Characteristics of Ponds Used by Breeding Mottled Ducks on the Chenier Plain of the Texas Gulf Coast

Abstract Mottled ducks Anas fulvigula are nonmigratory and primarily depend on habitats associated with coastal marshes of the Gulf Coast for their entire life cycle. Much of remaining available coastal marsh habitats of the Texas Gulf Coast are managed by state and federal agencies. The Texas Gulf Coast breeding population of mottled ducks has recently declined dramatically. To aid in development of management plans for breeding mottled ducks, we estimated the number of potential pair ponds available on the Texas Chenier Plain National Wildlife Refuge Complex relative to marsh type (fresh, intermediate, brackish, and saline), estimated occupancy, compared habitats of used and unused pair ponds, and evaluated pair pond selection relative to marsh type during spring 2004 and 2005. Greater than 18,000 ponds were recorded in >22,400 ha of coastal marsh with >74% of potential pair ponds in the intermediate marsh type. Average pond size of 425 randomly selected ponds across marsh types was 0.09 ha. Pond occupa...