Arctic sea ducks hardly reach the latitude of Gibraltar today but during the colder moments of the Pleistocene they did. We find them in the fossil record at Gorham's Cave and they speak of the freezing of Atlantic and other northern waters. At times the polar front was positioned at the latitude of Lisbon and icebergs drifted into the Mediterranean past the Strait of Gibraltar. Today, islands like the Farnes in the North Sea are the closest we will get to some of these Arctic species. One of the most spectacular is the Eider.