Brachiators are a type of primate mostly from the family Hylobatidae, which includes gibbons. Brachiators use their arms to move from tree branch to tree branch, through a process called brachiation. Their arms are longer than their legs, and are much more powerful.
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Most of these brachiators were smaller than average apes, so were able to move through the trees easier than gorillas or orangutans, although female orangutans do brachiate through the trees occasionally. The brachiators held their bodies upright in the trees, and would sometimes go on the ground and walk upright. This helped them survive in the plains when the forests began to die, because they were so unfamiliar to the predators that they would not be attacked.
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Currently, researchers classify gibbons and siamangs as the only true brachiators and classify the great apes as modified brachiators. All other brachiation behaviours that do not meet either of these classifications are referred to as forearm suspensory postures and locomotion. Some traits that allow primates to brachiate include a short spine (particularity the lumbar spine), short fingernails (instead of claws), long curved fingers, reduced thumbs, long forelimbs and freely rotating wrists. Modern humans retain many physical characteristics that suggest a brachiator ancestor, including flexible shoulder joints and fingers well-suited for grasping.
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Gibbons often retain the same mate for life, although they do not always remain sexually monogamous. In addition to extra-pair copulations, pair-bonded gibbons occasionally "divorce." Gibbons are among nature's best brachiators. Their ball-and-socket wrist joints allow them unmatched speed and accuracy when swinging through trees.
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Brachiators began as four- footed monkey-like creatures in the Tertiary Era in Africa and Northern Europe. Eventually, some of the monkeys began to use their arms to swing, and lost their tails, due to evolution. They became apes with strong arms. Through the ages, the ape-like ancestors developed stronger arms and the shoulder blades moved from the side of their chests to the back of their bodies.
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The close-up of head The fur coloring of the lar gibbon varies from black and dark-brown to light-brown, sandy colors. The hands and feet are white-colored, likewise a ring of white hair surrounds the black face. Both males and females can be all color variants, and the sexes also hardly differ in size. Gibbons are true brachiators, propelling themselves through the forest by swinging under the branches using their arms.
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Gibbons are very good brachiators because their elongated limbs enable them to easily swing and grasp on to branches. Arboreal animals frequently have elongated limbs that help them cross gaps, reach fruit or other resources, test the firmness of support ahead and, in some cases, to brachiate (swing between trees). Many arboreal species, such as tree porcupines, silky anteaters, spider monkeys, and possums, use prehensile tails to grasp branches. In the spider monkey, the tip of the tail has either a bare patch or adhesive pad, which provides increased friction.
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In contrast, virtually all locomotion functionality has been lost in humans while predominant brachiators, such as the gibbons, have very reduced thumbs and inflexible wrists. In ungulates the forelimbs are optimised to maximize speed and stamina to the extent that the limbs serve almost no other purpose. In contrast to the skeleton of human limbs, the proximal bones of ungulates are short and the distal bones long to provide length of stride; proximally, large and short muscles provide rapidity of step. The odd-toed ungulates, such as the horse, use a single third toe for weight-bearing and have significantly reduced metacarpals.
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Gibbons are very good brachiators because their elongated arms enable them to easily swing and grasp on to branches Due to the height of many branches and the potentially disastrous consequences of a fall, balance is of primary importance to arboreal animals. On horizontal and gently sloped branches, the primary problem is tipping to the side due to the narrow base of support. The narrower the branch, the greater the difficulty in balancing a given animal faces. On steep and vertical branches, tipping becomes less of an issue, and pitching backwards or slipping downwards becomes the most likely failure.
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Brachiation is a specialized form of arboreal locomotion, used by primates to move very rapidly while hanging beneath branches. Arguably the epitome of arboreal locomotion, it involves swinging with the arms from one handhold to another. Only a few species are brachiators, and all of these are primates; it is a major means of locomotion among spider monkeys and gibbons, and is occasionally used by the female orangutans. Gibbons are the experts of this mode of locomotion, swinging from branch to branch distances of up to 15 m (50 ft), and traveling at speeds of as much as .
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