Publications by year
In Press
Hockings K, Parathian H, Bessa J, Frazao-Moreira A (In Press). Humans and chimpanzees overlap extensively in their use of wild plant resources in an anthropogenic landscape: Implications for the management of complex social-ecological systems. Frontiers in Ecology and Evolution
Hockings KJ, Mubemba B, Avanzi C, Pleh K, Düx A, Bersacola E, Bessa J, Ramon M, Metzger S, Patrono LV, et al (In Press). Leprosy in wild chimpanzees.
Abstract:
Leprosy in wild chimpanzees
ABSTRACTHumans are considered the main host for Mycobacterium leprae, the aetiologic agent of leprosy, but spill-over to other mammals such as nine-banded armadillos and red squirrels occurs. Although naturally acquired leprosy has also been described in captive nonhuman primates, the exact origins of infection remain unclear. Here, we report on leprosy-like lesions in two wild populations of western chimpanzees (Pan troglodytes verus) in the Cantanhez National Park, Guinea-Bissau, and the Taï National Park, Côte d’Ivoire, West Africa. Longitudinal monitoring of both populations revealed the progression of disease symptoms compatible with advanced leprosy. Screening of faecal and necropsy samples confirmed the presence of M. leprae as the causative agent at each site and phylogenomic comparisons with other strains from humans and other animals show that the chimpanzee strains belong to different and rare genotypes (4N/O and 2F). The independent evolutionary origin of M. leprae in two geographically distant populations of wild chimpanzees, with no prolonged direct contact with humans, suggests multiple introductions of M. leprae from an unknown animal or environmental source.
Abstract.
2021
Bersacola E, Hill CM, Hockings KJ (2021). Chimpanzees balance resources and risk in an anthropogenic landscape of fear.
Sci Rep,
11(1).
Abstract:
Chimpanzees balance resources and risk in an anthropogenic landscape of fear.
Human-wildlife coexistence is possible when animals can meet their ecological requirements while managing human-induced risks. Understanding how wildlife balance these trade-offs in anthropogenic environments is crucial to develop effective strategies to reduce risks of negative interactions, including bi-directional aggression and disease transmission. For the first time, we use a landscape of fear framework with Bayesian spatiotemporal modelling to investigate anthropogenic risk-mitigation and optimal foraging trade-offs in Critically Endangered western chimpanzees (Pan troglodytes verus). Using 12 months of camera trap data (21 camera traps, 6722 camera trap days) and phenology on wild and cultivated plant species collected at Caiquene-Cadique, Cantanhez National Park (Guinea-Bissau), we show that humans and chimpanzees broadly overlapped in their use of forest and anthropogenic parts of the habitat including villages and cultivated areas. The spatiotemporal model showed that chimpanzee use of space was predicted by the availability of naturalised oil-palm fruit. Chimpanzees used areas away from villages and agriculture more intensively, but optimised their foraging strategies by increasing their use of village areas with cultivated fruits when wild fruits were scarce. Our modelling approach generates fine-resolution space-time output maps, which can be scaled-up to identify human-wildlife interaction hotspots at the landscape level, informing coexistence strategy.
Abstract.
Author URL.
Thurstan R, Hockings K, Hedlund J, Bersacola E, Collins C, Early R, Harrison M, Kaiser-Bunbury C, Nuno A, Van Veen F, et al (2021). Envisioning a resilient future for biodiversity conservation in the wake of the COVID-19 pandemic. People and Nature
Bessa J, Hockings K, Biro D (2021). First Evidence of Chimpanzee Extractive Tool Use in Cantanhez, Guinea-Bissau: Cross-Community Variation in Honey Dipping.
Frontiers in Ecology and Evolution,
9Abstract:
First Evidence of Chimpanzee Extractive Tool Use in Cantanhez, Guinea-Bissau: Cross-Community Variation in Honey Dipping
Wild chimpanzee tool use is highly diverse and, in many cases, exhibits cultural variation: tool-use behaviours and techniques differ between communities and are passed down generations through social learning. Honey dipping – the use of sticks or leaves to extract honey from hives – has been identified across the whole species’ range. Nonetheless, there seems to be marked variation in honey dipping at a species level, with most descriptions originating from central Africa, and involving the use of complex tool sets, or even multifunctional tools. In West Africa, while honey consumption is common, in most cases tools are not used. We document, for the first time, the use of honey dipping tools in unhabituated chimpanzee (Pan troglodytes verus) communities at Cantanhez National Park (CNP), Guinea-Bissau. Over a 23-month period we employed a combination of direct (camera traps, n = 1944 camera trap days) and indirect (1000km of reconnaissance walks, collection of abandoned tools) methods to study four neighbouring communities in central CNP. Fluid dipping tools were found in three of the four communities; here we analyse 204 individual stick tools from the 70 tool-use ateliers found. In addition to documenting individual tool dimensions and raw materials, we adopt methods from primate archaeology to describe the typology of different tools based on use-wear patterns. We describe differences in tools used for different honey types, between communities, and tools and tool kits that show an unexpected degree of complexity. Our data also suggest the use of tool sets, i.e. tools with different functions used sequentially toward the same goal; as well as possible multifunction tools (pounding and dipping), never before described for western chimpanzees. Our study fills gaps in our knowledge of the wild chimpanzee cultural repertoire and highlights how chimpanzee tool manufacture and use can vary even at local scales.
