Ask-A-Naturalist: What do osprey eat?

Written by Emily Ghods, NBC Naturalist 2017
Photos courtesy of Bill Halladay, NBC Naturalist 2014

Ospreys mostly eat fish, which they catch from the water. They dive into the water feet first. Ospreys are extremely successful hunters and will catch a fish one out of every four dives. The largest osprey catch on record weighed 2.5 pounds! They dive fromheights of 30 to 120 feet, and with such force that they are sometimes completely submerged under the water. Most other fish-eating birds of prey cannot fly away after being fully submerged and can only catch fish off of the surface, but ospreys are still able to fly away after getting completely soaked. When they dive under the water, they close their third eyelid, which is also known as a nictitating membrane. This acts as “goggles” for the osprey to see under the water. In addition, they can close their nares, or nostrils, to prevent water from going up their nose as they dive.

Ospreys also are unique in their ability to rotate their caught prey in their talons. They will turn the fish so that it is facing right-side up, with its head forward. This streamlined position makes it easier for them to fly the fish back to their nests. Two of the osprey’s toes face forward, while the other two face backwards, but they can change the configuration of their claws so that three are forward and one is in the back. This, combined with rough barbs on their talons, makes it easier for them to hold onto slippery fish. They are the only hawk in North America that feeds primarily on live fish. If fish are not available, they will eat other small mammals, birds, or reptiles, but they prefer to eat fish whenever possible.