Visual of thick-billed murre colony on cliffs; CU of female brooding egg on ledge (0:32). MSs of numerous murres flying on and off ledges (1:31). CS of herring gull soaring in the wind hovering near cliff with murres flying by, ZOOM OUT to MS (1:35). MSs of numerous murres flying on and off ledges (1:05). LAMCS of researcher on rock face measuring and weighing eggs (1:41).