Dryobates borealis (Red-cockaded Woodpecker) is considered a keystone cavity excavator, endemic to the fire-maintained Pinus (pine) forests of the southeastern US. This species excavates its roost and nest cavities in living pines. Larger woodpecker species sometimes enlarge these cavities, rendering the holes unsuitable for the Red-cockaded Woodpecker but suitable for larger cavity-nesting species. Here I report the first record of a Lophodytes cucullatus (Hooded Merganser) nesting in such a cavity at the Brosnan Forest on the Coastal Plain of South Carolina. In previous annual spring censuses, this enlarged Red-cockaded Woodpecker cavity was occupied by Aix sponsa L. (Wood Duck) (3 censuses), Sciurus niger (Fox Squirrel) (2 censuses), and a Pantherophis alleghaniensis (Eastern Rat Snake) (1 census).