The marbled murrelet is found both in summer and winter off of the British Columbia coastal waters. Young murrelets are quite distinctive in the black and white plumage that the adults will also adopt for the winter months. White shoulder patches and a white throat distinguish the Marbled Murrelets winter garb. The wintering grounds for the bulk of the population remain a mystery. Adult murrelets are believed to live as long as 25 years because there are few natural threats in their environment.
Human activities can have a serious effect on the population.
The feathers are unusually thick and dense to keep out the cold. The feet are webbed like a duck's, but very small, and are used for propulsion only when the bird swims on the surface. The murrelet uses mostly short dives, which last less than 30 seconds. Often, after a series of dives, it will flap its wings vigorously. This fluffs the plumage and restores the insulating effect of the feathers.