Comparative Investigations of Social Context-Dependent Dominance in Captive Chimpanzees (Pan troglodytes) and Wild Tibetan Macaques (Macaca thibetana)

Theoretical definitions of dominance, how dominance is structured and organized in nature, and how dominance is measured have varied as investigators seek to classify and organize social systems in gregarious species. Given the variability in behavioral measures and statistical methods used to derive dominance rankings, we conducted a comparative analysis of dominance using existing statistical techniques to analyze dominance ranks, social context-dependent dominance structures, the reliability of statistical analyses, and rank predictability of dominance structures on other social behaviors. We investigated these topics using behavioral data from captive chimpanzees (Pan troglodytes) and wild Tibetan macaques (Macaca thibetana). We used a combination of all-occurrence, focal-animal, and instantaneous scan sampling to collect social, agonistic, and associative data from both species. We analyzed our data to derive dominance ranks, test rank reliability, and assess cross-context predictability using various statistical analyses. Our results indicate context-dependent dominance and individual social roles in the captive chimpanzee group, one broadly defined dominance structure in the Tibetan macaque group, and high within-context analysis reliability but little cross-context predictability. Overall, we suggest this approach is preferable over investigations of dominance where only a few behavioral metrics and statistical analyses are utilized with little consideration of rank reliability or cross-context predictability

Playing it cool: Characterizing social play, bout termination, and candidate play signals of juvenile and infant Tibetan macaques (Macaca thibetana)

Play behaviors and signals during playful interactions with juvenile conspecifics are important for both the social and cognitive development of young animals. The social organization of a species can also influence juvenile social play. We examined the relationships among play behaviors, candidate play signals, and play bout termination in Tibetan macaques (Macaca thibetana) during juvenile and infant social play to characterize the species play style. As Tibetan macaques are despotic and live in groups with strict linear dominance hierarchies and infrequent reconciliation, we predicted that play would be at risk of misinterpretation by both the individuals engaged in the play bout and by those watching, possibly leading to injury of the players. Animals living in such societies might need to frequently and clearly signal playful intent to play partners and other group members to avoid aggressive outcomes. We gathered video data on 21 individually-identified juvenile and infant macaques (one month to five years of age) from the Valley of the Wild Monkeys, Mt. Huangshan, China. We used all-occurrence sampling to record play behaviors and candidate play signals based on an ethogram. We predicted that play groups would use multiple candidate play signals in a variety of contexts and in association with the number of audience members in proximity to the players and play bout length. In the 283 playful interactions we scored, juvenile and infant macaques used multiple body and facial candidate play signals. Our data showed that juvenile and infant Tibetan macaques use a versatile repertoire of play behaviors and signals to sustain play

Social network and dominance hierarchy analyses at Chimpanzee Sanctuary Northwest

Different aspects of sociality bear considerable weight on the individual- and group-level welfare of captive nonhuman primates. Social Network Analysis (SNA) is a useful tool for gaining a holistic understanding of the dynamic social relationships of captive primate groups. Gaining a greater understanding of captive chimpanzees through investigations of centrality, preferred and avoided relationships, dominance hierarchy, and social network diagrams can be useful in advising current management practices in sanctuaries and other captive settings. In this study, we investigated the dyadic social relationships, group-level social networks, and dominance hierarchy of seven chimpanzees (Pan troglodytes) at Chimpanzee Sanctuary Northwest. We used focal-animal and instantaneous scan sampling to collect 106.75 total hours of associative, affiliative, and agonistic data from June to September 2016. We analyzed our data using SOCPROG to derive dominance hierarchies and network statistics, and we diagrammed the group\u27s social networks in NetDraw. Three individuals were most central in the grooming network, while two others had little connection. Through agonistic networks, we found that group members reciprocally exhibited agonism, and the group\u27s dominance hierarchy was statistically non-linear. One chimpanzee emerged as the most dominant through agonism but was least connected to other group members across affiliative networks. Our results indicate that the conventional methods used to calculate individuals\u27 dominance rank may be inadequate to wholly depict a group\u27s social relationships in captive sanctuary populations. Our results have an applied component that can aid sanctuary staff in a variety of ways to best ensure the improvement of group welfare

