With their large, hooked beaks and sharp talons, eagles are well-equipped for catching fish But does their diet consist solely of aquatic prey? Or do these raptors fish for only part of their food? Let’s dive into the details of what different eagle species eat.
Eagles fall into four main groups: sea eagles, fish eagles, snake eagles, and booted eagles. This highlights how not all eagle species rely on fish as their staple food. While fish comprise the bulk of many eagles’ diets, they supplement with other prey when needed.
Sea Eagles – The Piscivores
Sea eagles live along coasts and rivers to be near water-based prey. Their diet consists mainly of fish giving them the name “piscivores.”
The bald eagle and Steller’s sea eagle are two prime examples. Here are some key facts
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Bald eagles are opportunistic feeders. Fish comprise 70-90% of their food, especially spawning salmon. They also eat small mammals, waterfowl, turtles, and carrion.
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Steller’s sea eagles feed almost exclusively on fish like salmon, trout, and pollock. Over 90% of their diet is fish.
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Sea eagles frequent shorelines, estuaries, and large water bodies to find fish. Some steal catches from ospreys and other birds.
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Sharp talons and backward-facing spikes on their tongues help sea eagles securely grasp slippery fish.
So for eagles specializing in coasts and rivers, fish are certainly the main course. But they supplement with other prey based on availability.
Fish Eagles – The Aquatic Hunters
Fish eagles derive most of their diet from freshwater sources, not the ocean. African fish eagles and Asian grey-headed fish eagles exemplify this group.
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Fish comprise over 75% of their diet. They favor catfish, perch, and carp found in lakes, rivers, and wetlands.
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Birds, reptiles, amphibians, small mammals, and carrion round out their menu.
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Hunting perches overlook waterways where fish eagles can spot aquatic prey. Their toes and talons are ideal for snatching fish.
While dependent on waterways, fish eagles are less selective in their fish preferences than sea eagles. They readily exploit whatever freshwater species are locally abundant.
Snake Eagles – The Reptile Raiders
In contrast to fish-centric eagles, snake eagles target land-based prey, especially reptiles. The Philippine snake eagle demonstrates these raptors’ preferences:
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Over 85% of its diet is snakes like cobras, vipers, and pythons. Snakes are easier for snake eagles to find and catch than fast-swimming fish.
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Lizards, amphibians, small mammals, and insects comprise the rest of its prey. Fish are rarely taken.
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Forested habitats rich in reptiles are this eagle’s prime hunting grounds. It lacks the fish-grasping feet of sea/fish eagles.
For snake eagles, forests supersede shorelines for finding food. Thanks to snakes’ slow speed on land, they make far easier quarry than fish.
Booted Eagles – The Generalists
This versatile eagle group exhibits the most diverse diets. Booted eagles like the African hawk-eagle shift prey based on what’s available seasonally.
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Mammals constitute over 50% of the diet. Rodents are a bootied eagle favorite during winter months.
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Birds, reptiles, amphibians, fish, and insects round out their prey variety throughout the year.
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Booted eagles frequent mixed habitats from wetlands to grasslands to hunt. This exposes them to diverse food sources.
With a broad habitat range and flexible diet, booted eagles can hunt anything from fish to fowl depending on the time of year.
Eagle Vision – Spotting Fish From Afar
A key factor enabling eagles to fish is their exceptional long-distance vision:
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An eagle’s eyesight is up to 8 times sharper than a human’s. They can spot prey over a mile away.
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Dense concentrations of photoreceptors give eagles visual acuity optimized for hunting.
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Eagles discern fish rippling the water’s surface and shallows from great heights. This helps them pinpoint aquatic prey.
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Telescopic binocular vision and independently swiveling eyes enhance fish detection across wide fields.
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Nictitating membranes protect eagle eyes from water and debris when swooping to grab fish.
While not all eagles rely on fish equally, their universally sharp vision equips those who do specialize in fishing. An eagle eye evolved for spotting prey translates well to spying fish.
An Eagle’s Diet Depends on Habitat
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Sea eagles specialize in fish from coasts and rivers. Fish comprise over 75% of their diet.
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Fish eagles take majority fish, but from freshwater sources like lakes and wetlands.
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Snake eagles focus on inland reptiles rather than aquatic prey. Fish are a rarity.
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Booted eagles opportunistically eat anything abundant including seasonal fish.
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Excellent vision adapted for spotting prey helps eagles spy and catch fish.
So while fish are a staple for most eagles, their dietary flexibility lets them hunt other prey when needed. An eagle’s menu ultimately depends on the habitat it calls home. Their diverse diets reflect adaptations to thrive in a variety of environments across the world.
