Patuxent River Estuary Winter Waterbird Survey

The objective of this survey is to document the diversity and distribution of waterbirds along the 72 km (45 mile) length of the Patuxent River estuary. This survey takes place annually in early February, a time when migration is at a minimum and those species that are dependent on the estuary are present in large, stable numbers. Volunteers make surveys from about 100 points that are established along the western and eastern shore of the estuary.
The map of the estuary is divided into 8 km segments which we use in our analyses of abundance and distribution.

The graph below shows the distribution of all waterbird species combined (about 40 species) along the length of the estuary. The mid-point of the estuary, from 16 to 40 kilometers (10 to 25 miles) up from the mouth at Solomons, consistently supports the greatest numbers. Ruddy Ducks, Canada Geese, gulls, scaup and Canvasback are some of the abundant species found here every winter. HIghest numbers of Canvasback and Ruddy Ducks on the entire estuary occur near the turbidity maximum zone, near Benedict, close to the Chalk Point Power Plant.

We have also described how waterbirds can be used to develop Indices of Biotic Integrity (IBIs) for assessing wetland functions and values.