The idea that a fish could successfully prey on a bird seems to defy the natural order of the aquatic world. Most people view fish as strictly submerged predators, or perhaps as the usual target of avian hunters like osprey and pelicans. While the phenomenon of fish eating birds is rare, it is a documented instance of specialized predatory behavior in both freshwater and marine environments. This surprising role reversal occurs among a small number of fish species that have developed unique strategies to exploit prey from the air or water’s surface.
Why Bird Predation is Unusual
For a fish, attacking prey outside the water represents a high-risk scenario that requires a massive expenditure of energy. Launching the body into the air demands explosive power to overcome gravity and the density of water. The fish must also contend with the risk of exposing itself to terrestrial or aerial predators during the attack. Most fish rely on the aquatic food chain, which provides a more consistent and less demanding source of nutrition.
The caloric return from capturing a bird often does not justify the energy and danger involved in the hunt. Consequently, most documented cases of fish eating birds are examples of highly opportunistic feeding. The behavior typically targets vulnerable prey, such as young birds or those struggling near the water’s edge. This specialized hunting only emerges when environmental factors, like a localized abundance of inexperienced birds, make the risk worthwhile.
Identification of Avian-Eating Fish Species
One of the most famous examples is the Giant Trevally (Caranx ignobilis), a powerful marine predator found across the tropical Indo-Pacific region. These large, silvery fish, which can grow to over 170 pounds, have been filmed targeting Sooty Terns in the Seychelles. The Giant Trevally’s diet is primarily other fish, but they gather in shallow coastal areas during the terns’ fledging season for this unique hunting opportunity. Their remarkable ability to calculate the trajectory of flying birds has astonished researchers.
In the freshwater realm, the African Tigerfish (Hydrocynus vittatus) exhibits similar predatory behavior against flying prey. This species, found in rivers and lakes across Southern Africa, is known for its sharp, interlocking teeth and aggressive nature. Scientists first documented them leaping out of the water to catch Barn Swallows skimming the surface for a drink. This learned behavior suggests a remarkable level of cognitive adaptation by the fish to a non-traditional food source.
Another notable species is the Wels Catfish (Silurus glanis), the largest freshwater fish in Europe. A particular population of these massive, whiskered fish in the Tarn River in France has developed an unusual technique for catching pigeons. These catfish have been observed partially beaching themselves on gravel banks to seize and swallow birds that come to the river to bathe. This specific, learned hunting method has not been recorded in other populations of Wels Catfish.
Methods of Attack and Targeted Prey
The various fish species employ distinct, specialized methods to overcome the physical barrier between water and air. The Giant Trevally uses sheer power and speed to launch itself completely out of the water, sometimes over three feet high, to intercept low-flying Sooty Terns. These explosive aerial strikes are precise, requiring the fish to accurately estimate the bird’s speed and path from below the surface. They focus their attacks on young, inexperienced fledglings or adults that hesitate near the surface.
The African Tigerfish utilizes a calculated surface strike, often targeting Barn Swallows that fly extremely close to the water. To successfully capture the birds, the fish must overcome the visual distortion caused by the water’s surface, a complex calculation known as refraction. Their ambush relies on rapid, vertical acceleration, snatching the swallow mid-flight before the bird can react. This technique is most effective in deep, clear water where the fish can approach undetected.
The Wels Catfish uses a partial stranding technique on inclined banks to catch pigeons. By sensing the vibrations of the birds with their sensitive barbels, the catfish lunges, often sliding its head and part of its body onto the land. This high-risk behavior allows the fish to engulf the terrestrial prey before quickly wriggling back into the river. Prey selection across all species is largely limited to small, lightweight birds like terns, swallows, and pigeons, or vulnerable young birds such as ducklings.