Réunion - L'ile intense part VII: Fishing Herons

Between two trips, I had some time to spare before catching my next bus. While resting in the park at Saint Denis, a bird bathing in a small tub caught my attention. Since it wasn’t shy in the least, I took the chance to snap a few close-up shots. Just then, an older man with a camera approached me. His name was Alain, a retired journalist who visited the park almost every day and seemed to know all the staff. Before long, as his latest discovery of the day—a young Belgian, of all people—I was introduced around. What started as a quiet break quickly turned into a lively little gathering.

I should have guessed it: the heron was being fed by visitors. I’m not a fan of that—bread is harmful to birds since it swells in their stomachs. What I didn’t realize, though, was how cleverly this heron was turning the situation to its advantage. The tub was full of fish, and they, too, were attracted to the bread. For a heron, of course, a fresh fish is far more rewarding than a dry crust. So it had worked out its own equation: 1 + 1 = 2. Using the bread as bait, it lured the fish to the surface, then snapped them up with lightning speed. A heron using tools—I’d never seen anything like it before.

In more natural settings, herons sometimes use small feathers as bait. This species is actually one of twelve bird species documented to show such behavior—true fishing birds. The big question for biologists is whether this is an instinctive reflex or a learned skill. Research suggests a strong learning component. For instance, the behavior is surprisingly common when human objects are involved (like bread). While rare overall, it has been observed in multiple individuals at the same site, which points to social learning—herons picking up the trick by watching others. Some even reposition their bait while waiting, a sign of notable problem-solving ability.

So it’s clear: intelligence is not only a human thing, far from that!
As a biologist, seeing fascinating animal behaviour make my heart beat faster. All in all, a successful two-hour visit to the city park.