Effects of Complex Feeding Enrichment on the Behavior of Captive Malayan Sun Bears (Helarctos malayanus).

All zoos grapple with challenges of keeping captive animals engaged in natural behaviors, especially for bears which prove to be among the more challenging species to keep stimulated. In captivity, a common indicator of poor welfare is the presence of stereotypic behaviors. This study tests whether providing complex feeding enrichment devices decreases the duration of stereotypic behavior and increases enrichment interaction for three adult female sun bears (Helarctos malayanus) at Oakland Zoo in California. This study uses two different enrichment devices presented at three complexity levels. After three weeks of baseline data collection when no complex enrichment is present, the complex enrichment is introduced three times a week per level over six weeks. Sun bear interaction with the enrichment devices is also measured to examine the effect of complexity on enrichment use. Providing complex enrichment decreased the duration of stereotypic behavior when compared to baseline. Across the six weeks, the duration of stereotypic behavior is significantly less on the complex enrichment days compared to non-complex enrichment days. The complex enrichment has variable effects on enrichment use. These results suggest that providing complex enrichment may have a positive influence on the behavior of captive bears.

The utility of social network analysis for informing zoo management: Changing network dynamics of a group of captive hamadryas baboons (Papio hamadryas) following an introduction of two young males.

Comprehensive knowledge of social groups within zoos allows for better understanding of the issues surrounding group stability and how to provide captive animals with optimal care. A developing area of sociality research that works to improve this understanding is social network analysis (SNA), which allows scientists to apply quantitative measures of group systems to represent social structure. In December 2015, Oakland Zoo introduced two new males to the hamadryas baboon (Papio hamadryas) exhibit. We examined the changing group structure of these baboons over the course of 6 months (July-December 2016) using social network analysis, specifically focusing on the changing social structure of the existing group and the utility of SNA methods for optimal care of captive animals. This study found that over time, the new males decreased their overall individual centrality, while some individuals had an increase in betweenness, a measure of an individual's intermediary role in the network. The results also illustrate the utility of social network analysis as tool for zoo management to examine how husbandry may have an impact on their animals, specifically for social species. Further research on the social networks of hamadryas baboon multi-clan formation could provide more information about the societal structure of this primate species, as well as the use of social network analysis as a valuable tool in captive animal management.

Changes in ranging and agonistic behavior of vervet monkeys (Cercopithecus aethiops) after predator-induced group fusion.

Socio-ecological theory predicts that group fusion in female-philopatric primate species will be rare because females experience increased costs by associating with non-relatives. Indeed, fusion has been reported only 14 times in only 4 female-philopatric cercopithecines despite many years of observation. Here, we describe changes in ranging and agonistic behavior of vervet monkeys (Cercopithecus aethiops) after the fusion of two groups, the sole group fusion during 11 years of observation, induced by a brief but intense period of apparent leopard predation. Before fusion, both groups made few incursions into the other group's territory and spent most of the time in their own territories. After the fusion, the amalgamated group shifted its activities and used both territories in similar proportion. Rates of female agonism increased after fusion, particularly in the 2 weeks following fusion, and the small group females assumed the lowest ranks in the female dominance hierarchy. Rates of agonism returned to prefusion rates a month later. Although rates of high-intensity interactions (i.e., chases) did not increase after fusion, small group females were more likely to be the recipients of, and lose, agonistic interactions than large group females; a small group female and her infant were attacked and wounded by a coalition of large group females shortly after the fusion. The observations presented here reveal that the circumstances surrounding group fusions are more variable than previously realized, but are still in accordance with expectations from socio-ecological theory that predation can favor the formation of larger groups. In this case, under threat of severe predation, individuals may have surrendered group autonomy for the greater security of larger numbers.

After the fire: benefits of reduced ground cover for vervet monkeys (Cercopithecus aethiops).

Here we describe changes in ranging behavior and other activities of vervet monkeys (Cercopithecus aethiops) after a wildfire eliminated grass cover in a large area near the study group's home range. Soon after the fire, the vervets ranged farther away from tall trees that provide refuge from mammalian predators, and moved into the burned area where they had never been observed to go before the fire occurred. Visibility at vervet eye-level was 10 times farther in the burned area than in unburned areas. They traveled faster, and adult females spent more time feeding and less time scanning bipedally in the burned area than in the unburned area. The burned area's greater visibility may have lowered the animals' perceived risk of predation there, and may have provided them with an unusual opportunity to eat acacia ants.

Demography and Life Histories of Sympatric Patas Monkeys, Erythrocebus patas, and Vervets, Cercopithecus aethiops, in Laikipia, Kenya.

Mortality patterns are thought to be strong selective forces on life history traits, with high adult mortality and low immature mortality favoring early and rapid reproduction. Patas monkeys (Erythrocebus patas) have the highest potential rates of population increase for their body size of any haplorhine primate because they reproduce both earlier and more often. We report here 10 yr of comparative demographic data on a population of patas monkeys and a sympatric population of vervet monkeys (Cercopithecus aethiops), a closely related species differing in aspects of social system, ecology, and life history. The data reveal that 1) adult female patas monkeys have significantly higher mortality than adult female vervets; 2) infant mortality in patas monkeys is relatively low compared to the norm for mammals because it is not significantly different from that of adult female patas monkeys; and 3) infant mortality is significantly higher than adult female mortality in vervets. For both species, much of the mortality could be attributed to predation. An epidemic illness was also a major contributor to the mortality of adult female patas monkeys whereas chronic exposure to pathogens in a cold and damp microenvironment may have contributed to the mortality of infant vervets. Both populations experienced large fluctuations during the study period. Our results support the prediction from demographic models of life history evolution that high adult mortality relative to immature mortality selects for early maturation.