SEAFWA 2018

AUTHORS: Alex D. Davis, J. Brian Davis – Mississippi State University; Richard M. Kaminski, Clemson University; Scott E. Stephens, Ducks Unlimited Canada.

ABSTRACT: Use of artificial nesting structures (hereafter, nest boxes) for wood ducks (Aix sponsa) have a storied history in North America. Nest boxes are often used by other species of cavity-nesting birds, including hooded mergansers (Lophodytes cucullatus). Previous experiments using conventional-sized and small experimental nest boxes (approximately half the size of conventional boxes) at two sites in Mississippi documented variable use and wood duck duckling survival relative to box size, study area, time of breeding season, and other factors. Herein, we report preliminary results for shared use of next boxes by wood ducks and hooded mergansers at Noxubee and Yazoo National Wildlife Refuges in Mississippi, monitoring them at both areas from 1994-1997. At Noxubee, we found 460 total nests in 122 nest boxes, and 356 (77%) nests were successful. Of the successful nests, 87 (~25%) contained eggs of both duck species. At Yazoo, we found 423 nests in 77 nest boxes, and 259 nests (61%) were successful. Of the successful nests, 25 nests (~10%) contained eggs of both species. These results are preliminary; however, the number of shared nests for these species in this four-year study represents some of the greatest reported in North America. Ongoing analyses will explore clutch sizes and other metrics among all nests, and in large and small next boxes on both refuges. These results will provide some basis for exploring potential consequences of shared use of nest boxes given the differences in life history between these cavity-nesting Anatids in these southern wetlands.