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Orangutans (Pongo Pygmaeus) Man of the Forest Origins The word Orangutan consists of two Malaysian words Oran (person) and Human (forest). Orangutans belong to Primates order of Hominidae family. In Latin, they are referred to as Pongo Pygmaeus. It is believed that their origins can be traced back to Pleistocene period, about 2 million years ago.
The area of their habitat used to include most parts of Southeast Asia. However, in our time, orangutans can only be found in secluded areas of Sumatra and Borneo islands. Many biologists do not agree with the theories that place the origins of orangutans in Pleistocene, because there is no intermediate fossil record that would link modern orangutans to what is believed to be their ancestors. Andrew Harcourt and Michael Schwartz in their article Primate Evolution: A Biology of Holocene Extinction and Survival on the Southeast Asian Sunda Shelf Islands suggest that orangutans evolved from unknown sub-specie of Hominidae in more recent times: The evolution had simply redesigned orangutans. Neither of ancient Hominidae's, which are believed to be orangutans ancestors, were adapted for living on trees.
Therefore, it is much more logical to suggest that orangutans evolved from terrestrial primates (Harcourt, Schwartz. 2001. p. 17). Fossilized remains of ancient orangutans, which date back to 40. 000 years ago, suggest that they used to be at least 30 %- 40 % larger than todays specie. This implies that they were spending most of their time on the ground. Some biologists believe that the danger, posed by the predators like tigers, made orangutans to adapt for the life on trees, around the same time. Still, it appears doubtful whether the ancient orangutans were able to claim up the trees, because of their sheer size.
Therefore, much of uncertainty still surrounds the origins of orangutans. The Darwinist theory fails to explain evolution of orangutans in terms of survival of the fittest, because their adopted qualities did not come as the response to objective reality. In fact, the evolution of orangutans appears to be reversed. They used to much larger and they used to be a terrestrial primates. However, at present time, orangutans live up on trees, while being significantly smaller.
This contradicts the most basic law of natural selection, which states that evolution of life progresses from more primitive forms to more complex. We know that the rest of primates evolved in opposite direction. There is no anthropological evidence, which would support the claim that it was the fear of tigers that made orangutans to change the niche of their habitat. Lifestyle and Behavior Even though that there is only one specie of orangutans, those animals that live in Sumatra slightly differ from their Borneo's brethren's. They have less massive bodies and longer hair. The most distinctive feature of orangutans is the color of their hair.
It can often be a bright orange, which is unique among mammals. Orangutans males have a large cheek pads, which also makes their appearance very memorable. The adult males are twice as large as females. Orangutans long arms and legs allow them to move through the trees, but their size prevents them from doing it fast.
Usually, the adult orangutan reaches his arm to a closest branch and begins to shake it violently, in order to test whether it is going to support his weight. After this, he hangs on this branch and tries to reach another one, and so on. John Howard in his article Orangutan, which can be found at Honolulu Zoo web site, gives us an insight on how orangutans move: Considering the large size of the orangutan, movement from one tree or branch to another is graceful and agile, yet slow. An orangutan seldom covers more than mile in a day (1 km). However, they have a vast range in which they hunt for their food.
Males may use several thousand hectares and females use several hundred (Howard, 2002). Orangutans are active in daytime. Most of the day orangutans spend in searching for food, 60 % of which consists of fruits. However, they also eat birds eggs, insects and event small rodents, when available. Their most favorite food is a fruit of Durai tree, which has a strong garlicky odor. Orangutans discard the peel, but they swallow seeds, which helps propagation of Durai tree.
Every day, before it gets dark, orangutans build nest on trees branches, where they sleep overnight. They also build a temporary nest to take naps, during the day. Orangutans IQ is comparatively high, which allows them to memorize locations where they can find food. For example, these animals know the time when every particular tree yield fruits.
Recent studies suggest that orangutans posses a feeding plan, because their movements are well adjusted with ripening of various fruits that occurs in different times of year. Orangutans often use sticks and rocks to knock fruits off trees. Carl Zimmer in his article Tooling through the Trees - Tool use by Wild Orangutans suggests that these animals are much smarter then is it generally accepted: Orangutans use tools to eat fruit. When the fruit of the Neesia tree ripens, its hard, ridged husk softens until it falls open. Inside are seeds that the orangutans love, but they are surrounded by fiberglass-like hairs that, as van Schaik can personally attest, "hurt like hell. " A Neesia-eating Orangutan will select a five-inch stick, strip off its bark, and then carefully collect the hairs with it.
Once the fruit is safe, the ape pops the seeds out with the stick or with its fingers (Zimmer, 1995). Peter Kappeler in his work Primate Biogeography provides us with even more striking examples of orangutans intelligence: Borneo's orangutans are known to fold leafs in cups that they use for drinking water (Kappeler. 2002, p. 940). This points out to the fact of orangutans being very intelligent animals. Before they became endangered specie, orangutans were being widely used in circuses, because of their ability to learn tricks. Orangutans have a long life span. They are known to live up to 30 years in the wild.
In captivity, many of them live up to 50 years, because of being spared of natural dangers. Orangutans females mate with a few males, when they are in heat. Before actual mating, the couple might hang out together for a few weeks. However, after the copulation, males leave female in search for other partners. The degree of inbreeding among orangutans is insignificant, because males travel great distances in their search for females. This is also the reason why orangutans were able to survive, as specie, up until today.
Even though that the number of orangutans is declining, these animals managed to strengthen their biological quality, by avoiding inbreeding practices, which is very common among other primates. This, of course, cannot be considered as product of their rationalizing. Objective circumstances make orangutans to mate with each other in a way, if they were planning to have healthy babies. Despite the fact that female orangutans rarely give birth to more than one infant, at the time, the reproductive fitness of orangutans, as whole, appears to be high.
This is because orangutans after-birth survival rate reaches 80 %. It comes as the result of orangutans not having many natural enemies in the tropical forests of Borneo and Sumatra. Nevertheless, the reproductive fitness is also measured by species ability to colonize and dominate the environment. Such ability is directly linked to the quantity of birthed offspring. In this respect, orangutans fall behind other primates. Orangutans low fertility undermines their capacity to adapt to changing environmental conditions.
This is the real reason why number of orangutans is rapidly declining. Orangutans cannot be considered as genetically flexible specie, because the chance of new qualities emerging among them is reduced to almost a zero. Even a slight alteration of environmental conditions can lead to a full extinction of orangutans, as specie. The process of evolution gives us many examples of life forms losing their survival competitiveness. When survival of organism is not being constantly challenged by various environmental forces, its evolution development becomes stagnant. Biologists often refer to species that had lost their competitive edge, as the dead end of evolution.
It seems that this term can also be applied to orangutans. Therefore, attempts of various environmental organizations to save orangutans from extinction in their natural habitat can never be effective. It is much more likely that orangutans are only going to be able to survive, when they become a zoo exhibits. Group Size and Structure The main characteristic of orangutans social structure is that they are semi-solitary animals. In her article Orangutan (Pongo) Behaviour Kristina Cawthon Lang explains it by referring to animals large size: The social structure of orangutans is related, in some capacity, to their body size and diet. Because of their large size, they have high caloric needs and fruit is not uniformly available, spatially or temporally, in large enough amounts to permit permanent social groups.
As a result, there is evidence for individual-based fission-fusion grouping where animals associate in parties on a fairly regular basis, but mean party size tends to remain very small (Cawthon, 2005). Nevertheless, orangutans do form travel bands. This usually happens when the whole tribe relocates to a new place in search for more food or while escaping from some immediate danger, such as forest fire. In addition, sometimes orangutans are seen forming groups, in time when food is abundant. Biologists refer to such groups as feeding aggregations. Usually they consist of one dominant male and few submissive males and females, who come to feed, off the same tree.
There are no visible signs of discipline within such aggregations; however, this is a wrong impression. The dominant male remains firmly in control at all time, although he rarely needs to reinforce his authority. The closest social bonds among Orangutans exist between mother and her offspring. Female pregnancy usually last for nine months and results in giving birth to one infant. After this, baby orangutan follows mother until the he reaches the age of seven. Infants low mortality can be partially explained by the fact that mothers take a great care in raising their offspring.
They spend long hours for teaching their babies how to find food, how build a nest and how to defend themselves, while facing different kinds of danger. Orangutans are territorial animals, although the boundaries of male territories are not clearly defined. Very often male orangutans venture deep into the territories of their rivals, which sometimes results in violent clashes. It has also...
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Research essay sample on Dominant Male Social Structure
