Chimpanzee Sanctuary Research Articles

Orthognathic surgery to improve malocclusion in a chimpanzee (Pan troglodytes)

AbstractMalocclusion is a common finding in both companion animals and humans due to dental or maxillofacial discrepancies. Treatment depends on the complications and the species it presents in. In humans, orthognathic surgery is commonly performed to address skeletal malocclusions. A male chimpanzee born in 2002 and orphaned due to the bush meat pet trade was rescued in 2010 by Chimp Eden, a chimpanzee sanctuary. In 2017, it presented with inappetence and weight loss of 6‐month duration. After a computed tomography scan was performed and full mouth impressions were made, a diagnosis of asymmetry of the mandible with the left side markedly shorter and rotated along its long axis was made (malocclusion class IV in a side‐to‐side direction). A bilateral sagittal split operation was performed to correct the malocclusion and improve its feeding. At the time of writing this report, it was eating freely and no complications were seen on multiple post‐operative radiographs.

Observational approaches to chimpanzee behavior in an African sanctuary: Implications for research, welfare, and capacity-building.

Research in African ape sanctuaries has emerged as an important context for our understanding of comparative cognition and behavior. While much of this work has focused on experimental studies of cognition, these animals semi-free-range in forest habitats and therefore can also provide important information about the behavior of primates in socioecologically-relevant naturalistic contexts. In this "New Approaches" article, we describe a project where we implemented a synthetic program of observational data collection at Ngamba Island Chimpanzee Sanctuary in Uganda, directly modeled after long-term data collection protocols at the Kibale Chimpanzee Project in Uganda, a wild chimpanzee field site. The foundation for this project was a strong partnership between sanctuary staff, field site staff, and external researchers. We describe how we developed a data-collection protocol through discussion and collaboration among these groups, and trained sanctuary caregivers to collect novel observational data using these protocols. We use these data as a case study to examine: (1) how behavioral observations in sanctuaries can inform primate welfare and care practices, such as by understanding aggression within the group; (2) how matched observational protocols across sites can inform our understanding of primate behavior across different contexts, including sex differences in social relationships; and (3) how more robust collaborations between foreign researchers and local partners can support capacity-building in primate range countries, along with mentoring and training students more broadly.

Is it for real? Structural differences between play and real fighting in adult chimpanzees (Pan troglodytes).

In primates, as well as in other mammals, play fighting (PF) is a complex form of playful activity that is structurally similar to real fighting (RF) and may also be used in a competitive way. Here, we verify the structural key differences that can distinguish PF from RF in adult chimpanzees (Pan troglodytes). We collected 962 h of video recording on 30 adult individuals belonging to four chimpanzee groups (Mona Chimpanzee Sanctuary, Spain; La Vallée des Singes and ZooParc de Beauval, France). We applied different indices-two of which were borrowed from the ecological measures of biodiversity-to test for structural differences between PF (345 sessions) and RF (461 sessions) in the levels of behavior repetition (Repeatability of Same Behavior Index, RSBI), distribution uniformity (Pielou Index, J), variability (Shannon Index, H') and, symmetry (i.e., reciprocal exchange of offensive/defensive behaviors; Asymmetry Index, AI). Moreover, we compared the session duration between PF and RF. We found that duration and RSBI were higher in PF than RF while AI was higher in RF than PF. No difference was found between J and H'. Interestingly, both females and males maintained similar ranking positions (determined via Normalized David's scores) in RF and PF. Our study indicates that session duration, behavior repetition, and symmetry can be distinctive structural key features of PF whereas dominance role-reversal, behavior variability, and distribution uniformity were not. PF in adult chimpanzees may have elements of serious contexts (e.g., absence of role-reversal as in RF) which is in line with the view that play is a blended, multifunctional behavior deriving from the re-combination of different behavioral systems. Our findings highlight the need to investigate play structure and manifestation in a nuanced way to better understand the actual motivation that underlies what appears to be play.

