huluhub.com
umraniye escort pendik escort
sikis
bedava bahis

Web Documents



Ahrens 2008

Created By: Travis Ramirez
Font: small Large
http://bioweb.uwlax.edu/bio203/s2008/ahrens_just/adaptation.htm

[1] The name Orangutan means "Person of the Forest" in Malay language. This description of Orangutans could not be more exact since these animals are almost entirely Arboreal. They eat, travel, sleep, and rest all in the tree canopy with the aid of hook-like hands and feet to help them grasp branches.

[1.5] Orangutans are a group of primates that are part of the "Great Apes" which include Chimpanzees (Pan troglodytes), Bonobos (Pan paniscus), and Gorillas (Gorilla gorilla).
A distinction of Orangutans from the other Great Apes is that they possess arms that are roughly 7 feet long (almost twice the length of their legs) because of the amount of time Orangutans spend in the trees. Orangutans differ from Chimpanzees because these gentle & peaceful animals rarely exhibit the reckless and impulsive behavior that is common among the Chimps.


If you enjoy your rest then you would really love the lifestyle of an Orangutan. These Primates spend around 12 hours of the day sleeping! The tropics result in 12 hours of sunlight and 12 hours of darkness so the Orangutans rise and retire with the sun. They even spend some of the daytime resting and napping. Although estimates differ with different individuals, during a 12 hour day Orangutans will spend 46% feeding, 39% resting, 11% traveling between their resting and feeding sites, and the rest of the time is spent constructing their sleeping nests. The only time that Orangutans spend traveling considerable distances is when they need to find more food or to find females to mate with. Males will travel the farthest and the fastest. This may be the result of their larger caloric needs and to find suitable females or to control male intruders.

As noted before, when retiring for the evening or resting during the day, Orangutans construct sleeping nests. These nests are intricately woven with sticks and leaves. Every night an Orangutan constructs a new nest in a different location high in the trees. These nests are normally constructed near a food source that can provide a good amount of food for the Orangutan. The 40% of the day Orangutans spend resting is usually in quickly made sleeping nests.

Height: 1.25 meters (males), 1 meter (females)
Weight: 85 kg (males), 40 kg (females)
Lifespan: 35 to 40 years (60 years in captivity)
Diet: Omnivore
Travel Speed: .35 kilometers per hour (one tenth the speed of Chimpanzees)
Status: Endangered

[2] Orangutans posses many adaptations that help them live successfully in their habitat. Orangutans spend almost all of their day in the tree canopy so it is no surprise that they have adapted to live in the trees. The arm length of an Orangutan is 7 feet which allows them to hang on to branches and support themselves. The strength of Orangutans is believed to be 7 times greater than Human strength. Although Orangutans are considered brachiators, they are very cautious climbers and use any combination of their four grasping extremities. The term Brachiator is used loosely with Orangutans since they never jump or drop from tree limb to limb. Orangutans suspend their weight from their arms and tree sway using trees like a pole vault. Besides the length of their arms, Orangutans possess a more fully opposable big toe and a highly mobile hip. This adaptation is a consequence of their primary Arboreal lifestyle. In contrast, Gorillas and Chimpanzees live a primary Terrestrial lifestyle.

[2.5] Orangutans are the only Great Ape to travel predominantly through the trees. When Orangutans do come out of the trees and travel on the ground, they use a method of walking called "Fist Walking". This method of walking Quadrupedally is done by curling the thumb around their fist and as the name implies, walking on their fists. The other Great Apes (Gorillas, Chimpanzees, and Bonobos) travel terrestrially by walking quadrupedally on their knuckles, a method known as "Knuckle Walking".

The adult male Orangutan possess cheek pads and a drooping laryngeal throat pouch. These characteristics are not only intimidating to other Orangutans, but they also help the male Orangutan with his long call. Male Orangutans give off "long calls" that will notify other Orangutans of the male's location in the forest and keep other competing males from approaching the area.The cheek pads of adult males are believed to increase the distance of their long call and the massive size creates a convincing threat to their challengers. These pads are made up of subcutaneous collections of fibrous tissue between the eyes and ears.


Another adaptation shown by Orangutans is the replacement of sharp claws by flattened nails. Biologists believe that this adaptation led to the development of highly sensitive tactile pads on the phalanges. Orangutans can also use separate power & precision grips, and possess separate control of all their fingers. Additionally, In captivity Orangutans have been observed manufacturing and using tools, acquiring basic language skills such as sign language, and solving problems using insight and reasoning. Recently, Orangutans living in the wild have been seen using sticks to extract termites from trees and use large leaves as umbrellas when it is raining heavily.

