How Do Ospreys Catch Fish? Diving Feet-First Explained

A fish specialist

The osprey is one of the most specialized hunters among birds of prey. Unlike the bald eagle, which also takes waterbirds and carrion and often steals food, the osprey depends almost entirely on live fish that it catches itself.

It is not fussy about the species. Ospreys take pike, perch, trout, carp, suckers, mullet, herring, menhaden, flounder and many others, as long as they swim close to the surface. Typical prey weighs about 150–300 g (5–11 oz) and is about 25–35 cm (10–14 in) long, but ospreys can tackle fish weighing up to about 2 kg (4.4 lb).

Step 1: searching from the air

Most hunting starts with a search flight. The osprey flaps and glides slowly over the water at roughly 10–40 m (30–130 ft), head angled down. Ospreys also hunt from a perch such as a dead tree or post overlooking the water, but searching on the wing is more common.

When it sees a fish, the osprey often stops and hovers on rapidly beating wings, a skill few large raptors have. Hovering keeps the bird in one spot while it judges the fish’s position. Ospreys appear to correct for refraction, the way light bends at the water’s surface and makes a fish look like it is somewhere it is not.

Step 2: the feet-first dive

The bird then tips forward and drops, often in a series of steps, before folding its wings for the final plunge. Just before impact it swings its feet forward so that the talons hit the water first, with the wings held high above the back.

Ospreys usually hit the water with a big splash and may disappear completely below the surface for a moment. Even so, they can only reach about 1 m (3 ft) down, which is why they hunt in shallows and at the surface. Their nostrils can close to keep water out, and their dense, oily feathers resist soaking.

Step 3: gripping a slippery fish

The osprey’s feet are its most remarkable tool.

• Reversible outer toe. The outer toe can swing backward, so the osprey holds prey with two toes in front and two behind. Among raptors, only ospreys and owls can do this.
• Spiny soles. The undersides of the toes are covered in small, sharp, spiny scales called spicules that work like sandpaper on fish skin.
• Barbed scales and long talons. The talons are long, strongly curved and rounded underneath, and backward-facing scales help stop a fish from slipping out.

Step 4: lifting off and carrying the catch

Lifting off from the water with a wet body and a struggling fish is the hardest part. The osprey beats its long wings strongly to rise clear of the surface. Once airborne it often gives a quick shake, like a wet dog, to throw off water.

The bird then arranges the fish so that its head points forward, with one foot ahead of the other. This streamlined position reduces drag on the flight back to a perch or the nest. Ospreys usually eat on a perch near the water, starting at the head. In the breeding season, males often eat part of the fish before delivering the rest to the female or chicks.

How often do ospreys catch a fish?

Ospreys miss many of their dives. Studies in different places have recorded success rates from roughly a quarter of dives to around three-quarters. Success depends on the weather, water clarity, waves, the depth and type of fish, and the bird’s age and experience.

Young ospreys are much less skilled than adults and have to learn by trial and error, because their parents do not teach them. Calm, clear days are best; wind, rain and murky water make fishing harder.

Myths about osprey fishing

An old belief held that fish were so mesmerized by an osprey that they rolled belly-up in surrender. There is no truth in it, as the many missed dives show.

Another popular story says ospreys can lock their talons and are dragged underwater by fish too big to lift. A few such incidents have been reported, but they are rare. Ospreys normally let go of a fish that is too heavy, and if a catch is large they may half-fly, half-paddle it to shore.

Competition and theft

A successful osprey is not always safe with its catch. Bald eagles in North America and other large birds chase ospreys until they drop their fish. Gulls and crows may also harass them. For more about the bird’s life beyond fishing, see where do ospreys nest?