Marbled Murrelet: where and when to see them

The marbled murrelet is a small North Pacific seabird with an unusual connection between coastal waters and terrestrial nesting habitat. Across much of its range, it lays its single egg on a broad, mossy branch in an old tree. In parts of Alaska it also nests on the ground. Its understated appearance conceals a demanding life divided between marine feeding areas and secluded nesting sites.

Size

24–25 cm long

Weight

190–270 g

Lifespan

Not reliably established

Status

Endangered

Murrelets often appear as singles or pairs on sheltered coastal water, floating low and repeatedly disappearing while feeding. Breeding adults commute between the sea and nests, frequently around dawn or dusk. Their swift flights through forest corridors can be difficult to follow. Pairs share incubation and deliver individual fish to the chick, while secrecy and camouflage help reduce the risk of predators finding the nest. They are highly pelagic, spending most of their life at sea, only coming to land to nest. Courtship displays can involve aerial chases and synchronized swimming, though these are rarely observed. Adults are known for their high speed flights, sometimes reaching up to 100 km per hour, particularly when commuting to nests.

• The first widely recognized tree nest was discovered in California in 1974.
• Tree-nesting birds use existing branch platforms rather than constructing a conventional nest.
• The clutch consists of a single egg.
• Alaskan birds can nest on the ground where suitable large trees are absent.

May through August offers long daylight and broadly practical coastal travel in Alaska. Breeding-plumaged birds may be visible from sheltered shores, though distribution varies with food and weather. Some remain in coastal waters outside summer, when access and identification can become harder. The summer months provide the best chance to see birds in their distinctive breeding plumage, which features mottled brown and black tones. During this period, their foraging activities are highest, making them more frequently visible on the water. Observing them requires calm weather for stable viewing from a vessel or shoreline.

Nearshore bays, fjords, channels and protected coastal waters provide feeding habitat. Nesting often requires large old-growth trees with suitable platforms, although treeless ground sites occur in Alaska. This linkage makes both marine conditions and the condition of nearby terrestrial habitat important. Coastal forests up to 80 km inland can provide suitable nesting trees, demonstrating a unique dual dependency on both marine and terrestrial environments. This species primarily uses older growth coniferous trees such as Sitka spruce or western hemlock for nesting platforms. In Alaska, some populations nest on treeless mountaintops or cliffs, offering adaptation to regions with limited old growth.

Small fish such as sand lance, herring and capelin are important, alongside marine crustaceans. Diet varies geographically and seasonally with prey availability. Adults transport fish individually to chicks, making the accessibility and energy content of local prey especially significant during nesting. Prey is typically captured in shallow nearshore waters, often close to kelp beds or other productive marine habitats. Energy rich fish are crucial for provisioning growing chicks, with adults making numerous trips daily. The specific fish species consumed can vary significantly based on local oceanic conditions and prey migrations.

Common name

Marbled Murrelet

Scientific name

Brachyramphus marmoratus

Animal group

Birds

Size

24–25 cm long

Weight

190–270 g

Lifespan

Not reliably established

Status

Endangered

Identification

Compared with Kittlitz’s murrelet, it generally has a longer bill and darker breeding plumage, while nonbreeding birds show a contrasting white neck collar. Its size is similar to a robin, making it a relatively small seabird. The bill is short, stout, and black. In nonbreeding plumage, the white belly extends up into a prominent white collar around the back of the neck.