Essay about Primate study

Submitted By Samuel-Mueller
Words: 766
Pages: 4

My research was conducted at the San Diego Zoo on December second. The zoo houses a variety of primates including: prosimians, New World, and Old World, great apes, and small apes. For my research paper I observed the western lowland Gorilla gorilla gorilla. Their enclosure at the zoo was a fairly big landscape with multiple waterfalls. As for toys I didn’t spot any buy there was plenty of tree branches scattered around to climb on. In this enclosure I found there only to be three gorillas. They are located in western and eastern central Africa, within deep rain forests. The vegetation there supplies them with an ample amount of food to take care of their young. The dominant male is called the “Silverback” and is the largest male in the troop. Gorillas exhibit sexual dimorphism, so males are much larger than females. Based on weight a male can get up too 181 kg and a female: 98 kg. Height on the other hand is closer together than weight. A male’s weight can reach up too: 1700 mm and a female is up too 1500 mm. Distinction upon a silverback can easily be spotted because they have a striking silver coloration from their shoulders to rump. Additionally, Male gorillas have a noticeable sagittal crest. The pelage of gorillas ranges from dark brown, to black hair depending on geographic region; with longer faces as well as a broader chest. (Cawthon, 2005) These primates are primarily terrestrial and spend the majority of their lives on the ground. This is where their food is and there is no need to climb trees unless resources are available arboreally. This primate is a herbivore which means that it has a diet of a vegetarian. When it comes to locomotion pattern of gorillas, it is simple to see that they are a quadrupedal animal that exhibits knuckle walking. In apes, the foramen magnum is more posteriorly located and better situated for quadrupedalism. After observing them for only five minutes I quickly came to this conclusion. It is easy to recognize that their foramen magnum is closer towards the back of the skull because when you look at them you can see they don’t have an s-shape spine like humans. While observing a particular gorilla I discovered his teeth had a formation known as C/P3 honing complex. These apes have a large projecting canine, which fits into a space called the diastema behind the lower first premolar. Each time the mouth is closed, the back edge on each upper canine gets sharpened. (Hens, 2010) When looking at their bodies I noticed a distinct difference in their stride. Their locomotion is quadrupedalism, and I wondered why this was? One of the answers lie in their pelvic girdle. Humans are bipeds and have a wide bowl shaped pelvic girdle, which gives us the ability to balance on either foot while walking. Alternatively, gorilla’s have a much longer and narrower pelvic girdle. Their gluteal muscles act as hip extensors and allow forward propulsion when locomoting quadrupedally. While observing their prehensile feet, I noticed that they possess a divergent hallux. A divergent hallux allows gorillas and other non-human primates to have grasping ability (or prehensility) in their feet. (Hens 2010) For the great apes the taxonomic classification of western lowland gorillas is: