Nest Prospecting by Common Goldeneyes

We studied nest prospecting by Common Goldeneye (Bucephala clangula) females in north-central Minnesota. Adults unsuccessful in nesting, those with broods, and nonnesting yearlings were captured in nests while prospecting. Prospecting began in late May and continued into early July. Active nests received up to 25 prospecting visits per day with most visits occurring between 06:00 and 09:00 CDT. Adults appeared to prospect more (P < 0.05) in nest boxes that had contained successful nests during the current season than in those where nests were abandoned or destroyed or those that were unused. Nestbox status had no apparent effect on prospecting by yearlings. Body mass of prospecting adults that were unsuccessful nesters and yearling nonnesters was similar and was significantly less (P < 0.05) than that of females still incubating nests or those with broods. Our observations support the claim that prospecting females are preparing for the next breeding season, and we suggest that prospecting is a means of confirming information already gained during the current season. Prior knowledge of successful nest sites could explain the preferential use of previously successful nest boxes observed in a Swedish study.