Spatial variability of stereotypic behavior in three bear species

Captive animal welfare can be informed via observations of stereotypic behaviors (abnormal, repetitive motor functions) as they are perceived as indicators of poor welfare. Frequency of stereotypic behaviors can be modified by both enrichment, and visitor presence and proximity. This study examines the spatial variability of stereotypic behaviors in three species of bears and how the frequency of behaviors fluctuated with region of the enclosure and proximity to visitors. It was predicted that there would be individual variability in each subjects’ stereotypical behaviors, in terms of location and frequency, based on animal individuality and personality literature. Three species of Ursidae were studied, with six subjects observed in total: two grizzly bears (Ursus arctos), one Andean bear (Tremarctos ornatus) and one polar bear (Ursus maritimus) from the Saint Louis Zoo were observed in-person, and two polar bears were observed at the Kansas City Zoo via webcam. Focal follows of 30 minutes were conducted in which behaviors and enclosure location were recorded continuously, for a total of 6.5 hours of observation per subject. The study found that two subjects (the Andean bear, and one polar bear of the Kansas City Zoo) exhibited significant frequencies of stereotypic behaviors in specific portions of their respective enclosures, both at a far distance from visitors. The other four subjects lacked significant stereotypic behaviors, but their variation in preference for certain portions of their enclosures, and visitor proximity preference, has greater implications for individual variability in welfare studies. The variability in the activity budgets for each subject across their respective enclosures emphasizes a need for animal welfare studies to take on an individual, and longitudinal form, informed by an animal’s life history, temperament, and changes in behavior over time

Well-being and stress in orangutans at the Saint Louis and San Diego Zoos

Sumatran orangutans (Pongo abelii) are a critically endangered primate species that have experienced sharp population declines over the last half-century. Orangutans are largely solitary and arboreal animals in the wild, making well-being and stress research on the more constricted and social captive individuals important. This study sought to evaluate stress and non-stress related behavior in captive orangutans at the San Diego and Saint Louis Zoos. These groups were chosen due to similarities in their group demographics (count, sex, age) and differences in their enclosure environments (one group is housed in a mixed-species enclosure with siamangs). It was hypothesized that the Saint Louis orangutans would show less stress-related behavior, higher frequencies of arboreality, and lower frequencies of interaction and close proximity associations compared to the San Diego orangutans. Forty hours of observational data was conducted including a mixture of in-person (Saint Louis) and webcam (San Diego) instantaneous group scans and continuous focal follows to create a matched sample between the populations. Stress-related behaviors were found to be slightly higher in Saint Louis although both populations displayed remarkably low frequencies of stress-indicative behaviors. Arboreality and social behavior was shown to have higher frequencies among the San Diego orangutans, though using these as clear-cut indicators of stress and non-stress requires further research considerations. Overall, this study found that captive orangutans may not have the same preferences as wild orangutans

The Evolutionary and Comparative Elements of Social Roles

In human societies, individuals who hold social roles are recognized by others as possessing context- or task-specific proficiencies and skills. The social roles that are arguably unique to our societies confer many functional benefits, however multidisciplinary interests in the topic lack an evolutionary framework that allows for the comparative elements and emergence of social roles to be investigated. In this research, we put forth four elements of social roles in societies that can be compared across species: those that are context-specific, expressed over time, offer functional advantages, and individuals who hold social roles are recognized by conspecifics as possessing characteristics. To simultaneously assess comparative elements of the cognitive mechanisms that support social roles, we identify behavioral indicators of shared intentionality. With this framework, we examined aspects of social roles in the fission-fusion societies and social interactions of chimpanzees across multiple sites and settings. In the Goualougo Triangle (Republic of Congo) we examined patterns of party co-attendance and identified context-specific specializations that are consistently expressed by the same individuals, stable in their expression over many years, and functionally beneficial in expediting the possible transmission of information. Across nine chimpanzee social groups at Save the Chimps sanctuary (Florida, USA) and the Saint Louis Zoo (Missouri, USA) we found that individuals recognized the role-specific actions of skilled mediators of reparative conflict interventions. Additionally, we observed the chimpanzees to readily employ the cognitive mechanisms that support social roles via constructing joint commitments in mutual grooming and shared social attention in coalitionary aggression. Our results provide some of the first systematic evidence of social roles and shared intentions in chimpanzees. These results place new emphasis on the social pressures that likely shaped the emergence of social roles and shared intentions. Additionally, the enhanced understanding of chimpanzee social roles that we provide expands the known range of behavioral diversity of this species. It is critical to consider social complexity as an integral part of chimpanzee behavioral diversity to best inform initiatives that safeguard wild chimpanzees and promote the wellbeing of captive populations

