Chimpanzees, otherwise known as Pan Troglodytes, are a species of higher primates that inhabits the tropical forests of central Africa (Shefferly). According to Shefferly, the common chimpanzees are found from Gambia to Uganda, excluding the region bordered by the Congo and Lualaba rivers. Shefferly goes on writing about how chimpanzees can make a habitat out of various types of forests, ranging from tropical rainforest to forest-savanna to mountain forests. Adult chimpanzees possess a head and body length of around 635-925mm, 25-36. 42in for those not versed in the metric system (Shefferly).
There is sexual dimorphism in regards to the weight and size of male and female chimpanzees. The weight of male chimpanzees varies between 34-70kg, 74. 96-154. 32lbs, while female chimpanzees weigh around 26-50kg, 57. 32-110. 23|bs (Shefferly). Shefferly notes that captive chimpanzees tend to accumulate more weight; the top weight recorded was 80kg, 176. 37lbs, for a male and 68kg, 149. 91lbs, for a female. In general, the male chimpanzees are larger than the female chimpanzees. The chimpanzee is capable of brachiating through the trees, as hinted by their long hands and fingers.
Shefferly notes that they possess short thumbs in addition to the longer hands and thumbs. When on the ground, they exhibit knuckle-walking, where they would, as one would assume, walk on all fours, using its hand’s knuckles to support its upper body. The face of adult chimpanzees, according to Shefferly, is usually black, or smeared with some brown; the hair color ranges from black to brown, with white hairs scattered about around the face. Shefferly notes that infants can easily be identified by their white tuft of hair on their rear ends.
She also notes that chimpanzees lose hair on their head as they age, as well as having hair becoming grey around the lumbar region being a common phenomenon of aging as well. Tool Manufacturing and Use among Common Chimpanzees in the wild The first example, in no particular order, of chimpanzees manufacturing (or modifying, whatever floats your cement boat) tools would be termite fishing. A chimpanzee will modify a twig or a blade of grass then insert the contraption into a small hole that the chimpanzee had made beforehand by prying at the termite mound with its finger.
The chimpanzee then fishes out termites that latch on to the rod (Lonsdorf). The chimpanzee will then place the rod between its lips and pull it sideways, similar to someone pulling a piece of meat off of a kebab. The second example of tool manufacturing amongst the chimpanzees would be the use of leaves to collect water. As Tonooka observed in “Leaf-folding behavior for drinking water by wild chimpanzees (Pan troglodytes verus) at Bossou, Guinea,” the chimpanzees folded leaves in 3cm intervals and soaks it in water; the chimpanzee proceeds to then stick the leaf/leaves into its mouth and drink the water from the sponge.
There are other instances where the chimpanzee simply chews up a wad of leaves and sticks it into a water source, rather than folding the leaves. The third example of tool use amongst the chimpanzees in the wild is the use of stones to crack open nuts, as observed by Benito-Calvo in “First GIS Analysis Of Modern Stone Tools Used By Wild Chimpanzees (Pan Troglodytes verus) In Bossou, Guinea, West Africa. ” Captive Chimpanzees
In Horner’s article titled, “Causal Knowledge and Imitation/ emulation Switching in Chimpanzees (Pan Troglodytes) and Children (Homo Sapiens),” Horner sets up a series of experiments for captive chimpanzees in order to test their abilities to solve puzzles. The first experiment consisted of twelve chimpanzees and two different types of boxes that were equipped with doors and the like for the chimpanzee to solve. The boxes were designed identically with the exception of the box’s transparency. One of the boxes is opaque while the other is clear.
Horner hypothesized, and confirmed, that the chimpanzees that received the box that was opaque would attempt to look down the opaque tube to find out the contents of the box, as casual information is restricted. The test subjects were played with or groomed for roughly five minutes before entering the testing room, where the tests were conducted individually and began when the subjects were deemed comfortably situated. Whiten, Horner’s co-author, proceeded to demonstrate opening the box three times in a row prior to the first trail.