An Evaluation of Ethograms Measuring Distinct Features of Enrichment Use by Captive Chimpanzees (Pan troglodytes).

Simple SummaryEnvironmental enrichment for chimpanzees is important in order to minimize boredom and stress in captivity and to provide opportunities to engage in species-typical behaviors. However, few studies have investigated potential associations between enrichment objects, manipulation behaviors, and social contexts, nor have they examined if individual chimpanzees vary in their enrichment object preferences. In the current study, three ethograms were used to code the use of enrichment objects, engagement in manipulation behaviors, and social contexts of enrichment use of captive chimpanzees (Pan troglodytes). Data mining from a video archive consisting of 2054 videos collected over a decade allowed the ethograms to be applied to 732 min and 58 s of videos. Some enrichment objects were more often associated with specific manipulation behaviors and social contexts, indicating that enrichment objects might serve distinct social and behavioral purposes. The chimpanzees differed in their enrichment object preferences, suggesting that caregivers of captive chimpanzees should consider individual needs when providing enrichment in order to improve chimpanzees’ experiences in captivity. Finally, the majority of enrichment object use and manipulation behaviors were able to be categorized, indicating that our ethograms were largely effective in coding enrichment use.Environmental enrichment provides mental stimulation and minimizes abnormal behaviors in captive animals. In captive chimpanzees, individual animals may vary in the ways in which they benefit from enrichment or use enrichment devices, so investigating nuances in enrichment use may improve the welfare of captive chimpanzees. In the current study, three ethograms measuring distinct features of enrichment use (i.e., enrichment object, manipulation behavior, and social context) were evaluated by coding videos of captive chimpanzees (Pan troglodytes) at Chimpanzee Sanctuary Northwest in Cle Elum, WA. A total of 732 min and 58 s of video footage was coded from a larger video archive (i.e., 2054 videos) of enrichment use that spanned a decade. A principal component analysis (PCA) revealed that different categories of enrichment objects were more often associated with specific manipulation behaviors and social contexts, suggesting that enrichment objects might fulfill different behavioral and social needs in captivity. Specifically, toy objects were associated with active tactile behaviors in affiliative contexts while oral behaviors were used with foraging objects in solitary contexts. Additionally, individual chimpanzees showed unique preferences for enrichment objects, indicating that caregivers of captive chimpanzees should consider individual needs instead of a “one size fits all” approach to enrichment provisions.

GENOMIC CHARACTERIZATION OF MULTIDRUG-RESISTANT EXTENDED-SPECTRUM β-LACTAMASE-PRODUCING ESCHERICHIA COLI AND KLEBSIELLA PNEUMONIAE FROM CHIMPANZEES (PAN TROGLODYTES) FROM WILD AND SANCTUARY LOCATIONS IN UGANDA.

Farm and wild animals may serve as reservoirs of antimicrobial-resistant bacteria of human health relevance. We investigated the occurrence and genomic characteristics of extended spectrum β-lactamase (ESBL)-producing bacteria in Ugandan chimpanzees (Pan troglodytes) residing in two environments with or without close contact to humans. The ESBL-producing Escherichia coli and Klebsiella pneumoniae were isolated from fecal material of chimpanzees from Budongo Forest and Ngamba Island Chimpanzee Sanctuary in Uganda and were more commonly isolated from chimpanzees in Ngamba Island Chimpanzee Sanctuary, where animals have close contact with humans. Selected ESBL isolates (E. coli n=9, K. pneumoniae n=7) were analyzed by whole-genome sequencing to determine the presence of resistance genes, as well as sequence type and virulence potential; the blaCTX-M-15 gene was present in all strains. Additionally, the ESBL genes blaSHV-11 and blaSHV-12 were found in strains in the study. All strains were found to be multidrug resistant. The E. coli strains belonged to four sequence types (ST2852, ST215, ST405, and ST315) and the K. pneumoniae strains to two sequence types (ST1540 and ST597). Virulence genes did not indicate that strains were of common E. coli pathotype, but strains with the same sequence types as isolated in the current study have previously been reported from clinical cases in Africa. The findings indicate that chimpanzees in close contact with humans may carry ESBL bacteria at higher frequency than those in the wild, indicating a potential anthropogenic transmission.