Orangutan Taxonomy
Domain: Eukarya
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Primates
Family: Hominidae
Genus: Pongo
Species: P. albelii or P. pygmaeus

Orangutans are classified in the domain Eukarya because their cells contain a nucleus and membrane bound organelles, and they are multicellular organisms. In contrast, Prokaryotes are unicellular organisms (such as bacteria) that do not contain a cell nucleus or membrane bound organelles.

They belong to the kingdom Animalia because Orangutans are Heterotrophs that ingest food into an internal cavity. Organisms belonging to the kingdom Animalia also lack cell walls and are motile at some stage during their life cycle.

The phylum Chordata includes animals that possess a Notochord at some stage during their development. Other distinguishing characteristics are the presence of a tail and pharyngeal gill slits at some stage in development, a complete digestive system, bilateral symmetry, and a well developed Coelom.

Orangutans are contained in the class Mammalia because they are warm-blooded, possess hair on their body, have a four-chambered heart, and females produce milk from their mammary glands to nourish their young.

The order Primates has defining characteristics that are present in Orangutans such as the presence of differentiated tibia & fibula in the shank and ulna & radius in the forearm, presence of a clavicle, and possess five digit feet.

[3] The family Hominidae exhibit both an opposable thumb and big toe (except humans), elimination of a tail, a large braincase, and flattened nails at the ends of the phalanges.

Orangutans are separated into the genus Pongo because they share less characteristics with humans than do Gorillas and Chimpanzees.

Orangutan Phylogeny

Courtesy of Justin R. AhrensExplanation of Phylogenetic Tree Levels:

Catarrhini: Humans, Great Apes, and Old World Monkeys
Platyrrhini: New World Monkeys
Tarsii: Tarsiers
Strepsirrhini: Lemurs and Lorises
Cercopithecidae: Old World Monkeys
Hominidae: Humans, Gorillas, Chimpanzees, Bonobos, and Orangutans
Hylobatidae: Gibbons
Pan: Chimpanzees and Bonobos
Ardipithecus: close relative of Humans
Australopithecus: close relative of Humans
Gorilla: Gorillas
Homo: Humans
Pongo: Orangutans

[4] Orangutans are found in Indonesia on the islands of Sumatra and Borneo. These apes were once widespread throughout mainland Asia during the Pleistocene. Orangutans prefer a habitat that exists along waterways and in lowlands because of their high dependence on fruit. Biologists have described their habitats as inaccessible, swamp logged, leech-laden tropical forests. The islands of Borneo and Sumatra have vast mountain ranges and Orangutans are rarely seen in elevations that exceed 500 meters. An Orangutan's normal habitat is the tropical rainforest that is dominated by trees of the family Dipterocarpaceae, which interestingly enough, is also becoming endangered in parts of the world.

[4.5] In Sumatra, Orangutans are entirely arboreal because of large predators (such as tigers, leopards) patrol the forest floor. Borneo contains fewer large predators so males will travel Terrestrially and feed on the ground, but females will remain in the trees because of their smaller size. In traveling through trees, Orangutans have shown intelligence by using common routes and showing the ability to back track to their original route if need be. Orangutans are slow and deliberate animals and their movement in the trees reflects this. It has also been seen that Orangutans can occupy peat swamp forest in addition to tropical forest. Their habitat mainly reflects areas where the greatest majority of food is located and areas that will give them the most protection.

Reproduction

[5] Orangutans have a reproductive cycle that is similar to Humans. A female Orangutan's reproductive stage lasts roughly nine months, which is similar to the duration of a human female's reproductive stage. Female Orangutans are also similar to human females because they both do not show external signs of Estrus or Menstruation and their reproductive cycles last roughly 30 days. A female Orangutan will normally give birth to only one offspring at a time and this occurs every 6 to 7 years. They will be within constant contact of their offspring for the first year of life and stay within contact of their young for its first 7 years of life. The reproductive process for female Orangutans is very costly since feeding herself is already a daunting task without having to take care of the metabolic needs of an infant.
Juvenile Orangutans are 1.5 to 2 kg at birth and remain under 25 kg for the first 6 to 7 years of their lives. Orangutan young have the longest immaturity of all apes lasting 9 to 12 years and consisting of three stages of development: infant, juvenile, and adolescence. A female Orangutan reaches adulthood upon the birth of her first infant, around the age of 14 old 16 years old. Some females have given birth as early as age 7 in captivity and some males have fathered an offspring as early as age 6.5 in captivity (2). A male Orangutan reaches adulthood when his laryngeal throat pouch, cheek pads, and long call all emerge which is usually around the age of 18 to 20 years old. Males show an unusual two stage maturation with a sub-adulthood stage beginning around 10 years old and lasting to the age of 15, sometimes as late as age 19 or 20 (5). Courtesy of Wikipedia

