murres

Murres are seabirds in the auk family (Alcidae), comprising mainly two closely related species in the genus Uria: the common murre (Uria aalge) and the thick-billed murre (Uria lomvia). They are medium-sized, dive-oriented birds with a distinctive black-and-white plumage that gives them a tuxedo-like appearance.

They are highly adapted to life at sea. Murres are strong, foot-propelled divers and use their wings to chase prey underwater. Their diet consists primarily of fish and crustaceans, which they capture by pursuit diving to substantial depths. They are typically found along northern oceans, including the coasts of the North Atlantic and North Pacific, where they form large breeding colonies on rocky cliffs and islands during the summer and spend much of the rest of the year at sea.

Breeding occurs in colonies. Murres usually lay a single egg, which is often elongated to reduce the chance of rolling off a slope. Both parents participate in incubation, and the chick is cared for by one parent while the other forages. Eggs and chicks are particularly vulnerable to predation by rats, foxes, and gulls on islands, and adult birds face broader threats from oil spills, fisheries bycatch, and habitat disruption.

Distribution and population trends vary by region and by species. In parts of their range murre populations have declined due to anthropogenic pressures and environmental changes, while other populations remain relatively stable. Conservation efforts focus on protecting nesting sites, reducing oil pollution, and mitigating indirect impacts from fishing and climate change. Murres remain a characteristic feature of northern coastal ecosystems and are notable for their impressive diving abilities and colony-based breeding.