The Season of Chesapeake Ospreys

After six months of fall and winter, spring finally arrives to the Chesapeake region. The ospreys slowly return to their nests, waiting for their mates to join them. Their journey from their winter homes in Central and South America is usually a quick two- to three-day flight. They arrive hungry and tired, and immediately start fishing. They may even start to refresh their nest with fresh sticks and branches while waiting for their mates. When their mate arrives, they immediately “reconnect” and get right to work on the nest.

The male usually brings sticks and fish to the female. A decade ago I would observe them only bringing a few species of fish to the nest, but I have seen many different types of fish these past few years – rockfish, white and yellow perch, white shad, catfish, chain pickerel, alewife, pumpkin seed, and eels. I attribute this to cleaner waters in the Bay, and I have noticed clearer water and more grass growing in the shallows. This past year, their favorite catches were chain pickerel and alewife.

I can usually tell when the female is about to lay her eggs, as the male brings mud and leaves and places them in the middle of the nest. The eggs are usually laid the first week in April, and the female diligently incubates them for 38-42 days. She generally lays two or three brown and beige speckled eggs. The male will bring fish to the nest and may even incubate the eggs while the female exercises her wings. The ospreys are extremely protective and instinctual. They will guard the eggs through very challenging conditions such as storms, cold streaks, and even attacks from predators. I have seen females leave the nest when there are no survival options left, but this is a very rare occasion.

In mid-May, the female will start to sit up on top of the nest. This is a sign that the eggs have hatched. The chicks usually hatch a few days apart. The female will gently feed them pieces of fish and will sit on top of them to protect them from the environment and predators. As the chicks grow, they become more active and their feathers start to unfurl. The male brings a steady supply of fish, and the female will vocalize with a steady stream of “chirps” when more food is needed. The young chicks quickly learn the difference between warning chirps and food calls. They will become extremely active if they see Daddy flying nearby with a fish. Sometimes, the male will eat part of the fish before bringing it to the nest.

As the chicks grow to near-adult size, the female will leave the nest and give them space to exercise their wings. She will show them what she wants them to do when they fledge by flying in small circles around the nest. At an age of about six to seven weeks, they will exercise their wings. Eventually, they will jump up and down until they learn to control their lift. Their first flights are usually short and they stay close to home. They still do not know how to fish, so mom and dad have to supply the food. They will spend about a month practicing flight and learning to fish, with mom and dad watching somewhere close by or providing teaching moments.

Ospreys have many unique features. The adults have brilliant yellow eyes that enable them to see into the ultraviolet spectrum of light. This helps them to spot fish a long way off. The chicks are born with orange eyes, which eventually turn yellow. Ospreys also have a protective, translucent membrane that can cover their eyes when they dive for fish. Sometimes called the “third eye,” it is actually called a nictitating membrane. Their wings are “M” shaped, enabling them to dive at faster than normal speeds. They also have a unique white and black feather pattern which is believed to confuse fish. And finally, their outer toe, called a zygodactyl toe, can articulate inward to help hold fish and branches.

As late August approaches, the family is ready to head to their winter homes. The female usually leaves first, with the male staying another two weeks or so to continue teaching the young adults. Then, in early September, the male departs and the kids follow. The waters of the Chesapeake start to fall silent. By late September, almost all of the ospreys have left.

As spring approaches, they return to the same nest to start the cycle all over again.

Here are some historical notes. Ospreys and bald eagles nearly became extinct in the United States prior to the nationwide ban of the pesticide DDT in 1972. The destructive nature of DDT nearly wiped out these raptors, and it has taken decades to reverse its effects. Slowly, ospreys  returned to the Chesapeake Bay region. Today, thanks to aggressive environmental conservation efforts and a much, much cleaner Bay, ospreys and bald eagles are once again flourishing. Today, it is estimated that there are between 10,000 and 12,000 mated pairs of ospreys calling the Chesapeake region their home in the spring and summer. The abundance of ospreys and eagles, the diversity of their nesting substrates, and the abundance and varieties of fish all demonstrate that the health of the Chesapeake is improving.

The Chesapeake region is home to the largest concentration of nesting osprey in the world, and there are many public parks and refuges along the Chesapeake watershed where these beautiful raptors can be observed. The Eastern Shore of Virginia National Wildlife Refuge supports osprey platforms with a live video feed of nesting activity of one platform available in the visitor center during nesting season. Ospreys are common from the spring through the fall at the Blackwater National Wildlife Refuge. They use nesting platforms that have been placed throughout the marsh. At Blackwater, ospreys and eagles are frequently seen competing for fish – sometimes with some dramatic aerial displays. For more than 30 years, Patuxent River Park and Jug Bay Wetlands Sanctuary have conducted scientific research to monitor the local population of ospreys, including installing nest towers and equipping birds with leg bands.

You can also follow ospreys from the comfort of your own home with the Crazy Osprey Family, explore.org and  Chesapeake Conservancy’s webcam. The wildlife web camera chronicles the lives of Tom and Audrey, their mating, nest building, incubating, and chick rearing.

Blackwater National Wildlife Refuge

Blackwater National Wildlife Refuge (NWR), located on Maryland's Eastern Shore, attracts a vast number of waterfowl to model Chesapeake Bay tidal wetlands. While primarily a tidal marsh, the refuge also includes a mature pine forest.

Eastern Shore of Virginia National Wildlife Refuge

The Eastern Shore of Virginia National Wildlife Refuge, located at the mouth of the Chesapeake Bay, contains 1415 acres of maritime forest, myrtle and bayberry thickets, grasslands, and fresh and brackish ponds.

Jug Bay Wetlands Sanctuary

Jug Bay Wetlands Sanctuary, located near the mid-point of the Patuxent River, represents an important network of critical habitats of regional and national importance.

Patuxent River Park Jug Bay Natural Area

Jug Bay Natural Area offers many activities including walking through wetlands, guided boat tours, hiking and horseback riding over eight miles of trails, boating, fishing, camping, hunting, and visiting a museum.