Overview of the Diet of Ospreys

The Osprey gets its common name from the latin word ossifragus, which means “bone breaker”. Ospreys (Pandion haliaetus) are commonly referred to as fish hawks. They get this name because most of their diet consists of live fish.  In fact, live fish make up 75 to 90 percent of an ospreys diet. Some scientists prefer to bring that percentage up to 98 percent. Generally it is only when live fish is scarce will an osprey decide to dine on small mammals and sources of live food.

Generally, not just any size fish will do for the osprey. One criteria seems to be that the fish is between a minimum of five to sixteen inches long. Even with this size, it leaves a wide variety of fish open to being a favorite prey for ospreys. Some of the favorite fish on the osprey menu includes a variety of trout species, perch, catfish, flounder, and grey mullet. Some residents close to communities with osprey have reported their koi fish missing. Although it hasn’t been confirmed that ospreys are responsible, residents believe it is a good possibility that koi has been added to the osprey’s list of favorite fish.

Because their diet is mainly live fish, ospreys typically live around water. Rivers, lakes, marshes, mangroves, and the ocean shoreline are some of the osprey’s favorite locations for hunting their prey. The largest concentrated population of ospreys in the world is around Chesapeake Bay. Chesapeake Bay is the largest estuary in the United States. It stretches across six states including Maryland, Virginia, West Virginia, New York, Delaware, and Pennsylvannia.

Ospreys are agile hunters. They will slowly fly along the surface of the water using their keen eyesight to look for fish. Unlike other birds of prey, the osprey can dive into the water to catch fish with surprising accuracy. Because of the osprey’s keen eyesight, they aren’t limited to skimming the water. They can dive from 30 to 200 feet above the water, going in feet first after their prey.

Ospreys have another unique feature that helps them hunt prey. They have an opposable toe. This toe can face backward or forward. When perched this toe helps grab on to the limb or whatever it has landed on. When hunting, this toe can face forward to aid in creating a streamline position for catching and transporting fish and small animals.

Again, when live fish is scarce the osprey turns to small animals for a meal. The osprey has been known to eat other birds, snakes, turtles, and rodents. Regardless, this shows how adaptable the osprey can be when it come to diet and survival.