Snag Trees: What Are They & Why Are They Good For Wildlife?

Some of us may be familiar with a snag in a garment or a snagged fingernail. But what is a snag tree? Snag trees are dead or dying plants that have begun to disintegrate, leaving openings in the trunk. A dead tree snag is a favorable hiding place, nursery, storage area, forage site, and living space for many insects, birds, and mammal species.

What Is a Snag Tree?

A snag tree occurs when a tree is diseased, damaged by lightning, insects, animals, or old age, or just crowded out. The interior will become exposed in one of these manners, often leading to tree death. A snag tree is most often defined as material that is at least 3 inches (7.62 cm) across. A tree snag is still standing, unlike the downed logs and branches that are common in a forest. It most often has at least 1 cavity and can house a host of organisms. In North America, over 55 bird species are cavity nesters. But nesting is only 1 important job this dead plant offers.

Benefits of Dead Tree Snags

Dead trees provide habitat for over 1,000 wildlife species. They provide cover, nesting sites, roosting areas, forage, and more. It’s not only our feathered friends that nest in snag cavities, but other furred beasts. Raccoons, squirrels, martens, porcupines, bats, and amphibians are just a few wild animals that will use snag cavities for protection.

As the snag decays or gets cleared out by birds like woodpeckers, the larger spaces become the homes for these secondary users. Over 45 species of animals forage in the dead trees. The broken-down plant material enriches the forest floor and provides cover for many insects and smaller animals. Dead material that falls into riverways or streams provides a protective aquatic habitat for fish and other organisms.

How to Create a Habitat With a Snag Tree

Forest management recommends keeping snags remaining over 60 percent of the land area. That indicates how important these old plants are to the ecosystem and preservation of life. If there are trees on your property you can create a snag with little effort. If there is one who has lost the top portion, nature will do the work for you. Or you can cut off the top one-third to allow it to rot. The most favored snags by wildlife are Douglas fir, cottonwood, big-leaf maple, alder, and western red cedar. Evergreen trees will rot more slowly, while deciduous trees will decompose far faster. Softwood trees provide more forage, while hardwood trees produce the best nesting and hiding spaces. Drilling holes and making slits in the side of the trunk will offer even further options to certain species of birds.

Frequently Asked Questions