Black egrets, a species of African herons, have a very unique hunting technique – they use their wings to from an umbrella, which not only reduces glare, but also lures fish into false sense of security.
Called “canopy feeding”, the hunting technique used by black herons has to be one of the sneakiest observed in the wild. The black wading bird walks about slowly through shallow water and then spreads its wings around its body, to create an umbrella of sorts that blocks out the light. Although it’s not perfectly clear why the African heron uses this specific technique, scientists hypothesize that it has several advantages, like reducing glare and attracting the fish into a trap.
One commonly accepted theory is that small fish looking for a place to hide from predators like the African heron are attracted to the shade created by the heron’s wings, so they technically rush towards their death. And because the shade gives the bird a better view of its victim, it can easily snatch it out of the water with its long beak.
“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,” Bill Shields, a professor emeritus at the SUNY College of Environmental Science and Forestry, told Audubon.
Interestingly, African herons have bright yellow feet, which may have once been used to disturb and distract their targets, the way other types of heron still do, but the canopy feeding technique proved to efficient, so the birds evolved to rely almost exclusively on it.
“It could also be argued that the lure of both the shade and the bright feet now work in tandem to attract fish into gobbling range,” Evans said.
The black egret is definitely one of the sneakiest predators in the animal realm.