The Common Murre:
Masters of the Sea Facing Modern Perils
The Common Murre (Uria aalge), often mistaken for a penguin due to its tuxedo-like black-and-white plumage and upright posture on land, is a remarkable seabird adapted to the harsh realities of northern oceans.
This large auk, measuring 38–46 cm in length with a wingspan of 61–73 cm, inhabits the low-Arctic and boreal waters of the North Atlantic and North Pacific.
Unlike true penguins, murres can fly, though their flight is labored, requiring rapid wingbeats to stay aloft. They are, however, exceptional swimmers, using their slender wings like flippers to "fly" underwater in pursuit of prey.
Common Murres are circumpolar in distribution, found along rocky coasts from Alaska to California in the Pacific, and from eastern Canada to Europe in the Atlantic. They spend most of their lives at sea, venturing far offshore over continental shelves, but return to land only for breeding.
Permanent residents in many areas, northern populations migrate south in winter to avoid ice, reaching as far as New England or southern California. In breeding season, they favor steep coastal cliffs, islands, and sea stacks, often nesting in mixed colonies with other seabirds like puffins and storm petrels.
Physically, breeding adults sport a sleek black head, back, and wings contrasting with white underparts, a thin dark bill, and gray legs. In non-breeding plumage, the face whitens with a dark streak behind the eye.
Weights range from 775–1,250 grams, with northern birds heavier. Some Atlantic populations feature "bridled" individuals with white eyerings, more common northward. After breeding, both sexes molt and become flightless for 1–2 months, relying on swimming for survival.
Behaviorally, murres are social and gregarious, forming dense colonies where nests pack so tightly that adults touch neighbors. They communicate via soft purring, guttural croaks, and higher bleats, creating a cacophonous symphony at breeding sites.
As pursuit-divers, they plunge to depths of 180 meters, staying submerged up to two minutes, though most dives are shorter and shallower. They forage alone or in flocks, often with other species, traveling up to 100 km from colonies if needed.
On land, they're clumsy, but at sea, they're agile predators.
Their diet consists primarily of small schooling fish like capelin, sand lances, herring, cod, and anchovies, supplemented by crustaceans, squid, marine worms, and mollusks.
Adults consume 20–32 grams daily, catching prey underwater and often eating it there, except when feeding chicks. They use sharp tongues and mouth denticles to grip slippery fish. Breeding is a highlight of murre life.
Monogamous pairs form at 4–5 years old, nesting in colonies without building structures—laying a single pear-shaped egg directly on bare rock to prevent rolling off cliffs.
Eggs vary in color from whitish to green with blotches, aiding parental recognition. Both parents incubate for 28–37 days, swapping shifts.
Chicks hatch downy, leaving the nest at 15–25 days by fluttering to sea, where fathers care for them until flight at 50–70 days.
Conservation status is concerning. Globally, populations were estimated at 12–18 million, but recent events have decimated numbers. A 2014–2016 marine heatwave, "the Blob," caused widespread starvation, killing about 4 million murres in Alaska—half the local population and the largest single-species die-off in modern history.
Colony sizes dropped 52–78% with no recovery by 2024, linked to food web disruptions from warmer waters. Threats include climate change, oil spills, overfishing, gill nets, pollution, and historical egg harvesting.
In Newfoundland, legal hunting persists, and human disturbances at colonies reduce breeding success. As sentinels of ocean health, Common Murres highlight the fragility of marine ecosystems amid climate change.
Protecting forage fish stocks, reducing pollution, and mitigating warming are crucial. With their resilience tested, these "flying penguins" remind us that ocean conservation is vital for all life dependent on the sea.
Nautical Mile Magazine
