Standing dead trees may appear to be useless eyesores, but a state wildlife biologist says actually they are important components of wildlife habitat and frequently in short supply.
"That ugly snag may provide a secure home for many kinds of animals and a virtual smorgasbord of insect food," said Laurel Barnhill, wildlife biologist with the S.C. Department of Natural Resources (DNR). "Downy, hairy, red-bellied, pileated and red-headed woodpeckers all feed heavily on wood-boring larvae of beetles and other insects and invertebrates found in snags."
Print out a wildlife management guide (Pdf file) on snags and downed logs or call the Columbia DNR office at (803) 734-3886.
Woodpeckers are also the primary excavators of nesting cavities in snags, Barnhill said. These cavities are later used by other species. Bluebirds, wrens, titmice, crested flycatchers, chickadees, nuthatches, barred owls, screech owls and kestrels all depend on cavities for successful nesting.
Mammals such as bats, squirrels, flying squirrels and raccoons also use cavities in snag trees. A single snag tree may contain many cavities useful to several different species, as well as providing a food supply.
"The value of snags to both wildlife and people are countless," Barnhill said. "Many snag-dependent species control insects and pests, and birds of prey prefer the vantage point snags afford for hunting rodents. The woodpecker’s diet is filled with many insects that can be harmful to our interests."
There are two kinds of snags, according to Barnhill. A "hard" snag may be only partially dead, with many limbs remaining and sound wood. This kind of snag will be beneficial for many years. A "soft" snag is more decayed, with no limbs left and advanced heart rot. Wildlife species make use of both kinds of snags, but larger snags have more value.
In woodlots, at least four to five snags per acre should be maintained, according to Barnhill. Snags left in open areas over water will also provide hunting perches for flycatchers, bluebirds, hawks and kingfishers. Osprey may nest in large snags near open water.
DNR protects and manages South Carolina’s natural resources by making wise and balanced decisions for the benefit of the state’s natural resources and its people.