An Investigation into the Influence of Different Types of Nesting Materials upon the Welfare of Captive Chimpanzees (Pan troglodytes).

Simple SummaryPresently, it is vital that captive chimpanzee populations are kept physically and mentally healthy, considering the number of individuals remaining in the wild continues to decrease. As such, we carried out this study to further understand how different types of nesting materials impact upon the welfare of captive chimpanzees living at Tacugama Chimpanzee Sanctuary (Sierra Leone). These nesting materials, including leaves and branches, long grass, cotton sheets, and shredded newspaper, served as a form of environmental enrichment—a strategy that is often adopted to enhance animals’ welfare. We found that the chimpanzees’ welfare was higher when nesting materials were present, compared to when they were absent, and that individuals favoured shredded newspaper. Our results reinforce the importance of supplying enrichments that are destructible, as these give individuals an increased sense of control, and simultaneously demonstrate that synthetic enrichment materials can be favoured over natural ones.Ensuring the welfare of captive chimpanzees (Pan troglodytes) is crucial, in part because they can act as a conservation resource in the case of wild populations becoming extinct. One strategy often adopted to ensure animal welfare is environmental enrichment. In this study, we investigated the impact of different nesting materials (leaves and branches, long grass, cotton sheets, and shredded newspaper) upon the welfare of chimpanzees housed at Tacugama Chimpanzee Sanctuary (Sierra Leone). Data was collected on 20 subjects (aged 4 to 15 years) between November 2019 and March 2020. Welfare was based on individuals’ relative frequency of affiliative, abnormal and agonistic behaviours, as well as their social and behavioural competence. We found that individuals’ welfare was higher when presented with nesting materials (compared to the control and post-treatment conditions), particularly when given shredded newspaper, regardless of whether the material was presented separately or in conjunction with another. In addition, welfare was highest: during the morning (vs evening); in groups of older individuals (vs younger); with females engaging in less agonistic behaviours compared to males; and males displaying relatively higher behavioural competence. Our results support previous research that captive chimpanzees be supplied with destructible nesting materials, and demonstrate that synthetic enrichments can indeed have a more positive impact upon welfare than their natural alternatives.

Mobonda Community Conservation Project: Chimpanzees, oysters, and community engagement in Sierra Leone.

Sierra Leone constitutes the western boundary to the West Africa Upper Guinea Rainforest, one of 35 global biodiversity hotspots. The country is home to the third-largest western chimpanzee (Pan troglodytes verus) population, a subspecies upgraded to Critically Endangered on the 2016 IUCN Red List. The main threats facing chimpanzees in Sierra Leone are habitat loss and increasing interactions with humans. The Mobonda Community Conservation Project (MCCP) is a component of Tacugama Chimpanzee Sanctuary's Community Outreach Program and Kids Environmental Education Program. The aim of MCCP is to promote community-based forest management in combination with wildlife conservation through carefully designed programs that benefit communities, wildlife, and ecologically significant habitats. MCCP also aims to promote self-sustained and integrated community landscape conservation, to facilitate policy discussions to strengthen wildlife laws, and to build the capacity of the Government to implement community-based wildlife and forestry protection projects. Since Tacugama began collecting data in Moyamba District in June 2015, the project has evolved into an assembly of components. MCCP currently works with five communities, running programs including environmental education, ecological research, biomonitoring including wildlife law enforcement, habitat rehabilitation through reforestation of identified wildlife corridors, improved sustainable livelihoods, and ecotourism initiatives. These programs contributed to a reduction in the threats facing wildlife in the area; the project has seen stable chimpanzee numbers where decrements to chimpanzee populations continue to be experienced elsewhere. Other MCCP outcomes include boosted sustainable agricultural production and higher oyster yields while decreasing the negative impact on the mangrove ecosystem allowing it to recover and support an array of important fauna and flora.

