One of the most numerous birds in the Pribilofs, Common Murres can be found by looking out to sea in any direction around the island, or by visiting any of the cliffs on the south or west coasts. It should be noted though, that virtually anywhere one looks, Common Murres will be outnumbered by their northerly cousins, the Thick-billed Murre. To separate these two species in flight, or on the ground, look for the chocolate brown upperparts (almost black in Thick-billed), long thin all dark bill, rounded upper margin to the white breast and dusky flank streaks of Common Murre. In flight the upperpart coloration is often evident, and in mixed flocks the Common Murres will appear more slender than the accompanying Thick-billeds. On the breeding cliffs the Common Murres tend to congregate on wide ledges, breeding several birds deep, whereas Thick-billeds will tend to be found in long strings of birds on narrower ledges.