Providing for Wildlife: Leaving Trees and Down Logs for Habitat

Screech Owl Illustration
Screech Owl Illustration done by Jane Chavey

Did you know that over 100 species of mammals, birds and amphibians depend on down logs to meet at least some of their habitat needs? The newly updated Forest Practices Illustrated—an overview of forest practices rules that the Washington State Department of Natural Resources (DNR) enforces—requires landowners to leave a minimum number and size of trees, as well as down logs, to provide habitat for current and future wildlife. Reptiles, insects, and a variety of plants also use trees and down logs for habitat.

Habitat needs of amphibians, mammals and birds include nesting, overwintering sites, dens, roosting, foraging, and food storage—all can be found in a down log. Some birds, such as sapsuckers and woodpeckers, excavate their own nests in standing dead or dying trees. Other birds occupy abandoned nests or natural tree cavities. Most cavity-nesting birds eat large quantities of insects each year. There is evidence that these birds eat so many insects that they help keep down the populations of tree killing insects, such as bark beetles. Dead, dying, live but deformed, and live trees are an important part of a healthy forest.

Squirrels and other small mammals use dying and dead trees as foraging sites, storing winter food supplies, and for roosting and denning. Bats use loose bark and hollow tree trunks for roosting. Numerous insects use dead trees as over-wintering sites; some eat portions of dead trees, contributing to the decomposition process.

The death of eventual falling of trees provide forest openings that encourage growth of vegetation and younger trees. This leads to improved habitat for species such as elk, deer, raptors and small mammals.

See more about the minimum amount of trees and down logs left for habitat and other important forestry rules in the newly updated Forest Practices Illustrated. This free download is an overview of rules DNR enforces on 13 million acres of state and private forestlands in Washington state to protect streams, wetlands, clean water, habitat and public resources, such as highways, utilities and built structures.