Harvest Distribution and Survival of a Gadwall Population

Gadwalls (Anas strepera) were trapped and banded in northcentral Colorado from July through September in 1975-85. Bands were recovered primarily near the area of banding and in central and coastal Texas, northern Utah, along the east and west coast of Mexico, and in the Interior Highlands of Mexico. Six percent of the adult males and 7.4% of the adult females were recaptured in subsequent years, most on the wetland where they were originally banded. We used models that treated both recaptures and recoveries to estimate survival, recapture and recovery rates, and fidelity to the banding area. Estimates of recovery and recapture rates were 2.14 ± 0.16 (SE) % and 4.21 ± 0.35% for adult males and, 1.86 ± 0.19% and 5.80 ± 0.62% for adult females. Mean survival rates were 75.24 ± 5.43% and 69.03 ± 6.51% for adult males and females, respectively. The annual return of adults to the banding area reflected a fidelity to local wetlands for breeding and to nearby reservoirs for molting.