Comparative Primate

Sociality and mating patterns.

Lemurs mostly live on the island of Madagascar in the tropical forest. These creatures are arboreal and mostly nocturnal. Lemurs are very active at night and have a unique mating pattern that differs from most primates. Lemur females tend to dominate the males in their social groups. Their social groups contain both male and female lemurs ranging from 11 to 17 animals. The social group is centered around the female lemurs because females remain in their natal group while the males emigrate to a new group when they reach puberty. When a female lemur is ready to mate, only the highest ranking male lemurs will be allowed to approach her. If a female lemur does not like the male, she will act aggressively and chase him away. Females will approach males they want to mate with by lifting her tail and looking over her shoulder at him. The reproductive success is highly dependent on the environmental conditions. If the weather is bad, the survival of the infant can be diminished drastically.

Spider monkeys are found living in South America in the tropical evergreen forests. They generally live in the high rainforests where they are not affected by seasonal weather such as flooding. Spider monkeys are arboreal and live mainly in the trees. They are incredibly social creatures and can live in social groups containing up to 35 members. They do however split up during the day to search for food. These subgroups can be around 2 to 8 animals. At puberty, females tend to leave their natal group to join a new group. The male spider monkeys rarely leave their natal group and stick together their entire lives. Spider monkeys tend to bark or growl when they feel threatened. Groups of spider monkeys are generally led by a female who directs the feeding pattern for the entire group. Most primates groom each other for social interaction but that is not the case with the spider monkeys, probably due to their lack of thumbs. Females give birth every 3 to 4 years. She chooses a mate within her social group and they both sniff each other before they mate. The gestation period is about 226 to 232 days.

Baboons are found in Africa in open savannahs and open woodlands and hills. They do not live in trees but spend their time on the ground. Baboons live in groups of around 50 animals. Some groups are smaller while others can be very large containing up to 250 baboons. Most baboon groups are based largely on a hierarchy structure. Male baboons can be very jealous and protective of their females. There are usually many aggressive fights between males over female baboons. Males who win the fight will take the female into their own group. Sometimes infants are taken hostage during these fights. Males can mate with any females in their group. The male mating order depends on their rank. The females will show her swollen hump to the male when she is ready to mate. Females give birth once every two years and care for their young mostly without the help of a male. Male baboons leave their natal group while females stay in their group their entire lives. Male baboons tend to be aggressive due to the environment they live in. They constantly have to protect their females while fighting off other males. Their aggressiveness is greatly influenced by its environment.

Gibbons are found in the subtropical evergreen rainforests in Asia. Gibbons are very social creatures and also extremely territorial. They will defend their territories by singing. They also sing to attract mates. Female gibbons will sing songs to attract males when they are ready to mate. If the male likes her song, he will do a mating dance in front of her. After his performance, they will mate for three days. Gibbons are arboreal and can move in great speeds swinging between trees. Gibbons usually live with a mate and their dependent offspring. The gibbons use their mating song to adapt to its environment. If they feel threatened, they will vigorously use their visual and vocal display to scare away any predators.

Chimpanzees are found in Africa in dry savannas, evergreen rainforests, swamp forests, and dry woodlands. Chimpanzees live in large social groups containing both males and females. The group is part of a hierarchy structure with one alpha male. However, there are other higher ranking individuals within the group to dominate lower rank members. The alpha male influences the whole group and resolves issues within the group. The alpha male ma puff up his hair to appear larger to other members of the group to retain his dominance over them. Higher ranking members will get the first access to food and mates. The alpha females tend to choose who the alpha male will be in their group. If the alpha male is no longer seen fit to lead the group, the alpha females will choose another male to take his place. Female chimpanzees will leave their natal group when she is ready to mate. Her anogenital swelling will allow her to be accepted into a new group and will attract many males. Females will mate with multiple male partners within their group. Females sometimes leave their own group temporarily to mate with males from other groups. The hierarchy also comes into play with mating. High ranking males will often dictate which male will mate with which female. The environment and culture they live in will also play a part in their mating patterns.

The environment affects the way these primates act in their social groups and their mating patterns. Lemurs only mate one or two times a year depending on the weather conditions. If the weather conditions are bad, the infant may not survive. Spider monkeys tend to bark or growl when they feel threatened while the gibbons sing songs to scare away predators. The use of these tactics also are used when mating in the case of the gibbons. Baboons tend to be aggressive due to their constant struggle to fight off other males and to protect their females. Baboons often strike their females if they stray too far from the group. Both baboons and chimpanzees belong to a hierarchical structured group. The higher ranking members tend to get better access to food and mates. The way these primates act in their social groups are affected by their own culture and the environment surrounding them.