J. Brian Davis

Wildlife managers commonly use herbicides to control invasive plant species and maintain early-successional vegetation communities in seasonally flooded moist-soil wetlands. However, there is limited information on how herbicides influence plant and animal communities following application. Thus, we investigated the response of vegetation, food density, and the abundance and activities of dabbling ducks (Anatini) to application of imazapyr herbicide in moist-soil wetlands in Tennessee to control invasive alligatorweed (Alternanthera philoxeroides). Imazapyr...

Bottomland hardwood forests in the southeastern United States provide important food and other socio-physiological resources for several wintering duck species. Duck presence and abundance in these wetlands can be influenced by periodicity and extent of flooding, disturbance from anthropogenic activities, and availability and coverage of certain vegetative communities. We tested if presence of flooding, anthropogenic disturbance, and certain vegetation types influenced wintering duck presence and abundance in Delta National Forest (DNF; Mississippi), the only National Forest which is...

Mottled ducks are typically geographically separated into two sub-species: peninsular Florida (Anas fulvigula fulvigula) and the western Gulf Coastal (WGC) (A. f. maculosa). Between 1975 and 1983, >1,200 mottled ducks were introduced to coastal South Carolina primarily from the WGC range. A late summer banding program was initiated in 2008 within the Santee Delta and the Ashepoo, Combahee, and Edisto Rivers Basin in South Carolina to estimate mottled duck survival and harvest probability. We acquired 3,594 banding and 525 recovery records of mottled ducks banded between 2008-2018. We...

The Mississippi Alluvial Valley (MAV) had extensive bottomland hardwood forests but less than 25% of this area remains forested today. Impounded greentree reservoirs (GTRs), have been managed for wintering waterfowl since the 1930s, and provide a source of aquatic invertebrates and acorns for foraging ducks and other wildlife. However, few studies of invertebrate community-composition, diversity, and biomass have been conducted at regional scales. We collected samples of aquatic invertebrates from three hardwood bottomlands in the MAV and one in the Mississippi Interior Flatwoods region...

Rice and natural seeds are important foods for waterfowl in rice growing regions such as the Gulf Coast Prairies of Louisiana and Texas. We conducted a study from August-November 2010 and collected 2,250 soil cores in 50 farmed and 50 idle rice fields in the Louisiana Chenier Plain (CP) and Texas Mid-Coast (TMC) to estimate biomass of waste rice and natural seeds. Estimates are necessary to assess carrying capacity for waterfowl in this region by the Gulf Coast Joint Venture. Waste rice abundance was greatest in CP farmed fields that produced a second crop of rice (i.e., ratoon) and were...

Managers of public lands affording waterfowl hunting strive to provide quality hunting opportunities while supporting biological needs of birds during winter. Understanding responses by mallards (Anas platyrhynchos) to diurnal hunting activities would help shape hunt regimes that satisfy management goals. We examined use of a wildlife management area (WMA) in western Mississippi by 28 radio-marked female mallards when waterfowl hunting season was closed and during the season when none, half, or all of the WMA was hunted during two winters 2010-2012. The proportion of each day that mallards...

Mottled ducks (Anas fulvigula) are endemic to Gulf Coastal United States, Florida, and Mexico. Birds from Florida, Louisiana, and Texas were released in coastal South Carolina from 1975 - 1983, and subsequent banding data suggest a dispersing and increasing population in the state. Because autecology of mottled ducks is little known in South Carolina, we radio-marked 116 females in August 2010 - 2011 in the Ashepoo, Combahee, and Edisto Rivers Basin to assess habitat use throughout the annual cycle. We monitored habitat use by aircraft during fall-winter and via ground reconnaissance...

Rice fields are important agricultural habitats for waterbirds (waterfowl, shorebirds, wading birds) worldwide. In the Texas Mid-Coast (TMC) and Louisiana Chenier Plain (LCP), >167,458 ha of rice are cultivated annually. Precise estimates of abundance of waste grain and natural seeds in harvested and idle rice fields are needed to guide conservation of waterbird habitat in this region, which is part of the Gulf Coast Joint Venture (GCJV) of the North American Waterfowl Management Plan. Our objectives were to estimate and compare waste rice and moist-soil seed abundance among rice...

The American black duck (Anas rubripes) has been declining throughout its range since the 1950s, especially in the Mississippi Flyway. Loss of quality wintering habitat and competition and hybridization with mallards (A. platyrhynchos) have been suggested as factors contributing to black duck decline. Tennessee and Cross Creeks National Wildlife Refuges (NWRs) are two primary wintering areas for midcontinent black ducks recording long-term population declines. To better understand habitat selection and habitat-related survival of black ducks at Tennessee NWR (TNWR), we radio marked 64...

Flooding harvested rice fields in winter provides important ecological services, including benefits to waterfowl, other waterbirds, agronomics, and soil and water conservation. We conducted experiments in six rice fields in Arkansas during winters 2004-2006 to evaluate effects of different post-harvest stubble-management practices and flooding on abundance of dabbling ducks, geese, and waste rice. During both winters, rolled rice paddies attracted the greatest diurnal density of mallards (Anas platyrhynchos; x− = 4.18 birds/ha/survey, SE = 0.36). Burned paddies attracted the greatest...