Abstract # 2342 Event # 63:

Scheduled for Friday, June 20, 2008 09:45 AM-09:55 AM: Session 7 (Meeting Room 1DE) Oral Presentation


DIFFERENTIAL BEHAVIOR PATTERNS IN ZOO-HOUSED APES (PAN TROGLODYTES AND GORILLA GORILLA) BETWEEN EXHIBITS AND HOLDING: EFFECTS ON WELFARE ASSESSMENT

S. R. Ross and K. E. Wagner
Lincoln Park Zoo, Lester E. Fisher Center for the Study and Conservation of Apes, 2001 North Clark Street, Chicago, IL 60614, USA
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     Behavioral measures to assess ape welfare have been widely used.  Housing conditions for zoo-housed apes however, may differ from other environments in that traditionally, groups spend some of their time in their publicly-viewed space (“exhibit”) and the rest of the time in off-exhibit space (“holding”).  While modern holding space is designed to meet the behavioral needs of apes, it is rarely as enriching as the exhibit.  Given that some zoo-housed apes may spend as much as 75% of their time in holding, welfare assessments sampling solely from exhibit time may be incomplete and potentially misleading.  We compared behavioral rates in two groups of apes (chimpanzees: one adult male, 3 adult females, 3 adolescents; gorillas: 1 adult male, 3 adult females, 1 adolescent, 2 juveniles) in two conditions: (a) throughout the day (10am-5pm) on public exhibit; and (b) during a short period of time in holding each morning (8am-10am).  There were significantly higher rates of scratching [z=2.20, p=0.028], self-directed behavior [z=2.03, p=0.043] and abnormal behavior [z=2.37, p=0.018] in holding.  Gorillas primarily demonstrated regurgitation and reingestion while chimpanzees primarily showed coprophagy.  While there are many factors that might help explain these differences (time, human interactions, space limitations), the fact that ape behavior differed so broadly supports our contention that time off-exhibit must be included as an important component of behavioral evaluations of ape welfare in a zoo setting.