Forschungsthemen
Lebensraum und Verbreitung
Der malaiische Name des Orang-Utans bedeutet übersetzt "Waldmensch". Man vermutet, dass die malaiischen Eingeborenen dem größten Menschenaffen Asiens aufgrund seines menschenähnlichen Aussehens und Gesichts- ausdrucks diesen Namen gaben. Daher ist es kaum verwunderlich, dass um diesen Waldmenschen viele Mythen und Legenden entstanden. Orang-Utans sind als ausgesprochene Einzelgänger bekannt. Da dieser Umstand Freilandstudien zusätzlich er- schwert, ist über das Verhalten und Leben der Orang-Utans in freier Wildbahn allgemein noch nicht so viel be- kannt, wie bei anderen Gattungen. Neuere Studien haben jedoch mittlerweile gezeigt, dass auch Orangs durchaus in Familien oder kleinen sozialen Gruppen leben. Im Folgenden werden die wichtigsten Charakteristika der Orang-Utans aufgelistet:
Bezeichnung: Es existieren 2 Unterarten: - Pongo pygmaeus abelii (Sumatra-Orang-Utan) - Pongo pygmaeus pygmaeus (Borneo-Orang-Utan)
Lebensraum: Wie oben schon angedeutet, leben Orang-Utans heutzutage auf den Inseln Borneo (Malaysia/ Indonesien) und Sumatra (Indonesien). Früher waren die Orang-Utans über weite Teile Asiens verstreut. Körpermaße: Genau wie alle anderen Menschenaffen besitzen Orang-Utans keinen Schwanz. Körperlänge: Männchen ca. 137 cm Weibchen ca. 115 cm Gewicht: Männchen ca. 60-90 kg Weibchen ca. 40-50 kg Aussehen: Sumatra-Orang-Utan: lange rötliche Behaarung, bei Jungtieren leuchtend orang, bei Erwachsenen in Braun übergehend, Gesicht nackt Borneo-Orang-Utan: etwas schlanker, kürzere und dunklere Behaarung Besondere Merkmale: Erwachsene Männchen bilden auffällige Backenwülste und Kehlsäcke aus. Ernährung: 60 % Früchte, 40 % andere Pflanzenteile; auch Wurzeln, Rinde und gelegentlich Vogeleier Fortpflanzung und Lebenslauf: Tragzeit: ca. 227-275 Tage; 1 Kind pro Geburt, sehr selten Zwillinge Geburtsgewicht: ca. 1,5-1,7 kg Entwöhnungsalter: ca. 2-3 Jahre Geschlechtsreife: zwischen 7-10 Jahren Lebensdauer: Wildnis: ca. 40 Jahre Menschenobhut: über 50 Jahre
Lebensweise: Tagaktive Baumbewohner (zu etwa 95 % baumlebend) der Tieflandwälder (in Regen-, Mangroven-, Sumpf-, Torfmoor- und Bergwald), selten über 1000 m bauen manchmal Tag-, aber stets Nachtnester lockere Familiengruppen, meist jedoch eher solitär Feinde:Tiger, Rothund (nur Sumatra), Nebelparder, Leopard, Mensch!!!
Orangutans are large apes that live in southeast Asia (on the islands of Borneo and Sumatra). These apes mostly live in trees (they are arboreal) and swing from branch to branch using their arms.
The word orangutan means "man of the forest" in the Malay language. As its habitats are being usurped by man, the orangutan's population is decreasing and it is in grave danger of extinction.
ANATOMY Orangutans have a large, bulky body, a thick neck, very long, strong arms, short, bowed legs, and no tail. Orangutans are about 2/3 the size of the gorilla.
Hair: They are mostly covered with long reddish-brown hair.
The Head: The orangutan has a large head with a prominent mouth area. Adult males have large cheek flaps (which get larger as the ape ages).
Senses: Orangutans have senses very similar to ours, including hearing, sight, smell, taste, and touch.
Hands and Feet: Orangutan hands are very much like ours; they have four long fingers plus an opposable thumb. Their feet have four long toes plus an opposable big toe. Orangutans can grasp things with both their hands and their feet. The largest males have an arm span of about 7.5 feet (2.3 m).
SIZE Orangutans are about 2/3 the size of the gorilla.
Orangutans Height Weight Female 2.6-3.5 ft (0.8-1.1 m)100 lb (50 kg) Male 3.2-4.5 ft (1-1.4 m) 200 lb (90 kg)
DIET Orangutans are omnivores (they eat both plants and animals) but are mostly herbivorous (plants comprise most of their diet). They eat fruit (their favorite food), leaves, seeds, tree bark, plant bulbs, tender plant shoots, and flowers. They also eat insects and small animals (like birds and small mammals). Orangutans don't even have to leave their tree branches to drink, they drink water that has collected in the holes between tree branches.
INTELLIGENCE AND LANGUAGE Orangutans are very intelligent. They have been known to use found objects as tools; for example, they use leaves as umbrellas to keep the rain from getting them wet. They also use leaves as cups to help them drink water. BEHAVIOR AND SOCIAL HABITS Orangutans are shy, solitary animals that are active during the day (they are diurnal). They live alone in large territories. This is probably due to their eating habits; they need a large area in order to get enough food and too many orangutans in one area might lead to starvation. The only long-lasting orangutan social group is the mother and offspring, who live together for about 7 years. When mating, the male and female orangutan stay together for only a few days. Sleeping Platforms: Each evening, orangutans construct a "nest" in the tree branches for the night in which they will curl up and sleep. These nests are made out of leaves and branches. Nests are shared by a mother and her nursing offspring. Sometimes, the orangutan will use a leaf as a "roof" to protect itself from the rain. Orangutans often nap in the afternoon after a morning spent obtaining food. COMMUNICATION AND VOCALIZATION Male orangutans are capable of very long, loud calls (called "long calls") that carry through forests for up to 0.6 mile (1 km). The "long call" is made up of a series of sounds followed by a bellow. These calls help the male claim his territory, call to females, and keep out intruding male orangutans. Males have a large throat sac that lets them make these loud calls. LOCOMOTION Orangutans usually move by swinging from one branch to another; this is called brachiating. Orangutans can also walk using their legs (but rarely do). Orangutans do not swim. LIFE SPAN Orangutans live about 50 years in captivity; their life span in the wild is only 30-45 years (like most animals, they live longer in captivity). HABITAT Orangutans live in tropical rain forests. DISTRIBUTION Orangutans live in Asia. They are the only great ape from Asia. They are found in tropical rain forests in northern Sumatra, Indonesia and in low-lying swamps in Borneo.
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