Leave those Snags and Brush Piles in the Woods
A dead tree? Your impulse is to cut it down and remove it. Branches on the ground, brush from pruning your shrubs? Gather ‘em up and take ‘em to the transfer station or to the curb for pick-up.
But wait! The mammals, birds, and other animals would appreciate less clean-up in your woods.
Leaving dead or dying trees where they stand is one way to help your local wildlife. Some people are concerned that these “snags” are a sign of forest ill health. This is rarely the case. Instead, snags are part of the natural forest life cycle that provides habitat for animals and then returns nutrients stored in the tree to the soil.
Snags provide food, shelter, and nesting places for many birds, mammals and other animals. Many species of birds in New Hampshire nest in holes made or found in snags. Mammals, amphibians and reptiles also use these cavities as shelters, nests, or food storage bins.
A woodpecker fashions a hole in a snag and uses it for nesting. If the location is right, chickadees, owls, titmice, wrens, swallows—even bluebirds—may use the cavity when the woodpecker is done. Bluebirds like snags at the edge of fields.
Snags provide insect-eating birds, such as nuthatches and woodpeckers, with a reliable food source. These birds also eat insects in the surrounding area. Another insect-eater, the bat, seeks shelter under the loose bark of snags.
While bigger is better, a snag at least three inches in diameter at breast height (referred to as dbh) and at least six feet tall has value for wildlife. Ideally, you’ll have snags from several species of trees located at a distance from another, with at least three of them 12 inches dbh or more. Different animals will use varying sizes.
Particularly good locations for snags include field edges, clear-cuts, wildlife openings, and spots within 100 feet of a wetland, stream, or body of water. Of course, snags eventually fall down and thus could pose a safety hazard if left standing near a building, trail, or road.
Snags provide food and shelter for insects and other invertebrates. Squirrels and other small mammals store winter food in snags. They nourish lichens and fungi. Snags next to streams and water bodies often fall into the water, improving habitat for young fish. Snags may provide places for turtles to sunbathe next to the stream.
A brush pile is a pile of logs, sticks and brush. While you can simply collect in one place branches you’ve pruned or found on the ground, a constructed brush pile will provide a better shelter for animals. The National Wildlife Federation Web site describes the goal as a “topography of nooks and crannies, a fortress of crevices and interlocking branches to provide hiding places for dozens of animal species.”
A brush pile has two layers, a base and a top. The base should provide easy access for animals seeking shelter. Construct the base of logs, large rocks, or piles of stones. If you use logs, you’ll need about a dozen, four to six inches in diameter and six to 10 feet long Arrange half the logs about 10 inches apart as the first layer. Then put a second layer at right angles to the first. Alternatively, you could use four to six large rocks or piles of stones as a base instead of logs.
After the base, add smaller branches and brush to provide shelter. Including some evergreen branches will increase the pile’s value as a winter shelter. The ideal brush pile is four to eight feet tall and 10 to 20 feet in diameter.
Where should you construct your brush pile? The edges of fields or in the woods within 10 feet of a field or open area make good locations. Near a stream or water body is also good, so long as the site is well-drained. At least half of the pile should get daily sun. The animals will appreciate our locating the brush pile close to food sources such as viburnum or other native fruit-bearing shrubs.
It’s better to build several small brush piles than one large one, ideally at least four piles per acre placed at least 100 feet apart.
Do keep your piles away from buildings and children’s play areas, to minimize confrontations with the animals that may choose to live in your brush pile.
To learn more about improving wildlife habitat see “Wildlife
Habitat Improvement - Woodlands and Wildlife” and “Protecting
and Enhancing Shorelands for Wildlife”. Click here for
other information, including a diagram of a brush pile, check.
By Honey Hastings, UNH Cooperative Extension Coverts Cooperator
For more information call the UNH Cooperative Extension's Family, Home & Garden Center's Info-line (toll free) at 1-877-398-4769 or send us an email. Volunteers are available to answer your questions Monday through Friday 9:00am to 2:00 p.m.
3/15/06