Abstract.
Hockings KJ, Mubemba B, Avanzi C, Pleh K, Düx A, Bersacola E, Bessa J, Ramon M, Metzger S, Patrono LV, et al (2021). Leprosy in wild chimpanzees.
NatureAbstract:
Leprosy in wild chimpanzees
AbstractHumans are considered as the main host for Mycobacterium leprae1, the aetiological agent of leprosy, but spillover has occurred to other mammals that are now maintenance hosts, such as nine-banded armadillos and red squirrels2,3. Although naturally acquired leprosy has also been described in captive nonhuman primates4–7, the exact origins of infection remain unclear. Here we describe leprosy-like lesions in two wild populations of western chimpanzees (Pan troglodytes verus) in Cantanhez National Park, Guinea-Bissau and Taï National Park, Côte d’Ivoire, West Africa. Longitudinal monitoring of both populations revealed the progression of disease symptoms compatible with advanced leprosy. Screening of faecal and necropsy samples confirmed the presence of M. leprae as the causative agent at each site and phylogenomic comparisons with other strains from humans and other animals show that the chimpanzee strains belong to different and rare genotypes (4N/O and 2F). These findings suggest that M. leprae may be circulating in more wild animals than suspected, either as a result of exposure to humans or other unknown environmental sources.
Abstract.
Heinicke S, Ordaz-Nemeth I, Junker J, Bachmann ME, Marrocoli S, Wessling EG, Byler D, Cheyne SM, Desmond J, Dowd D, et al (2021). Open-access platform to synthesize knowledge of ape conservation across sites.
AMERICAN JOURNAL OF PRIMATOLOGY,
83(1).
Author URL.
Andrasi B, Jaeger JAG, Heinicke S, Metcalfe K, Hockings KJ (2021). Quantifying the road‐effect zone for a critically endangered primate. Conservation Letters
2020
Hockings K, Dunbar R (2020).
Alcohol and Humans a Long and Social Affair., Oxford University Press, USA.
Abstract:
Alcohol and Humans a Long and Social Affair
Abstract.
Bessa J, Hockings K, Biro D (2020). Chimpanzee Cultural Behaviour in the Anthropogenic Landscape of Guinea-Bissau.
Author URL.
Hockings KJ, Bersacola H, Bessa J, Minhos T, Ramon M, Parathian H, Frazao-Moreira A (2020). Developing an Evidence-Based Conservation Strategy for Cantanhez National Park, Guinea-Bissau.
Author URL.
Catarino L, Frazão-Moreira A, Bessa J, Parathian H, Hockings K (2020).
FIELD GUIDE - PLANTS USED BY CHIMPANZEES AND HUMANS IN CANTANHEZ, GUINEA-BISSAU., LAE/CRIA Environmental Anthropology and Behavioural Ecology Laboratory Centre for Research in Anthropology.
Full text.
Catarino L, Frazão-Moreira A, Bessa J, Parathian H, Hockings K (2020).
GUIA DE CAMPO - PLANTAS USADAS POR CHIMPANZÉS E HUMANOS NO CANTANHEZ, GUINÉ-BISSAU., LAE/CRIA Laboratório de Antropologia ambiental e Ecologia comportamental Centro em Rede de Investigação em Antropologia.
Full text.
Payne T (2020). Human-wildlife coexistence at Gola Rainforest National Park, Sierra Leone.
Abstract:
Human-wildlife coexistence at Gola Rainforest National Park, Sierra Leone
In light of global human population growth and increased spatial overlap between human and wildlife populations, effective conservation must increasingly incorporate the patterns of and threats to human-wildlife coexistence. Gola Rainforest National Park (GRNP) is the largest area of the Upper Guinean Forests of West Africa remaining in Sierra Leone and is of vital conservation importance. However, there has been limited research to examine the interactions between wildlife and the human populations that inhabit this landscape. This thesis aims to inform conservation management strategies at GRNP to mitigate the potential negative impacts of interactions between humans and wildlife.
Firstly, in light of investment in the cocoa industry at GRNP, a cross-disciplinary approach was used to investigate wildlife crop foraging at GRNP, a major conservation and development concern. Semi structured interviews (n=71) and participatory risk mapping were used to determine the perceptions of local farmers. It was found that wildlife cocoa foraging was the main concern of GRNP farmers, with other factors such as climate of less importance. To compare perceptions to measured crop damage by three major groups, western chimpanzees, monkeys and squirrels, crop foraging traces were counted at 24 plantations. Monkeys were found to cause more damage than chimpanzees and squirrels, yet tolerance towards chimpanzees was disproportionately negative, suggesting the need for specific knowledge sharing amongst farmers to protect this critically endangered species. Investigation of the spatial characteristics and crop defence strategies that impact the susceptibility of plantations to crop foraging revealed variation between species groups in the most appropriate plantation management initiatives, including land use planning. A local cocoa farming and development initiative was also evaluated, with member farmers found to experience reduced crop foraging and show increased acceptance of wildlife. Our findings suggest community engagement is vital to the success of local conservation.
