Abstracts

Q.2-14: Use of moist-soil management for wintering waterfowl in fallow rice fields on the upper Texas coast

Michael D. Whitson, Department of Natural Resources Management, Texas Tech University, Lubbock, Texas
Warren C. Conway, Department of Natural Resources Management, Texas Tech University, Lubbock, Texas
David A. Haukos, U.S. Geological Survey, Kansas Cooperative Fish and Wildlife Research Unit, Kansas State University, Manhattan, Kansas
Daniel P. Collins, U.S. Fish and Wildlife Service, Albuquerque, New Mexico
Jena A. Moon, Inventory and Monitoring, U. S. Fish and Wildlife Service, Winnie, Texas
Patrick Walther, Texas Chenier Plain National Wildlife Refuge Complex, U.S. Fish and Wildlife Service, Anahuac, Texas

Presented by Michael D. Whitson - Email: michael.d.whitson@ttu.edu

Abstract: Wetlands on the Texas coast provide important winter habitat for millions of waterfowl, crucial stopover sites for migrating shorebirds, year-round habitats for mottled ducks (Anas fulvigula), and summer breeding habitats for a variety of other avifauna, including fulvous whistling ducks (Dendrocygna bicolor) and black-bellied whistling ducks (D. autumnalis). Moist-soil management (MSM) is effectively used in other regions to improve the quality of wetland habitats by promoting seed and invertebrate production for waterfowl forage through manipulation of wetland hydrology to direct plant community composition towards favored hydrophytic species. The extended growing season on the upper Texas coast, and existing hydrologic infrastructure, provides an opportunity to implement a variety of MSM strategies for waterfowl. We conducted a two-year research project in 21 fallow rice fields (~260 ha) on Anahuac National Wildlife Refuge in Jefferson County, Texas. Fields were subjected to variations in inundation seasonal timing, duration, depth, and drawdown length. We quantified plant community composition, seed production, and winter invertebrate biomass to measure responses to these MSM strategies, estimate waterfowl food production, and duck-energy-days (DEDs). Highly desirable plant species (65%) dominated early-season inundated fields and accounted for 50% of the cover in fields subjected to fast drawdown treatments and 61% cover in fields subjected to slow drawdown treatments. Measured MSM plants produced enough seeds and available metabolizable energy for nearly 20,000 DEDs and biomass from estimated winter macroinvertebrate assemblages could provide metabolizable energy for an additional 45,000 DEDs on our 21 MSM fields. Collectively, these results provides strong support for MSM implementation on fallow rice fields on the upper Texas coast that will provide substantial waterfowl benefits and support regional waterfowl goals.