On 13th November 2007, the Little Heron (Butorides striatus) has been under care for 11 days. All this time it was fed pieces of fish fillet, later pieces of whole fish. The bird was offered the pieces at the end of a pair of tweezers. It lunged at the pieces and immediately swallowed them, taking two to three pieces one after the other, although sometimes it had difficulties getting them down its throat.
Then it was transferred to a large cage (left). The sides of the cage needed to be lined with newspapers as it kept on trying to squeeze through the wires. Here, its behaviour changed. Every time it was fed, it took the first piece offered, refusing subsequent pieces, until an interval of time.
On the 13th evening I tried a strategy suggested by Victor Lee: “…As to learning to forage, what I used to do at Jurong BirdPark was to put birds like these inside a paddock with a small pool, etc. Put in live fish, tadpole, frogs, etc. and get them to work it out themselves. When they are hungry enough, they will forage and learn to pick up the live food. Hope this helps.”
So I purchased a bag of mixed guppies and mollies sold by aquarium shops for feeding predatory fishes kept by hobbyists. Two dishes, each with nine fish were placed inside the cage. One was a shallow dish (right), the other deeper.
The bird, not fed for the last six hours, simply stared at the fish in one dish, not moving a step. When I dropped a piece of the usual fish inside the dish together with the swimming fish, it took the piece and swallowed it after about ten minutes.
One of the live fish jumped out of the dish and died. This dead fish was placed on a spoon and left inside the cage. It was subsequently eaten.
Three hours later when I looked inside the cage, the shallow dish was devoid of fish. The bird had eaten all the eight remaining fish, leaving the fish inside the deeper dish uneaten. Overnight, the nine live fish in the deeper dish were also eaten save for a dead one floating in the water. This was removed from the dish and offered to the bird who immediately took it.
The images above show the sequence of the bird taking the fish from the deeper dish the following day.
When the guppies and mollies were all eaten, I got small goldfishes that were slightly larger. When offered in a dish of water, the bird went straight for one but the fish slipped out of its grasp before its head could be positioned for swallowing (below). It had to try again a few times before it succeeded in swallowing it. Subsequent attempts also had to be repeated.
After eating more than 30 goldfishes, the bird became well versed in handling the fish. Just before posting, I fed the remaining five and it took every one of them head first and swallowed them on the first attempt.
So the experiment is a success, thanks to Victor Lee. The bird should have a reasonable chance of survival when released into the wild.
“Give the bird a fish and you feed it for a day. Teach the bird to fish and you feed it for a lifetime.”
Victor Lee & YC Wee
(Images by YC Wee)
a simple approach which in my opinion is pretty effective. the borrowed chinese proverb fits in nicely. lao tzu will be proud that his proverb is now famous in the birding world. 🙂
wow this is so amazing!! indeed this is the perfect example for the proverb! wow im still absolutely amazed and impressed by this whole experiement. im so glad to hear the lil one has learnt to fish. hopefully it’ll be just as easy fishing in the wild!
However, I have been told that putting fish in a dish of water makes it too easy for the bird. I should scatter leaves, etc in the water for the fish to hide. This will make the bird work for its dinner. In the wild it needs to hunt for its food. I will be trying this out soon.
YC, good idea ….perhaps create a miniature wetland…..:)
With a small cage, I can only have a basin-sized wetland. YC
With all those goldfishes sacrificed for one fish eater, this Little Heron sure must be one of the luckiest golden bird to be in your custodian care.
It’s a kind of Pavlov’s experiment tailormade to a beautiful proverb put into practice.
well, basin-sized…or whatever fits the cage. now, maybe you can also give some options for hunting. the goldfish color is too obvious. i think a mixture of tilapia fingerling, guppies, etc. any comments?
Agreed. Am now trying other fish species. Goldfish was just a curiousity, not seen in the natural habitat. Also trying froglets, etc as suggested by Victor Lee.
Susan Wong Chor Mun
Hah..hah.. what a honour for this little Heron can have
GOLDFISh for it’s meal.. When it was release to the wild hope that it would not frequent lurking around all the aquarium shops
for goldfish… 🙂
BTW YC, maybe can also try small prawns that are being sell at the aquarium shops.
Thanks for the suggestion Susan. Will try if I can find a shop selling prawns. Have tried crickets and small frogs. More of this later…
yeah did the camouflaging with leaves deter the chick? updates please! 🙂
The bird is extremely patient, standing still for long periods. It waits for the fish to appear from under the leaf litter and then zapped it. All the fish then swim to the bottom of the container which is too deep for the bird to reach. But they soon surface and once noticed by the bird, they become instant bird food. Every one was, in due course eaten.
Hi, I’m new here and curious about the part eating fish head-first. Why do birds eat fish head first ?
Fish have fins and spines. Swallowing it tail-first will force the fins to become erect and damage the throat. Head-first will ensure that the fins are safely “closed”. Also, it is easier to swallow the bigger end first.