Secondly, the presence and distribution of wildlife across GRNP and the impacts of proximity to human infrastructure and activities, including hunting, deforestation and agriculture, were explored. A camera trap survey conducted over 13 months resulted in detections of 26 medium to large bodied size mammals, forming the most recent assessment of the GRNP mammal community. Detected species included five globally threatened species, including critically endangered western chimpanzees, and one previously unconfirmed at the national park, giant forest hog. Species richness was found to be similar within two protected forest blocks and in the surrounding community-managed multi-use landscape. Variation between camera trap sites in ecological characteristics and proximity to anthropogenic infrastructure (roads and villages) showed no impact on site species richness, but an occupancy modelling approach revealed different responses between the 11 most detected species. The occupancy of six species was impacted by anthropogenic covariates, highlighting the varied abilities of species to occur in human-impacted environments. This study provides a vital contribution to conservation planning and management, including land use planning and prioritisation of species for continued monitoring in light of changing threats at GRNP.
This body of work contributes vital information about the patterns and impacts of human-wildlife coexistence at GRNP from both ecological and human perspectives, providing management suggestions that promote both the long-term preservation of biodiversity and the needs of local people.
Abstract.
Full text.
Wessling E, Humle T, Heinicke S, Hockings K, Byler D, Williamson E (2020). Regional action plan for the conservation of western chimpanzees (Pan troglodytes verus) 2020–2030. Gland, Switzerland, IUCN.
McLennan MR, Hintz B, Kiiza V, Rohen J, Lorenti GA, Hockings KJ (2020). Surviving at the extreme: Chimpanzee ranging is not restricted in a deforested human‐dominated landscape in Uganda. African Journal of Ecology, 59(1), 17-28.
2019
Vieira WF, Kerry C, Hockings KJ (2019). A comparison of methods to determine chimpanzee home-range size in a forest-farm mosaic at Madina in Cantanhez National Park, Guinea-Bissau.
Primates,
60(4), 355-365.
Abstract:
A comparison of methods to determine chimpanzee home-range size in a forest-farm mosaic at Madina in Cantanhez National Park, Guinea-Bissau.
Human activities impact the distribution of numerous species. Anthropogenic habitats are often fragmented, and wildlife must navigate through human-influenced and 'natural' parts of the landscape to access resources. Different methods to determine the home-range areas of nonhuman primates have not considered the additional complexities of ranging in anthropogenic areas. Here, using 6 months of spatial data on the distribution of chimpanzee presence (feces, feeding traces, nests, opportunistic encounters; n = 833) collected across the wet and dry seasons, we examine different analytical techniques to calculate the home-range size of an unhabituated chimpanzee (Pan troglodytes verus) community inhabiting a forest-farm mosaic at Madina, Cantanhez National Park in Guinea-Bissau. The minimum convex polygon method and the grid cell (500 m × 500 m cell size) method estimated the chimpanzees home-range size at 19.02 and 15.50 km2, respectively with kernel analysis calculating a lower value of 8.52 km2. For the grid cell method, home-range estimates varied with cell size, with larger cells producing larger estimates. We compare our home-range estimates with other chimpanzee research sites across Africa. We recommend the use of kernel analysis for determining primate home ranges, especially for those groups exploiting fragmented habitats including forest-farm mosaics, as this method takes account of inaccessible or infrequently used anthropogenic areas across the complete home range of the primate group. However, care must be taken when using this method, since it is sensitive to small sample sizes that can occur when studying unhabituated communities, resulting in underestimated home ranges.
Abstract.
Author URL.
Full text.
Gruber T, Luncz L, Mörchen J, Schuppli C, Kendal RL, Hockings K (2019). Cultural change in animals: a flexible behavioural adaptation to human disturbance.
Palgrave Communications,
5(1).
Abstract:
Cultural change in animals: a flexible behavioural adaptation to human disturbance
In recent decades, researchers have increasingly documented the impact of anthropogenic activities on wild animals, particularly in relation to changes in behaviour. However, whether human-induced behavioural changes in wildlife may be considered evidence of cultural evolution remains an open question. We explored whether behavioural responses to different types of human activities in species already known to display behaviour transmitted through social learning, particularly non-human primates (NHPs), are suggestive of cultural evolution in the wild. Results indicate that human influence on NHP cultural repertoires includes the modification and disappearance of existing cultural traits, as well as the invention of novel traditions with the potential to become cultural. These examples are found mostly in the domain of food acquisition, where animals modify their diet to include new resources, and adopt novel foraging strategies to avoid humans. In summary, this paper suggests that human activities can act as a catalyst for cultural change in animals, both in terms of threatening existing traditions and fostering new ones. The current situation may echo environmental changes thought to have triggered major behavioural adaptations in our own evolutionary history and thus be useful for research on human cultural evolution. As wildlife is increasingly exposed to humans and their activities, understanding how animal behaviour patterns and cultures are impacted and change in response to anthropogenic factors is of growing conservation importance.
Abstract.
Full text.
Hockings KJ, McLennan MR (2019). Inclusive chimpanzee conservation. Science, 364(6445).
Heinicke S, Mundry R, Boesch C, Hockings KJ, Kormos R, Ndiaye PI, Tweh CG, Williamson EA, Kühl HS (2019). Towards systematic and evidence-based conservation planning for western chimpanzees.
American Journal of Primatology,
81(9).
