fall moult where their upper plumage become barred with light grey and white, their head is a pale grey, their underparts white, and legs and feet a pale red. They retain their white wing patch, black beak and red inside their mouth. The call in the breeding season is a high whistle. The red gape is also prominent then. Juveniles and immatures can easily be identified by the spotting of the white wing patch with grey or brown feathers and is easy to see even at far distances in the field. Taxonomy and Evolution There are five listed subspecies of the black guillemot: C. g. mandtii – (Lichtenstein, 1822): northeast Canada to Svalbard to northern Siberia and northern Alaska C. g. arcticus – (Brehm, 1824): northeast United States, southeast Canada and south Greenland to Ireland and Britain, southern Scandinavia and the White Sea C. g. islandicus – (Hørring, 1937): Iceland C. g. faroeensis – (Brehm, 1831): Faroe Islands C. g. grylle – (Linnaeus, 1758): Baltic Sea Distribution and habitat The Black Guillemot is a circumpolar species distributed in the boreal, low arctic and high arctic regions of the north Atlantic and arctic oceans and breeding between 43° and 82°N. The 5 listed subspecies inhabit different parts of this range. In North America they can be found as far south as the Gulf of Maine and New England and across parts of the northern coast of North America as far as Alaska, where they are replaced by the pigeon guillemot in the North Pacific. In Europe and Asia they are found from the British Isles and Northward across the northern coast of Asia. They are one of the few birds to breed on Surtsey, Iceland, a new volcanic island. In the UK it is a fairly common breeding bird in western and northern Scotland and Ireland. In the rest of Great Britain they only breed at St. Bees Head in Cumbria, the Isle of Man and on east Anglesey in north Wales. Approximately 40% of the population breeds in the high arctic where the largest colonies are found, 30% in the low arctic, and 30% in boreal waters. In the winter some of the birds in the high arctic waters are forced south by the winter ice making them seasonal migrants, but in more temperate zones the species is essentially resident. Typically restricted to rocky shores, black guillemots utilize the cliffs,