An evaluation of video cameras for collecting observational data on sanctuary-housed chimpanzees (Pan troglodytes).

Video cameras are increasingly being used to monitor captive animals in zoo, laboratory, and agricultural settings. This technology may also be useful in sanctuaries with large and/or complex enclosures. However, the cost of camera equipment and a lack of formal evaluations regarding the use of cameras in sanctuary settings make it challenging for facilities to decide whether and how to implement this technology. To address this, we evaluated the feasibility of using a video camera system to monitor chimpanzees at Chimp Haven. We viewed a group of resident chimpanzees in a large forested enclosure and compared observations collected in person and with remote video cameras. We found that via camera, the observer viewed fewer chimpanzees in some outdoor locations (GLMM post hoc test: est. = 1.4503, SE = 0.1457, Z = 9.951, p < 0.001) and identified a lower proportion of chimpanzees (GLMM post hoc test: est. = -2.17914, SE = 0.08490, Z = -25.666, p < 0.001) compared to in-person observations. However, the observer could view the 2 ha enclosure 15 times faster by camera compared to in person. In addition to these results, we provide recommendations to animal facilities considering the installation of a video camera system. Despite some limitations of remote monitoring, we posit that there are substantial benefits of using camera systems in sanctuaries to facilitate animal care and observational research.

An evaluation of nest-building behavior by sanctuary chimpanzees with access to forested habitats.

All of the great apes build nests, but captive chimpanzees rarely have vegetation from which to build nests. The forested environment at Chimp Haven does allow captive chimpanzees to build nests of natural vegetation. Between February 2007 and December 2010, 238 nests were found in 2 forested habitats. Nests were made of naturally available vegetation, and more nests were made on the ground than in the trees (Z = 7.27, p < 0.001); nests were also built in the interior forest rather than on the periphery (Z = 7.06, p < 0.001). There was no correlation between the number of months in the habitat and the nests built per chimpanzee (rs = -0.07, p = 0.52). More nests were observed when more wild-born females were in the group (rs = 0.27, p = 0.01), and during warmer temperatures (rs = 0.45, p < 0.001). These findings support the goal of naturalistic environments in suitable climates for captive chimpanzees.

Behavioral Welfare Research for the Management of Sanctuary Chimpanzees (Pan troglodytes).

Chimp Haven is a sanctuary for chimpanzees retired from biomedical research, rescued from the pet trade, or re-homed after other organizations could no longer care for them. To provide optimal care for over 300 chimpanzees, Chimp Haven's animal care team includes experts in behavioral science, veterinary treatment, and husbandry practices. To aid these teams in making routine welfare management decisions, a system of behavioral metrics provides objective data to guide decisions and track outcomes. Chimp Haven has built and piloted seven behavioral metric protocols over the past 5 years to provide staff with an objective and comprehensive picture of the chimpanzees' behavioral welfare. The data from behavioral observations, staff surveys, and routine staff documentation are analyzed and processed through Google Forms, ZooMonitor, Microsoft Power Bi, Microsoft Excel, and R. Each metric assists staff in making data-based decisions regarding the management of captive chimpanzees related to abnormal behavior, hair loss, wounding, social relationships, positive reinforcement training and overall wellness. In this article, we explore examples of each metric and how they have been utilized to monitor and make decisions for both social groups of chimpanzees as well as individuals. These metrics can be collected and shared easily in an understandable format, which may provide an important framework for others to follow to enable the tracking of welfare for other sanctuaries, non-human primates, as well as other species.

How Sanctuary Chimpanzees (Pan troglodytes) Use Space after Being Introduced to a Large Outdoor Habitat.

Wild chimpanzees live in large, mixed-sex groups that display a fission-fusion social organization. To provide a social environment more like that of wild chimpanzees, Chimp Haven integrated smaller groups of 3-4 individuals into one large group of 18 individuals. This large group was introduced to a 20,234.28 m2 forested habitat and associated indoor areas. This space was designed to allow the individual chimpanzees to choose their proximity to social companions and provide the group with a more natural environment in which they could express more species-typical behavior. The study took place over a 7-month period that began two weeks prior to the first groups being integrated and ended 4 months after the chimpanzees were released into the habitat. We collected data on the chimpanzees' arboreal, terrestrial, indoor, and outdoor spatial use. The chimpanzees' proximity to their nearest neighbor was also recorded, noting whether they were touching or within arm's reach. Data were collected during daytime and nighttime hours and were utilized to make management decisions about potential group formations. We examined the data using generalized linear mixed models (GLMMs) with individual subjects as a random factor and months as a repeated measure for location and proximity results. There were significant differences in the use of arboreal and outside space over the 7-month time frame, with females more likely to use the arboreal space than males. The chimpanzees were more likely to utilize the habitat over time and increased their proximity to group mates. The results of this study indicate that the chimpanzees responded positively to living in large groups in a spacious naturalistic environment.

Chimpanzees (Pan troglodytes) in U.S. Zoos, Sanctuaries, and Research Facilities: A Survey-Based Comparison of Species-Typical Behaviors.

