In zoos, we often see young monkeys in monkey mountains or monkey enclosures imitating the behaviors of adult monkeys. In circuses, monkeys can play drums and cymbals, direct goats in performances, and even ride on the backs of horses. Apes and monkeys not only mimic basic human actions but can also learn more complex activities. In experiments, monkeys have been observed watching humans hammer nails and then attempting to mimic the action with nails and a piece of wood on the ground, eventually learning to accurately hammer nails into the wood. Some primates, more intelligent than monkeys, can use past experiences to approach similar situations, demonstrating a certain level of memory. This illustrates that primates possess developed cognitive abilities, unlike the arithmetic abilities of dogs in circuses.
Why can apes and monkeys imitate humans and even complete tasks through rudimentary forms of “thought”? This ability is linked to their advanced intellectual behaviors. While the brain of a gorilla is smaller than that of a human relative to body weight, it is proportionally substantial, about one hundred and fifty times the size relative to body weight. Human brains, by comparison, occupy about thirty-five to forty-five times their body weight. Because apes and monkeys are arboreal, their brains have evolved under the influence of arboreal life, requiring greater flexibility and coordination of muscles for tree-based movement, thus promoting the development of their central nervous system, especially the brain. As brain capacity increases and the cerebral hemispheres expand, including the cerebellum being completely covered, intelligence develops, enabling them to express various emotions and begin to recognize and learn, hence their strong imitative abilities.
In terms of dietary needs, all animals require varying levels of salt supplementation. Among zoo animals, hippos are known to consume the highest amounts of salt. Each hippo needs to ingest 600 grams of salt daily to meet its physiological needs.