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 oncontemporary discussions of interspecies social relationships, captive welfare, health, translocation, and husbandry protocols for captive chimpanzees and other nonhuman primates.

Browsing impacts on Acacia drepanolobium Sjostedt and associated ant guilds in Ol Pejeta Conservancy, Kenya.

The numbers of Acacia drepanolobium trees are declining over much of Africa and large mammals particularly more prone and vulnerable to loss of habitat owing to human settlement encroachment. In Ol pejeta conservancy a sanctuary for the protection of the endangered black rhino, there is significant browse and vegetation pressure on the habitat particularly on the Acacia drepanolobium tree population. This study aimed to investigate the Acacia drepanolobium and ants’ interaction under different browsing intensities, determine effect of prescribed burnings on Crematogaster ants and Acacia drepanolobium interaction, investigate the tenancy dynamics of ants under varying morphological characteristics of Acacia drepanolobium trees, and finally to determine if Crematogaster ants’ communities/ colonization on Acacia drepanolobium change over time. Twelve (12) randomly chosen plots (keyed in a waypoint on the GPS) with fifty or more Acacia drepanolobium trees were studied for the study as follows, two (2) in a Chimpanzee Sanctuary where elephant, giraffe and rhino are excluded (control), six (6) in the reserve and four (4) in the Ranch. Two (2) plots treated with prescribed burning (fire) were compared with two un-burnt plots. All data collected was fed and entered into Excel spreadsheet and Statistical Package for the Social Science version 20 for analysis. The data were then processed into quantitative tables to give a comparative analysis for response obtained. Size class distributions of the reserve, Ranch and control were compared by means of Analysis of Variance (ANOVA) and other relevant parametric statistics. The result shows that in Ol pejeta conservancy browsing levels has statistically significant effect on Crematogaster ants and Acacia drepanolobium interaction. There was a strong and notable distinction between the four acacia ant species in the overall extends and levels of tenancy while responding to varied browsing pressures; Crematogaster mimosae and Tetraponera penzigi were found to be the most abundant/frequently observed ant species occupying trees in the reserve where there is intensive browsing (Reserve) and the ranch with medium browsing intensity. From this research experimental evidence explains the ability of trees to re-induce greater spine and gall numbers and that ant tenancy in A. drepanolobium is influenced by the tree’s morphological characteristics. The findings and results also indicated that prescribed burning significantly affected the type of ant inhabiting the A. drepanolobium tree. Going by the results of this paper, it was concluded that this mutualism is a key component of Ol pejeta biodiversity and ecosystem function. The study recommends that the results in this research should be used in determining ecological factors that influence conservation sustainability and predict the consequences of heavy browsing pressure, morphological characteristics and prescribed burning on the health of Acacia drepanolobium.

Fixing the ecosystem: Conservation, crisis and capital in Rwanda's Gishwati Forest.