Abstract:
Towards systematic and evidence-based conservation planning for western chimpanzees
As animal populations continue to decline, frequently driven by large-scale land-use change, there is a critical need for improved environmental planning. While data-driven spatial planning is widely applied in conservation, as of yet it is rarely used for primates. The western chimpanzee (Pan troglodytes verus) declined by 80% within 24 years and was uplisted to Critically Endangered by the IUCN Red List of Threatened Species in 2016. To support conservation planning for western chimpanzees, we systematically identified geographic areas important for this taxon. We based our analysis on a previously published data set of modeled density distribution and on several scenarios that accounted for different spatial scales and conservation targets. Across all scenarios, typically less than one-third of areas we identified as important are currently designated as high-level protected areas (i.e. national park or IUCN category I or II). For example, in the scenario for protecting 50% of all chimpanzees remaining in West Africa (i.e. approximately 26,500 chimpanzees), an area of approximately 60,000 km2 was selected (i.e. approximately 12% of the geographic range), only 24% of which is currently designated as protected areas. The derived maps can be used to inform the geographic prioritization of conservation interventions, including protected area expansion, “no-go-zones” for industry and infrastructure, and conservation sites outside the protected area network. Environmental guidelines by major institutions funding infrastructure and resource extraction projects explicitly require corporations to minimize the negative impact on great apes. Therefore, our results can inform avoidance and mitigation measures during the planning phases of such projects. This study was designed to inform future stakeholder consultation processes that could ultimately integrate the conservation of western chimpanzees with national land-use priorities. Our approach may help in promoting similar work for other primate taxa to inform systematic conservation planning in times of growing threats.
Abstract.
Full text.
2018
Parathian H, McLennan MR, Hill CM, Frazao-Moreira A, Hockings KJ (2018). Breaking through disciplinary barriers: Human–wildlife interactions and multispecies ethnography.
International Journal of Primatology Full text.
Parathian HE, Frazao-Moreira A, Hockings KJ (2018). Environmental psychology must better integrate local cultural and sociodemographic context to inform conservation.
Conservation Letters Full text.
Bersacola E, Bessa J, Frazão-Moreira A, Biro D, Sousa C, Hockings KJ (2018). Primate occurrence across a human-impacted landscape in Guinea-Bissau and neighbouring regions in West Africa: using a systematic literature review to highlight the next conservation steps.
PeerJ,
6, e4847-e4847.
Full text.
2017
Hockings KJ (2017). An Introduction to Primate Conservation.
PRIMATES,
58(1), 259-260.
Author URL.
Hockings KJ, Yamakoshi G, Matsuzawa T (2017). Dispersal of a Human-Cultivated Crop by Wild Chimpanzees (Pan troglodytes verus) in a Forest–Farm Matrix.
International Journal of Primatology,
38(2), 172-193.
Abstract:
Dispersal of a Human-Cultivated Crop by Wild Chimpanzees (Pan troglodytes verus) in a Forest–Farm Matrix
With the conversion of natural habitats to farmland, nonhuman primates (hereafter primates) are increasingly exposed to agricultural crops. Although frugivorous primates are important seed dispersers that sometimes feed on agricultural fruits, evidence for dispersal of crops by primates is lacking. Here, we examine flexible feeding on cacao (Theobroma cacao) fruit and seed dispersal patterns by chimpanzees (Pan troglodytes verus) at Bossou in Guinea, and consequent cacao germination and survival. From direct observations, we confirm that cacao fruit is not an important food to chimpanzees, representing 0.23 % of focal animal feeding time. Chimpanzees ingest cacao pulp and either spit out the large seeds intact from unripe cacao fruit or swallow the seeds from ripe cacao fruits, which are consequently deposited in feces. From ecological surveys we show that chimpanzees distributed cacao extensively throughout their home range, at a mean distance of 407 m ± SE 0.6 (N = 90 clusters, range: 4–1130 m) from cacao plantations. As distance from the cacao plantation increased, cacao plants were more likely to survive. Other factors, including number of cacao plants in a cluster, plant height, and openness of the understory did not predict short-term cacao survival. Cacao plants within the forest did not produce fruit. By contrast, when chimpanzees deposited seeds in a plantation, cacao plants produced fruits as a result of farmers’ maintenance of the area. Our local-scale findings emphasize the complex behavioral and ecological interconnections between coexisting humans and primates in agricultural landscapes and generate interesting questions regarding primate niche construction and crop “ownership” related to who “plants” the crop.
Abstract.
Full text.
McLennan MR, Spagnoletti N, Hockings KJ (2017). The Implications of Primate Behavioral Flexibility for Sustainable Human–Primate Coexistence in Anthropogenic Habitats.
International Journal of Primatology,
38(2), 105-121.
