American (Fulica americana) and Caribbean (F. caribaea) coots nested colonially at brackish Southgate Pond, St. Croix, United States Virgin Islands (USVI), following a 50-year rainfall event in mid-November 2003. Breeding occurred during three time periods: seven pairs bred from 6 December to 2 January (early), seven from 17 January to 15 February (middle), and eight from 26 April to 19 May (late) (range of clutch initiation dates = 165 days). Hatching success was high (65.3%), but overall reproductive success was low (27%) owing to poor brood survival. Coots built all but 2 of 22 nests at the water line in sturdy crotches of small, live white mangroves (Laguncularia racemosa); two late nests were built on remnant stubs of dead white mangroves after water levels had sharply declined. Early pairs nested in manglars (islets of one or more mangroves without solid land) farther away from shore and in deeper water than middle or late pairs (65.6 versus 42.1 and 29.0 cm, respectively). Southgate Pond remains the preferred breeding site for coots on St. Croix and the USVI. Coots have also recently nested on St. Croix at seven semi-permanent or permanent, man-made, freshwater ponds where they have probably been overlooked, as coots respond rapidly to changes in water levels at semi-permanent or permanent wetlands. Predominance of non-assortative pairing at Southgate Pond suggests that American and Caribbean coots are morphs of one species.