Fish use gestures to help catch prey

This one is new to me and it seems almost unbelievable. Apparently, there are three types of fish that work together to catch prey. Ah, but it's even stranger than that.

The roving coralgrouper, a predator fish of the tropical reef, uses sign language to advise fellow hunters of hiding prey.

The coralgrouper works with the giant moray eel and the Napoleon wrasse to capture prey. Apparently, the coralgrouper is the instigator. Here's how it works:

The grouper has "burst speed" to capture prey in open water, while the eel can slide into crevices where small fish lurk and the wrasse has powerful extendable jaws that can suck out prey from a hole or smash the reef around it.

The grouper has two signals it uses in these hunts, according to the paper.

The first is a "high frequency shimmy," or a kind of body shake, that it performs in front of the moray as a general invitation to join it in a chase.

The second is specific, or "referential."

It is a headstand, which the grouper performs vertically and head-down, indicating to the moray or the wrasse where a prey is hiding or where it was last seen.

I would not have thought this possible yet this study confirms the behavior. It's amazing. Once again, we learn that non-human creatures engage in complex behavior. I say it all the time: the difference between us and other creatures is a matter of degree, not a grand change in categories. We are not the only intelligent creatures on this planet. We're just smarter than the other creatures. (At least, that's the working supposition.)

Great story about animal intelligence

Check out this BBC article by Jason G. Goldman. I've always suspected that animals - particularly other primates - are a lot smarter than we give them credit for. And now it seems there is reliable evidence that they can imagine:

Kanzi, the famous bonobo, liked to pretend as well. Primatologist Sue Savage-Rumbaugh described watching Kanzi hide invisible objects under blankets or leaves, later removing them from their hiding spots, and pretending to eat them. "Kanzi also engages the participation of others" in these games, Savage-Rumbaugh notes, "by giving them the pretend object and watching to see what they do with it."

How can you not love a story like that? There are other eye-opening behaviors reported in the article. It's worth reading, if such things interest you.

BTW, I've followed Jason Goldman's rise from lone blogger to respected science writer. He always wrote great posts and I'm glad he's seeing some success in the wider world of science writing. His words never fail to catch my interest -- and he seems to be a very decent fellow, to boot. Good for him!