Abstract:
The Implications of Primate Behavioral Flexibility for Sustainable Human–Primate Coexistence in Anthropogenic Habitats
People are an inescapable aspect of most environments inhabited by nonhuman primates today. Consequently, interest has grown in how primates adjust their behavior to live in anthropogenic habitats. However, our understanding of primate behavioral flexibility and the degree to which it will enable primates to survive alongside people in the long term remains limited. This Special Issue brings together a collection of papers that extend our knowledge of this subject. In this introduction, we first review the literature to identify past and present trends in research and then introduce the contributions to this Special Issue. Our literature review confirms that publications on primate behavior in anthropogenic habitats, including interactions with people, increased markedly since the 2000s. Publications concern a diversity of primates but include only 17% of currently recognized species, with certain primates overrepresented in studies, e.g. chimpanzees and macaques. Primates exhibit behavioral flexibility in anthropogenic habitats in various ways, most commonly documented as dietary adjustments, i.e. incorporation of human foods including agricultural crops and provisioned items, and as differences in activity, ranging, grouping patterns, and social organization, associated with changing anthropogenic factors. Publications are more likely to include information on negative rather than positive or neutral interactions between humans and primates. The contributions to this Special Issue include both empirical research and reviews that examine various aspects of the human–primate interface. Collectively, they show that primate behavior in shared landscapes does not always conflict with human interests, and demonstrate the value of examining behavior from a cost–benefit perspective without making prior assumptions concerning the nature of interactions. Careful interdisciplinary research has the potential to greatly improve our understanding of the complexities of human–primate interactions, and is crucial for identifying appropriate mechanisms to enable sustainable human–primate coexistence in the 21st century and beyond.
Abstract.
Full text.
2016
Fernandes M, Frazão-Moreira A, Hockings KJ, Alves-Cardoso F (2016). Across disciplinary boundaries: Remembering cláudia sousa.
Etnografica,
20(3), 633-640.
Abstract:
Across disciplinary boundaries: Remembering cláudia sousa
This dossier pays homage to the primatologist Cláudia Sousa and is the result of a seminar held in her memory. It collates the presentations of Cláudia’s colleagues on themes that demonstrate not only the importance of her work but also the legacy that she left. It highlights the potential for novel ways to bring together social and human sciences and biological sciences in the field of anthropology.
Abstract.
Hockings KJ (2016). Chimpanzee behavioural flexibility and the sustainability of human-chimpanzee interactions at cantanhez national park, guinea-bissau.
Etnografica,
20(3), 659-662.
Abstract:
Chimpanzee behavioural flexibility and the sustainability of human-chimpanzee interactions at cantanhez national park, guinea-bissau
This paper incorporates research conducted by Cláudia Sousa and demonstrates the importance of examining chimpanzee behavioural flexibility alongside chimpanzee interactions with local people for the conservation of biodiversity in anthropogenic habitats.
Abstract.
Fujisawa M, Hockings KJ, Soumah AG, Matsuzawa T (2016). Placentophagy in wild chimpanzees (Pan troglodytes verus) at bossou, guinea.
Primates,
57(2), 175-180.
Abstract:
Placentophagy in wild chimpanzees (Pan troglodytes verus) at bossou, guinea
© Japan Monkey Centre and Springer Japan 2016 Despite intensive observation of nonhuman great apes during long-term field studies, observations of great ape births in the wild are rare. Research on wild chimpanzees (Pan troglodytes verus) at Bossou in the Republic of Guinea has been ongoing for 35 years, yet chimpanzee parturitions have been observed on only two occasions. Here we provide information regarding both chimpanzee births, with detailed information from the close observation of one. During this birth, the mother built a day nest in a tree before parturition. After giving birth, the mother consumed the placenta, and the other chimpanzees in her party gathered near her and her neonate. However, she did not share the placenta, and consumed it all herself. In the second observation, the mother also built a nest in a tree and subsequently gave birth. Thereafter, she shared the placenta with some individuals and consumed part of the placenta herself. Although maternal placentophagy is a ubiquitous behavior among the majority of non-human primates, observations of placenta sharing by wild primates are infrequent, and the proximate and ultimate explanations for the behavior remain unclear.
Abstract.
Hockings KJ, McLennan MR (2016). Problematic primate behaviour in agricultural landscapes: Chimpanzees as ‘pests’ and ‘predators’. In Waller M (Ed) Ethnoprimatology: Primate Conservation in the 21st Century, Switzerland: Springer, 137-156.
Cannon TH, Heistermann M, Hankison SJ, Hockings KJ, McLennan MR (2016). Tailored Enrichment Strategies and Stereotypic Behavior in Captive Individually Housed Macaques (Macaca spp.).
Journal of Applied Animal Welfare Science,
19(2), 171-182.
Abstract:
Tailored Enrichment Strategies and Stereotypic Behavior in Captive Individually Housed Macaques (Macaca spp.)
The welfare of nonhuman animals in captivity is widely dependent on the natural psychological, physical, and behavioral needs of the animals and how adequately these needs are met. Inability to engage in natural behaviors can lead to chronic stress and expression of stereotypic behavior. The majority of research on decreasing stereotypic behavior in captivity addresses problems at the group level and does not account for individual variability in each animal's needs, history, and preferences. This study combined physiological and behavioral measures of well being to comprehensively assess the unique needs of individually housed captive macaques (Macaca spp.) with the aim of developing tailored welfare strategies. Behavioral and hormonal data were collected under 2 conditions: baseline and individualized enrichment. The results showed a significant decrease in stereotypic behavior under the enrichment condition. Additionally, 7 out of 9 individuals showed a decrease in fecal glucocorticoid (stress hormone) levels, indicating a reduction in hypothalamic-pituitary-adrenal activity. Addressing welfare on an individual, rather than group, level allows for a better overall characterization of well being and maximizes the probability of improving the welfare of each animal.
Abstract.
2015
Hockings KJ, McLennan MR, Carvalho S, Ancrenaz M, Bobe R, Byrne RW, Dunbar RIM, Matsuzawa T, McGrew WC, Williamson EA, et al (2015). Apes in the Anthropocene: Flexibility and survival.
