U.S. Geological Survey review of Marbled Murrelets
found a 70 percent decrease in the number of birds in Alaska and Canada. The unusual sea bird nests up to 50 miles inland on the branch of an old-growth fir or hemlock.
USGS sea bird biologist John F. Piatt, lead author of the review, said none of the known human-caused threats to marbled murrelets — loss of nesting trees to logging, getting caught in gillnets, and oil spills — can by themselves explain the dramatic and widespread decline, particularly in Alaska.Photo courtesy of U.S. Fish and Wildlife Service
"Nobody was really expecting that kind of change," Piatt said from Port Townsend, Washington. "Natural influences may be more important than human-caused," changes.
Even areas like Alaska's Glacier Bay, where there has been no logging, saw dramatic declines, raising the likelihood that something larger was a major factor, he said.