Marbled Murrelets: An In-Depth Look at These Elusive Seabirds

A marbled murrelet in Alaskan waters | John Yunker

Few North American seabirds live a life as unexpected as the Marbled Murrelet. At first glance, this compact auk seems perfectly at home on the cold waters of the Pacific, diving beneath the surface in search of small fish. But when breeding season arrives, many Marbled Murrelets leave the ocean behind, fly deep into coastal forests, and settle onto massive moss-covered branches high above the forest floor.

For decades, scientists knew surprisingly little about where these secretive birds nested. Their elusive behavior, solitary nesting habits, and preference for enormous old-growth trees made their breeding life extraordinarily difficult to study. Even today, the Marbled Murrelet remains one of the most fascinating links between the marine environment and the ancient forests of the Pacific Coast.

🐦 Marbled Murrelet Overview

The Marbled Murrelet (Brachyramphus marmoratus) is a small seabird belonging to the auk family, Alcidae, making it a relative of puffins, guillemots, murres, and auklets.

Most members of this family breed in colonies on rocky cliffs, islands, or coastal ledges. The Marbled Murrelet breaks that pattern dramatically. Across much of its range, it travels inland to nest alone in mature and old-growth coastal forests.

At sea, the species can be easy to overlook. It is roughly robin-sized, sits low in the water, and often appears alone, in pairs, or in relatively small groups rather than enormous seabird colonies. Its rapid wingbeats and compact body make it surprisingly fast in flight.

⚡ Marbled Murrelet Fast Facts

Fact	Details
Common Name	Marbled Murrelet
Scientific Name	Brachyramphus marmoratus
Bird Family	Alcidae
Bird Order	Charadriiformes
Type	Seabird / auk
Length	About 9.8–11.4 inches (25–29 cm)
Wingspan	About 18–20 inches (45–50 cm)
Weight	About 7.1–8.8 ounces (200–250 g)
Range	Pacific Coast of North America from Alaska and western Canada south into California
Primary Habitat	Nearshore marine waters and mature coastal forests
Diet	Small fish, krill, and other marine invertebrates
Nest	Usually a mossy platform on a large old-growth tree limb; ground nesting also occurs in parts of Alaska
Eggs	Usually 1
Global Conservation Status	Endangered
U.S. Federal Status	Threatened in Washington, Oregon, and California

Size measurements are consistent with descriptions from Audubon, while federal wildlife agencies describe the species as a small, robin-sized diving seabird.

🔬 Scientific Classification

Classification	Marbled Murrelet
Kingdom	Animalia
Phylum	Chordata
Class	Aves
Order	Charadriiformes
Family	Alcidae
Genus	Brachyramphus
Species	Brachyramphus marmoratus

The family Alcidae contains specialized marine birds adapted for pursuing prey underwater. Although their wings propel them through the air, they also use those wings to effectively “fly” beneath the ocean surface.

🔎 How to Identify a Marbled Murrelet

Identifying a Marbled Murrelet can be challenging because its appearance changes considerably with the seasons.

Breeding Plumage

During the breeding season, adults are covered in mottled brown plumage. The irregular pattern of chocolate-brown, tan, and pale markings gives the bird the “marbled” appearance responsible for its common name.

This coloration may appear surprisingly plain for a seabird, but it provides excellent camouflage when a murrelet is sitting among moss, lichens, and shadowy branches in an old-growth forest.

The bird has a compact, somewhat chunky body, a short neck, pointed wings, a short tail, and a relatively slender dark bill. Males and females look very similar.

Nonbreeding Plumage

Outside the breeding season, Marbled Murrelets undergo a striking transformation.

Their upperparts become dark gray to nearly black, while the underside becomes bright white. A noticeable white collar around the neck can be particularly helpful for identification. The face remains dark around the eye, creating a contrasting black-and-white appearance.

From a distance, a nonbreeding Marbled Murrelet can look like a very small black-and-white auk floating low in the water.

Identification in Flight

In flight, watch for an extremely rapid wingbeat. Marbled Murrelets often fly low over the ocean, and birds traveling between their marine feeding areas and inland nesting forests may move quickly overhead.

