DRILL MONKEY
Description
The adult male drill is one of the more colorful monkeys in the world. A mature male has a red chin on a black face with raised grooves on the nose. The rump is colored pink, mauve and blue. These bright colors help his family follow him through the forest. Female drills are less colorful.
Habitat
The drill is mainly found in the African Rain Forests.
Behavior
A single male leads a group of around 20 females and is father to all the young. This group of 20 may join others forming super groups of over 200 individuals. They will often rub their chests onto trees to mark their territory.
A drill can live for about 28 years.
Diet
The drill is omnivorous, with a diet ranging from fruit, herbs, roots to small animals.
Lifestyle
Drills live in large social groups (as many as 20 individuals) with many dominant adult males (but only one leader). These groups can merge with other groups, creating large groups of over 200 individuals. Besides facial expressions, drills also utilize a wide range of vocal, olfactory, visual and tactile forms of communication to keep their group together, as well as to keep other groups away. They mark their territory by rubbing their chests on trees. Drills are diurnal, so they are most active during the day.
Food
Drills are mainly frugivores (eating primarily fruit), but will also eat insects and edible plants. In addition to those items, the Zoo’s drills also eat vegetables, lettuce and a dry food containing vital nutrients.
Life Cycle
Females reach sexual maturity at about 3 years old, while males are sexually mature at about 6 years old. Gestation is 179-182 days, and a drill female usually gives birth to asingle offspring (there has been one documented case of twins). The offspring stays with its mother for 15-16 months until it is fully weaned. Males will usually disperse from their natal group to form new groups. The average life span is 28-30 years.
Some of My Neighbors (IN THE WILD)
Chimpanzees, olive pigeons, Rumpi mouse shrews, Preuss’s monkeys and African pygmy squirrels
Population Status & Threats
Drills are among Africa’s most endangered primates because their numbers have been declining in all known habitat areas for decades. The decline is due to illegal commercial hunting, habitat destruction and fragmentation, and human development. Unfortunately, fewer than 10,000 drills remain in the wild, and numbers may be as low as 4,000. Drills are fully protected by law in Nigeria and Cameroon, and portions of their habitat are technically safeguarded as national parks. However, little real protection from hunting exists for drills, even in so-called protected areas.
Noisy and curious, intelligent and social, the chimpanzee is the mammal most like a human. Chimpanzees fascinate humans and are favorites both in zoos and the wild.
Habitat
They are able to wedge nuts between the roots of a tree and break the shells open with a stone.Chimps are both arboreal and terrestrial, spending much of their daytime hours on the ground. They are quadrupedal, walking quickly on all fours with the fingers half-flexed to support the weight of the forequarters on the knuckles. They occasionally walk erect for short distances.
Predators
Orangutans are the only exclusively Asian genus of extant great ape. The largest living arboreal animals, they have longer arms than the other, more terrestrial, great apes. They are among the most intelligent primates and use a variety of sophisticated tools, also making sleeping nests each night from branches and foliage. Their hair is typically reddish-brown, instead of the brown or black hair typical of other great apes.Native to Indonesia and Malaysia, orangutans are currently found only in rainforests on the islands of Borneo and Sumatra, though fossils have been found in Java, the Thai- Malay Peninsula, Vietnam and Mainland China. There are only two surviving species, both of which are endangered: the Bornean Orangutan (Pongo pygmaeus) and the critically endangered Sumatran Orangutan (Pongo abelii). The subfamily Ponginae also includes the extinct genera Gigantopithecus and Sivapithecus. The word “orangutan” comes from the Malay words “orang” (man) and “(h)utan” (forest); hence, “man of the forest”.
Orangutans live a more solitary lifestyle than the other great apes. Most social bonds occur between adult females and their dependent and weaned offspring. Adult males and independent adolescents of both sexes tend to live alone. The society of the orangutan is made up of resident and transient individuals of both sexes. Resident females live with their offspring in defined home ranges that overlap with those of other adult females, who may be their relatives like mothers and sisters. One to several resident female home ranges are encompassed within the home range of a resident male, who is their primary breeder. Transient males and females range broadly. They usually travel alone, but as sub-adults they may travel in small groups. However this behavior does not extend to adulthood. The social structure of the orangutan can be best described as solitary but social. As the ranges of males and females overlap, they commonly encounter each other while traveling and feeding and may have brief social interactions.Interactions between adult females range from friendly, to avoidance to antagonistic. Resident males may have overlapping ranges and interactions between them tend to be hostile.
During dispersal, females tend to settle in home ranges that overlap with their mothers. However, they do not interact when them any more than the other females and they do not seem to form bonds though affiliation, grooming, or agonistic support. Males disperse much farther from their mothers and enter into a transient phase. This phase lasts until a male can challenge and displace a dominant, resident male from his home range.There are dominance hierarchies between adult males that regularly encounter each other with the most dominant males being the largest and having the best body conditions. Adult males dominate sub-adult males. Both resident and transient orangutans aggregate on large fruiting trees to feed. The fruits tend to be abundant, so competition is low and individuals may benefit from social contacts. Orangutans will also form travelling groups in which members coordinate travel between food sources for a few days at a time. These groups tend to be made of only a few individuals. They also tend to be mating consortships, each made of an adult male and female traveling and mating.


