Line-transect sampling and indices to estimate wintering wood ducks and mallards in Mississippi green-tree reservoirs / David E. Sherman.
Material type:
TextPublication details: Mississippi State, MS : Mississippi State University, 1990.Description: xi, 122 leaves : ill. ; 28 cmOnline resources: Abstract: Line-transect sampling, flying duck counts, and aerial surveys were evaluated for estimating winter abundances (1988-89 and 1989-90) of wood ducks (Aix sponsa) and mallards (Anas platyrhynchos) in 3 Mississippi green-tree reservoirs (GTRs). Density estimates for both species were generated using perpendicular-distance data and a Fourier-series estimator in program Transect II. Across GTRs and years, wood duck and mallard densities ranged from 0.45 to 12.69 ducks/ha and 1.06 to 11.37 ducks/ha, respectively. Coefficients of variation (CV) ranged from 15%to 61% and 27% to 56% for wood ducks and mallards, respectively.Computer simulations revealed that density estimates with CVs<-30%require >15 observations of a duck(s). Line-transect sampling should be conducted when duck numbers are near peak levels. Line-transect sampling costs about $14/km2. Counts of ducks flying into GTRs at dusk and from a helicopter were positively correlated with duck density in the GTRs, but further testing o
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Thesis(M.S.)--Mississippi State University, 1990.
Includes bibliographical references (leaves 84-89).
Line-transect sampling, flying duck counts, and aerial surveys were evaluated for estimating winter abundances (1988-89 and 1989-90) of wood ducks (Aix sponsa) and mallards (Anas platyrhynchos) in 3 Mississippi green-tree reservoirs (GTRs). Density estimates for both species were generated using perpendicular-distance data and a Fourier-series estimator in program Transect II. Across GTRs and years, wood duck and mallard densities ranged from 0.45 to 12.69 ducks/ha and 1.06 to 11.37 ducks/ha, respectively. Coefficients of variation (CV) ranged from 15%to 61% and 27% to 56% for wood ducks and mallards, respectively.Computer simulations revealed that density estimates with CVs<-30%require >15 observations of a duck(s). Line-transect sampling should be conducted when duck numbers are near peak levels. Line-transect sampling costs about $14/km2. Counts of ducks flying into GTRs at dusk and from a helicopter were positively correlated with duck density in the GTRs, but further testing o