Nieder’s experiment showed that the birds were actively evaluating how to solve a particular problem they were confronted with. In effect, they were thinking it over. This ability to consciously assess a problem is associated with the cerebral cortex in the brains of humans. But birds have no cerebral cortex. Nieder found that in crows, thinking occurs in the pallium—the layers of gray and white matter covering the upper surface of the cerebrum in vertebrates.
Other studies support the notion that the bird brain can, in principle, support the development of higher intelligence. This idea had been dismissed in the past due to the small size of birds’ brains. But recent research has shown that in birds, the neurons are smaller and more tightly packed, which makes sense to reduce weight and make it easier to fly. The total number of neurons in crows (about 1.5 billion) is about the same as in some monkey species. But because they are more tightly packed, communication between the neurons seems to be better, and the overall intelligence of crows may be closer to that of Great Apes such as the gorilla.Dirk Schulze-Makuch, “Crows Are Even Smarter Than We Thought” at AirSpaceMag (2021) The paper is closed access.
It’s hard to know how to assess the claim that the crows are “conscious” because consciousness is a very poorly understood concept. We humans know we have it but we don’t understand how it is produced or what it means. It might be better, for research purposes, to just stick with “Crows are even smarter than we thought.”
But that leads to another question: It’s unclear why crows are significantly smarter than other birds. Most birds probably could not outperform apes. The field is fraught with unanswered questions like these.
Here are a few more interesting findings:
➤ Dogs may not be as intelligent as seals. “Hambrick, a cognitive psychologist, also notes that bottlenose dolphins and the grey seals were better able to follow human hand signals, even though dogs are bred to be sensitive to human communications.” Ofcourse, it is much easier for humans to live with dogs than with seals.
➤ Yes, even lizards can be smart. If you catch them at the right time: “Reptiles lack some brain structures found in mammals but they can use what they’ve got for behavior that we would describe as intelligent: Crocodilians (alligators and crocodiles) have been reported to use sticks as decoys, play, and work in teams. Exothermy [coldbloodedness] slows intelligence but does not absolutely prevent it: Anole lizards were found as capable as tits (birds) in a problem-solving test for a food reward. But the anoles, being exothermic, don’t need much food — which, of course, hinders research.”
➤ So can fish: “In 2009, evolutionary biologist Giacomo Bernardi was able to film a fish intentionally using a rock as a tool.” But not all fish. Just some fish.
➤ And now for the invertebrates. The octopus, considered by some researchers to be a “second genesis” of intelligence (that is, a genesis among invertebrates) breaks all the rules about why some life forms are smart. It lives alone and dies young, which is usually associated with lesser animal intelligence. And the octopus belongs to a phylum, Mollusca, most of whose members (think clams) are not particularly intelligent at all.
Just how animal species develop a higher level of intelligence than other species in their biological category (phylum) is unknown. There are two questions here, why? and how?: Why animals develop problem-solving intelligence probably relates to need. A clam, attached to a rock, doesn’t need to be intelligent. But an octopus, which controls eight tentacles that it uses to secure food, probably survives mainly by conducting intelligent searches.
That might, in turn, enable other complex behaviors in the octopus:
But now we come to the difficult question, the “how?” Just how an animal species gains greater intelligence than others is still a mystery.
One could simply say, “Evolving more intelligence helped the animal to survive.” The trouble with that explanation is, many free-roaming life forms would probably survive more readily if they were more intelligent. But they do not develop greater intelligence on that account. There must be more to the story.
We are only beginning to scratch the surface of the mysteries of animal intelligence.
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In what ways are cats intelligent? Cats have nearly twice as many neurons as dogs and a bigger and more complex cerebral cortex.
In what ways are dogs intelligent? There is no human counterpart to some types of dog intelligence.