[brey-kee-ey-shuh
n, brak-ee-] 
| locomotion accomplished by swinging by the arms from one hold to another. |
| bra·chi·ate (brā'kē-ĭt, -āt', brāk'ē-) adj. Zoology Having arms or armlike appendages. intr.v. (-āt') bra·chi·at·ed, bra·chi·at·ing, bra·chi·ates To move by swinging with the arms from one hold to another, as certain apes do. [Latin brācchiātus, from brācchium, arm. V., from New Latin brāchiāre, brāchiāt-, from brācchium; see brachium.] bra'chi·a'tion n. |
brachiation
in animal behaviour, specialized form of arboreal locomotion in which movement is accomplished by swinging from one hold to another by the arms. The process is highly developed in the gibbon and siamang, which are anatomically adapted for it in the length of their forelimbs, their long hooklike fingers, and the mobility of their shoulder joints. The South American spider monkey, considered a semibrachiator, uses its prehensile tail as a third arm. Spider monkeys both run along branches and swing from them.
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