The artful crocodiles can hunt cooperatively.

By Dave Armstrong - 22 Nov 2014 20:44:0 GMT
The artful crocodiles can hunt cooperatively.

The salt-water or estuarine croc. exhibits a great range of abilities that we should disregard at our peril. In this fabulous photograph, look at those eyes and imagine that ancient brain is now thought capable of cooperative hunting at a level comparable with the most advanced mammals and birds.; Estuarine crocodile image; Credit: © Shutterstock

Ethology, Ecology and Evolution is a sort of catchy name for a scientific journal. This issue has Vladimir Dinets of the University of Tennessee with his forum presentation, Apparent coordination and collaboration in cooperatively hunting crocodilians. It is a shock to realise that scientist and layman alike have been misinterpreting the crocodiles’ apparent slowness.

Cooperative hunting and care of offspring has been noted in crocodiles, but this is the first time they has been regarded as a norm for crocodiles. Collaboration is here also discovered to be an even rarer and more sophisticated part of their hunting. Of the many mistaken and homespun tales of some crocodile species, the idea of being restricted to aquatic hunting is wrong. Many species regularly hunt on land, while the author has already published a paper extolling the skills of 2 species in using hunting lures.

In a paper last year, Vladimir also related how, individual crocodilians adjust their signaling to habitat structure. This entailed describing how infrasounds, vocals and slaps carried messages over long distances through both air and water. Now it seems, we are to get some idea of how these signals are useful to the reptiles’ communication systems through an evolved set of adaptations.

The observations in this simple set of stories include the hunting of an unfortunate pig that is frightened into a trap on both sides of a path, formed by 2 collaborators when a big estuarine crocodile, Crocodylus porosus leaps out of the water with its jaws wide and threatening. All 3 feasted on pork that evening. The interest lies partly in whether these animals would be related, just as in lions stalking or the orca’s great chases at sea. They may well not be related, but this takes nothing away from the skills shown in these examples. More needs to be gathered to provide evidence of the exact behavioural and sensory mechanisms involved.

To complete the picture of the sadly diminished total number of 23 crocodile species, here is one shy and retiring (and almost extinct) Filipino named Crocodylus mindorensis.