Trends in Ecology and Evolution,
30(4), 215-222.
Abstract:
Apes in the Anthropocene: Flexibility and survival
We are in a new epoch, the Anthropocene, and research into our closest living relatives, the great apes, must keep pace with the rate that our species is driving change. While a goal of many studies is to understand how great apes behave in natural contexts, the impact of human activities must increasingly be taken into account. This is both a challenge and an opportunity, which can importantly inform research in three diverse fields: cognition, human evolution, and conservation. No long-term great ape research site is wholly unaffected by human influence, but research at those that are especially affected by human activity is particularly important for ensuring that our great ape kin survive the Anthropocene.
Abstract.
Bessa J, Sousa C, Hockings KJ (2015). Feeding ecology of chimpanzees (Pan troglodytes verus) inhabiting a forest-mangrove-savanna-agricultural matrix at Caiquene-Cadique, Cantanhez National Park, Guinea-Bissau.
American Journal of Primatology,
77(6), 651-665.
Abstract:
Feeding ecology of chimpanzees (Pan troglodytes verus) inhabiting a forest-mangrove-savanna-agricultural matrix at Caiquene-Cadique, Cantanhez National Park, Guinea-Bissau
With rising conversion of "natural" habitat to other land use such as agriculture, nonhuman primates are increasingly exploiting areas influenced by people and their activities. Despite the conservation importance of understanding the ways in which primates modify their behavior to human pressures, data are lacking, even for well-studied species. Using systematically collected data (fecal samples, feeding traces, and direct observations), we examined the diet and feeding strategies of an unhabituated chimpanzee community (Pan troglodytes verus) at Caiquene-Cadique in Guinea-Bissau that inhabit a forest-savanna-mangrove-agricultural mosaic. The chimpanzees experienced marked seasonal variations in the availability of plant foods, but maintained a high proportion of ripe fruit in the diet across months. Certain wild species were identified as important to this community including oil-palm (Elaeis guineensis) fruit and flower. Honey was frequently consumed but no other insects or vertebrates were confirmed to be eaten by this community. However, we provide indirect evidence of possible smashing and consumption of giant African snails (Achatina sp.) by chimpanzees at this site. Caiquene-Cadique chimpanzees were confirmed to feed on nine different agricultural crops, which represented 13.6% of all plant species consumed. Consumption of fruit and nonfruit crops was regular, but did not increase during periods of wild fruit scarcity. Crop consumption is an increasing and potentially problematic behavior, which can impact local people's tolerance toward wildlife. To maximize the potential success of any human-wildlife coexistence strategy (e.g. to reduce primate crop feeding), knowledge of primate behavior, as well as multifaceted social dimensions of interactions, is critical.
Abstract.
McLennan MR, Hockings KJ (2015). The aggressive apes? Causes and contexts of great ape attacks on local persons. In (Ed)
Problematic Wildlife: a Cross-Disciplinary Approach, 373-394.
Abstract:
The aggressive apes? Causes and contexts of great ape attacks on local persons
Abstract.
Hockings KJ, Bryson-Morrison N, Carvalho S, Fujisawa M, Humle T, McGrew WC, Nakamura M, Ohashi G, Yamanashi Y, Yamakoshi G, et al (2015). Tools to tipple: Ethanol ingestion by wild chimpanzees using leaf-sponges.
Royal Society Open Science,
2(6).
Abstract:
Tools to tipple: Ethanol ingestion by wild chimpanzees using leaf-sponges
African apes and humans share a genetic mutation that enables them to effectively metabolize ethanol. However, voluntary ethanol consumption in this evolutionary radiation is documented only inmodern humans.Here, we report evidence of the long-term and recurrent ingestion of ethanol from the raffia palm (Raphia hookeri, Arecaceae) by wild chimpanzees (Pan troglodytes verus) at Bossou in Guinea, West Africa, from 1995 to 2012. Chimpanzees at Bossou ingest this alcoholic beverage, often in large quantities, despite an average presence of ethanol of 3.1% alcohol by volume (ABV) and up to 6.9% ABV. Local people tap raffia palms and the sap collects inplastic containers, and chimpanzees use elementary technology—a leafy tool—to obtain this fermenting sap. These data show that ethanol does not act as a deterrent to feeding in this community of wild apes, supporting the idea that the last common ancestor of living African apes and modern humans was not averse to ingesting foods containing ethanol.
Abstract.
2014
Hockings KJ, McLennan MR, Hill C (2014). Fear beyond predators. Science, 344(6187).
McLennan MR, Hockings KJ (2014). Wild chimpanzees show group differences in selection of agricultural crops.
Scientific Reports,
4Abstract:
Wild chimpanzees show group differences in selection of agricultural crops
The ability of wild animals to respond flexibly to anthropogenic environmental changes, including agriculture, is critical to survival in human-impacted habitats. Understanding use of human foods by wildlife can shed light on the acquisition of novel feeding habits and how animals respond to human-driven land-use changes. Little attention has focused on within-species variation in use of human foods or its causes. We examined crop-feeding in two groups of wild chimpanzees-a specialist frugivore-with differing histories of exposure to agriculture. Both groups exploited a variety of crops, with more accessible crops consumed most frequently. However, crop selection by chimpanzees with long-term exposure to agriculture was more omnivorous (i.e. less fruit-biased) compared to those with more recent exposure, which ignored most non-fruit crops. Our results suggest chimpanzees show increased foraging adaptations to cultivated landscapes over time; however, local feeding traditions may also contribute to group differences in crop-feeding in this species. Understanding the dynamic responses of wildlife to agriculture can help predict current and future adaptability of species to fast-changing anthropogenic landscapes.
