For hundreds of thousands of years human beings have been set apart from the rest of the creatures on earth due to our apparent superior intelligence. No other species on the earth can do several things that a human can do such as use language, entertain abstract thoughts, produce art, etc. However, all these things have only been made possible through evolution as humans have adapted to various environments to become the intelligent and diverse people we are today. Given elements of evolutionary continuity between many different species, it would seem strange to see no aspects of intelligence at all in other species.
These are generally reviled due to their tendency to harbour disease, but this does not mean they are clever. Scientists have used them for years as initial test subjects for studies they eventually wish to test on humans. They have the ability to find solutions to puzzles and mazes designed in countless laboratory experiments.
Bees may not seem intelligent according to the common meaning of the word but they do exhibit amazing abilities in certain areas. The “waggle dance” they perform in the hive to signal nectar location to other bees is a very complex and precise series of movements which encodes a large amount of information. After viewing this dance, bees can fly off to find the nectar source with an accuracy of a few metres, even if the source is miles away from the hive.
Who would have thought these gormless looking creatures could possess intelligence? Well they do. Cows have been shown to have socially complex interactions, being able to hold grudges against other cows, amongst other interesting social behaviors. Cows mourn the death of other cows, even crying in certain cases. Research has demonstrated they understand causality, learning to push levers to get water when thirsty or food when hungry in a novel environment. This information may come as a surprise, given how cows are generally perceived.
It’s no coincidence that elephants can be found in many circuses around the world performing tricks. They are very smart animals. They can use implements much like humans, often sculpting their trunks into relatively maneuverable hand-like structures to grasp and manipulate objects, and have been known to use stealth to steal bananas from plantations whilst farmers are asleep. Elephants have been observed mourning their dead, exhibiting decidedly sad behavior on the discovery of a dead elephant; in some cases even “burying” the dead elephant with leaves and branches.
Squirrels have been demonstrated to be deceptive, pretending to cache their food in an attempt to throw would be thieves off the trail. A lab study showed that this deceptive caching increased when squirrels observed humans stealing their food, a potential sign that squirrels can understand the intentions of other sentient creatures.
Some scientists consider the pig as the most intelligent domestic animal of all. They have been known to trick other pigs whilst maintaining all the food for themselves. They can even use mirrors to find food. A study in the 1990s showed that they could manipulate a cursor with their snouts which they then used to distinguish between markings they recognised and markings they were seeing for the first time. They accomplished this task as quickly as chimps.
Crows are crafty tool users, constructing implements out of twigs and other bits of debris to grab food in difficult to reach places. One study demonstrated that certain crows were able to craft quite sophisticated tools, e.g. manipulating a length of wire into a hook shape at the end to snare the food hidden at the end of a tube.
The Australian crimson spotten rainbowfish has been shown to remember how to escape from a net in a tank 11 months after initially learning how to do it, which is the equivalent of humans remembering a lesson learnt 40 years ago.
For a long time dolphins have been a respected and much loved animal. Their intelligence has been closely aligned to that of our own. Their brain to body mass ratio is second only to humans, and larger than all other mammals. They are known to display complex play behaviours, produce creative responses, have self-awareness, and – famously – show empathy for human swimmers in need by helping them.
This is a species which is closest to humans in every way. In fact, apes share 99% of our genetic makeup. Their intelligence levels are not that far behind either. Apes can perform feats of intelligence which have included problem solving and reasoning. They have also been observed mourning the death of their kin. Apes are always at the forefront of any discussion of animal intelligence. They are indeed our closest relatives.