Rissa tridactyla; kittiwakes are surely the most exciting gulls to observe in their breeding colonies. The noise from the colonies of the screaming gulls is immense. Typically the scream of a bird is "keeteehwah", hence the American English name. In England they are also known as three-toed gulls (similar to the Dutch drieteenmeeuw, also official species name "tridactyla"). On first sight they resemble herring and even more so common gulls. However they can easily be recognized by the all black wing tips (herring/common gulls have white spots in the black wing tips) but even more characteristic are the black legs and feet. None of the gulls on Iceland carry this trait with the exception of the winter visitor the Ivory gull (an all white gull from the high arctic regions). Unlike other gulls they breed on steep cliffs. Contrary to many auks who breed on similar cliffs they do however, make nests on horizontal ledges by cementing grass and sea weeds with saliva to the rocks. They breed all over the north Atlantic. But outside the breeding season they generally leave the coasts for the oceans. A few individuals however stay on Iceland during the winter.