The Intelligence of (some) Animals

"It suggests the octopus is carrying these tools [stacked coconut shells] around because it has some understanding they may be useful in the future."
"[Researchers have argued that smarter animals] cooperate and learn from other members of the same species."
"We can't take for granted that there's just one way to intelligence. There could be different paths [nature devises for her various creatures]."

"Octopuses, unlike many other molluscs, they do not have a protective shell. So [octopuses] are very, very vulnerable to many kinds of predators — from fishes to marine mammals to birds — and the idea is that by becoming quite smart, this is a kind of weapon they can use to avoid being eaten."

Piero Amodio, graduate student, Cambridge University, Britain

A two-month-old octopus tries to unscrew the lid of a jar to get hold of its content, a crab, at Denmark's Aquarium in Copenhagen. (JORGEN JESSEN/AFP/Getty Images)

Scientists have focused on studies to reveal how different animals' intelligence evolved and have come up with some pretty astonishing findings. None more strange than the intelligence of cephalopods, an animal grouping including octopuses, squid and cuttlefish. In a paper published recently in Trends in Ecology and Evolution, Piero Amodio and five other biologists who focus on animal intelligence explore this biological mystery.

Generally speaking, shared factors of intelligent animals have been identified by scientists; large brains, animals whose lifespan is long, and animals that evolve a social culture forming long-lasting social bonds. For the conundrum of how certain animals have evolutionarily become intelligence those similarities explain much.

 One intelligence hypothesis speaks of intelligence evolving as a foraging adaptation. Some animals enjoy the advantage of a reliable food supply in their habitat, while others must cope with the unpredictability of food availability. And then there are those species which form cooperative bonds, learning from the experiences and successes of others within their community.
 

It was the middle of the night and no one saw Inky the octopus leave New Zealand's national aquarium, but staff found a trail of water leading from the tank to a 50-metre drainpipe leading to the ocean. (National Aquarium of New Zealand)

Cephalopods are known to behave in ways suggesting high intelligence, demonstrated when an octopus escaped from the National Aquarium of New Zealand, by exiting his enclosure, slithering into a floor drain and presumably out to sea and freedom. There is an instructive video showing an octopus pulling two halves of a coconut shell together to enable it to hide inside. The octopus subsequently stacks the shells like nesting bowls and hauls them off as it leaves the area.

In Israel, researchers at Hebrew University placed octopuses alongside an L-shaped box with food placed within. The animals then managed to figure out they could push and pull the food through a tiny aperture in the wall of their tank to access the tempting morsel. Cephalopods have a good-sized brain; most of the neurons the brain instructs are located in the arms of the octopus, differentiating it substantially from other animals with large brains and high intelligence.

Among scientists involved in researching intelligence in  animals like cephalopods it is theorized that some 275 million years ago their ancestors lost their external shells leaving the animals free to explore places they were unable to access with a shell -- such as rocky crevices, in their hunt for prey. With the loss of the shell cephalopods became vulnerable to predators which may have led to the need to outwit those predators.

In so doing cephalopods learned to disguise themselves and to escape threatening situations, accomplishing this through the evolution of their large brains leading to the capacity to solve new problems; even plan for the future, such as occurred with the octopus that took along those coconut shells (or clam shells) which could prove useful at some future time.

And though most intelligent animals are thought to live long with their large brains, cephalopods do not, with some living up to two years, and others only a few months. Cephalopods are also social loners, they don't form social bonds. The traits that identify other animals' propensity for intelligence are obviously not shared by these creatures, making their high-grade intelligence all the more perplexing to science.

A veined octopus hides in an coconut shell. Scientists have filmed the octopus collecting and assembling coconut shells for shelter. (Associated Press/Museum Victoria, Roger Steene)