• Mississippi National River and Recreation Area


    National River & Recreation Area Minnesota

2010 Waterbird Survey

Ranger with field scope

A park ranger conducts the waterbird survey.

The Mississippi River is a great place to observe migrating birds. In the Twin Cities, fall migration runs from September through December and spring migration occurs from late February through May.

The National Park Service monitors the distribution and abundance of waterbirds and waterfowl each fall on Pig's Eye and Red Rock Lakes, just southeast of downtown St. Paul, MN (map). Even though they're within the city, and surrounded by industry and a former landfill, these two lakes have a rich marsh habitat that provides valuable food and shelter for birds migrating along the Mississippi Flyway.

The purpose of this study is to better understand our Park's resources, ensure the health of waterfowl and waterbird populations, and to protect these resources for the enjoyment of future generations. Surveys data helps biologists and officials make important decisions about hunting regulations and habitat management. This is the second year we have surveyed here.

What we saw

Twenty-five species of waterbirds were observed on these urban lakes from late September through early December. This included nine species of diving ducks, six species of dabbling/puddle ducks, and several other species of migrating waterbirds, from the towering Great Blue Heron to the inconspicuous Pied-billed Grebe.

Each species of waterbird has its own unique migration strategy, which means that groups of birds arrive at different times. Over a two year study of Red Rock Lake, diving duck numbers peaked during the third week in November, while other waterbirds had more variable migratory peaks. See the graphs below for more details.

Take a closer look at the Pig's Eye and Red Rock Lake survey results for further findings from the 2010 NPS Fall Waterbird Survey season.

Ducks & Geese Graph 2010
The difference in migratory peaks seen here is mainly influenced by numbers of Canada Geese and Mallards. All other diving and dabbling/puddle duck species are included in these numbers. Weather conditions and food supplies, which become increasingly important with the approach of cold weather, can change the timing of migration seasonally or from year to year. Long term continuation of studies like these can provide important information about population and habitat health.
Peak numbers of diving ducks were observed during the 3rd week in November in both 2009 and 2010 survey seasons. Hooded Mergansers are a key species of diving duck on Red Rock Lake along with Buffleheads and Ring-necked Ducks.
Waterbirds Graph
The above graph shows the total number of waterbird species, excluding ducks and geese, over the fall migration period. The large peaks in numbers through mid-to-late October are largely influenced by American Coot populations. Other species included in these counts are the Double Crested Cormorant, Bald Eagle, Great Blue Heron, Herring Gull and Great Egret.

Did You Know?

Coon Rapids Dam

Over 600 men worked around the clock using hand tools, horses and coal powered shovels to build the original Coon Rapids Dam in 1913. The dam was rebuilt between 1995 and 1997.