SHOREBIRD USE ON MISSISSIPPI RIVER POOL 8 DURING THE 2001 EXPERIMENTAL WATER 
LEVEL REDUCTION

Ric Zarwell1, Lara Hill2, Amy Papenfuss2
1Birding Contractor, Lansing, IA 52151  2U.S. Fish and Wildlife Service, Upper 
Mississippi River National Wildlife and Fish Refuge

A weekly shorebird monitoring survey was conducted on lower Pool 8 between June 
11th and September 26th, 2001.  The survey was to determine the migratory 
shorebird use of new habitats created during the drawdown.  Shorebird monitoring 
took place one day per week for 15 weeks.   Twenty-two species of shorebirds and 
1,211 individual shorebirds were observed during this time. Due to weather 
conditions and water flows, the target level drawdown of 1.5 feet was achieved 
for only about 6 weeks, from July 10 through August 14.  During these six 
surveys, 921 (73.3%) of the 1,225 total individual shorebirds were observed, and 
the average number of species observed was 8.3. The other nine surveys 
contributed only 26.7% of the total shorebird observations, and the average 
number of species observed was 4.8.   Even though there are no other surveys for 
comparison, the 2001 data suggests that the water level reduction in Pool 8 
created vital feeding habitat for migrating shorebirds.   This had a positive 
impact on the number of shorebirds, and increased species diversity.  

Keywords: shorebirds, drawdown, Mississippi River