Abstract.
2013
Hockings KJ, Sousa C (2013). Human-chimpanzee sympatry and interactions in Cantanhez National Park, guinea-bissau: Current research and future directions.
Primate Conservation,
26(1), 57-65.
Abstract:
Human-chimpanzee sympatry and interactions in Cantanhez National Park, guinea-bissau: Current research and future directions
Increasing human populations and the rapid conversion of forest to agricultural land increase the likelihood of interactions and conflict between humans and nonhuman primates. Understanding such interactions requires a broad cross-disciplinary approach that assesses the implications of sympatry for primate conservation and human social, cultural and economic needs. Although chimpanzees were declared extinct in Guinea-Bissau in 1988, recent reports estimate that between 600 and 1,000 individuals are currently present, with the largest population occupying the Cantanhez National Park (105,700 ha; northeast limit: 11°22′58″N,14°46′12″W; southwest limit: 11°2′18″N,15°15′58″W). These heavily fragmented coastal forests have been identified as one of seven priority areas in West Africa for urgent chimpanzee conservation efforts (Kormos et al. 2003. West African Chimpanzees. Status Survey and Conservation Action Plan. IUCN, Gland. 2003). Here we set the context for human-chimpanzee sympatry in Guinea-Bissau, and provide a platform from which further studies can expand. We review past findings that might affect current and future sympatric relationships, and integrate preliminary data on resource competition from one hitherto unstudied chimpanzee (Pan troglodytes verus) community inhabiting a forested-agricultural matrix in Caiquene and Cadique, central Cantanhez National Park. While local human cultural traditions provide a degree of tolerance and protection to chimpanzees in Cantanhez National Park, which is beneficial for long-term conservation initiatives, human-chimpanzee interactions have the potential to grow increasingly negative in character, especially as human populations expand and further pressure is exerted on the land.
Abstract.
2012
Carvalho S, Biro D, Cunha E, Hockings K, McGrew WC, Richmond BG, Matsuzawa T (2012). Chimpanzee carrying behaviour and the origins of human bipedality. Current Biology, 22(6).
Hockings KJ, Humle T, Carvalho S, Matsuzawa T (2012). Chimpanzee interactions with nonhuman species in an anthropogenic habitat.
Behaviour,
149(3-4), 299-324.
Abstract:
Chimpanzee interactions with nonhuman species in an anthropogenic habitat
Interactions between wildlife species are numerous and diverse, ranging from commensalism to predation. Information on cross-species interactions in anthropogenic habitats are rare but can serve to improve our understanding of animal behavioural and ecological flexibility in response to human-induced changes. Here we report direct observations of interactions between chimpanzees (Pan troglodytes verus) and wild and domesticated species in a forest-farm mosaic at Bossou, Guinea, recorded between 1997 and 2009. The low diversity and abundance of wildlife, in particular typical chimpanzee prey species, are reflected in both the low interaction rates (one interaction per 400 observation hours) and the low number of species with which chimpanzees interacted (nine species, mostly mammals, but also birds and reptiles). Chimpanzees generally chose either to make direct physical contact with a species or not; interactions that involved direct contact lasted longer than noncontacts. Interactions with mammals showed the greatest diversity in nature and duration. Adults most often consumed a captured animal, while immatures most often engaged in playful behaviours with other species. Immatures also exhibited distinctive accompanying behaviours whereas adults rarely did so. Species-specific behaviours that depend on the age-class of the interactant are consistent with the idea that chimpanzees categorise different animals. We anticipate that chimpanzee interactions with sympatric species inhabiting humanised habitats will change over time to include more domesticated species. Conservation management strategies should anticipate behavioural flexibility in response to changing landscapes. © 2012 Koninklijke Brill NV, Leiden.
Abstract.
Hockings KJ, Sousa C (2012). Differential utilization of cashew-a low-conflict crop-by sympatric humans and chimpanzees.
ORYX,
46(3), 375-381.
Abstract:
Differential utilization of cashew-a low-conflict crop-by sympatric humans and chimpanzees
Modification of natural areas by human activities mostly has a negative impact on wildlife by increasing the geographical and ecological overlap between people and animals. This can result in escalating levels of competition and conflict between humans and wildlife, for example over crops. However, data on specific crops and crop parts that are unattractive to wildlife yet important for human livelihoods are surprisingly scarce, especially considering their potential application to reducing crop damage by wildlife. Here we examine the co-utilization of a nationally important and spatially abundant cash crop, cashew Anacardium occidentalis, by people and chimpanzees Pan troglodytes verus inhabiting a forested-agricultural matrix in Cantanhez National Park in Guinea-Bissau. In this Park people predominantly harvest the marketable cashew nut and discard the unprofitable fruit whereas chimpanzees only consume the fruit. Local farmers generally perceive a benefit of raiding by chimpanzees as they reportedly pile the nuts, making harvesting easier. By ensuring that conflict levels over crops, especially those with high economic importance, remain low, the costs of living in proximity to wildlife can potentially be reduced. Despite high levels of deforestation associated with cashew farming, these findings point to the importance of cashew as a low-conflict crop in this area. © 2012 Fauna & Flora International.
