Abstract # 186:

Scheduled for Friday, August 19, 2005 07:00 PM-09:00 PM: (Cambridge/Oxford Room) Poster Presentation

Visual examine behavior as a function of context, age and relatedness in captive western lowland gorillas (gorilla g. gorilla)

L. Lane1, T. Stoinski1,2 and D. Forde1
1Zoo Atlanta, 800 Cherokee Ave, Atlanta, GA 30315-1440, USA, 2Dian Fossey Gorilla Fund International
     A close visual inspection of a conspecific is hypothesised to provide benefits for younger individuals in a social group, such as supplying valuable information about food a conspecific is eating and indicating social attraction. To determine the role of visual examination behaviours in gorillas, 410 hours of data were collected on 18 gorillas in 3 social groups at Zoo Atlanta. A total of 354 incidences of visual examinations and recipient behavioral context were collected on an all occurrence basis. Mixed design ANOVA’s found that juveniles were the primary initiators of examinations whether the recipient was another adult (P < 0.001), juvenile (P = 0.039) or kin (P = 0.009). The initiator’s age class was related to behavioral context as juveniles examined unrelated adults significantly more in a feeding context compared to a resting (P = 0.003), social (P = 0.001) and other context (P = 0.001). However, rates of kin examination during feeding for both age classes were comparable to rest. Examinations of unrelated juveniles were not context dependant. Visual examine behaviors in a feeding setting may represent information seeking gestures by younger individuals to older, more knowledgeable individuals, especially adaptive when relating to food. The results indicate flexible use of visual examinations depending on context, age and relatedness.