A survey was sent to zoos, research facilities, and sanctuaries which housed chimpanzees. Data collected included information about 1122 chimpanzees' age, sex, social group-size, rearing history, and enclosure. Respondents were also asked to indicate if certain behaviors had been observed in each chimpanzee over the prior two years. Species- typical behaviors (STBs) were queried, including copulation, tool-use, nest-building, and social grooming. Tool-use was reported present for 94.3% of the sample (n = 982), active social grooming for 85.7% (n = 1121), copulation for 68.3% (n = 863) and nest-building for 58.9% (n = 982). Of the subjects for whom we had data regarding all four STBs (n = 860), 45.6% were reported to engage in all four. Logistic regression analyses using forward Wald criteria were conducted to determine the best model for each STB based on the predictors of age, sex, rearing history, group-size, facility-type, and a sex-by-rearing interaction. The best model for copulation (χ2(6) = 124.62, p < 0.001) included rearing, group-size, facility-type, and the sex-by-rearing interaction. Chimpanzees were more likely to copulate if they were mother-reared, in larger groups, living in research facilities, and, if not mother-reared (NOTMR), more likely to copulate if they were female. The best model for tool-use retained the predictors of age category, facility-type, and sex-by-rearing (χ2(5) = 55.78, p < 0.001). Chimpanzees were more likely to use tools if they were adult, living in research facilities, and if NOTMR, were female. The best model for nest-building included facility-type and rearing (χ2(3) = 205.71, p < 0.001). Chimpanzees were more likely to build nests if they were MR and if they were living in zoos or in sanctuaries. The best model for active social grooming retained the predictors of age, sex, rearing, and type of facility (χ2(6) = 102.15, p < 0.001). Chimpanzees were more likely to engage in active social grooming if they were immature, female, mother-reared, and living in zoos. This research provides a basic behavioral profile for many chimpanzees living under human care in the United States and allows us to determine potential methods for improving the welfare of these and future chimpanzees in this population.

Aggressive, Submissive, and Affiliative Behavior in Sanctuary Chimpanzees (Pan Troglodytes) During Social Integration.

Chimp Haven is a sanctuary for chimpanzees being retired from biomedical research and from facilities that can no longer care for them. Chimpanzees often live in smaller groups in captive settings; however, Chimp Haven integrates them into larger, more species-typical groups. Social integrations, the process of introducing unfamiliar chimpanzees to one another, are often complex in terms of logistics and can be stressful due to the territorial nature of the animals, reduced space in captivity, and the fact that these situations are engineered by humans. From 2005 to 2015, Chimp Haven conducted 225 social integrations including 282 chimpanzees (male: n = 135; female: n = 147). Each integration involved 2 to 26 chimpanzees (mean = 9) and their age ranged from < one year old to 59 years old (mean = 30). We collected data ad libitum during the first 60 min after doors were opened between unfamiliar chimpanzees. The chimpanzees' affiliative, aggressive, and submissive behaviors were examined, comparing the subject's sex, rearing history, location/enclosure type, and group size impacts on these behaviors. The subject's sex, location, and group size were associated with the frequency of affiliative behaviors observed during social integration. All variables except for group size were associated with the frequency of aggressive behavior. The frequency of submissive behavior differed based on the subject's sex, rearing history, and group size. We were unable to make comparisons between successful and unsuccessful integrations, as most of these integrations were successful.

An evaluation of thermal imaging as a welfare monitoring tool for captive chimpanzees.

Among the growing list of novel tools with which to assess animal welfare is the use of thermal (infrared) imaging. The technology has already been utilized to identify emotional arousal in several nonhuman primate species, though most of these approaches have necessitated the use of relatively controlled settings. Here, we were interested to determine the feasibility of such techniques in a sanctuary setting in which chimpanzees were unrestrained and able to move freely around their enclosures. Furthermore, we sought to evaluate how such thermal images could be paired with corresponding long-term behavioral data and contribute to a multifactorial welfare monitoring system. Over a 6-month period, we simultaneously collected both behavioral and thermographic data on 29 chimpanzees living in four social groups. While we took a thermal image with every behavioral data point, we found that only a small proportion (6.38%) of the thermal images we captured were of sufficient quality to analyze. Most of these usable thermal images (55%) corresponded with a behavioral observation scored as "inactive," and thus other, less frequent behaviors are not so well represented in our final data set. From our data set, we were able to determine that nasal temperatures were relatively lower when chimpanzees were categorized in active behaviors compared to inactive behaviors, providing some validity measures to our approach. While there are other potential applications for thermal imaging in the behavioral management of chimpanzees, managers should consider the practical limitations of developing long-term welfare monitoring programs that rely on thermographic data.

Ethical issues in African great ape field studies.

Great apes have been systematically studied in the wild for over half a century. Great apes are now critically endangered and this raises significant ethical issues for field primatologists who study and work to conserve these primates and their habitats. The most immediate ethical concerns involve the well-being of the subjects, but there are also important ethical considerations involved in researchers' interactions with local human populations and extracting industry representatives. This essay will discuss some of the ethical issues raised by African great ape research, with the hope of generating greater dialogue about best practices. After briefly presenting the history of great ape fieldwork, the ethical issues associated with habituation, intervention, and conservation will be discussed. This text will end with specific proposals that focus on the ethical concerns in great ape field studies.