Orangutans reproduce so slowly it results in fierce competition for males to find females. The main consequence of this life cycle is that it can take decades to replace population losses of Orangutans. Also, females are selective in the mating process. They will seek out desirable males and turn away males they do not want to mate with. This process can lead to forced copulations that are often referred to as "rape". Sub-adult males will often try to mate with adult females until a larger adult male will come along and displace the competing smaller males. Some biologists argue that this process has led to the Sexual Dimorphism seen in Orangutan species.

Nutrition

[6] Over 50% of an Orangutan's diet is made up of fruit. Orangutans travel as far and as fast as they need to in their home ranges to find food. Although fruit is their primary food source, Orangutans have been known to eat up to 400 different things! When the Orangutan is not spending time resting or sleeping during the day, they are foraging for food. This is necessary because Orangutans have a high caloric need and high quality food is not always readily available. Orangutans belong to the group of Primates called "Nutcracker Primates" which crack open hard-coated fruits for food. In the wild, Orangutans have shown intelligence by using leaves of trees as gloves when handling fruit covered in sharp points.


Some of an Orangutan's Popular Food Items
sap young leaves flowers
honey shoots stems
seeds nuts bamboo
fungus pith of plants bark
soil termites ants
eggs invertebrates sometimes hunt small mammals

Animal Interactions

[7] Orangutans are mainly a solitary animal that live high up in trees in the forests of Sumatra and Borneo. Both species of Orangutans hardly encounter each other so it is not surprising that they rarely encounter other species of animals. However, Orangutans have been seen threatening and even attacking Leopards and Lions, but must be aware of tigers roaming the forest floor.

Interactions of Orangutans With Other Orangutans

[8] Male Orangutans are the most solitary. They are intolerant of each other in adulthood and will threaten one another using long calls, starring, shaking of tree branches, and inflating their laryngeal throat pouches. Sometimes these encounters can escalade to hand to hand combat and even to the death. Sexual contact with females is the only interaction that males have and it will only last for a few weeks when females are receptive to mating. After contact, males will abandon females a few days after a female becomes pregnant.

Females are usually accompanied by only one or two young when they travel. Occasionally groups of females may be seen together with their young, but this does not persist for more than a day normally. Females are less solitary than males and even semi-social. It has been observed that females tend to travel with other females of whom they associated with as an adolescent. Adult females have stable home ranges that may overlap, but each female recognizes clear boundaries to other home ranges. A female's home range is usually 5 to 6 km2.

Adolescent females are the most sociable of all the Orangutans. The females can often be seen grooming each other or the males that they may be consorting with. Interestingly though, once an adolescent female gives birth to her first offspring, she becomes intolerant of other females that she previously had a friendly relationship with. Adolescent females have been observed to establish home ranges that are close in proximity to their mother's range.

Male Orangutans have home ranges that are usually larger than their female counterparts. Adult males will occupy home ranges that intercept two or more ovulating females or they will travel long distances to seek opportunistic females. Males can be identified based on two criteria: Wanderer Males and Resident Males. A Resident Male Orangutan will have a specified home range that is similar in size to an adult female's home range. Wanderer Male Orangutans will travel over a larger area covering more ground looking for females or a steady food source. Male Orangutans will typically disperse and settle on a home range father from their mothers than what a female would. However, male settlement depends on the nearby female's ability to conceive and also on food sources.

In addition to adolescent females being social, juvenile Orangutans will establish friendships with their same sex & age mates. Also, adult males will normally tolerate sub-adult males, but could easily displace them (2). In addition, sub-adult males almost always tolerate one another in most instances.

Interesting Facts

Largest living arboreal animals.

Orangutans possess 32 teeth, the same number present in Humans.

It is believed that Humans share a common ancestor with the Great Apes that existed 12-15 million years ago.

