Have you ever seen a sleek, brown-and-white bird hover above the ocean, fold its wings and drop into the water like a cannonball, only to surface seconds later with a fish in its grip? If so, you have probably seen an osprey.
A water-loving bird of prey
Ospreys are birds of prey, also known as raptors. Birds of prey are carnivorous predators that actively hunt and feed on other animals. However, unlike most birds of prey, the osprey’s diet consists of approximately 99% live fish, including catfish, trout and mackerel. Because of their feeding habits, ospreys, also called sea hawks, have unique traits that make them elite hunters of the sea.
Structure and hunting
When ospreys spot a fish, they dive from nearly 100 feet in the air. During the dive, they close their nostrils, called nares, to prevent water from entering.
Ospreys are the only birds of prey that can dive feet-first into water, allowing them to form a streamlined shape that helps them pierce the surface and protect their heads. Their dense, oily feathers act like a wetsuit, keeping them water-resistant during dives.
Once they make contact with prey, they use their reversible outer toes and barbed foot pads, called spicules, to grip the slippery scales of the fish.
After securing their catch, ospreys use their nearly six-foot wingspan to generate the lift needed to carry fish that can weigh nearly as much as they do out of the water.
Finally, once airborne, the osprey rotates the fish to point headfirst, an aerodynamic adjustment that reduces wind resistance on the flight back to the nest.
Get Ocean Updates in Your Inbox
Sign up with your email and never miss an update.
Habitat and breeding
Because of their dependence on fish, ospreys always live within sight of water. They typically build their nests atop dead trees or man-made structures along harbors and bays, such as channel markers, duck blinds and utility poles.
Both parents help construct the nest. These large structures, sometimes exceeding 300 pounds, are built with sticks and lined with materials like moss and seaweed.
Ospreys breed across every continent except Antarctica, inhabiting ocean coastlines, saltwater marshes, lagoons, estuaries, river mouths and even coral reefs.
Osprey pairs incubate an average of three eggs for roughly one month before they hatch. Chicks then remain in the nest for about 55 days before fledging, the stage in a bird’s life when it develops its feathers and wings enough to leave the nest and fly for the first time.
Why are ospreys important for our ocean?
Ospreys serve as living indicators of ocean health. Because they sit at the top of the marine food chain, they are highly sensitive to pollution and changes in fish populations. A decline in osprey nesting success can signal pollution, overfishing or habitat degradation.
That is why at Ocean Conservancy, we are working to address the ocean’s biggest threats, from plastic pollution to the climate crisis. But we cannot do this work alone. We need advocates like you to protect ospreys and all marine wildlife. Please take action and help us defend our ocean today.
