Cercocebus atys

The head and body length of male white-naped white-browed monkeys is 47-67 cm, and that of females is 45-60 cm; the tail length is 40-80 cm; the weight of males is 7-19 kg, and that of females is 4.5-7 kg. It is a medium-sized monkey living in Africa, with a tail longer than its body. It is also called the black-naped white-browed monkey, with dark smoky-gray fur, lighter underparts, and slightly darker hands and feet. There is a fairly long whisker on the nose and mouth, and the exposed facial skin is dark gray or mottled. The upper eyelids are amazingly pure white. The eyelids can be clearly seen flickering in combination with various expressions, which are used for communication.
There are 2 subspecies: the nominate subspecies (black-naped white-browed monkey) and the white-naped subspecies. As the name suggests, the black-naped white-browed monkey has smoky-gray black fur all over, occasionally with a small stripe on the back, but never has a whorl or crown of different colors o

Distributed in Burkina Faso, Côte d'Ivoire, Ghana, Guinea, Guinea-Bissau, Liberia, Senegal, Sierra Leone.
It inhabits tropical rainforests, primary forests, secondary forests, forest belts and swamp wetlands of terrestrial biomes, and resides in moist and dry valleys and mangroves. It is distributed from tropical savannas to woodlands in Guinea. It also inhabits forests and palm groves along rivers and near swamps in farming areas. The Tai National Park in southwestern Ivory Coast is the only primary forest left in West Africa, where many wild populations of white-naped white-browed monkeys are found, providing a broad basis for studying the species. In this park, the average rainfall is 1,830 mm and the average temperature is 24 degrees Celsius in the second season of each year. The vertical height at which the white-naped white-browed monkey lives ranges from sea level to more than 1,000 meters.

White-naped mangabey (scientific name: Cercocebus atys), also known as Sooty Mangabey in English, is a medium-sized monkey living in Africa.

White-naped mangabey lives in multi-male and multi-female family groups, with 15-100 individuals in each group. This social structure results in a promiscuous breeding system, where both males and females have multiple mating partners.

Females are more selective in this promiscuous system, however, females are often victims of male aggression, and males will mate with multiple females in their group during estrus, and females can also mate with multiple males. Males from outside the group often attack females with infants, killing infants and succeeding repeatedly. Older and higher-ranking males defend the females they have mated with and protect their infants. Females immediately go into estrus after infanticide.

White-naped mangabeys are diurnal monkeys that live on the ground. They have sexually dimorphic behavior patterns: males engage in social behaviors more frequently, such as fighting. Although mostly terrestrial, they occasionally roost in trees, especially to avoid predators.

The diet of white-naped mangabeys is relatively narrow, mainly eating fruits and nuts, especially palm fruits, but also eating stems, roots, buds, grains and swamp plants, as well as leaves of grasses, seeds, fungi and fungi. Invertebrates are another staple. They have extremely strong jaws and large incisors to facilitate the consumption of hard food. 25% to 80% of the entire diet varies seasonally, mostly nuts recovered from forest floor litter, and the powerful rear molars can bite the shells of hard nuts. Occasionally, they eat animal food, such as ground insects and worms, excluding arthropods.

Male white-naped mangabeys have sexual awakenings before the age of 1, but their earliest ejaculation is at the age of 4. The puberty of females is 4 years old, and they reach sexual maturity for reproduction at 5-6 years old. Male adolescents mature earlier than females. Females will have their first menarche at 30-39 months, when their genitals swell, and usually give birth to their first baby about a year later at 49 to 55 months old. The average interval between each birth is 13-16 months, and the low infant mortality rate is related to the longer birth interval. Female white-naped white-browed monkeys give birth to one baby at a time, with a birth rate of 0.92/year.

The breeding season of white-naped white-browed monkeys is from May to September, with an average gestation period of 167 days, the earliest weaning period is 4 months, the average weaning period is 10 months, and the average age of reproductive maturity is 4 years. After the baby is born, it will be carried by the mother on the ventral side, but in the next few months it will cling to its back. The female will give the baby 2-7 months of careful feeding and care, and the lactation period is 4-10 months. The relatives of the cubs, there are other brothers and sisters and elders aged from 10 to 12 months old in the group. If the female loses her cubs within 6 months, she will immediately enter the estrus period again, so the males will kill these cubs within 6 months, and infanticide will occur in order to mate with the females. After birth, the status of the cubs in the group ranks second only to the mother, but the male offspring will rise rapidly and rank above the mother after a few years.

The biggest survival crisis facing the white-naped white-browed monkey is habitat degradation caused by forest fragmentation, which is caused by human logging and forest loss. There are also local people who hunt for meat. Another major threat is that the species invades agricultural areas, raids crops or is hunted. However, in the northern and western areas of its distribution, where Muslims live, hunting is not considered a major threat. The nominate subspecies lives in some protected areas, including Tai National Park and Sapo National Park. The white-naped subspecies lives in Comoe National Park, but is still threatened by civil conflict and hunting, and is in urgent need of protection and is listed as endangered. It has also been recorded in Dadieso Forest Reserve in Côte d'Ivoire and Malawi National Park. Many protected areas should be upgraded to national park status.

Listed in the 2012 IUCN Red List of Threatened Species ver 3.1 - Vulnerable (VU).

Nominated subspecies - Vulnerable (VU); [4]  White-naped subspecies - Endangered (EN).

Protect wild animals and stop eating game.

Maintaining ecological balance is everyone's responsibility!