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Monkey locomotion on inclined surfaces
Author(s) -
Prost J. H.,
Sussman R. W.
Publication year - 1969
Publication title -
american journal of physical anthropology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.146
H-Index - 119
eISSN - 1096-8644
pISSN - 0002-9483
DOI - 10.1002/ajpa.1330310107
Subject(s) - arboreal locomotion , jump , squirrel monkey , terrestrial locomotion , kinematics , inclination angle , gait , anatomy , biology , geology , geodesy , mathematics , physical medicine and rehabilitation , geometry , physics , ecology , medicine , classical mechanics , quantum mechanics , habitat
Abstract Motion pictures were taken of a subadult, female squirrel monkey moving on level and inclined surfaces. The gaits for the various degrees of incline were compared. The noncontact periods were not affected by changes in inclination. The contact periods, which were inversely related to speed, were affected, by changes in slope and intersect constants. When the incline was steep the animal was forced to jump and zig‐zag to retain its progression. The affect of inclination was advantageous at 16° and disadvantageous at higher and lower inclines. At the 16° inclination the animal's short fore legs and long hind legs held the body horizontal, cancelling the effect of the incline. It is reasoned that limb proportions may be adaptive for progression on inclined surfaces and that the locomotor niches for the various arboreal primates may be usefully categorized in terms of the inclinations of their substrates.