Distribution and Abundance The Platte River Valley is an important early spring staging area for the midcontinent populations of mallards, white-fronted geese and Canada geese. Several thousand mallards and Canada geese also winter along the River. Spring migration begins in late February and early March with the exact arrival date dependent on weather conditions and availability of open water. Waterfowl tend to utilize the Platte River early in the season and move to the Rainwater Basin Area when it becomes ice-free. Mallards and Canada geese account for most of the winter waterfowl use on the study area.
Largest numbers occur during years of mild weather and little snow cover.
Mallard distribution and abundance during the winter months of 1979 and 1980 are shown in Appendix E . The distribution of mallards varies with the extent of ice-free riverine habitat. Milder weather during the following winter caused much of the river channel to remain open. Mallards were more dispersed along the River during the 1979-80 winter but the major concentration remained in the Overton area. The primary wintering sites are between Gibbon and Lexington with the highest numbers of geese occurring between Elm Creek and Lexington where warm water discharge from power plants adjacent to the Tri-County Canal maintains open areas throughout the winter months.