Primates

Lemur (Prosimians/Strepsirhini)

This particular primate lives “exclusively on the island of Madagascar and the nearby Comoro Islands” as stated by the website anthro.palomar.edu. Madagascar has a tropical climate on the coast, and arid in the south.

These primates body size varies within lemurs, some species are slightly larger than mice and others are up to four feet long. They have long bushy tails that are used for balancing as they jump from branch to branch. However they cannot grip with their tails, they use their hands and feet to move through the trees. Most lemurs rarely go on the ground but ring tail lemurs spend majority of their time on the ground. They like to feed at night so they can avoid larger predators, and are mostly nocturnal. They also have a well-developed sense of smell and often mark territorial limits with scent.

When it comes to sexual dimorphism, Lemurs are different from other primates because the females are usually bigger than the males. Also in certain species of lemurs you can determine the sex by their fur color.

A larger lemur needs less energy than a smaller lemur would. Their diets prove this is true because larger lemurs are herbivorous while the small dwarf and mouse lemurs have an insectivorous diet. Therefore their body size is adaption to their environment. 

 

Spider Monkey (new world monkey/ Platyrrhini)

New World monkeys are limited to tropical forest environments of southern Mexico, Central, and South America

The New World Monkeys vary in sizes, which range from 18 to 25 inches and weigh around 10- 19 pounds. Due to the lack of dimorphism, males and females are relatively the same size. However the males can be slightly bigger than females.  Due to the fact that this species are all small and they don’t need to be bigger to attract a female or fend off any other males they do not differ in size too much. 

 

 

Baboon (Old World Monkey/Cercopithecidae)

Like the chimpanzee, the baboon is an African species. Baboons generally prefer savanna and other semi-arid habitats, though a few live in tropical forests according to national geographic.

On average baboons weigh from 33 to 82 pounds. Baboon bodies are 20 to 40 inches long, not including substantial tails of varying lengths. They do not have gripping tails like many other old world monkeys, but they can and do climb trees. The website http://anthro.palomar.edu states “cercopithecines are usually very sexually dimorphic…Adult males are often twice as large as females and much more aggressive.   Male savanna baboons grow up to 80 pounds and have powerful jaws with long canine teeth.”

These male traits are influenced by the environment because they are effective weapons in defense against predators and competition with other males for mates.

 

The baboon on the left is a female, and the baboon on the right is a male.

Gibbon (lesser ape/ Hylobatidae)

Along with orangutans, gibbons live in the dense forests of south Asia.

According to the website anthro.palomar.edu, gibbons are the smallest and the most arboreal species. Most gibbons are about 3 feet tall while standing upright. They weigh around 12-20 pounds, however the males in the biggest gibbon species can weigh up to 30 pounds. The anthro.palomar.edu website also states “Gibbons have little sexual dimorphism in body size, with the exception of siamangs.  However, the sexual dimorphism of siamangs is slight compared to that of the great apes.”

Their body size has been influenced by the environment because they live in the forests of Asia. They move around from tree to tree using suspensory climbing. If they were bigger or weighed more it not only would be difficult for the species, but a lot of the tree branches in the forest would not be capable of carrying all of that weight. 

 

 

Chimpanzee (great ape- hominidae)

Along with gorillas and bonobos, chimpanzees are exclusively African apes. Chimpanzees can be found in the rain forests and wet savannas of Africa.

Male chimps grow to 5½ feet tall and average about 100 pounds with 6 foot arm spans. The female chimpanzees are usually only around 82 pounds and are less muscular. This species is comfortable with walking on all fours, or swinging from trees. The difference between a male and a female chimp is their size. The males are bigger and the females are smaller as stated before. Males need to be bigger and stronger to be dominant over other males.

The male chimps size is important because their size attracts female chimps, and is an advantage when fighting other males for dominancy and passing on their genes.