Abstract # 13444 Event # 69:

Scheduled for Thursday, August 22, 2019 03:15 PM-03:30 PM: (Room 326) Oral Presentation


EXCHANGE BEHAVIOR DURING SPONTANEOUS ROBBING AND BARTERING BY FREE-RANGING LONG-TAILED MACAQUES IN BALI, INDONESIA

J. V. Peterson and A. Fuentes
University of Notre Dame, Department of Anthropology, 260 Corbett Family Hall, Notre Dame, IN 46556, Notre Dame, Indiana 46556, USA
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     Spontaneous “robbing and bartering” by long-tailed macaques (Macaca fascicularis) at Uluwatu, Bali, Indonesia combines multiple behaviors into a single behavioral sequence. We characterize the “robbing and bartering” sequence as follows: 1) robbing the item; 2) holding and/or manipulating the item before the potential exchange; and 3) exchanging the item. In this study we analyze data from the exchange phase to assess patterns of exchange at the individual level. Data were collected from two groups at the Uluwatu temple site from May 2017 to March 2018 totaling 197 observation hours on 13 sub-adult male macaques. We recorded 44 exchanges from 90 total robberies following 176 attempts. Exchange occurrence per individual correlated strongly with their centrality in group proximity networks in Riting (rs = 0.748, p = 0.05) and Celagi (rs = 0.754, p = 0.08). Exchange efficiency (i.e., successful exchanges per robbery attempts) also correlated strongly with individual centrality in Riting (rs = 0.778, p = 0.04), but not in Celagi (rs = 0.0, p = 1.0). These results indicate that exchange patterns vary at the individual level based on their social position. Individuals with stronger social connections tend to exchange stolen items more frequently. These results may inform captive studies of exchange in nonhuman primates by showcasing the important role of individual social position for its spontaneous exhibition. Supported by the National Geographic Society (WW-082R-17).