An accomplished fisherman at Hoan Kiem Lake

I (Sebastien) was at the Hoan Kiem lake (dowtown Hanoi) on the morning of the 21th January when I came across the local Little Heron (I know this bird for at least 4-5 years), doing an unusual thing.  It was picking up pieces of bread and dropping them into the water, and then snatching the fish that were attracted to it! The bird kept repositioning his bait, like a fisherman casting his line over and over again! Amazing show ! The bird's high rate of success, as well as its dexterity in manipulating the bait, indicated that it was probably experienced in bait-fishing.

This behavior is well known among Little Herons (and also among the closely related North American Green Heron), but I’ve never seen it before.

I wonder whether this behavior is innate or learned?

According to literature only a small percentage of Little and Green Herons engage in bait-fishing.  It may indicate that it is not only an innate behavior, but a combination of innate and learned factors. According to some researchers only the exceptionally intelligent individuals acquire this skill. They can use lure bait (bread, small fruits, twigs, features, leaves) or live baits (flies and other small insects).

Active bait-fishing has also been reported for some Black-crowned Night Herons and... Crows !(look here, video from Israel). Passive bait-fishing, where the bird forages near bait but does not actually manipulate it, has been described for the Great Egret and the Great Blue Heron.

They are very few bird species that are known to use tools to capture food.

For a bird to learn this and know to use bread,which isn't a naturally acquired food in the wild and use it as bait, means that it probably isn’t an inborn instinct but aquired through observation, trial and error. It should give new meaning to the term "bird brain".

Source : vietnambirdnews[dot]blogspot[dot]com

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