Conservation-development projects are increasingly enacted across large expanses of land where human livelihoods hang in the balance. Recent initiatives–often called ‘landscape approaches’ or ‘ecosystem-based’ conservation–aim to achieve economic development and conservation goals through managing hybrid spaces. I argue that the landscape/ecosystem approach is a socioecological fix: an effort to resolve social-environmental crises through sinking capital (financial, natural, and social) into an imagined ecosystem. Rwanda’s Gishwati Forest has been the locus of diverse crises and fixes over the past 40 years, including an industrial forestry and dairy project, a refugee settlement, a privately managed chimpanzee sanctuary, a carbon sequestration platform, and, most recently, an “integrated silvo-pastoral conservation landscape.” This paper considers how these governance schemes have intersected with broader processes of agrarian change to generate crises that subsequent conservation/development projects then attempt to resolve. I demonstrate how visions for ecosystems privilege certain forms of governance around which imagined socioecological histories are mobilized to frame problems and legitimize certain solutions, technologies, and actors. The Gishwati ecosystem and its fixes are repeatedly defined through an imaginary of crisis and degradation that engenders large-scale landscape modification while foreclosing reflection about root causes of crises or how these might be addressed. Thus, even while conservation/development paradigms have shifted over the past 40 years (from separating people and nature to integrating them in conservation landscapes), this crisis-fix metabolism has consistently generated livelihood insecurity for the tens of thousands of people living in and around Gishwati. Imagining and enacting more just and inclusive social-environmental landscapes will require making space for diverse voices to define ecosystem form and function as well as addressing deeply rooted power imbalances that are at the heart of recurrent crises.

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’s 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’s 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’ dominance rank may be inadequate to wholly depict a group’s 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.

Finding Sarah: 49-Year Reunion with the Chimpanzee of David Premack's Language Studies

Sarah the chimpanzee was the primary participant in David Premack's language studies initiated at University of California at Santa Barbara in 1967. The first author was an undergraduate assistant training Sarah from 1967 to 1969. This article describes some of the early work with Sarah and our recent search for her. Sarah's whereabouts during the intervening years, and subsequent reunion with her in 2016 at Chimp Haven, a chimpanzee sanctuary in Louisiana, are described. It was found that despite her illness, Sarah engaged with the first author and demonstrated that she remembered him and the mechanics of the communication procedure that served as the foundation for testing Sarah's cognitive reasoning abilities as they pertained to language. There was no evidence she remembered any of the 5 symbolic nouns that were presented during a matching-to-sample procedure. The authors expressed their gratitude to the staff at Chimp Haven for the excellent care of Sarah.

Modelling travellers’ philanthropy: tourists’ motivations to donate at Sweetwater Chimpanzee Sanctuary

Parks and protected areas are often charged with addressing pressing conservation issues, but frequently face financial constraints. Travellers’ philanthropy is recognised as one form of ecotourism that can increase funding for conservation efforts, such as biodiversity preservation, within protected areas. While recent research has enumerated various factors that influence on-site donations in travellers’ philanthropy programmes, the strength of and relationships between these factors (e.g. messaging, trust, and caring) in influencing donation behaviour have not been studied. This exploratory mixed-methods study investigated factors influencing tourists’ motivations to donate to travellers’ philanthropy programmes, specifically at Sweetwater Chimpanzee Sanctuary in Kenya. Researchers examined the relationships between on-site messaging, trust in an organisation, feelings of caring for chimpanzees, on-site donation behaviour, and intentions to donate in the future. Results indicate that not all factors have equal influence on donation behaviour, and certain factors led to visitors’ future donation intentions, as opposed to actual on-site donations. These findings have implications for park and sanctuary managers in diverse settings seeking to implement and assess travellers’ philanthropy programmes, as well as design effective fundraising and outreach efforts.

Psychological Distress in Chimpanzees Rescued From Laboratories

The United States is one of the last countries allowing invasive research on chimpanzees. Biomedical research on chimpanzees commonly involves maternal deprivation, social isolation, intensive confinement, and repetitive invasive procedures. These physically harmful and psychologically traumatic experiences cause many chimpanzees to develop symptoms of psychopathology that persist even after relocation from laboratories to sanctuaries. Through semistructured interviews with chimpanzee caregivers, direct behavioral observations, and consultation of laboratory records, we were interested in qualitatively analyzing symptoms of psychological distress in a sample of 253 chimpanzees rescued from biomedical research now residing at an accredited chimpanzee sanctuary. We present the results of this analysis and include an illustrative case study of one rescued chimpanzee who engages in self-injurious behaviors and meets modified Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, criteria for posttraumatic stress disorder. We discuss our results in light of recent policy changes regarding the use of chimpanzees in biomedical research in the United States and their implications for those involved in the rescue and rehabilitation of chimpanzees from biomedical research.

