Northern Prairie Wildlife Research Center
The strongest association between duck numbers and wetland sites was recorded for the blue-winged teal, as befits a species with strong pioneering tendencies. The r value obtained for Woodworth was even higher than that found more generally by Johnson and Grier (1988). Numbers of this species also correlated negatively with temperatures in both April and May and positively with precipitation in April. The best regression model included none of these variables; however, it did include May ponds, continental population, and the previous year's count.