I’m continually surprised not so much by what animals can do as what we think they can’t do.
Just when we think we’re definitely the most amazing species on earth, we find that we have competition for that spot in our planet’s natural history. Research is increasingly showing that many abilities we thought were common only to smart apes — and we are the smartest among them — are not exclusive to us.
We tend to believe that many thought processes, including problem solving and tool making, separate us from animals — that we think, while animals depend on hard-wired, instinctive responses that require little or no intelligence. Our cerebral cortex, which plays an important role in many higher-level brain functions (perceptual awareness, attention, memory thought, language, consciousness), is pretty impressive. But many animals seem to do fine solving problems and without that extra layer of brain.
A honey bee has about 960,000 neurons, and an ant, about 250,000, compared with the average human’s 86 billion, housed in our much-larger brain. But, as in many things, size doesn’t matter when it comes to intelligence, according to the British website Teaching Biology:
“Brain size . . . is not a good predictor of intelligence, if it’s measured by behavioural repertoire, innovativeness or sociality. In any of those examples, a honeybee will come out as more intelligent than a human or a whale.”
And we think of whales as being way down the evolutionary ladder from us, although research is increasingly showing just how intelligent these social animals are. Bottlenose dolphins, for example, have learned to carry sponges in their beaks when foraging in rough-surfaced areas of the sea floor — “an activity that may help to protect their sensitive snouts from sharp rocks, stingrays, urchins and other things that might plague them, particularly as they forage for food along the seafloor,” according to an article in The Atlantic.
It was long thought that only humans and chimps use tools. Yet recent studies have shown that some parrots and crows not only use tools, but choose or modify them to solve a specific problem. Crows on the South Pacific island of New Caledonia, for example, figured out they could more easily dig out the insect larvae that are too deep inside trees to reach with just their beaks by turning the materials at hand — sticks — into hooks.
The crows strip one end of a stick and shape it into a small hook, as shown in a video at Io9.com. Repeated tests by researchers demonstrated that the birds were actually working out the problem, not just stumbling onto the solution through trial and error. In the video, a crow is given a straight metal wire to fish a small bucket of food out of a glass tube. After a few futile attempts, the crow decides to modify the wire, within seconds wedging it into the space between the tube and the pan it’s in and bending the end into a hook. The crow then maneuvers the hook under the handle of the bucket to pull the prize out of the tube. This is just one of many signs of intelligence crows have been observed demonstrating — not surprising for a bird that’s thought to have more distinct words in its vocalizations than any other avian.
Moving further down the evolutionary ladder, we come to insects. Research is showing that ants and bees — both part of the largest and most diverse insect order, Hymenoptera — are far smarter than we thought such “lowly” beasts could be. Some ant species “farm” aphids for their food, nurturing and protecting their livestock from predators to “milk” them for their nutritious excretions. And leafcutter ants store leaves, which they farm for the nutritious mold that grows on them, which also serves as an antibiotic.
According to an article on the Science Direct website, researchers at Arizona State University found that ants can solve problems through chemistry and crowd sourcing. One species sends out scouts to look for a new home, and, when a scout finds a suitable site, it goes back to the colony and says to another ant, through a pheromone message, “follow me.” If the ant that follows likes the site, it shares the message with another ant, and so on, with ants collecting at the preferred sites. The colony then chooses the site, collectively, that the majority finds most suitable.
Working together, army ants, which are continually on the move, also construct living suspension bridges or nests (bivouacs) consisting of individual members of their colony linked together by little hooks on their feet (“living Legos,” as Alex Wild of Myrmecos.net calls the ants). Other species of ants build complex underground housing that has inspired architects, and still others can figure out the quickest route to a food source and share it with colony members. No ant is in charge of a colony’s movements (the “queen” is only a breeder); each makes its own decision, but the decisions are shared in a way that makes an ant colony a “superorganism,” as social-insect experts Bert Hölldobler and Edward O. Wilson have referred to them in their book by the same name.
Bees, which are also highly social, use a “waggle dance” in which one bee shows the others in its colony exactly where a food source is — how far and in what direction. And that’s just one among many of their complex abilities.
Even nonsocial insects can accomplish tasks that seem beyond their tiny brains. Scientists have known for a while that birds navigate by using magnetic forces to determine the location of the North Pole, but now the dung beetle has been found to navigate using the Milky Way to get its food to its nest. It moves fast, in a straight line, to avoid other thieving members of their species from taking the food, while navigating rough terrain in which vision of the path ahead is limited for such a tiny creature. Scientists found out, almost by accident, that the beetles were orienting themselves by watching the stars. To ensure the beetles were doing this by sight, the scientists taped tiny hats on them so they couldn’t see the sky, which deterred them from finding their way home. (I keep imagining the look of concentration on the faces of the scientists and bewilderment on the faces of the beetles as the hats were attached.)
This is just a tiny sampling of the complex tasks other species can accomplish that should put our human abilities into perspective. And don’t get me started on plants — the things scientists are learning about how they communicate and control their environment will give a vegan pause, but that’s for another column.
Learning about the often-surprising, diverse abilities of other species is, for me, what makes studying nature so incredibly exciting and fulfilling. The various threads that make up the fabric of nature and how they are woven together become more clear the more we look closely at other species. Such insight can further advancements in human medicine and teach us more about living together as a social species — as well as give us a better appreciation for the other animals with which we share planet earth.