Marbled Murrelet

The Marbled Murrelet is a small, secretive seabird with an unusual and long-mysterious breeding habit: rather than nesting in colonies on cliffs or in burrows like most auks, it nests solitarily on wide, moss-covered branches high in old-growth conifer trees, sometimes many kilometers inland. In breeding plumage, birds are mottled dark brown overall, providing effective camouflage against tree bark and moss, while in winter they show a cleaner black-and-white pattern more typical of other small auks.

The species' reliance on ancient forest for nesting, combined with its use of nearshore marine waters for feeding, makes it an important indicator of the health of both old-growth forest and coastal marine ecosystems.

Key field marks

• Small, compact body with a short bill
• Mottled dark brown "marbled" plumage in breeding season
• Black-and-white pattern in non-breeding plumage, with a white scapular stripe
• Fast, direct flight low over the water

Similar species

• Long-billed Murrelet, a rare Asian relative, is very similar but slightly larger with subtle plumage differences and a longer bill; it is a rare vagrant elsewhere.
• Cassin's Auklet is similarly small but plainer grey overall, lacking the murrelet's mottled brown breeding plumage.
• Winter Marbled Murrelets can resemble small murres or guillemots at a distance but are much smaller and stockier.

Marbled Murrelets forage in nearshore marine waters along the North Pacific coast from California north through Oregon, Washington, British Columbia, and into southern Alaska, typically staying within a few kilometers of shore. Uniquely among seabirds, they fly inland, sometimes over 50 kilometers, to nest in old-growth or mature coniferous forest, selecting large trees with wide, moss-covered branches suitable for their unusual nesting habit.

The species does not undertake long-distance migration, but does shift somewhat between nesting and wintering areas along the coast, generally remaining within the broader North Pacific coastal region year-round.

Behavior

Marbled Murrelets commute between coastal feeding waters and inland forest nest sites, often flying at dawn or dusk under cover of low light to avoid predators, and their unusual nesting habits kept their breeding sites unknown to science until relatively recently.

Voice

A distinctive sharp, nasal "keer" call is given in flight, especially near forest nest sites and over water.

Feeding

Small fish and invertebrates such as krill are caught by diving in nearshore marine waters, with adults sometimes flying long distances inland to deliver a single fish to their chick.

Nesting and breeding

A single egg is laid directly on a wide, moss-covered branch high in an old-growth conifer, without any nest structure; both parents share incubation duties, commuting individually between the nest and coastal foraging areas to feed the chick.