Eagles are apex predators often associated with large bodies of water across North America. These powerful birds are highly opportunistic, consuming whatever food is most readily available. While their diet is diverse, fish constitute a major portion of their sustenance, especially for eagles inhabiting coastal and riparian environments. The specific types of fish they consume depend on the eagle species and local ecological conditions.
Focusing on the Bald Eagle: The Fish Specialist
The common perception of an eagle snatching a fish is linked almost exclusively to the Bald Eagle (Haliaeetus leucocephalus). This species is a true sea eagle, specialized for a diet dominated by aquatic prey, making it a dedicated piscivore. Bald Eagles prefer to live near coastlines, rivers, and large lakes where fish are abundant, sometimes relying on them for over 90% of their total intake in certain locations. In contrast, the Golden Eagle (Aquila chrysaetos), the other primary North American eagle, typically hunts in upland areas and prefers mammals like rabbits, ground squirrels, and marmots, rarely consuming fish.
Common Fish Species in the Eagle Diet
Bald Eagles consume a wide variety of fish, with over 100 species recorded in their diet. Prey choice is based less on specific preference and more on accessibility and ease of capture. In freshwater habitats, common targets include suckers, carp, gizzard shad, and various trout and bass species, such as rainbow trout and largemouth bass. These fish are often targeted when swimming close to the surface, injured, or during spawning runs.
Along the Pacific Northwest coast and anadromous rivers, the eagle diet is heavily influenced by salmonids, including kokanee, pink, and chum salmon. These fish become particularly accessible during spawning migrations when they are weak and concentrated in shallow waters. Coastal eagles also consume marine species like Pacific cod, rock greenlings, walleye pollock, and flounder. They prefer fish that naturally float when dead, making them easy to scavenge near the surface or shoreline.
Hunting and Scavenging Strategies
Bald Eagles are highly skilled hunters, employing a variety of methods to secure a meal. Active fishing involves a low-angle dive from a perch or soaring position, extending powerful talons just below the water’s surface to snatch a fish. The talons are equipped with specialized structures called spicules, which provide a rough, sandpaper-like grip to secure slippery prey. Unlike ospreys, eagles rarely fully submerge themselves, preferring a shallow strike to minimize energy expenditure.
A significant portion of their fish intake comes from opportunistic feeding strategies that require less energy. Scavenging involves consuming dead or decaying fish (carrion), which is an important food source, especially in winter. Eagles are also notorious for kleptoparasitism—stealing a catch from another bird, such as an osprey, gull, or fellow eagle. This behavior secures a meal with minimal effort.
Non-Fish Prey and Seasonal Variation
While fish are the mainstay, Bald Eagles are adaptable predators whose diet shifts dramatically based on local availability and season. During winter, when northern lakes and rivers freeze over, fish become inaccessible as they move to deeper water. This forces eagles to rely heavily on alternate food sources, notably carrion, such as deer carcasses or washed-up marine mammals, and waterfowl.
Birds like ducks, geese, and coots become a larger part of the diet in the cold season. Eagles sometimes hunt waterfowl by repeatedly harassing a flock until a weaker individual is exhausted. Smaller mammals, including rabbits, squirrels, and muskrats, are also taken, though they are secondary to fish and carrion. This flexibility ensures the eagle’s survival across its vast North American range.