Saturday, October 27, 2018

Animal Intelligence: Head of the Class

brain sizesWhen the topic of animal intelligence comes up, we might argue whether a crow or a parrot is the more clever, or if dolphins are smarter than manatees. Seldom do we ascribe smarts to life-forms such as insects, plants or fungi. And it is rare indeed that we question our intellectual primacy among animals. It is true that no other species can point to monumental achievements such as the Colosseum, acid rain, nerve gas and atomic bombs. But that does not mean other species are bird-brained. Metaphorically speaking.

It makes sense that elephants and whales are whiz-kids, given the size of their heads. Depending on species, whale brains weigh between 12 and 18 pounds (5.4-8 kg.), and Dumbo’s cranium would tip the scale at around 11 lbs. (5.1 kg.). Compared to them, our 3-pound (1.3 kg.) brains are small potatoes. What sets mammal brains apart from other classes of animal is the neocortex, the outermost region of the brain responsible for higher functions such as language and abstract thinking.

But size is not the only thing that counts. Our neocortices, unlike those of most animals, are highly convoluted, which means we make everything way more complicated than necessary. Actually, convolution gives our brains a lot more real estate by volume — as if Texas were a rug and it got scrunched up to the size of Vermont. A lot of acreage would fit in a small space if it were nothing but valleys and mountains. This greater surface area equates to more processing power than a less highly folded brain like a whale’s.

The ability to make and use tools, and to carry them for future use, is one of the widely accepted indicators of intelligence. In the past, it was thought that only humans and our close ape relatives used tools. Some gorillas in Borneo use sticks to spear catfish, and western lowland gorillas have been observed using a stick to gauge water depth. In at least one case, a gorilla used a log to fashion a bridge to cross a stream. I suppose if they started charging a toll, we would give them more respect.

Only just recently has the intelligence of cephalopods like cuttlefish, squid and octopodes been documented. Octopodes have been observed foraging for discarded coconut shells and using them to build sea-castles of sorts in which to hide. If their ability with tools progresses, I bet they could knit an awesome sweater in no time.

Birds also use tools — crows, for example, will use a stick to poke at bugs they can’t otherwise reach. When the insect bites the stick, the crow pulls the stick out and eats the bug. Humans always assumed birds were not very smart because their brains weigh a few grams, and range from pea-size to maybe the size of a walnut. Well, we’ve had to eat crow, because bird brains are far more neuron-dense than mammal brains. It’s like we were comparing the microchip brain of birds to the big vacuum-tube human brain and sneering, when in fact many birds test on par with primates for intelligence.

We know that honeybees use a sort of interpretive bee-dance to communicate with each other as to the location of flowers and picnickers. Our native bumblebees seem to have one up on them. In 2016, researchers at Queen Mary University of London found that bumblebees learned within minutes how to roll a tiny ball into a little hole to get a sugar-water reward. I assume the researchers are now busy with bumblebee golf tournaments.

Even vegetables can learn new tricks. Experiments have shown Pavlovian responses when light and other stimuli are presented together from various angles. Plants of course will grow in the direction of light. But when the light was switched off, the plants tilted toward the other stimuli, just like the way Pavlov’s dogs salivated when they heard bells. I imagine the winter holiday season was frustrating for those drool-pooches.

Humans, apes, squids, birds, bugs, and plants — there’s nowhere to go but down. Enter the plasmodial slime mold, a slow-moving single-cell organism that can scout the landscape, find the best food, and engulf it, growing ever larger. Coming soon to a theater near you. It sounds like a sci-fi film, and a blob of pink, yellow or white slime mold, possibly a square yard in area, does look pretty alien. They usually live in shaded forest environments, but can show up on your flower bed, and a friend once sent a picture of a slime mold which had engulfed his empty beer can left out overnight.

Researchers discovered that a plasmodial slime mold uses complex algorithms to make decisions — logical ones, it turns out — regarding which direction to proceed as it slimes across the landscape. One of the lead researchers in the 2015 study is Simon Garnier, an Assistant Professor of Biology at New Jersey Institute of Technology. He said that “[studying slime molds] challenges our preconceived notions of the minimum biological hardware required for sophisticated behavior.”

And in a story that sounds right out of The Onion, last year the Amherst, MA-based Hampshire College named a slime mold to its faculty as a “plasmodial scholars-in-residence.” True story. In an announcement on the college’s website, Hampshire biology professor Megan Dobro explained that “Slime molds have navigated complex ecosystems…for a billion years, proving themselves to be some of the foremost optimizers on the planet.” Algorithms used by slime molds will be studied for applications to difficult human problems.

Maybe it’s time we paid more attention to our non-human relatives. I bet they have a lot to teach us.

