xanthosternos and Burmese long-tailed macaques ( Macaca fascicularis aurea). One form of tool use that has received more scientific attention recently, is the use of percussive stone tools on encased foods by non-human primates: West African chimpanzees ( Pan troglodytes verus) robust capuchins Sapajus libidinosus and S. From these reports, we know many animals use tools for a variety of functions, and employ tools of differing material characteristics and with different modes of actions. Tool use has been reported in a wide variety of animal species. We compare our study to other stone-using primates, and discuss implications for further research. Unimanual edge hammering was relatively frequent (13%), compared to the other thirteen rare action patterns (<5%). The most common patterns were unimanual point hammering (58%), symmetrical-bimanual face hammering (47%) and unimanual face hammering (37%). Analysis of scans showed that 80% of individuals used tools, each employing one to four different action patterns.
Point hammering and sessile edge hammering compared to prior descriptions of axe hammering, while face and unattached edge hammering compared to pound hammering.
Edge hammering also showed distinct differences depending on whether such hammering was applied to sessile or unattached foods, resembling point hammering for sessile foods and face hammering for unattached foods. Point hammering was significantly more associated with sessile foods, smaller tools, faster striking rates, smoother recoil, unimanual use, and more varied striking direction, than were face and edge hammering, while both point and edge hammering were significantly more associated with precision gripping than face hammering. We collected 3077 scan samples from 109 macaques on Piak Nam Yai Island’s coasts, to determine the proportion of individuals using each hammering class and action pattern. Action patterns were not, owing to insufficient instances of most patterns. Hammering class was analyzed for associations with material and behavioural elements of tool use.
Action patterns were discriminated by tool material, hand use, posture, and striking motion. Hammering class was based on the stone surface used for striking food, being face, point, and edge hammering. We catalogued variation into three hammering classes and 17 action patterns, after examining 638 tool-use bouts across 90 individuals. We explored variation in patterns of percussive stone-tool use on coastal foods by Burmese long-tailed macaques ( Macaca fascicularis aurea) from two islands in Laem Son National Park, Ranong, Thailand.
0 kommentar(er)
