The Marbled Murrelet (Brachyramphus marmoratus) is a small seabird from the North Pacific. This unusual member of the auk family nests far inland in old growth forests instead of in colonies close to shore. Its habit of nesting in trees was not known until a tree-climber found a chick in 1974.
The Marbled Murrelet and the closely related Kittlitz’s Murrelet are thought to have experienced declines in numbers recently. Their decline and association with forests have made them a flagship species in the anti-logging movement. Two subspecies are recognized, B. marmoratus marmoratus in North America, and B. marmoratus perdix, (from Kamchatka and the Sea of Okhotsk), which is considered by some authorities a separate species, the Long-billed Murrelet B. perdix.
The Marbled Murrelet is a small (25 cm), chunky auk with a slender black bill, pointed wings and plumage that varies by season. Non-breeding plumage is typically white underneath with a black crown, nape, wings and back (with a white collar in B. m. marmoratus), and an all over mottled brown barring in the breeding plumage. The Long-billed Murrelet is longer billed and slightly larger than the Marbled Murrelet.
Behavior and breeding
The Marbled Murrelet feeds at sea both in pelagic offshore areas (often associating with upwellings) and inshore in protected bays. It feeds mainly on sand eels but will also take herring, capelin and shiner perch.
The breeding behavior of the Marbled Murrelet is very unusual. Unlike other seabirds it does not nest in colonies or even close to the sea. Instead it nests on branches of old-growth conifers such as Western Hemlock, Sitka Spruce and Douglas Fir, as far as 60 km inland. The female lays one egg on a platform of lichen or moss on these branches (less often on the ground). The egg is incubated for a month and then the hatchling is fed for around 40 days until the chick is able to fledge. The chick then leaves the nest and flies unaccompanied to the sea. Breeding success is low and chick mortality high.
Marbled Murrelets and Humans
The Marbled Murrelet is considered globally threatened, having declined across its range over the last few decades. The biggest threat to the murrelet is the loss of the old growth forest to logging. It was listed as endangered in 1992 by the U.S. Fish and Wildlife Service due to concerns about habitat loss, entanglement in fishing gear and oil spills. The species became a flagship species in efforts to prevent the logging of old-growth forests along the Pacific coast from California to Alaska.