Marbled murrelets are not the background singers in a ‘60s band. Rather, they are a native sea bird species whose population south of Canada is declining.
Like the Pacific Northwest’s iconic northern spotted owl, this small seabird’s nesting habitat may be threatened by the loss of coastal old-growth forests in that region, according to a report co-authored by scientists from the U.S. Forest Service and published in The Condor.
A relative of the puffin, the marbled murrelet spends most of its time foraging in coastal waters, from central California to the Aleutian Islands. Unlike most seabirds, however, it flies up to 50 miles inland to nest on the branches of large, old-growth trees. And it is this nesting habit that might explain the reasons for the murrelet’s shrinking population, including continuing loss of suitable nesting habitat and the increased number of predators preying on the murrelet’s eggs and chicks.
“Our finding that murrelet numbers are declining means it is especially important to continue monitoring this population to see if the decline continues or reverses, and to better understand why this trend is happening,” said Martin Raphael, a U.S. Forest Service Pacific Northwest Research Station research wildlife biologist, and one of the study’s authors.
Although climate change is not cited as a direct reason for the seabird’s decline, changing sea temperatures may lead to a reduction in the quality and quantity of the murrelet’s prey, which includes small fish and krill. The study’s authors underscored the need to better understand the causes of the observed decline, which may provide options for managing forests and other resources to conserve the murrelet.
In 1992, the marbled murrelet population south of Canada was listed as threatened under the federal Endangered Species Act, a designation that requires federal agencies to carry out conservation measures for listed species. The Northwest Forest Plan was intended to help conserve and restore the murrelet’s habitat in an effort to aid in the recovery of the bird’s populations.
That a population decline is still being observed suggests that conversation measures to protect nesting habitat on federal lands have not yet taken hold.