Rights, affect and precarity: Post-racial formations in carework

Bringing together two sites of carework, the human household and the chimpanzee sanctuary, this article considers the limits of a politics of precarity, where vulnerabilities and differences are conceptualized as shared rather than hierarchical. Outlining the ways the notion of shared precarity produces a post-racial landscape where the labor taking place in human households is rendered equivalent to the work of providing lifelong care for captive chimpanzees formerly used in state-sponsored biomedical research—both captured under the shared sign of “carework”—we argue instead for attention to the different and differentiating mechanisms that come to define carework. We trace the ways differentiation takes place at the site of carework, both among humans and between human careworkers and chimpanzees in order to highlight the ways the politics of shared precarity reproduces the very differentiation it claims to move beyond. We examine the differential dispersal of deserving subjectivity through affective economies that govern and also exceed the legal personhood of the careworker; we argue that affect enables equivocal analogies of understanding carework for chimpanzees as like carework for humans, hiding the ways the frame of moral obligation for and to care institutes differentiating mechanisms on which the notion of humanity is itself constructed.

Chimpanzee Sanctuary: “Surplus” Life and the Politics of Transspecies Care

At the outset of the twenty-first century, chimpanzees have become the first nonhuman great ape species to achieve substantial protections in the form of state-recognized legal rights and care programs. In the United States, this development has been institutionalized by the 2000 Chimpanzee Health Improvement, Maintenance, and Protection Act, which established the first federally funded system of animal asylum in order to provide humane care for chimpanzees who have been “retired” from state-funded medical research. While the phasing out of chimpanzee research and the federal funding of chimpanzee sanctuaries was heralded by animal activists and primate conservationists, state recognition of ethical duties toward chimpanzees results from complex set of changes in biomedical research, ethological knowledge, and neoliberal governance that limit the use of chimpanzees for budgetary and technical as well as ethical reasons. Based on our interviews with paid workers at one nonprofit sanctuary, we argue that the national chimpanzee sanctuary project stakes the possibility of justice for nonhuman animals exploited in projects of imperial technoscience on a neoliberal ethic of care. Idealizing recognition of animal minds and empathetic connections to humans, the state profits from the undervaluation of the feminized labor at chimpanzee sanctuaries. Out of these constraints, we argue that the improvisational practices of care and enrichment negotiated on a daily basis between female careworkers and captive chimpanzees articulate a vision of justice that differs fundamentally from rights- and conservation-based models resting on universal conceptions of life, rights, or freedom. The sanctuary workers resist collapsing the project of the sanctuary into global rights frameworks; they instead attend to the complexity and limits of affective relation within the “surplus time” of postresearch captivity. These practices of care-awaiting-death help us reflect on recent invocations of an affect-based ethic of transspecies care articulated by feminist animal studies scholars. To the extent that affective relation produces an ethical project in the chimpanzee sanctuary, it is one that resists generic analogies between race, gender, and species as well as idealized notions of care that work to sustain the neoliberal undervaluation of feminized labor.

Intestinal schistosomiasis in chimpanzees on Ngamba Island, Uganda: observations on liver fibrosis, schistosome genetic diversity and praziquantel treatment

