The Marbled Murrelet (Brachyramphus marmoratus) is a small seabird from the North Pacific. It is a member of the auk family. It nests in old-growth forests or on the ground at higher latitudes where trees cannot grow. Its habit of nesting in trees was suspected but not documented until a tree-climber found a chick in 1974 making it one of the last North American bird species to have its nest described. The Marbled Murrelet has experienced declines in their numbers since humans began logging their nest trees beginning in the latter half of the 1800s. The decline of the Marbled Murrelet and its association with old-growth forests have made it a flagship species in the forest preservation movement.
The Marbled Murrelet is considered globally threatened, with some evidence of decline across its range over the last few decades. The biggest threat to the marbled murrelet was long considered to be loss of nesting habitat (old-growth and mature forests) to logging. Additional factors including high predation rates due to human disturbances and climate-driven changes in ocean conditions are also considered important now.
Scientists at Redwood National Park have established a connection between human presence in marbled murrelet territory and corvid predation of marbled murrelet chicks. Corvid populations, such as Steller's jays, crows, and ravens, are expanding into old-growth forests. Lured by food scraps left by campers and hikers, with increased access aggravated by the patchwork forests created by industrial logging, corvids more frequently discover marbled murrelet nests in areas where these predator species were not previously found.
The populations in Washington, Oregon and California were listed as threatened in 1992 by the U.S. Fish and Wildlife Service due to concerns about loss of nesting habitat, entanglement in fishing gear and oil spills. The remaining populations (Alaska and Canada) are currently under review. The species became a flagship species in efforts to prevent the logging of old-growth forests along the Pacific coast from California to Alaska.
Source: Wikipedia (All text is available under the terms of the GNU Free Documentation License)
For more information (background, pictures, experiments and references): Marbled_Murrelet