The Common Murre is distributed around the north Atlantic and north Pacific with breeding colonies mainly on rocky cliffs around the coast. They are usually in very large colonies such as the one on Westray shown in the last two photos. This has a population of about 60,000 birds. They spend much of the year at sea and some immatures spend all the year at sea.
Some of the birds are of the "bridled" variety showing a thin white line encircling the eye and extending along the furrow behind the eye. Photos 2 and 10 show "bridled" birds. These become more numerous further north. A survey in Orkney in the 1980s showed that about 10% of Common Murres in that area were "bridled".
Common Murres lay their eggs on ledges such as those formed on sedimentary rocks around the coasts of Scotland. There is no nest as such but the eggs are very pointed at one end in order to minimise the possibility of falling off the ledge. There is only one egg in a clutch and the young birds leave their ledge before they are fully fledged which is one reason why the colonies are mainly on vertical cliffs. The young can just fall into the sea where they are accompanied by the male parent for about 12 weeks before they set out on their own (see photo 5).