Orangutans are greatly camouflaged in rainforests because of the little sunlight that filters through the dense canopy reflects green light and absorbs the red-orange light that is similar to the color of the Orangutan's coat (5).

Orangutans can travel anywhere from 50 meters to 1,000 meters in one day.

It has been proposed that the sexual dimorphism seen between male and female Orangutans is the result of the larger male's ability to overtake the smaller sub-adult males in the mating process (2).

[9] Orangutans are mostly solitary, which is rare since primates usually have rich social lives. Some theories suggest that being solitary is a necessity for Orangutans since their caloric needs are so large they cannot share. Also, no large predators except for humans threaten Orangutans so they do not need large social groups to protect themselves.

Conservation Efforts

[10]The Orangutan is currently an endangered species, with the Sumatran Orangutan (P. albelii) listed on the critically endangered list. There are two main reasons for the decline in Orangutan populations: the destruction of their habitat and the illegal trade & poaching of the species. The population of P. pygmaeus in Borneo has decreased from 23,000 in 1995 to 15,400 in 1998, a decrease of a third of the population in less than three years. Estimates are similar for P. albelii population decreases in Sumatra.

Agencies are continuing their conservation efforts of Orangutans throughout Indonesia. In Sumatra, roughly 70% of population of P. albelii has been protected by the Leuser Ecosystem in contrast to Borneo where only 16% of Orangutan habitat has been protected (4). The Leuser Foundation and Park will play a key role in protecting important refuges of the critically endangered Sumatran Rhino (Dicerorhinus sumatrensis), Elephant (Elephas maximus sumatranus) and Tiger (Panthera tigris sumatrae) (7). In addition to the Leuser Ecosystem, agencies are also using zoos to rehabilitate Orangutans that have been recovered from illegal trade or have lost their habitats. Estimates of zoo populations throughout the world are 306 Sumatran Orangutans and 385 Bornean Orangutans.

Destruction of Habitat

[11] The population of Indonesia has grown from roughly 15 million people in 1900 to now over 200 million in 2000. With population expected to exceed 300 million in less than two decades it is no surprise that the habitat of Orangutans has been increasingly destroyed. Human population increase coupled with the increase in profitable palm oil plantations has drastically decreased the Orangutan's natural habitat. The size of Orangutan habitat in Borneo is currently around 155,000 km2 compared to just under 27,000 km2 in Sumatra (4). However, in Sumatra the survival rate is predicted to be higher for Orangutans because their main habitat is located along the Barisan Mountain Range in northern Sumatra which is inhabitable for humans.

Illegal Trade & Poaching

Orangutans are constantly struggling with humans for rights to territory. This struggle has lead to the illegal poaching and capture of Orangutans. These animals are suffering from a decreased size in habitat that leads Orangutans to travel outside of their normally dense forests and into populated areas where humans will often capture them or shoot them. Also, in some instances, humans have set fire to Orangutan forests to force out the animal populations and log the resulting forest. If caught the animals fleeing from these forest fires will be shot or captured and used to gain large profits in illegal animal trading. This trade began when 1,000 illegally imported infant Orangutans showed up in Taiwan in 1900 (4) and it still continues today, but probably greater numbers.Conservation Efforts

The Orangutan is currently an endangered species; listed on the critically endangered list. There are two main reasons for the decline in Orangutan populations: the destruction of their habitat and the illegal trade & poaching of the species. The population of orangutans  in Borneo has decreased from 23,000 in 1995 to 15,400 in 1998, a decrease of a third of the population in less than three years. Estimates are similar for P. albelii population decreases in Sumatra.

Agencies are continuing their conservation efforts of Orangutans throughout Indonesia. In Sumatra, roughly 70% of population of P. albelii has been protected by the Leuser Ecosystem in contrast to Borneo where only 16% of Orangutan habitat has been protected (4). The Leuser Foundation and Park will play a key role in protecting important refuges of the critically endangered Sumatran Rhino (Dicerorhinus sumatrensis), Elephant (Elephas maximus sumatranus) and Tiger (Panthera tigris sumatrae) (7). In addition to the Leuser Ecosystem, agencies are also using zoos to rehabilitate Orangutans that have been recovered from illegal trade or have lost their habitats. Estimates of zoo populations throughout the world are 306 Sumatran Orangutans and 385 Bornean Orangutans.







Category: Spring Research Documents | Comments: 0 | Rate:
0 Votes
You have rated this item.