May 3, 2024: Ospreys return to local nesting sites in spring, refreshing their old nests or building new ones. They gather materials, weave nests, line them with soft vegetation, lay eggs, and then rear chicks. This Osprey was recently seen building up a nest atop a marine crane in Quissett Harbor!

Ospreys, also known as sea hawks or fish eagles, are majestic birds of prey commonly found along coastlines and near bodies of water all over Cape Cod. They typically return to their nesting sites in the spring after migrating south for the winter. The nest-building process for ospreys on Cape Cod follows a fascinating sequence:

1. Return to Nesting Sites: Ospreys usually return to their established nesting sites from their wintering grounds in late March or early April. They are known for their fidelity to nesting sites, often returning to the same location year after year.

2. Selection of Nest Site: Ospreys prefer nesting sites near water bodies, such as along the coastlines, rivers, or lakes. They often choose locations with a good vantage point for hunting and sturdy structures for nest building, such as dead trees, tall poles, or artificial nesting platforms.

3. Gathering Nesting Materials: Once they’ve selected a site, ospreys begin gathering materials for their nest. These materials typically include sticks, twigs, grasses, seaweed, and any other suitable debris found nearby.

4. Building the Nest: Ospreys are skilled builders, and both the male and female play active roles in constructing the nest. They weave together the gathered materials to create a large, sturdy nest platform. Osprey nests can grow quite large over time, sometimes reaching several feet in diameter.

5. Lining the Nest: After the basic structure of the nest is complete, ospreys line it with softer materials such as moss, grass, or other vegetation. This lining provides a comfortable and insulated surface for the eggs and later the chicks.

6. Egg Laying and Incubation: Once the nest is complete, the female osprey lays her eggs, typically 2-4 eggs per clutch. Both parents take turns incubating the eggs, which usually hatch after about 5-6 weeks.

7. Rearing Chicks: After hatching, the parents continue to care for the chicks, bringing them food and protecting them from predators. The chicks grow rapidly and eventually fledge the nest after about 8-10 weeks.

8. Post-Breeding Season: After the breeding season, ospreys may abandon their nests until the following spring, though they often return to the same nesting site in subsequent years.

Throughout this process, ospreys demonstrate remarkable nesting behavior, contributing to their status as one of nature’s most impressive avian engineers.