After the first trail, the subject would then have only one demonstration prior to the other trials. The trials lasted five minutes or when the box is opened and the reward is retrieved, whichever happens first. When a trail is over and the box needed to be rebaited, the subject was guided to another room and brought back after the box had been reset. There were multiple ways the box could have been open. Horner noted multiple attempts at opening the box, such as lifting the door, sliding the door, banging on the box, or using a tool to open the box.
The second experiment Horner conducted with the same twelve chimpanzees a week after the first experiment. This experiment was again an individual task. Horner set up the experiment like so: there would be two metal rakes side by side, positioned in a way where it would encourage the chimpanzees to pull the rake towards them. One rake had a reward that is directly attainable by simply pulling the rake towards them. The other rake had the fruit located somewhere off of the rake’s trajectory, so if the chimpanzee were to pull that rake, obtaining the fruit would be nigh impossible.
Surprisingly, Horner observed that the correct tool was chosen significantly more than what was expected. The third experiment is conducted by another set of people, lead by House in “Task Design Influences Prosociality in Captive Chimpanzees (Pan Troglodytes). ” The experiment was conducted with socially housed chimpanzees, where one chimpanzee would be the actor and the others would be the recipients. The experiment functioned by giving the actor the choice of obtaining a reward, which were slices of apples, by pulling a basket located at the top of the actor’s cage.
The actor’s basket is linked to the recipients’ basket, which is located at the bottom of the recipients’ cage. Both baskets are visible to the actor. The experiment was run multiple times, where the payoff, ratio of apples for the actor and for the recipients, varied from 1:1, 1:0, 0:1, 0:0, and 1:3. House observed that actors were more likely to pull the bin when the recipients were to receive a reward, which was contrary to his hypothesis of the actor acting for selfish causes. Culture among Chimpanzees
The scholarly definition of the word culture, as defined by “Culture Definition,” is defined by the following quote: Culture refers to the cumulative deposit of knowledge, experience, beliefs, values, attitudes, meanings, hierarchies, religion, notions of time, roles, spatial relations, concepts of the universe, and material objects and possessions acquired by a group of people in the course of generations through individual and group striving (“Culture Definition”). Analyzing this definition of culture, there is some gleaning that must be done.
Firstly we can take care of the most obvious things that chimpanzees do not have. Chimpanzees do not have experiences, beliefs, values, attitudes, meanings, hierarchies, religion, notions of time, roles, spatial relations, concepts of the universe, nor material objects (well, as far as we know anyways). The only two traits that are left to define culture are simply the aspects of knowledge and hierarchies. The passage of knowledge is noted in chimpanzees, such as the skill of termite fishing is passed down from the mother (Lonsdorf) or other behaviors, like leaf sponges Tonooka) or stone uses (Benito-Calvo).
Hierarchy indeed exists amongst the male chimpanzees, but there isn’t much to say about the hierarchy system as it isn’t as complicated as human’s hierarchy system. Chimpanzees possess some aspects of culture, which was defined by humanity for humanity, but only makes the cut for only two of the thirteen requirements of the definition of culture. Conclusion In general, the chimpanzees, otherwise known as Pan Troglodytes, are a species of higher primates that can live in multiple biomes in their natural habitat (Shefferly).
They can use tools for simplistic things, such as opening nuts (Benito-Calvo), fishing for termites (Lonsdorf), and drinking water (Tonooka). Regarding culture development amongst the chimpanzees, believe that there is some form of culture amongst the chimpanzees. This is already exhibited by how the use of tools is passed down from parent to child (Lonsdorf). There are some actors in the definition of culture that I cited which cannot be acquired by the chimpanzees, religion being just one of the many defining factors of culture.
There may be some factors that may have not yet been observed amongst chimpanzees that contribute to culture, such as material objects and beliefs. One thing I wish to point out was what was discussed in class, when a captive chimpanzee blatantly lied to its trainer. The act of lying may have much greater significance than one may think. The act of lying shows that the chimpanzee was aware that it had done something wrong and attempted to cover up its wrongdoings. Somewhere, that chimpanzee had learned to or had been taught how to lie.
