Wednesday, September 17, 2014

Body Size and Sexual Dimorphism?.... Party of 5!

Lemur
There are several different species of Lemurs and all of which live in the top of the rain forest. The body size of lemurs can range from 1 ounce to 15lbs. However, even though there is a large size variety, there is no size difference between the sexes. One sexual dimorphism that is seen is the variance of color between one specific species, the Black Lemur. In this case the male is black while the female lemur is brown (pictured below). In analyzing the body size of the lemur and their environment, I would say that the environment definitely has an impact on the body size of lemurs. They need to be small and agile in order to navigate the top of the rain forest and climb through trees.



 Spider Monkey
Spider monkeys also live at the top of the forest in the tree canopy. They feast on nuts and other vegetation. One sexual Dimorphism of Spider monkeys is the body size of males and females differ. Males usually range around 24lbs while females are around 21lbs. Because the Spider monkey is larger than most canopy primates, they utilize their long tails to maneuver the trees. Their environment in the canopy affects the body size of the Spider Monkey in their large tails. If they did not have the need to maneuver in the trees, then possible their tails would be smaller.

Baboon
Baboons are a larger primate and can vary anywhere from 30lbs to 90lbs. Most species of Baboons live in Africa or Arabia. They tend to prefer savanna or other arid habitats. This primate is not typically seen in trees like the two previously mentioned. There is a strong case of sexual dimorphism in this species seen in body size, color and even canine development. Female baboons can weigh around 40lbs while males typically weigh double the female, at 80lbs. Also, in Hamadryas baboons, the male baboon typically has a long mane type hair around his face (see below). In the picture below you can see the size difference and color variation between the male and female baboons. In the case of Baboons, it is hard to tell if the body size and sexual dimorphism is a reflection of their environment. However, in looking at the picture below I definitely thing the coloration of the two baboons would help to disguise them in an arid environment.


Gibbon
Gibbons primarily live in the tropical rain forests. There they can be seen swinging from branch to branch reaching up to 35mph. Gibbons display sexual dimorphism in their coloring. Depending on sex, Gibbons can vary from light brown to dark brown and even black to white. Also, males tend to weight around 16 lbs and are larger than females. Similar to the spider monkey and lemurs I think the Gibbons body size is affected buy their environment. The gibbons have to be small enough to maneuver through the trees but they also use their long arms to swing from tree to tree very quickly to get food or avoid enemies. 
                                                  


Chimpanzee
Chimpanzees are found in Africa. They typically live in tropical rainforests, but continue to adapt to their ever changing environment as needed. Chimpanzees are the largest species discussed here. A male chimpanzee can weigh as much as 150lbs. Chimpanzees show sexual dimorphism in size because the males are slightly larger than the females. Chimpanzees are very versatile creatures and can be seen gathering food or sleeping in trees, but they also “Knuckle walk” on the forest floor. Chimpanzees are really suited for their environment. I think at one point the chimpanzees environment pushed them to be able to knuckle walk and not just swing from tree to tree. This may have been caused by low food sources in the tops of the trees.