Inside their hidden world: Tracking the elusive marbled murrelet
OREGON—The marbled murrelet (Brachyramphus marmoratus) is a threatened coastal bird that feeds on fish and nests in old-growth forests. In northwest Washington, murrelet populations are declining despite protections provided by the Northwest Forest Plan.
Wildlife biologists Martin Raphael and Tom Bloxton, with the Pacific Northwest Research Station, used radio telemetry to develop a detailed picture of the challenges faced by marbled murrelets. This was the first study of its kind in Washington. Teresa Lorenz, also with the station, analyzed the resulting data to gain further insights into the ecology of these elusive birds.
Between 2004 and 2008, the scientists captured 157 murrelets in their marine feeding grounds, fitted them with transmitters and tracked their movements. They wanted to gain a better understanding of the birds’ nesting habitat and, as a result, be able to provide information that can contribute to conservation plans.
They found that factors on land and on water may be responsible for murrelet decline. Human activity on the water, coupled with the changing ocean conditions, likely affected the abundance of fish in the water. On land, a continuing decrease in nesting habitat is resulting in fewer nests, leading to lower rates of reproduction and a smaller population size. Although murrelet habitat in federal forests is protected, these areas tend to be farther inland than unprotected private and state forests in northwest Washington.
The Northwest Forest Plan, which is perhaps the most comprehensive murrelet habitat protection program to date, protects nesting habitat only on federal land such as national parks and national forests. Murrelets could potentially benefit from improved nesting habitat on state and private forests, which in northwestern Washington are often closer to marine areas.
Please visit Treesearch for the complete article. Past issues of Science Findings are available through Treesearch, and subscriptions can be managed through the Pacific Northwest Research Station subscription page.
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