Orangutan family at Chimelong Safari Park\長隆野生動物園的紅毛猩猩一家

Orangutans are great apes native to the rainforests of Indonesia and Malaysia. They are now found only in parts of Borneo and Sumatra, but during the Pleistocene they ranged throughout Southeast Asia and South China. Classified in the genus Pongo, orangutans were originally considered to be one species. In 1996, they were divided into two species: the Bornean orangutan (P. pygmaeus, with three subspecies) and the Sumatran orangutan (P. abelii); a third species, the Tapanuli orangutan (P. tapanuliensis), was identified definitively in 2017. The orangutans are the only surviving members of the subfamily Ponginae, which diverged genetically from the other hominids (gorillas, chimpanzees, and humans) between 19.3 and 15.7 million years ago.

The most arboreal of the great apes, orangutans spend most of their time in trees. They have proportionally long arms and short legs, and have reddish-brown hair covering their bodies. Adult males weigh about 75 kg (165 lb), while females reach about 37 kg (82 lb). Dominant adult males develop distinctive cheek pads or flanges and make long calls that attract females and intimidate rivals; younger subordinate males do not and more resemble adult females. Orangutans are the most solitary of the great apes: social bonds occur primarily between mothers and their dependent offspring. Fruit is the most important component of an orangutan's diet, but they will also eat vegetation, bark, honey, insects and bird eggs. They can live over 30 years, both in the wild and in captivity.

Orangutans are among the most intelligent primates. They use a variety of sophisticated tools and construct elaborate sleeping nests each night from branches and foliage. The apes' learning abilities have been studied extensively. There may be distinctive cultures within populations. Orangutans have been featured in literature and art since at least the 18th century, particularly in works that comment on human society. Field studies of the apes were pioneered by primatologist Birutė Galdikas and they have been kept in captive facilities around the world since at least the early 19th century.

All three orangutan species are considered critically endangered. Human activities have caused severe declines in populations and ranges. Threats to wild orangutan populations include poaching (for bushmeat and retaliation for consuming crops), habitat destruction and deforestation (for palm oil cultivation and logging), and the illegal pet trade. Several conservation and rehabilitation organisations are dedicated to the survival of orangutans in the wild.
紅毛猩猩，又叫人猿、紅猩猩、紅毛猩猩，靈長類人科的一屬，起源於印尼和馬來西亞的熱帶雨林。儘管在更新世時期，猩猩的活動範圍遍及整個東南亞和中國南部，但如今它們僅分佈於婆羅洲和蘇門答臘部分區域。過去人們認為猩猩屬下面只有一個物種，但1996年其被分成兩個物種：蘇門答臘猩猩和婆羅洲猩猩。而在2017年，科學家亦定義了第三個猩猩物種打巴奴裡猩猩。

猩猩是所有大型猿猴中最擅長樹棲的，它們大部分的時間都在樹上度過。猩猩的前肢較長，後肢較短，全身覆蓋紅棕色毛髮。成年雄性猩猩體重約75公斤，雌性則為37公斤。在領地中佔支配地位的雄性猩猩會發展出獨特的寬臉頰，並使用長呼號吸引雌性猩猩或威嚇競爭者。年輕的從屬地位雄猩猩的外觀與雌性猩猩更為相似。猩猩偏好獨居，社交關係僅限於母親和子女。它們主要以水果為食，但有時也食用草本、樹皮、蜂蜜、昆蟲、鳥類等。通常情況下，猩猩的壽命可達30歲。

猩猩的智力程度極高，能使用多種工具。它們採集樹枝和樹葉，用於建造複雜的巢穴。科學家廣泛的研究了猩猩的學習能力。不同族群的猩猩或許有不同的文化。自18世紀以來，猩猩的形像出現在許多文學和藝術作品中，尤其是關於社會評論的作品。人們自19世紀開始圈養猩猩。

猩猩的三個物種都處於瀕危狀態，人類活動導致了它們的種群數量下降和棲息範圍縮小。猩猩面臨的威脅主要有：偷獵（用於製作叢林肉，或為報復對農田的破壞）、棲息地破壞、森林砍伐（伐木或擴建棕櫚油種植園）以及非法寵物交易。有一些組織致力於野生猩猩的保育和棲息地修復。