Abstract # 9:

Scheduled for Saturday, August 26, 2017 06:00 PM-08:00 PM: (National Ballroom AB) Poster Presentation


BEHAVIOR DIFFERENCES IN A SILVERBACK IN THE PRESENCE OF MALE VS FEMALE CONSPECIFICS: A CASE STUDY

V. James-Aldridge
Gladys Porter Zoo, Brownsville, TX 78520, USA
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     In the course of introducing a new silverback to an existing family group of zoo housed lowland gorillas (Gorilla gorilla gorilla; n=10), keepers occasionally mentioned that the male’s indoor behavior appeared to vary depending on which of several other animals were also present at the time. Systematic observations were conducted in May and June of 2016 to see if this was, in fact, happening. Approximately 16 hours of focal animal samples were collected across four conditions. Summary descriptive measures revealed a clear difference between one condition and each of the remaining three: The silverback spent much more time in both locomotion (23.5% of total observation time) and manipulation (37.8%) when three adult females were indoors near him and two other young adult males were outdoors than when the females were outdoors and the other males were indoors (4.6% and 8.0%, respectively), or when both females and other males were inside, either early (4.6% and 23.4%), or late (3.8% and 20.6%). Further, this behavior pattern differed from that of another silverback and from patterns averaged across all other group members who were present. Although they seem somewhat counterintuitive, these results can be related both to the reported behavior of silverbacks in the wild and the rearing history of this particular male. The results also confirm the accuracy of the anecdotal observations made previously by his keepers.