Inland Bays Osprey Survey

December 2024

Ospreys of the Inland Bays

The return of ospreys to the Inland Bays is always a welcome sign of spring, but their survival and nesting success is directly linked to the health of the Inland Bays.

Ospreys are important indicators of the health of the Bays because they are at the top of the food chain. In a process called biomagnification, the birds ingest chemicals that may accumulate in the fish that they eat.

Researchers have been tracking data on the number of active eagle and osprey nests around the Bays for decades (eagle surveys began in the late 1980s and osprey surveys began in the early 1990s). In prior years, pesticides greatly impacted these species, and since DDT was banned and the level of pesticides found in the fish they eat has declined, populations have rebounded significantly.

The comeback story of ospreys (and eagles) is truly good news for the health of the Inland Bays.


Survey Goals

The Osprey Survey is conducted every five years. Previous surveys were overseen by the Department of Natural Resources and Environmental Control, which has discontinued their survey efforts several years ago for various reasons. The Center wants to continue to track local osprey populations, even though it is a success story and they’re doing well. Nesting data is an important indicator of the health of the Bays and is used in the Center’s State of the Bays reports released every five years.

What’s it like to do a Survey?

The osprey survey will be conducted by volunteers from land and/or on water! You can walk, kayak, drive, or boat along the assigned survey zone to count active nests and adult osprey pairs.

Volunteers, individually or in small teams, will be assigned to specific areas within the Inland Bays watershed to collect information on the location of nesting sites and the number of actively bonded pairs using individual nesting sites. This survey will not collect information on eggs or hatchlings, and volunteers should use binoculars to participate in the survey.

Assigned sites will be monitored at least twice a month (or more frequently!) by volunteers in April and May when nests are active.

Osprey Survey Zones. To see enlarged images of zones, scroll down to the “Volunteer Resources/Documents” section for additional image options.

Get Involved

Volunteer registration for the 2021 survey season is now closed.

If you would like more information about other volunteer opportunities, fill out the Center’s Volunteer Application. Another way to support the Center’s mission is by donating HERE!

Volunteer Resources/Documents


Additional Osprey Survey Efforts

The Center’s new Volunteer Osprey Survey is NOT a substitution for the Delaware Department of Natural Resources and Environmental Control’s Citizen Osprey Monitoring Program. The Center’s Survey is an additional effort to focus on osprey monitoring in the Inland Bays during the months of April and May.

If you are interested in continuing the monitoring efforts, we encourage volunteers to continue monitoring their nests for the DNREC Citizen Science Osprey Monitoring Program through September by creating a free Osprey Watch account. In June, all volunteers can start entering data from their observed nests using the Nest # or ID that Jodi McLaughlin will have provided during the Center’s Survey efforts. For more information, go to or contact Jordan Brown at