Frank C. Rohwer

Contrasts of Waterfowl Hunter Surveys: Open Web and Random Mail Surveys Produce Similar Policy Results

We conducted random mail and open web surveys of Louisiana waterfowl hunters following the 2011-2012 season, asking identical questions about waterfowl hunting effort, success, satisfaction, proposed regulatory actions, and demographics. We received 1,096 usable responses to our mail survey, and 1,286 usable responses to an on-line survey that was open for anyone to answer. Respondents to the web survey hunted much more, harvested more ducks, and were somewhat younger; but we noted similarities across survey methods in attitudes toward proposed regulatory actions. Using five variables...


Effects of Backpack Radio Packages on Mass of Captive-reared Mallards Released in Maryland

Radio telemetry has been an invaluable technique to study waterfowl ecology, but impacts of radio packages on ducks have not been experimentally assessed during the non-breeding season. We tested the hypothesis that backpack-style radios with 2 body harness loops influenced the body mass dynamics of 8-week-old captive-reared mallards (Anas platyrhynchos) released in Maryland in August. We attached mock radio packages and visual markers to 477 experimental ducks and visual markers only to 582 control birds. Half of experimental and control birds were released on a tidal marsh and received...


Nest Success and Nesting Habitats of Mottled Ducks on the Mississippi River Delta in Louisiana

Waterfowl management is a major goal at the Delta National Wildlife Refuge, yet there is little information on mottled duck (Anas fulvigula) nesting on the Mississippi River Delta (MRD) in Louisiana to guide management decisions. In 1998 and 1999, we determined nest success and its relationship to sites and habitat types. Average Mayfield nest success for all locations and years was 20.0%. Nest success differed among sites in 1998 and among habitat types in 1999. Greatest nest success (56.7%) was on Mississippi River levee sites and lowest nest success (0.3%) was on canal banks. Most nest...


Habitat Use and Productivity of Mottled Ducks on the Atchafalaya River Delta, Louisiana

We studied nesting habitat selection, nest density, and nest success of mottled ducks (Anas fulvigula) on islands in the Atchafalaya River Delta, Louisiana, 1995-1996. Nesting mottled ducks preferred shrub-moderate habitats and avoided shrub-sparse and marsh habitats. Other habitats were neither preferred nor avoided. Nest densities using non-random plot sampling in 1995 and line-transect sampling in 1996 averaged 3.9 nests/ha and 1.3 nest/ha, respectively. Mayfield nest success estimates on individual islands ranged from 6.0% to 67.1%. The Atchafalaya River Delta is potentially one of the...