Abstract # 142:

Scheduled for Sunday, September 14, 2014 07:00 PM-09:00 PM: Session 22 (Decatur B) Poster Presentation


DOES THE FULL MOON AFFECT WOUNDING IN CAPTIVE CHIMPANZEES (PAN TROGLODYTES)?

J. Bridges1, L. A. Reamer1, S. P. Lambeth1 and S. J. Schapiro1,2
1Department of Veterinary Sciences, Michale E. Keeling Center for Comparative Medicine and Research, University of Texas MD Anderson Cancer Center, Bastrop, TX, USA, 2Department of Experimental Medicine, University of Copenhagen and University Hospital, Copenhagen, Denmark
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     Reducing the frequency of wounding is an aim of facilities managing socially-housed chimpanzees. Some animal studies have shown a correlation between lunar cycle and behavior, specifically regarding increases in aggression during the full moon phase. No studies currently exist that have investigated the lunar cycle’s effect on chimpanzee wounding aggression; however, this information could be beneficial for captive management. This retrospective study examined wounding incidents among 8 social groups of captive chimpanzees (42F, 46M) over 118 months, to determine whether moon phases (New, Waxing, Full, Waning) were associated with changes in rates of wounding aggression. Chimpanzees were housed in open-top corrals or Primadomes®, with continuous inside/outside access. Clinical staff surveyed all chimpanzees daily to identify wounds or other health-related issues. Of the 4,018 days of the study, there were 408 full moon days (10.2% of total days) and 3,610 non-full moon days (89.8% of total days). Within the study period, 392 wounds were observed, 48 (12.2%) occurred during the full moon phase; whereas 344 wounds (87.8%) occurred during non-full moon phases. While wounding occurred slightly more frequently during the full moon phase, the distribution did not differ significantly from chance (?2=4.583, df=3, p=0.205). This suggests that, contrary to some subjective impressions, the full moon does not have a significant effect on wounding aggression in captive chimpanzees.