Their flight can seem almost insect-like because their relatively small wings beat so rapidly.

🌎 Range and Habitat

Marbled Murrelets inhabit the Pacific Coast of North America, with populations extending from Alaska through British Columbia and south through Washington, Oregon, and California.

Their lives revolve around two radically different ecosystems.

For most of the year, the birds are associated with coastal marine environments. They commonly forage in bays, inlets, channels, tidal areas, and nearshore ocean waters. The U.S. Fish and Wildlife Service notes that marine feeding areas are often within roughly 1.2 to 3 miles of shore and frequently in water less than 100 feet deep.

During the breeding season, however, many birds commute inland to forest nesting sites.

These forests tend to be moist, mature coastal forests containing very large trees with broad limbs. Important nesting trees can include Douglas-fir, western hemlock, western redcedar, Sitka spruce, Alaska yellow cedar, and coast redwood.

🌲 The Remarkable Old-Growth Nests of Marbled Murrelets

The nesting habits of the Marbled Murrelet are what truly set this species apart.

Instead of gathering twigs, grass, or other materials and constructing a conventional bird nest, a Marbled Murrelet usually lays its egg directly onto a naturally occurring platform on a large tree branch.

Moss, lichens, accumulated needles, or other organic material may create just enough of a depression to hold the egg.

The trees providing these platforms are often extremely old. Mature forests offer the massive horizontal limbs, complex canopy structure, moss growth, and sheltered conditions that younger forests often lack.

In Washington, nests have been documented as far as 53 miles inland from marine waters, demonstrating the extraordinary commute some murrelets may undertake between their ocean feeding grounds and forest nesting areas.

In parts of Alaska where suitable large trees are absent, Marbled Murrelets may also nest on the ground, including rocky slopes and other sparsely vegetated locations.

🥚 Breeding and Life Cycle

Marbled Murrelets are remarkably secretive breeders.

Rather than gathering in noisy nesting colonies like many other seabirds, they generally nest as isolated pairs. This solitary behavior contributed to the mystery surrounding their breeding biology.

A female normally lays a single egg.

Both parents participate in incubation, taking turns that can last approximately 24 hours. The egg is incubated for around a month, with adults often exchanging duties during periods of low light or darkness.

Once the chick hatches, both parents bring food from the ocean to the nest. Instead of carrying a crop full of food, the adult generally transports individual fish crosswise in its bill.

The young bird grows rapidly.

At roughly four weeks of age, it leaves the nesting platform and makes one of the most dangerous journeys of its life: its first flight from the forest toward the ocean.

There is no gradual progression of hopping between branches or following its parents down the tree. The juvenile must essentially launch itself into flight and head toward suitable water.

That extraordinary first journey illustrates just how closely the survival of this seabird is tied to both healthy forests and a productive ocean.

🐟 What Do Marbled Murrelets Eat?

Marbled Murrelets are primarily carnivorous and feed on small marine animals.

Common prey can include:

Sand lance
Herring
Capelin
Smelt and other small schooling fish
Krill and euphausiids
Amphipods
Mysids and other crustaceans

Their exact diet changes according to location, season, and the availability of prey.

Like other members of the auk family, Marbled Murrelets are excellent underwater hunters. They dive beneath the surface and propel themselves with their wings, pursuing prey through the water much as they fly through the air.

They frequently forage relatively close to shore, particularly around productive coastal areas where currents concentrate small fish.

🌊 Life at Sea

When Marbled Murrelets are not breeding, nearly everything important in their lives happens on the water.

They feed, rest, preen, molt, and interact with other murrelets in the marine environment. Birds are frequently seen in pairs or small groups rather than the enormous rafts formed by some colonial seabirds.

They can be particularly associated with tidal rips, river mouths, kelp edges, bays, and other locations where currents and underwater structure concentrate prey.

Their ability to disappear beneath the surface can make watching them frustrating—and rewarding. One moment a murrelet may be bobbing quietly in the water, and the next it has vanished beneath the waves.

