seedling damage. Protect nest sites of all predators that control rodents and snowshoe hares that can damage regeneration.
• Even when using selection harvesting, time your work to take place from late summer to early spring, outside of prime breeding season. Hawks and owls nest from March through mid-July and should have special protection zones. The general rule is no cutting within 100 m (110 yards) of these nests, although it would be safer to double this. Nest buffers themselves are no assurity of success. Even with buffers up to 200 hectares (500 acres), nestling production of Northern goshawks in Arizona dropped by 94% when partial harvesting occurred outside the protected area.
• Transplant wild trees and shrubs to provide more food and habitat for wildlife. Some of the fruit-bearing trees do well on the sides of roads or in small openings where there is more sun. These include serviceberry (Indian pear), apple, wild roses and mountain ash. Nutbearing trees and shrubs, (red oak, beech, butternut and beaked hazelnut) tolerate more shade. See Tips on Transplanting in Appendix.
• Until suitable habitat becomes available, create nesting boxes for tree swallows, American kestrels, etc. See Nest Boxes in Appendix.
• Insecticides clearly harm insects and invertebrates with major roles to play in the ecosystem – as a source of food for birds, mammals, fish and amphibians, and through nutrient recycling and pollination. Remember the complexity of forest ecosystems. The death of non-target bees, for example, can seriously reduce the fruit-set on small shrubs. This adversely affects bird and mammal populations that feed on fruit. Insecticides also can have direct negative impacts on pond and stream life and forest birds and have no place in a forest community.
• Respect habitat requirements of all forest inhabitants. Where do flying squirrels, essentially treetop dwellers, go after a clearcut? No trees, no flying squirrels. Worse still, what about salamanders and frogs that spend time under logs and in moist woodlands? Amphibians, unlike plants and many invertebrates, have no resting, spore or seed phases to tide them over rapid changes, nor do they have wings to help them escape to new areas.