Black Guillemots have a very limited breeding range in Alaska. Small colonies exist along the Chacotka Peninsula, Saint Lawrence (unconfirmed) and the North Coast of Alaska. In early spring (mid May to early April) and in fall (mid September on) a few individuals are found annually on Saint Lawrence Island. Very rarely some Black Guillemots will linger around the Seward Peninsula and Saint Lawrence over the summer months. Given this limited Nordic range it is surprising that the species reaches the Pribilofs with any regularity. It is generally believed that in winter Black Guillemots follow the edge of the pack ice south into the Bering Sea. On good ice years the edge of the pack ice can extend south of Saint Paul Island. Black Guillemots are found in one out of every three or four years, generally in late May. As Pigeon Guillemots occur during May and early June in good numbers it is imperative that the clean white underwing of any potential Black Guillemot is seen well. The black wedge that extends into the white wingpatch of Pigeon Guillemots can be very difficult to detect. If your candidate bird is sitting on the water an extended vigil will likely result in the bird undergoing some wing-flapping behavior, showing their underwing color. Most island records come from the harbor breakwall and involve flyby birds.