猩猩從它們在婆羅洲雨林的樹上生活環境走下來可能要比以前的傳聞更頻繁。發表在本期Scientific Reports上的一篇研究論文，提供了所有年齡的雄性和雌性猩猩在地面上行走的證據。該研究表明，猩猩對生活環境劇烈變化的適應能力可能要比人們以前所認為的更強。
婆羅洲猩猩(Pongo pygmaeus)是世界最大的樹棲哺乳動物。有關其在地面上行為的記錄很少，並且往往與生活環境受到擾動有關。Marc Ancrenaz及同事利用在婆羅洲16個地點通過隱藏相機捕捉到的全面數據對猩猩在地上的活動進行了一次大規模分析。作者的意圖是，評估猩猩從樹上下來在地面上行走的程度以及人類造成的擾動是否會影響這種行為。
所有年齡-性別類別的猩猩都被發現在地面上活動，其中那些身材高大、像長著凸緣的雄性（即那些長著獨特臉盤、喉囊和長毛的雄性）在地面上出現得最頻繁。另外，猩猩在原始森林以及嚴重退化的生境中都被發現在地面上活動，說明人類對林冠的破壞可能會影響它們在地面上活動，但卻並不是造成這種行為的惟一原因。這些發現表明，地面活動在婆羅洲猩猩的自然行為中所起作用可能要比人們所預料的更大。（生物谷Bioon.com）
生物谷推薦的英文摘要
Scientific Reports doi:10.1038/srep04024
Coming down from the trees： Is terrestrial activity in Bornean orangutans natural or disturbance driven？
Marc Ancrenaz， Rahel Sollmann， Erik Meijaard， Andrew J. Hearn， Joanna Ross， Hiromitsu Samejima， Brent Loken， Susan M. Cheyne， Danica J. Stark， Penny C. Gardner， Benoit Goossens， Azlan Mohamed， Torsten Bohm， Ikki Matsuda， Miyabi Nakabayasi， Shan Khee Lee， Henry Bernard， Jedediah Brodie， Serge Wich， Gabriella Fredriksson
The orangutan is the world's largest arboreal mammal， and images of the red ape moving through the tropical forest canopy symbolise its typical arboreal behaviour. Records of terrestrial behaviour are scarce and often associated with habitat disturbance. We conducted a large-scale species-level analysis of ground-based camera-trapping data to evaluate the extent to which Bornean orangutans Pongo pygmaeus come down from the trees to travel terrestrially， and whether they are indeed forced to the ground primarily by anthropogenic forest disturbances. Although the degree of forest disturbance and canopy gap size influenced terrestriality， orangutans were recorded on the ground as frequently in heavily degraded habitats as in primary forests. Furthermore， all age-sex classes were recorded on the ground (flanged males more often). This suggests that terrestrial locomotion is part of the Bornean orangutan's natural behavioural repertoire to a much greater extent than previously thought， and is only modified by habitat disturbance. The capacity of orangutans to come down from the trees may increase their ability to cope with at least smaller-scale forest fragmentation， and to cross moderately open spaces in mosaic landscapes， although the extent of this versatility remains to be investigated.