🪽 Calls and Behavior

Marbled Murrelets are vocal both near their nesting forests and at sea.

One commonly described call is a clear, plaintive “keer” or series of similar notes. Their vocalizations can sometimes reveal the presence of murrelets flying through forests before the birds themselves are visible.

In breeding areas, researchers often conduct surveys around dawn when adults may be traveling between the forest and the ocean.

Because actual nests are so difficult to find, simply observing murrelets flying above or through a forest can provide important evidence that suitable nesting habitat is being used.

🔭 Where to See Marbled Murrelets

For most birdwatchers, looking for Marbled Murrelets at sea is much easier than trying to find them in a forest.

Good areas include protected coastal waters throughout the Pacific Northwest, British Columbia, and Alaska.

The Olympic Peninsula in Washington, coastal British Columbia, southeast Alaska, and portions of the northern and central California coast can all provide opportunities.

Look beyond the kelp line, around tidal rips, and near river mouths. A spotting scope can be particularly helpful because these birds are small and may remain some distance offshore.

Trying to locate an active nesting site is another matter entirely. Murrelet nests are difficult to detect and can be sensitive to disturbance, so birdwatchers should observe suitable forest habitat responsibly rather than attempting to approach known nests.

Marbled Murrelet swimming in the sea. they are small seabird that breeds in old-growth evergreen forests, sometimes far from the coast. | 2009fotofriends

🔄 Marbled Murrelet vs. Similar Birds

Several related seabirds can create identification challenges.

Kittlitz’s Murrelet

Kittlitz’s Murrelets overlap with Marbled Murrelets in Alaska. Both are small diving seabirds and can appear similar at a distance.

Careful attention to facial pattern, plumage, bill shape, and location can help separate them.

Long-Billed Murrelet

The Long-billed Murrelet is closely related and was once considered part of the same species. Its normal range is primarily in northeastern Asia, although occasional individuals have appeared in North America.

Other Auks

Small auklets can also appear similar at long range, particularly when observers see little more than a dark bird sitting low on rough water.

Plumage pattern, bill shape, body proportions, behavior, and location are all important clues.

⚠️ Why Are Marbled Murrelets Endangered?

The unusual lifestyle that makes the Marbled Murrelet fascinating also makes it vulnerable.

The species depends on two ecosystems at once. It needs productive marine habitat for feeding and suitable nesting habitat on land.

Loss of Old-Growth Forest

Historic logging and continued loss or modification of mature coastal forests have removed substantial amounts of potential nesting habitat.

Suitable murrelet nesting characteristics can take a very long time to develop. The U.S. Fish and Wildlife Service notes that approximately 100 to 250 years may be required for forests to develop the structures associated with murrelet nesting habitat.

Forest Fragmentation

Even when old trees remain, breaking large forests into smaller fragments can reduce habitat quality.

Forest edges may alter temperature, humidity, and other conditions surrounding nesting areas. Fragmentation can also make nests more accessible to predators.

Nest Predators

Eggs and chicks may be taken by predators such as corvids, including ravens, crows, and jays.

Human activity around campgrounds, roads, and developed areas can sometimes increase food opportunities for these predators, potentially increasing pressure on nearby murrelet nests.

Changes in the Marine Food Web

Murrelets also depend on abundant, appropriately sized fish.

Changes in ocean temperatures, currents, prey abundance, and the marine food web can affect how much food is available to both adults and chicks. Climate change is therefore an increasingly important concern.

Oil Spills and Marine Pollution

Because Marbled Murrelets spend so much time on nearshore waters, oil spills can be especially dangerous.

Oil can directly harm birds by coating their feathers, destroying the insulation and waterproofing that seabirds require for survival. Pollution can also affect the fish and invertebrates on which they depend.

Fisheries Bycatch

Murrelets can become entangled in fishing gear, including gillnets, and drown underwater.

Although regulations and changes to fisheries have reduced some of these risks, accidental bycatch remains part of the broader collection of threats facing the species.

🛡️ Conservation Status

The Marbled Murrelet is considered Endangered globally.

