Technology at the Zoo: The Influence of a Touchscreen Computer on Orangutans and Zoo Visitors

A computer‐controlled touchscreen apparatus (hereafter referred to as “touchscreen”) in the orangutan exhibit at Zoo Atlanta provides enrichment to the animals and allows cognitive research to take place on exhibit. This study investigated the impact of the touchscreen on orangutan behavior and visibility, as well as its impact on zoo visitors. Despite previous research suggesting that providing a single computer system may negatively affect orangutan behavior, there was not a significant increase in aggression, stereotypic, or distress‐related behaviors following the activation of the on‐exhibit touchscreen. We also investigated the possibility that zoo visitors may be negatively affected by technology because it deviates from naturalism. However, we did not find a change in stay time or overall experience rating when the computer was turned on. This research was the first to assess visitor attitudes toward technology at the zoo, and we found that visitors report highly positive attitudes about technology for both animals and visitors. If subjects visited the exhibit when the computer was turned on, they more strongly agreed that orangutans benefit from interacting with computerized enrichment. This study is the first investigation of an on‐exhibit touchscreen in group‐housed apes; our findings of no negative effects on the animals or zoo visitors and positive attitudes toward technology suggest a significant value of this practice. Zoo Biol 31:27;–39, 2012. © 2011 Wiley Periodicals, Inc.     

Visitor effects on the behavior of captive Western lowland gorillas: the importance of individual differences in examining welfare

Given the conflicting and somewhat limited findings available on the effect of zoo visitors on primate behavior, the primary purpose of this study was to provide additional data on gorillas' response to variations in crowd size and to look at what other factors—both intrinsic (e.g. personality, sex, and rearing history) and extrinsic (e.g. group)—might influence such responses. Subjects included four groups (three mixed‐sex and one bachelor) of captive western lowland gorillas living at Zoo Atlanta. Overall activity budgets and rates of social behaviors in high and low crowd conditions were compared. Behaviors suggestive of general welfare did not vary as a function of crowd size alone, although we did observe one significant interaction and several trends. Specifically, two groups spent more time engaged in undesirable behaviors in the high crowd condition, whereas the other two groups showed the opposite response pattern. Additionally, males, but not females, showed a trend toward greater rates of contact aggression in the high crowd condition, although wounding rates did not vary with crowd size. We also found trends towards variation in response to crowd size as a function of individual personality ratings. These results suggest that although the visitor effect may constitute an impediment to optimal animal welfare, this may only apply to some individuals or groups. We emphasize the importance of continuing to explore individual differences and the limitations of a one‐size‐fits‐all approach when describing influences on animal welfare. Zoo Biol 31:586‐599, 2012. © 2011 Wiley Periodicals, Inc.     

Behavioral response of captive western lowland gorillas (Gorilla gorilla gorilla) to the death of silverbacks in multi‐male groups

In both free‐ranging and captive western lowland gorillas, a silverback provides protection and leadership, mediating conflict within a group. In the wild, when a dominant silverback dies the group will disperse or transfer to a solitary male, unless a subsequent male is present to inherit the group. In captivity, studies have focused on groups containing one male and therefore it is unclear how gorillas respond to the death or removal of a silverback in multi‐male groups. This study examined the behavior of a bachelor group (Cleveland Metroparks Zoo) and a multi‐male, mixed‐sex group (Pittsburgh Zoo and PPG Aquarium) following the death of two older silverbacks in 2005. Both of the younger but dominant males maintained their same level of dominance after the death. We predicted that agonism would increase after the death as groups struggled for social stablility. We did observe an increase in both agonism and displacements among the bachelor group, but only observed an increase in displacements among the mixed‐sex group. Although we predicted that there would be no change in solitary behavior, both groups decreased feeding and the mixed‐sex group increased self‐directed behavior post‐death. In the bachelor group, self‐directed behavior decreased and undesirable behavior increased. We also observed a difference in spatial distance after the death with members of the mixed‐sex group becoming more dispersed and members of the bachelor group more converged. This study demonstrates that there is a period of transition for multi‐male groups after the death or removal of the oldest silverback. Future research could integrate physiological measures with behavioral analyses before and after the death or removal of a prominent member of the group. Zoo Biol 29:16–29, 2010. © 2009 Wiley‐Liss, Inc.     

Variability in the developmental life history of the genus Gorilla

Life history is influenced by factors both intrinsic (e.g., body and relative brain size) and extrinsic (e.g., diet, environmental instability) to organisms. In this study, we examine the prediction that energetic risk influences the life history of gorillas. Recent comparisons suggest that the more frugivorous western lowland gorilla shows increased infant dependence, and thus a slower life history, than the primarily folivorous mountain gorilla to buffer against the risk of starvation during periods of food unpredictability. We further tested this hypothesis by incorporating additional life history data from wild western lowland gorillas and captive western lowland gorillas with the assumption that the latter live under ecological conditions of energetic risk that more closely resemble those of mountain gorillas and thus should show faster life histories than wild members of the species. Overall, we found captive western lowland and wild mountain gorillas to have faster developmental life histories than wild western lowland gorillas, weaning their infants approximately a year earlier and thus reducing interbirth intervals by a year. These results provide support that energetic risk plays an important role in determining gorilla life history. Unlike previous assertions, gorillas do not have substantially faster life histories, at least at the genus level, than other great apes. This calls for a re‐evaluation of theories concerning comparative ape life history and evolution and highlights the need for data from additional populations that vary in energetic risk. Am J Phys Anthropol 152:165–172, 2013. © 2013 Wiley Periodicals, Inc.     

Male-immature relationships in multi-male groups of mountain gorillas (Gorilla beringei beringei)

We examined the pattern and possible functions of social interactions between adult males and immatures in three free-ranging, multi-male groups of mountain gorillas (Gorilla beringei beringei). Previous studies conducted during the 1970s when groups contained one to three adult males concluded that male-immature relationships were likely to be a form of low-cost paternal investment [Stewart, Mountain gorillas: three decades of research at Karisoke. Cambridge, UK: Cambridge University Press, 2001]. We evaluated whether this hypothesis still held in groups containing six to nine adult males, or if male-immature relationships might serve other functions (e.g. mating effort, kin selection, or alliance building). Overall, we found that immatures spent the most time near, and interacted most with, the alpha silverback. These behaviors peaked during the period when infants were still quite vulnerable but increasing their independence from their mothers. Such findings suggest that parenting effort remains the primary function of male-immature relationships; however, there is some evidence for the mating effort hypothesis as well.     

Orangutans (Pongo pygmaeus) do not form expectations based on their partner's outcomes

Several primate species form expectations based on others' outcomes, responding negatively when their outcomes differ from their partners'. The function and evolutionary pathway of this behavior are unknown, in part because all of the species which have been tested thus far share traits related to a gregarious lifestyle, intelligence, and cooperativeness. Our goal was to test whether inequity is a homology among primates or a convergence by comparing one species known to show social comparisons, the chimpanzee, to another great ape which differs on several of these life history characteristics. Using a protocol identical to one used previously with chimpanzees, we tested whether orangutans, an intelligent but predominantly solitary species with few opportunities to cooperate, responded similarly. To allow for a strong comparison with chimpanzees (and other species), we used socially housed adults of both sexes, tested with members of their social group. Orangutans did not respond negatively to inequity, supporting previous findings and indicating that inequity responses in apes are likely a convergence based on either sociality or cooperative tendency. These results in such closely related species highlight the need for additional comparative studies to understand better the function and evolution of social behaviors.