Like most wading birds, Black Herons have lengthy legs, necks, and beaks. When it’s time to dine, this jet-black African species transforms into an umbrella.
Of course not. In the process of fishing, the bird tucks its head down and creates a sunscreen with its wings. Paul Wheatley, a nature videographer from Leeds, filmed the behavior in the above video while visiting the Gambia. Wheatley’s phone scoped four minutes of the heron, quickly hiding its face before snagging up food on Lake Kotu. But why does this behavior exist?
Canopy feeding has multiple potential benefits, says Kenn Kaufman, Audubon’s field editor and an expert on birds. According to one explanation, little fish seeking refuge are drawn to the heron’s wings’ shade. Canopy feeding may also allow the bird to better view its prey, says Bill Shields, emeritus professor at SUNY College of Environmental Science and Forestry. Shields compares it to fishing with polarized sunglasses. Similar to how sunglasses minimize glare, the wings’ shade may allow the bird to see through the surface. Shields speculates that the heron may be camouflaging itself so that the fish see nothing but a dark mass until they’re sucked up by the bird. “It’s all part of heron hunting tactics,” Shields adds.
Other herons, such as the Reddish Egret, use similar tactics. Unlike the Black Heron, the Reddish Egret is a mesmerizing dancer. The coastal North American wader would zigzag with its wings outstretched to confuse and distract the fish before forming a partial canopy. According to Lianne Koczur, a post-doctoral research associate at Texas A&M Transportation Institute who researched Reddish Egrets for her dissertation, the fish would inadvertently swim toward their demise.
When Wheatley recently published his video on Twitter, it earned over 6,000 retweets. Isn’t that flash of color a warning to fish? According to Alex Evans of the University of Leeds, bright yellow heron feet may have been initially employed to upset and distract targets. The Little Egret adopts a similar hunting method, shuffling their feet as they walk to stir up aquatic prey, then dash with wings outstretched to ambush.
Evans thinks if the bird ever utilized its feet like the Little Egret. Black Herons began to feed on the canopy, which proved to be a more efficient hunting tactic. Maybe the heron uses both tactics to become a fantastic hunter.
« The shade and the bright feet now work together to entice fish into gobbling range, » adds Evans. “It would be interesting to explore how foot color affects canopy feeding success.” Kaufman acknowledges that the diverse methods may have evolved through time and may now benefit the birds. One of those benefits may have nothing to do with hunting. No one has yet proposed another possible reason for the Black Heron’s feeding behavior: Maybe the birds just love playing “nighttime, daytime.”