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Paul Hetzler has been an ISA Certified Arborist since 1996. His work has appeared in the medical journal The Lancet, as well as Highlights for Children Magazine.You can read more of his work at or by picking up a copy of his book Shady Characters: Plant Vampires, Caterpillar Soup, Leprechaun Trees and Other Hilarities of the Natural World

16 Responses

  1. Boreasfisher says:

    Fascinating stuff.

    Jim Gould, the noted honey bee biologist and student of Donald Griffin, did some interested work on honeybee awareness some years ago based on the realization that navigation to food sources meant keeping some kind of mental map of terrain, perhaps a prerequisite for awareness. He was often asked if bees could think to which he often responded “I hope not”.

    But more tellingly about anthropomorphic interpretations of intelligence in other creatures was the French Canadian poet and Professor at McGill, Louis Dudek who was known to talk and write poems to his plants to make them grow. I always thought that was perhaps a better illustration of the lack of animal intelligence, but what do I know?

  2. JRS says:

    So Hampshire’s slime mold figured out a new route to tenure (he said with an academic sneer).

  3. Tim-Brunswick says:

    Was the ADK. Almanac short on material or what….really!!

    • JohnL says:

      C’mon Tim. This IS interesting…..and way better than another rails versus trails ‘discussion’. Thanks Paul.

      • John,
        Thank you–I have been taken to task about the gorilla, and have been going through the sources I used. I believe it was a captive female that built a bridge, but still can’t find the citation. Some details make a big difference.
        Very best wishes,

  4. Zephyr says:

    Maybe aliens arriving from space will choose to communicate with slime molds after observing what humans have done to the Earth.

  5. John Omohundro says:

    A thought-provoking essay, as always, Paul. One thought provoked: how did those gorillas get to Borneo? Congrats on your new book.

  6. Charlie S says:

    JohnL says: “C’mon Tim. This IS interesting…”

    His field of vision is by far narrower than yours (and mine) JohnL which should not come as such a surprise to you.

  7. Charlie S says:

    “Seldom do we ascribe smarts to life-forms such as insects, plants or fungi.”

    Some of us do! Even a worm has a level of intelligence if you think about it. It will shrink up or stretch out to avoid the incursion of a blade. Awareness of danger! Which is innate in every living form. We should be taught to respect all living things on earth as every “thing” serves a purpose. Right now we are on reverse course…..unfortunately.

    • Boreasfisher says:

      Completely agree about understanding and respecting nature…but there are some tradeoffs worth considering to an over exuberant interpretation of awareness. Endowing everything with “consciousness” means we may only find it appropriate to eat man-made green slime… A boon for the nanotechnologists among us. Of course, we may be headed that way regardless.

      • Charlie S says:

        For one Boreasfisher I’m not a purist. We don’t need beef, or chicken for that matter I suppose. I’m not a vegetarian but I don’t eat beef or pork or fish, just poultry.Some of the plant-based foods coming out are out of this world, loaded with protein… and taste just as good as beef if not better. Some of the new companies cropping up are producing plant-based breakfast sausages, veggie burgers, you name it… which have just as much protein as meats…if protein is what we seek when eating meat. If it’s taste we’re after plant-based foods are just as good as, if not better than, meats. Most certainly we’re headed in some direction. Time will tell soon enough what that direction is.

        • boreasfisher says:

          Thanks for sharing your gustatory preferences. I am personally an omnivore, as I believe was evolutionarily mandated. (Not that anyone should care what I eat.)

          I was trying to say that if we beatify everything that lives, we might even be confused about eating viruses. I do believe that the longer we live the less mysterious life becomes.

          But knowledge does not protect us from the bias of parochial short term thinking. So in a few generations, we may truly be headed for made up food. SciFi writers have been known to predict the future. (Ballard’s “The Drowned World” is looming large.)

          But hey, if it floats the boat, that’s better than the opposite. I’ll share my oar if you’ll share yours.

  8. Randy Fredlund says:


    Thanks for an interesting and thought provoking article.

    I’m temped to sign this, “The Slime Mold,” but that might be doing the mold a disservice.

  9. This is not in response to anyone in particular, but the thread about food choices reminded me of the fact that white-tailed deer have been observed killing and eating mice (hey, they have canine teeth, y’know), and that many supposed herbivore species such as wallabies are known to eat meat when opportunity and appetite coincide.
    Which makes me think of the 1970s song “Junk-Food Junkie” by Larry Groce–Oh, but folks lately I been spotted, With Big Mac on my breath, Stumbling into a Colonel Sanders, With a face as white as death…
    OK, past my bedtime, sorry.

  10. Boreasfisher says:

    Just added Larry Groce-Oh to my playlist!