Effects of Human Disturbance on Success of Artificial Duck Nests

Abstract

Waterfowl management on the breeding grounds focuses on improving nest success. Gauging the success of habitat management often depends on measures of nest success, yet the effect of researchers on nest failure is not well known. We used artificial duck nests to determine the effect of human disturbance on nest success in the Prairie Pothole Region in southwestern Manitoba, Canada. We created nests with and without human trails leading to them in 3 types of cover: wetland edge, dense nesting cover, and roadside right-of-way. In wetland edges, nests with trails were depredated more often (P = 0.003) than nests without trails during 1993 but not 1994 (P = 0.317). In roadside right-of-way habitat during 1993, rates of nest destruction did not differ (P = 0.072) between nests with and without trails. In 1994, however, nests in roadside right-of-way habitat with an observer's trail were preyed upon more often than nests without trails in 2 trials (Trial 1: P = 0.025; Trial 2: P = 0.003). In dense nesting cover, predation of nests was not affected by presence of observer trails in either 1993 (P = 0.439) or 1994 (P = 1.000). We placed duck feces on artificial nests, which were then depredated more often (P = 0.020) than nests without such odors. We also found nests created with damaged eggs were depredated substantially more often (P < 0.001) than nests without damaged eggs. Our work demonstrates increased egg losses associated with duck feces and cracked eggs, but the effects of a human trail to the nest were equivocal.