Macaque

Macaques are a diverse genus of Old World monkeys belonging to the subfamily Cercopithecinae. They are highly successful primates because they are incredibly adaptable to different environments. Aside from humans, macaques are the most widespread primate genus on Earth. They live in many different landscapes, from tropical rainforests in Southeast Asia to arid mountains in Pakistan. Some species even live in temperate mountains in Japan, China, or Morocco.

Their ability to survive in such varied climates makes them unique among non-human primates.

Physically, macaques are robust animals with arms and legs of similar length. Their fur is usually shades of brown or black. They have rounded muzzles with nostrils located on the upper surface. A key feature is their cheek pouches, which they use to store extra food. This allows them to gather food quickly and eat it later. Their tails vary by species; some are long, while others are short or even missing. Although some species lack tails, they are true monkeys and not apes.

Macaques are primarily frugivorous, meaning they prefer to eat fruit. However, their diet is very flexible and includes seeds, leaves, flowers, and tree bark. Some species, like the long-tailed macaque, also eat meat from insects, shellfish, or small mammals. In Malaysia, a southern pig-tailed macaque might eat about 70 large rats every year. When living near humans, they often raid crops like rice, wheat, or sugarcane. They may also eat garden fruits such as mangoes, papayas, and melons.

Social life for macaques is centered around complex groups called troops. A typical troop contains between 20 and 50 individuals. These groups are usually organized around dominant matriarchs, or female leaders. While males can be dominant, their rank often shifts frequently. Female dominance tends to last longer and depends on their family position. The group composition often includes 35% adult females and 15% adult males. The rest of the group consists of infants and juveniles.

Life stages in a macaque troop follow a specific pattern. After one year, infants move into the juvenile stage. During this time, they play and tumble with other young macaques. They typically reach sexual maturity between three and five years of age. Females generally stay with their birth group for life. In contrast, young adult males often disperse to find new groups. Some males may remain solitary for many years if they cannot join a new troop. Most macaques live between 20 and 30 years.

Because macaques share similar emotional and cognitive development with humans, they are often used in medical research. Scientists study them to understand the neuroscience of the visual system. This research involves studying areas like the premotor cortex.

However, this use in experimentation has caused the long-tailed macaque to become endangered. In 2018, scientists in China even used somatic cell nuclear transfer to create the first two crab-eating macaque clones. These clones were named Zhong Zhong and Hua Hua.

Macaques can also be synanthropic, meaning they live alongside humans. This can lead to conflicts in urban areas of Southeast Asia. Some macaques have become invasive in other parts of the world. For example, rhesus macaques live in Florida after being abandoned following a failed boat safari. Long-tailed macaques are also invasive in Mauritius. In these areas, they can damage local ecosystems by eating native seeds or destroying bird nests.

This can lead to the decline of species like the pink pigeon.

Living near macaques requires caution because they can carry diseases. Many captive rhesus macaques carry the herpes B virus. While this virus is harmless to the monkeys, it can be fatal to humans. This risk is one reason why macaques are not suitable as pets. To manage growing populations, some experts suggest sterilization. They estimate that sterilizing 80% of females every five years could keep populations in check. Other methods include live trapping or using specific vaccines to cause infertility.