What Is the Smartest Land Animal? What Studies Measured

There is no single smartest land animal, because "smartest" depends on the task. On a self-control test given the same way to many species, chimpanzees scored 100% (5 animals), orangutans 99.1% and gorillas 94.4%, and the best non-primate mammal was the coyote at 95.0% (8 animals). The elephant, known for a mirror test, scored lowest of all species on a second task. Humans have no score on these tests.

Below: what each land animal was tested on, which results hold up, what we found for farm animals, and how this page fits our guides to the smartest animals of the ocean, the air and the lab.

What is the smartest land animal?

No test ranks all land animals, so an honest answer cannot name one winner. People also ask what is the smartest animal on land, and the answer is the same: researchers have tested self-control, mirror self-recognition and word learning, and different animals come out on top. Counting neurons gives a fourth answer.

We count apes and other primates as land animals. Birds, ocean animals, reptiles, insects and fish have their own guides. Humans have no score on the self-control tasks below, so we leave people out of the comparison and come back to us at the end.

How do land animals compare on the same test?

The best like-for-like evidence is a 2014 study in PNAS by MacLean and colleagues, who tested 567 animals from 36 species on two self-control tasks. In the cylinder task, food sits visible inside a clear tube, and the animal must go around to the open end instead of reaching straight at it. In the A-not-B task, the animal first finds food in one container three times, then watches it moved to a second container and must search there instead. The scores below are the share of correct tries, from our smartest animals data set, which we built from the published tables.

• Chimpanzee: 100% (5 animals); orangutan: 99.1% (11); gorilla: 94.4% (9)
• Coyote: 95.0% (8 animals)
• Dog: 79.1% (66 animals); gray wolf: 77.3% (11)
• Mongolian gerbil: 68.9% (11 animals); fox squirrel: 66.9% (13)
• Asian elephant: no cylinder score in our data; in the A-not-B task, the lowest score of any species, 0.0% (7 animals)

Two cautions apply. The counts are small: the coyote's 95.0% rests on 8 animals and the chimpanzee's 100% on 5, while the dog's 79.1% rests on 66. And absolute brain volume predicted self-control best across the 36 species, yet the Asian elephant, the largest-brained species, had the lowest A-not-B score. Among primates, the authors found that dietary breadth, but not social group size, predicted self-control. One test does not predict another.

Which land animals pass the mirror test or learn words?

Elephants have passed a mirror test, and one border collie learned over a thousand words. Plotnik, de Waal and Reiss exposed three Asian elephants to a large mirror and a mark test, and reported mirror self-recognition in an Asian elephant (PNAS, 2006). Three animals were tested, so it is a landmark result, not a score for the species.

Chaser, a border collie, was taught the names of 1,022 objects over three years of intensive training and still knew them at the end (Pilley and Reid, Behavioural Processes, 2011). She also learned three common nouns, which are words for categories rather than single objects, and worked out by exclusion that a new word belonged to the one object she had no name for. It is one dog, so it shows what a dog can do, not what a typical dog does. Our dog IQ guide covers the wider picture.

What is the smartest farm animal: a pig, cow or horse?

The pig has the most experiments we could read, but the evidence is mixed, so the smartest farm animal is not settled. A 2009 study reported that pigs used a mirror to find hidden food. A 2014 attempt to repeat it with two groups of 11 piglets did not. In the first group two pigs located the food, and in the second only 1 mirror-experienced pig and none of the mirror-naive pigs used the detour (Gieling and colleagues, Applied Animal Behaviour Science). The authors read this as pigs not understanding the mirror image, and add that mirror use may sit at the upper limit of what young pigs can do.

A 2021 study did better. Four pigs, two micro pigs and two Yorkshire pigs, learned to steer a cursor with a joystick, and all four were above chance on their first attempts at one-walled targets (Croney and Boysen, Frontiers in Psychology). For cows and horses we did not find a single study to set beside these two, so we make no ranking claim. Our guides to pig IQ, cow IQ, horse IQ and chickens hold what each page covers.

Is there a ranking of the smartest land animals?

No, and any ranking you see online mixes unlike tests. Where animals share a test, apes lead the land animals. Where they share a brain count, the elephant leads on neurons. Where one animal was trained, as with Chaser, the result shows capacity rather than typical performance. The smartest land animals on one list are rarely the same on the next.

How do land animals compare with ocean animals, birds, reptiles and primates?

Our other habitat guides ask the same question under the same rule, and each finds that the leader changes with the task. See the smartest animal in the ocean, the smartest bird in the world, the smartest reptile, the smartest insect, the smartest fish and the smartest primate.

Birds hold their own against the land animals. In the same cylinder data the common raven scored 100% (5 animals) and the jackdaw 97% (10), so on that test the leading land animals do not beat the leading birds.

Where do humans sit among land animals?

Humans have no score on these self-control tasks, so the studies cannot place us. On neurons the human brain has about 86.1 billion (Azevedo and colleagues, 2009), 16.3 billion of them in the cortex. Counts for some other land animals, from our data set:

• Human: 86.1 billion neurons in the brain; 16.3 billion in the cortex
• African elephant: 257.04 billion; 5.59 billion (one adult male)
• Giraffe: 11.21 billion; 1.67 billion
• Dog: 2.25 billion; 0.53 billion (mean of two dogs)
• Pig: 2.22 billion; 0.29 billion

The elephant has about 3.0 times the human neurons in the whole brain but about a third of the human cortex count (our arithmetic from Herculano-Houzel and colleagues, 2014). Neurons are not intelligence, and no IQ exists for animals, as our human brain vs dog brain guide also shows. Humans can compare themselves with the IQ percentile calculator.

Take the IQ Metrics test to see where you stand, or read our guide to elephant IQ.

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