Master of Science (MS)


Forestry, Wildlife, and Fisheries

Document Type



Age ratio estimates obtained annually by the Cooperative Waterfowl Parts Collection Survey (PCS) serve as important estimates of annual waterfowl recruitment. To determine if age and sex ratios are biased due to repeat sampling of hunters across years, I examined PCS data collected from 1991-2000. Mean seasonal harvest increased with number of consecutive years hunters responded to the PCS. Proportions of juveniles in the mallard (Anas platyrhynchos) harvest and harvest of all species combined decreased with increasing seasonal harvest level. Proportions of males in the harvest increased with increasing harvest level. Proportions of juveniles in the harvest of hunters responding to the PCS 3 and 4 consecutive years were slightly lower than proportions in the harvest of hunters responding only once or twice. Proportion of males in the mallard harvest increased with number of years hunters remained in the PCS. Although large sample sizes produced statistically significant effects (P < 0.05) of seasonal harvest and repeat sampling, actual differences in predicted proportions were quite small. My results suggest that age and sex ratio estimates remain relatively unaffected by repeat sampling in the PCS.



Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

Frank C. Rohwer