Mandrill

The mandrill (Mandrillus sphinx) is a large primate native to west-central Africa.

It is recognized as one of the most colorful mammals on Earth. These monkeys primarily inhabit tropical rainforests, though they also navigate savannas and gallery forests.

They are diurnal animals, meaning they are active during the day. Most mandrills spend the majority of their time traveling on the forest floor. Because they rely on specific forest types, they are currently classified as vulnerable on the IUCN Red List. This status is due to hunting for bushmeat and the destruction of their natural habitats.

Mandrills exhibit extreme sexual dimorphism, which means males and females look very different.

Males are much larger and more stocky than females. They possess much longer canine teeth, which can reach up to 2 inches in length.

The males also feature much more vibrant skin coloration. This color is produced through two different biological processes. The red hues come from blood vessels located near the skin's surface. The blue colors are a result of structural coloration. This occurs because collagen fibers are arranged in parallel layers.

In males, these blue sections are supported by ridged bone swellings on the face. Females have more subdued facial colors due to melanin, a natural pigment.

Socially, mandrills live in massive, stable groups called "hordes."

These groups are not just temporary gatherings of smaller groups. They are cohesive social units that can include hundreds of individuals. In Gabon's Lopé National Park, researchers found an average horde size of 620 members. Some massive groups have even reached 845 individuals.

Within these hordes, females form the core social structure. They live in matrilineal groups, which are families based on female relatives. These connections help maintain social cohesion and improve offspring survival. Adult males are typically solitary. They only rejoin the large hordes during the breeding season. Dominant males often have the brightest colors and the most success in siring young.

Mandrills are omnivores with a highly varied diet.

They consume over one hundred different plant species. In Lopé National Park, fruit makes up 50.7% of their diet, followed by seeds at 26.0%. They also eat leaves, pith, and flowers. Mandrills are particularly skilled at eating seeds. Some adult males can even bite through the hard shells of Detarium microcarpum seeds.

Their diet also includes animal matter, which accounts for about 4.1% of what they eat. This includes invertebrates like ants, termites, and scorpions. They may also eat birds, eggs, frogs, and rodents. In some cases, they have been known to prey on larger animals like juvenile bay duikers. They may even cooperate with others to hunt these animals.

Understanding the mandrill's history involves looking at both names and science.

The name "mandrill" comes from the English words "man" and "drill." It has been used since 1744, though it originally referred to chimpanzees. The scientist Georges-Louis Buffon first used the name for this monkey in 1766. Earlier, Thomas Pennant called them the "great baboon" or "ribbernosed baboon." Conrad Gessner first depicted them in the mid-1500s, but he mistakenly thought they were a type of hyena. Carl Linnaeus formally classified the species in 1758 as Simia sphinx. Later, in 1824, Ferdinand Ritgen coined the current genus name, Mandrillus.

Modern science has changed how we view the mandrill's family tree.

For a long time, scientists thought mandrills and drills were baboons. However, genetic and morphological studies show they are actually more closely related to white-eyelid mangabeys. Genetic research in 2011 confirmed that Mandrillus and Cercocebus are separate sister lineages. These two lineages split approximately 4.5 million years ago. The mandrill and the drill split from each other about 3.17 million years ago. While some scientists once suggested there were different subspecies, most now agree there is only one: Mandrillus sphinx sphinx. Recent studies of their DNA have even helped scientists understand how certain viruses, like SIV, evolve within these populations.

Mandrills face several natural challenges in the wild.

Predators like leopards can hunt mandrills, while eagles may target the young. To stay safe, mandrills use different reactions based on the threat. When they sense a leopard, they often flee up into the trees. When they sense an eagle, they are more likely to seek cover. They also deal with various parasites. These include gastrointestinal parasites, ticks, and blood parasites like the malaria-causing Plasmodium. Despite these dangers, mandrills are resilient animals. In the wild, they typically live between 12 and 14 years. However, in captivity, they can live much longer, reaching 30 to 40 years of age.