The Kingfisher’s Fishing Techniques

There are over a hundred species of kingfisher birds primarily found in the tropical regions of Asia, Africa, and Australasia, as well as in Great Britain. Despite the word “fish” in the name “kingfisher,” not all kingfisher species eat fish! In the tropical regions of Asia, Africa, and Australasia, ninety percent of kingfishers hunt and eat snakes, mice, and the chicks of other bird species in forests and woodlands instead of eating fish. Only about ten percent of kingfishers in those regions, and the local kingfishers of Great Britain, are actually found to eat small fish. A kingfisher consumes roughly its own weight in small fish each day, which amounts to almost five thousand in summer—a bit more than in winter! So, you can imagine just how much effort a kingfisher has to put in every day to fill its belly!

Once a kingfisher decides to fish in a certain waterbody, it sits for a while on a nearby branch, watching to select which swimming fish to catch. By keeping its body still but bobbing its head back and forth several times, it estimates the exact depth at which the fish is swimming. The kingfisher’s eyes are unique in that they have two regions in the retina densely packed with light-sensitive cells—one is known as the central fovea, the other as the auxiliary fovea. While observing the fish from the branch, the kingfisher uses its central fovea. Then, keeping its head at the forefront of its body, the bird dives from the branch toward the waterbody, and while airborne, it flaps its wings several times to gain more speed.

As the kingfisher enters the water from the air, it firmly tucks its wings along its sides and plunges into the water at a speed of up to twenty-five miles per hour. Nature has designed the kingfisher’s body, including its beak and head, in a special aerodynamic shape (much like a missile), so when it dives into water, the splashes are minimal and water droplets barely resist its motion. As a result, when the kingfisher dives from air into water, there is very little disturbance, so the fish isn’t alerted! Kingfishers have three eyelids, the third being a transparent “nictitating membrane.” Just as swimmers use special transparent goggles while swimming, the kingfisher’s nictitating membrane covers its eyes after entering the water, allowing it to keep its eyes open and track the fish’s movement underwater. Usually, vision becomes blurry underwater, so to maintain sharp vision beneath the surface, the kingfisher switches from using the central fovea to the auxiliary fovea. Many think kingfishers spear fish with their sharp, knife-like beaks—but they don’t. Instead, the kingfisher swiftly grabs the fish between the upper and lower parts of its beak and lifts it out of the water and onto a branch in the blink of an eye. While lifting the fish out of the water, the kingfisher first brings up its beak with the fish, followed by its head and body, so the chances of the fish escaping are minimized! After all these efforts, a small fish makes its way into the kingfisher’s stomach! So, as you can see, this is how a kingfisher hunts nearly five thousand small fish every day—one at a time!