Marbled Murrelet and selective logging
How the practice of selective logging in coastal old-growth forests in the Pacific Northwest often removes the trees that Marbled Murrelets are most likely to choose as nest locations.
Published: April 20, 2012
The Marbled Murrelet is a 10-inch-long seabird that nests in an unlikely place for a bird of the ocean: coastal old-growth forests. In most cases, pairs looking for a place to lay a single egg each year select a mossy platform on a branch of the largest tree within a patch of woods.
Photo by U.S. Fish and Wildlife Service
Unfortunately for the murrelets, the trees they most prefer to nest in are most likely to be harvested through selective logging practices of commercial foresters.
The birds occur along coastlines from California to Alaska. The species is listed as Threatened in British Columbia, Washington, Oregon, and California.
After studying murrelets at sites in southern British Columbia, researchers Michael Silvergieter and David Lank of Simon Fraser University wrote that the birds’ nesting trees averaged 15 to 20 percent taller than neighboring trees and had significantly larger stem diameters, more potential nesting platforms, and more moss. Nesting trees were about three times more likely than other trees to have the most extreme values of height and width.
The authors note that helilogging — cutting trees and then lifting them by helicopter — often involves removing “larger veteran trees from old-growth patches that are less amenable to normal clear-cut forestry operations.” The practice has less environmental impact than typical logging, but its impact on murrelets is unknown.
The birds do not choose nest trees at random, Silvergieter and Lank say, and their preference for “distinctive trees, often among the very largest” may prevent them from reproducing successfully after the helicopters leave.
The researchers described their findings in Avian Conservation and Ecology.