Abstract # 4469 Poster # 98:

Scheduled for Thursday, June 20, 2013 07:00 PM-09:00 PM: Session 9 (SG Foyer ABC) Poster Presentation


WOUNDING RATES IN BACHELOR AND MIXED-SEX GROUPING OF LOWLAND GORILLAS (GORILLA GORILLA GORILLA).

B. I. Neier1, D. Boyer2, K. E. Lukas3,4 and S. R. Ross1
1Lester E. Fisher Center for the Study and Conservation of Apes, Lincoln Park Zoo, Chicago, Illinois 60614, USA, 2Saint Louis Zoological Park, Saint Louis, Missouri , 3Cleveland Metroparks Zoo, Cleveland, Ohio, 4Case Western Reserve University, Cleveland, Ohio
line
     Western lowland gorillas in the wild typically live in harem groups composed on one adult male and 3-4 females with offspring. This type of grouping is difficult to maintain in zoos due to a nearly equal birth sex ratio and the eventual incompatibility of maturing males with the resident silverback. Formation of bachelor groups is a successful management strategy that permits long-term socialization for males not housed with females in mixed-sex groups. Currently there are 23 zoos housing 72 males in 27 bachelor groups. Although more than half of all gorilla facilities maintain at least one bachelor group, there remains relatively little empirical information about the degree to which their behavior and social stability differs from mixed-sex groups. We requested daily records of wounding from 11 AZA-accredited zoos that included 6 bachelor groups and 6 mixed-sex groups. Twenty-six months of data on 35 gorillas were analyzed to determine the effect of wound severity and group composition. A total of 383 wounds (10.9 wounds per individual) were recorded. An ANOVA demonstrated there were significantly more minor wounds recorded than severe wounds across both group types (F(1,20)=57.7, p<0.001) but no difference in the frequency of wounding in bachelor groups compared to mixed-sexed groups (F(1,20)=0.033, p=0.86). These findings may be informative to those managing bachelor groups of gorillas and for those anticipating management challenges associated with those groupings.