Are We Smart Enough to Know How Smart Animals Are?(77)

Octopuses have an odd life cycle. Most live only one or two years, which is unusual for an animal with their brainpower. They grow fast while trying to stay away from predators until they have a chance to mate and reproduce, after which they die. They stop eating, lose weight, and go into senescence.25 This is the stage about which Aristotle observed: “after giving birth … [they] become stupid, and are not aware of being tossed about in the water, but it is easy to dive and catch them by hand.”26

These short-lived loners have no social organization to speak of. Given their biology, they have no reason to pay attention to one another, except as rivals, mates, predators, and prey. They are certainly not friends or partners. There is no evidence that they learn from others or spread behavioral traditions, the way many vertebrates, including fish, do. The absence of social bonds and cooperation, and their cannibalistic ways, make cephalopods quite alien to us.

Their main worry is predation, because apart from their own kind, they are eaten by almost everything around, from marine mammals, diving birds, sharks, and other fish to humans. When they get larger, they become formidable predators themselves, as the Seattle Aquarium accidentally found out. Worried about their giant Pacific octopus in a tank full of sharks, staff were hoping that the animal would know how to hide. But then they noticed one dogfish (a small shark) after another disappearing from the tank—and found to their astonishment that the octopus had turned the tables. The octopus may be the only playful invertebrate. I say may since play behavior is almost impossible to define, but the octopus appears to go beyond mere manipulation and checking out of novel objects. The Canadian biologist Jennifer Mather found that given a new toy, the animal will move from exploration (“What is this?”) to repeated lively movements and tossing around (“What can I do with it?”). With their funnel, they blow jets of water at a floating plastic bottle, for example, to move it from one side of their tank to another, or to have it tossed back at them by the water flow of the filter, which makes them look as if they were bouncing a ball. Such manipulations, which serve no obvious purpose and are repeated over and over, have been taken as indications of play.27

Tied to the immense predation pressure under which these animals live is their ability for camouflage. Perhaps their most astonishing specialization, it provides an inexhaustible “magic well” for those who study them. The octopus changes color so rapidly that it out-chameleons the chameleon. Roger Hanlon, a scientist at the Marine Biological Laboratory in Woods Hole, Massachusetts, has collected rare underwater footage of octopuses in action. All we see at first is a clump of algae on a rock, but hidden among it is a large octopus indistinguishable from its surroundings. When the approaching human diver scares the animal, it turns almost white, revealing that it represented almost half the clump of algae. It speeds away while shooting a dark cloud of ink, which is its secondary defense. The animal then lands on the sea floor and makes itself look huge by spreading all its arms and stretching the skin between them into a tent. This frightening expansion is its tertiary defense.

When this video clip is slowed down and played backward, it is easy to see how superb the original camouflage was. Both structurally and color-wise, the large octopus had made itself look exactly like an algae-covered rock. It did so by making its chromatophores (millions of neurally controlled pigment sacs in its skin) match their surroundings. But instead of exactly mimicking its background, which is impossible, it did so just well enough to fool our visual system. And it probably did more than that, since the octopus also takes other visual systems into account. Humans see no polarized or ultraviolet light and don’t have great night vision, whereas the octopus’s camouflage needs to trick all these visual capacities. In doing so, it draws on a limited set of patterns that it has in stand-by mode. Turning on one of these “blueprint” patterns allows it to blend in in a fraction of a second. The result is an optical illusion, but one realistic enough to save its life hundreds of times.28

Sometimes an octopus mimics an inanimate object, such as a rock or plant, while moving so slowly that one would swear it is not moving at all. It does so when it needs to cross an open space, an activity that exposes it to detection. Imitating a plant, the octopus waves some of its arms above itself, making them look like branches, while tiptoeing on three or four of its remaining arms. It takes tiny little steps in line with the water movements. If the ocean is wild, plants sway back and forth, which helps the octopus disguise its steps by swaying in the same rhythm. On a waveless day, on the other hand, nothing else moves, so the octopus needs to be extremely careful. It may take twenty minutes to cross a stretch of sea floor that it otherwise might have crossed in twenty seconds. The animal acts as if rooted to the spot, counting on the fact that no predator will take the time to notice that it is actually inching forward.29

The champion of camouflage, finally, is the mimic octopus, a species found off the coast of Indonesia that impersonates other species. It acts like a flounder by adopting this fish’s body shape and color as well as its typical undulating swimming pattern close to the sea floor. The repertoire of this octopus includes adopting the likeness of a dozen local marine organisms, such as lionfish, sea snakes, and jellyfish.

We don’t know exactly how octopuses achieve this astonishing range of mimicry. Some of it may be automated, but there is probably also learning involved based on observations of other creatures and adoption of their habits. As primates, we find it impossible to relate to these remarkable capacities, and we may hesitate to call them cognitive. We tend to view invertebrates as instinct machines, arriving at solutions through inborn behavior. But this position has become untenable. There are too many remarkable observations—including the deceptive tactics of cuttlefish, close relatives of the octopus.