The African Bird That Tricks Fish with a Shadow Umbrella

Quick Take

• Fish don't just get caught by this bird. They actually swim toward it voluntarily, and there's a clever reason why. See why fish are lured →
• The black heron's hunting trick works for the same reason polarized sunglasses help fishermen. Explore the glare reduction →
• Its all-black feathers aren't just a color. They're a weapon that took millions of years of evolution to perfect. Discover the evolved feathers →
• Most herons stand and wait, but this one does something different. See the wing canopy explained →

A video from the Pangolin Wildlife Photography YouTube channel gives us insight into the extraordinary hunting style of the black heron (Egretta ardesiaca). The Chobe River, which forms the border between Botswana and Namibia in Southern Africa, is home to nine species of herons. Many herons catch their food by standing still in shallow water and striking with lightning-fast speed when they spot a fish. Black herons hunt a little bit differently, using a hunting style called canopy feeding. In this style of hunting, the bird uses its wings to form an umbrella, which casts a shadow around its body.

The Black Heron’s Umbrella Hunting Trick

As its name suggests, the black heron, also known as the black egret, has all-black plumage. In contrast are its bright yellow eyes and yellow feet. When the black heron gets hungry, it tucks its head down and spreads its wings in an umbrella shape around its body. By doing this, it creates a sun shade in the water below. The heron then looks down and stirs its feet. If a fish is in reach, it strikes quickly with its beak.

Why Shade Gives Black Herons a Hunting Advantage

According to the video, one possible explanation for this behavior is that it creates the illusion of a refuge for the fish. When the fish see the shadow, they may believe they have found a safe hiding spot, but instead, they end up swimming directly into the mouth of the heron.

Another benefit of this unusual hunting style is reducing glare on the water. Underneath the shade, the bird has a better view of the fish swimming below.  Bill Shields, a professor emeritus at the SUNY College of Environmental Science and Forestry, told Audubon Magazine that it’s the same technique used by fishermen wearing polarized sunglasses to reduce the sun’s glare. Shields explained it may also help camouflage the bird so the fish can only see a large shadow above. “It’s all part of the hunting tactics of herons that spend a lot of time looking for particularly smaller prey just below the surface,” he told Audubon Magazine.

The Evolution of the Heron’s Hunting Technique

Scientists believe this behavior didn’t develop overnight, but rather evolved over many years of evolution, resulting in the bird’s specialized wing feathers that can create an umbrella shape. By adapting its hunting strategies, the black heron has developed a unique and effective technique for catching fish in shallow waters.