The large herd dynamics and social behavior of domesticated donkeys

Little research has been conducted regarding the social behavior of domesticated donkeys (Equus asinus). However, a species as profuse and well-known as donkeys require a deeper look into their social preferences, especially in order to determine the best living conditions for these animals. This research examines the social dynamics of a large herd of donkeys, and it was predicted that the donkeys would exhibit group-specific social behavior through conspecific interactions and associate with preferred smaller groups and form strong bonds with other individuals. By using a live webcam of the indoor barn at The Donkey Sanctuary (Sidmouth, England), 81 barn scans were conducted where 816 social clusters were observed. On average, 17 donkeys and 10 social clusters were observed per barn scan. The results from the study indicate that donkeys have an overwhelming preference for social environments and therefore need to be provided with opportunities for social interactions with conspecifics. Thus, this research provides important context for maximizing donkey welfare by ensuring these animals are able to practice social behavior in captivity. Additionally, the results imply that donkeys are capable of thriving in large herds

Course-based research experiences in behavioral ecology

The Course-Based Undergraduate Research Experience in Behavioral Ecology curriculum (CURE-BxEco) aims to provide the curriculum necessary for students across the globe to access independent research experiences in animal behavior and behavioral ecology. This curriculum includes instructional materials to teach students how to conceptualize, design, conduct, and report independent research projects using behavioral observations collected either in person or using freely accessible live animal webcams. Within this curriculum, we also aimed to incorporate an open science initiative to provide students with training in open scholarship as well as catalyze expansive and comparative research by future students. Each Component of this OSF Project represent the products of a student's course-based independent research project. This repository and database will continue to be updated

Human caregivers are integrated social partners for captive chimpanzees

In a captive environment, it is challenging to ensure the highest level of social and psychological well-being for species with naturally complex social organizations and structures. There is a growing need to meet the social requirements for individuals of these species, especially chimpanzees, housed in zoos, sanctuaries, rehabilitation centers, and laboratories. Complex social interactions and broader social structures can be aptly described via social network analysis. We expand on the literature regarding captive chimpanzee social networks, but uniquely consider their human caregivers as potential social partners. We observed the social interactions between one group of seven chimpanzees (Pan troglodytes) and their caregivers in six behavioral contexts (nearest neighbor, play, aggression, grooming, grooming solicitation, and social vigilance) at Chimpanzee Sanctuary Northwest (USA). By constructing multiple chimpanzee and chimpanzee-caregiver social networks, our results indicate that caregivers are integrated partners in this group’s social structure. Additionally, we observed that the type and strength of chimpanzee-caregiver relationships varied between the chimpanzees. These results support the notion that caregivers offer additional opportunities (i.e., beyond those with conspecifics) for captive chimpanzees to construct and maintain meaningful social relationships. Our results show that considerations of captive primate social dynamics should include caregivers as potentially important social partners. Our results also highlight the importance of evaluating individual chimpanzee characteristics when developing philosophies of care and adopting husbandry practices that offer fulfilling social niches. Our findings bear influence on contemporary discussions of interspecies social relationships, captive welfare, health, translocation, and husbandry protocols for captive chimpanzees and other nonhuman primates

Behavioral ethogram.

<p>Behavioral ethogram.</p