Goldeneyes feed during the day on a wide range of invertebrates such as small bivalve molluscs and crabs (5). They are able to dive to depths of 4 meters and can stay submerged for over 30 seconds (6). At the start of the breeding season in late winter and early spring, males can be seen displaying. They throw their heads back over their body whilst producing a growling noise. Several males gather to perform in this way and one or more females will watch. The nest is typically built 10-15 m off the ground in a tree hole or in a specially built nesting box (6). The female lays between 8 and 11 eggs, which are incubated for up to 30 days. The young will have fledged after a further 57 to 66 days (3).