Despite treatment with praziquantel (PZQ) at 40 mg/kg in food, several chimpanzees on Ngamba Island Chimpanzee Sanctuary (NICS) continue to excrete eggs of Schistosoma mansoni. To monitor disease, 8 animals were closely examined under anaesthesia in March 2011 with portable ultrasonography and by rectal snip biopsy. Schistosome genetic diversity had been previously assayed within 4 of these chimpanzees, finding extensive diversity with 27 DNA barcodes encountered, although none was common to all animals. Calcified schistosome eggs were found in the rectal snips from 5 chimpanzees and liver fibrosis was clearly documented, indicative of progressive disease in 6 animals, the latter being surprisingly advanced in a younger chimpanzee. All 8 animals were treated under anaesthesia by oral gavage with PZQ at 60 mg/kg dosing that was well tolerated. These animals were again re-examined in June 2012 using stool and urine sampling. Only 1 chimpanzee appeared to be free from infection and active egg excretion was confirmed in 6 animals. If intestinal schistosomiasis is to be controlled within this setting, a long-term disease management plan is required which should combine active case-detection with an insistent treatment regime with praziquantel for these chimpanzees, exploring perhaps the performance of even higher dosing.

Stopping schistosomes from ‘monkeying-around’ in chimpanzees

Ngamba Island Chimpanzee Sanctuary (NICS) in Lake Victoria, Uganda is currently home to 44 wild-borne, semi-captive chimpanzees. Despite regular veterinary health checks, it only came to light recently that many animals, and sanctuary staff, were naturally infected with Schistosoma mansoni. Indeed, local schistosome transmission appears firmly engrained for intermediate snail hosts can be found along almost the entirety of Ngamba's shoreline. Here, the epidemiology of infection is a dynamic interplay between human and chimpanzee populations, as revealed by genetic analyses of S. mansoni. In this review, our present understanding of this complex and evolving situation is discussed, alongside general disease control activities in Uganda, to highlight future interventions towards stopping schistosome morbidity and transmission within this conservation sanctuary setting.

Environmental Influences on Sleep Behavior in Captive Male Chimpanzees (Pan troglodytes)

Little is known as to the influence of captivity and stressful events on sleep patterns in primates. We investigated the sleep patterns of 19 male chimpanzees living under similar conditions at the Chimpanzee Sanctuary Uto (CSU) in Kumamoto, Japan, using a behavioral sleep index. We conducted nighttime observations of all subjects during a stable period and then observed three subjects after relocation to an unfamiliar facility at CSU. We estimated length of sleep and nonsleep periods over 13-h video recordings using instantaneous sampling at 1-min intervals to record sleep, which we defined operationally as an inactive posture with the body lying down with the head on the floor or on nesting materials. The 19 subjects slept for a mean ± SEM of 11.3 ± 0.26 h during the stable period, and sleep patterns varied significantly among the subjects. The three relocated subjects all showed temporarily decreased sleep duration in the post-move period but subsequently recovered to the levels observed during the stable period when habituated to the new living quarters. These results suggest that a stressful event may induce temporary sleep shortage lasting for >1 wk in captive chimpanzees. Sleep patterns may serve as a useful behavioral index of the stress response, as it is less confounded by other behaviors and the actions of human caretakers than other indices.

DNA Barcoding of Schistosome Cercariae Reveals a Novel Sub-Lineage within Schistosoma rodhaini From Ngamba Island Chimpanzee Sanctuary, Lake Victoria

While Schistosoma rodhaini is typically considered a parasite of small mammals and is very scantly distributed in the Lake Victoria basin, it is known to hybridize with the more widespread Schistosoma mansoni, the causative agent of intestinal schistosomiasis. As part of broader parasitological and malacological surveys for S. mansoni across Lake Victoria, schistosome cercariae were harvested from a field-caught Biomphalaria choanomphala taken on Ngamba Island Chimpanzee Sanctuary, Uganda. Upon DNA barcoding, these cercariae were found to be a mixture of both S. rodhaini and S. mansoni, with further phylogenetic analysis revealing a hitherto unknown sub-lineage within S. rodhaini. Despite repeated sampling for eggs and miracidia from both chimpanzees and staff on Ngamba Island Sanctuary, detection of S. rodhaini within local definitive hosts awaits additional efforts, which should be mindful of a potential host role of spotted-necked otters.