Priorities for Future Research

Although the Common Goldeneye is among the best studied sea ducks, especially in Europe, much remains to be learned. Nearly all recent studies of this species’ breeding biology have been conducted on populations breeding in nest boxes. Patterns of behavior and success may vary considerably in natural cavities, but few studies have examined this dimension. As in most birds, the ecology of Common Goldeneyes during the period from fledging to first breeding is virtually unknown. Given that Common Goldeneyes exhibit delayed maturity and may not breed until they are 3–4 years old, this is an especially important period. The winter ecology of Common Goldeneyes is also poorly understood; this is a key period when pair bonds are established and when survival may be strongly influenced by habitat quality and the effects of environmental stress (oil spills, disturbance, changing thermal regimes). Research on the social behavior of Common Goldeneyes (territoriality, infanticide, brood parasitism, and brood amalgamation) has indicated a complex and rich social structure; additional research in these areas may provide new insight into current ecological and evolutionary theory. Finally, recent work in e. North America, Scandinavia, and Russia has shown that Common Goldeneyes respond directly and rapidly to changes in prey quality as a result of environmental degradation. Thus, the Common Goldeneye may prove to be an important bioindicator species to monitor environmental impacts on aquatic habitats, particularly those of the poorly understood boreal regions of North America.