In the United States, the population in Washington, Oregon, and California has been federally listed as Threatened under the Endangered Species Act since 1992. A U.S. Fish and Wildlife Service five-year review released in 2024 concluded that the population continues to meet the definition of a threatened species.

In Canada, where the species occurs primarily along the coast of British Columbia, the Marbled Murrelet is also designated Threatened under federal conservation programs.

Protecting the species involves preserving and restoring nesting forests while also maintaining healthy coastal marine ecosystems.

🌿 Why Marbled Murrelets Matter

The Marbled Murrelet is more than an unusual bird. It is an extraordinary example of how ecosystems that appear completely separate can actually be connected.

An old Douglas-fir standing miles from the ocean and a school of tiny fish moving through a coastal bay may seem to have very little in common.

To a Marbled Murrelet, both are essential parts of home.

Protecting murrelets therefore means thinking beyond individual nesting trees. Large blocks of mature forest, healthy watersheds, productive coastal waters, sustainable fisheries, and functioning food webs all play a role in the species’ future.

The murrelet is a reminder that conservation rarely stops at the edge of a single habitat.

💡 Fascinating Marbled Murrelet Facts

Their nesting habits remained a mystery for generations. Although the species had been known to science since the 18th century, the first widely recognized tree nest in North America was not discovered until 1974.

They belong to the same family as puffins. Both Marbled Murrelets and puffins belong to Alcidae.

They effectively fly underwater. Their wings provide propulsion while pursuing fish beneath the surface.

Their plumage changes dramatically. Breeding birds are mottled brown, while winter birds become sharply patterned in black, gray, and white.

They normally lay only one egg. That low reproductive output means successful breeding is especially important for maintaining populations.

Some commute remarkable distances. Nesting murrelets may fly many miles inland from the ocean every day.

They don’t need a conventional nest. A suitable moss-covered platform on a huge tree limb may be enough.

❓ Frequently Asked Questions

Is a Marbled Murrelet a puffin?

No, but it is closely related to puffins. Both belong to the auk family, Alcidae, along with murres, guillemots, and auklets.

Where do Marbled Murrelets live?

They occur along the Pacific Coast of North America from Alaska and British Columbia south through Washington, Oregon, and California. Most of their lives are spent in coastal marine waters, while breeding birds may travel inland to forest nesting sites.

Do Marbled Murrelets really nest in trees?

Yes. Across much of their range, they nest on broad limbs high in mature or old-growth coniferous trees. Ground nesting also occurs in portions of Alaska.

How high are Marbled Murrelet nests?

Nest height varies considerably, but tree nests may be many dozens of feet above the forest floor. Large branches, deformities, and moss-covered platforms are particularly important.

What do Marbled Murrelets eat?

Their diet consists mainly of small fish and marine invertebrates, including sand lance, herring, capelin, krill, amphipods, and similar prey.

How many eggs does a Marbled Murrelet lay?

Normally just one egg is produced during a nesting attempt.

Why are Marbled Murrelets difficult to study?

They spend most of their lives at sea and nest individually in enormous coastal forests, often high in the canopy. Their quiet, secretive nesting behavior can make an active nest extremely difficult to detect.

Are Marbled Murrelets endangered?

The species is classified as Endangered globally. The Washington, Oregon, and California population is federally listed as Threatened in the United States, while the species is also designated Threatened in Canada.

🪶 A Seabird That Depends on Ancient Forests

The Marbled Murrelet challenges almost every expectation of what a seabird should be.

It dives through Pacific waters for fish, flies miles inland beneath the cover of dawn and dusk, lands high in centuries-old trees, and raises a single chick on little more than a bed of moss.

That extraordinary lifestyle also leaves the species dependent on a delicate combination of conditions that can take generations to create. Ancient forests must remain standing, coastal waters must remain productive, and the long route connecting the two must continue to function.

For birdwatchers, the fleeting sight of a tiny Marbled Murrelet floating beyond a Pacific shoreline may not initially seem dramatic. Knowing the remarkable journey behind that little bird makes the encounter entirely different.