The marbled murrelet (Brachyramphus marmoratus) is a small seabird native to the Pacific Northwest, known for its unique nesting habits in far from its oceanic feeding grounds. The marbled murrelet, which EPIC affectionately calls the MaMu, has been at the heart of much of our work, particularly in the fight to save the old-growth redwoods of Headwaters Forest. A recent 5-year status review conducted by the U.S. Fish & Wildlife Service highlights both the bird's resilience and the increasing challenges it faces.
Since being listed as a federally threatened species in 1992, the marbled murrelet has continued to experience habitat loss due to timber harvest, wildfires, and coastal development. Approximately 71% of its nesting habitat loss is attributed to logging, primarily on non-federal lands. While the listing of the murrelet and other protections, such as the Northwest Forest Plan, have slowed the decline, conservation efforts are still insufficient to stop habitat loss entirely. 1.38% (20,847 acres) of the remaining nesting habitat has been lost due to logging since the species’ listing.
One of the most pressing concerns for the species is its low reproductive success. Marbled murrelets are known to have low fecundity, laying only one egg per year. Unfortunately, the conditions needed for successful reproduction—close proximity between high-quality nesting sites in old-growth forests and adequate foraging grounds in the ocean—are becoming increasingly scarce. Climate change further compounds the problem, altering oceanic food supplies and increasing the risk of drought and fire in nesting habitats.
Marbled murrelet population estimates show stability at a broad scale but reveal significant regional declines, particularly in Washington and Northern Oregon, which have seen decreases of 58% and 33%, respectively, since 2001. While the population in southern Oregon and California has seen modest increases, these gains are insufficient to offset the overall reproductive challenges.
Threats to the marbled murrelet are diverse. Predation, particularly by corvids and raptors, remains a significant factor in marbled murrelet nest failure. Coastal development, such as increased shipping traffic and marine infrastructure, has impacted the bird’s foraging habitats. Climate change, which brings rising sea temperatures and changing prey availability, adds a layer of unpredictability to the survival of the species.
The 2024 review concludes that the marbled murrelet remains threatened, with no change to its listing status. While conservation efforts have slowed the species’ decline, new and evolving threats continue to challenge its recovery. Without additional, targeted conservation actions, the long-term survival of the marbled murrelet remains uncertain. The fate of this small seabird serves as a reminder of the intricate connections between terrestrial and marine ecosystems, and the urgent need for coordinated conservation efforts across regions.
コメント