Abstract.
Hockings KJ, McLennan MR (2012). From forest to farm: Systematic review of cultivar feeding by chimpanzees - management implications for wildlife in anthropogenic landscapes.
PLoS ONE,
7(4).
Abstract:
From forest to farm: Systematic review of cultivar feeding by chimpanzees - management implications for wildlife in anthropogenic landscapes
Crop-raiding is a major source of conflict between people and wildlife globally, impacting local livelihoods and impeding conservation. Conflict mitigation strategies that target problematic wildlife behaviours such as crop-raiding are notoriously difficult to develop for large-bodied, cognitively complex species. Many crop-raiders are generalist feeders. In more ecologically specialised species crop-type selection is not random and evidence-based management requires a good understanding of species' ecology and crop feeding habits. Comprehensive species-wide studies of crop consumption by endangered wildlife are lacking but are important for managing human-wildlife conflict. We conducted a comprehensive literature search of crop feeding records by wild chimpanzees (Pan troglodytes), a ripe-fruit specialist. We assessed quantitatively patterns of crop selection in relation to species-specific feeding behaviour, agricultural exposure, and crop availability. Crop consumption by chimpanzees is widespread in tropical Africa. Chimpanzees were recorded to eat a considerable range of cultivars (51 plant parts from 36 species). Crop part selection reflected a species-typical preference for fruit. Crops widely distributed in chimpanzee range countries were eaten at more sites than sparsely distributed crops. We identified 'high' and 'low' conflict crops according to their attractiveness to chimpanzees, taking account of their importance as cash crops and/or staple foods to people. Most (86%) high conflict crops were fruits, compared to 13% of low conflict crops. Some widely farmed cash or staple crops were seldom or never eaten by chimpanzees. Information about which crops are most frequently consumed and which are ignored has enormous potential for aiding on-the-ground stakeholders (i.e. farmers, wildlife managers, and conservation and agricultural extension practitioners) develop sustainable wildlife management schemes for ecologically specialised and protected species in anthropogenic habitats. However, the economic and subsistence needs of local people, and the crop-raiding behaviour of sympatric wildlife, must be considered when assessing suitability of particular crops for conflict prevention and mitigation. © 2012 Hockings, McLennan.
Abstract.
Little AC, Hockings KJ, Apicella CL, Sousa C (2012). Mixed-ethnicity face shape and attractiveness in humans.
Perception,
41(12), 1486-1496.
Abstract:
Mixed-ethnicity face shape and attractiveness in humans
Many studies show agreement within and between populations and cultures for general judgments of facial attractiveness. Studies that have examined the attractiveness of specific traits have also highlighted cross-cultural differences for factors such as symmetry, averageness, and masculinity. One trait that should be preferred across cultures is heterozygosity. Indeed, several studies suggest that mixed ethnicity, in terms of appearing to possess a mixture of traits from different human population groups, may be found attractive, which could reflect preferences for heterozygosity. We examined preferences for manipulated face shape associated with different populations in both Europeans (Britain) and Africans (Guinea-Bissau). We found that mixed-ethnicity face shapes were more attractive than enhanced single-ethnicity face shape across both populations. These results are consistent with evolutionary theories suggesting individuals should prefer heterozygosity in partners because facial cues to mixed-ethnicity are likely to indicate diverse genes compared to cues that indicate a face belongs to a single particular culture or population. © 2012 a Pion publication.
Abstract.
Hockings KJ, Anderson JR, Matsuzawa T (2012). Socioecological adaptations by chimpanzees, Pan troglodytes verus, inhabiting an anthropogenically impacted habitat.
Animal Behaviour,
83(3), 801-810.
Abstract:
Socioecological adaptations by chimpanzees, Pan troglodytes verus, inhabiting an anthropogenically impacted habitat
Despite the spread of human-impacted wildlife habitats, few studies have examined how animals adapt their socioecology in agricultural-forest ecotones. Anthropogenic processes such as agricultural development directly affect the ecological challenges that species face. In agricultural-forest ecotones cultivated foods that are palatable, energy-rich, easily digestible, and that often occur as large, clumped and spatially abundant orchards or fields may offer foraging advantages over natural foods. However, crop raiding can be risky: harassment, injury or even death may arise from confrontations with people. The factors that affect grouping decisions and activity budgets within anthropogenic environments are unknown. Twelve months of focal data were collected from direct observations of one chimpanzee community inhabiting a forest-farm mosaic at Bossou, Guinea. Wild fruit abundance did not directly influence daily party size. Instead, cultivated resource consumption, in combination with other social factors, provided chimpanzees with an alternative to fissioning. Chimpanzee party size did not differ between crop raids and wild feeds, but party cohesiveness did increase during raids. Furthermore, males and females adapted their activity budgets in different ways to integrate cultivated resources into their broader ecological strategy. As species are increasingly forced into anthropogenically impacted habitats, models of fission-fusion dynamics and other socioecological adaptations need to take into account exploitation of cultivated, energy-rich crops. © 2012 the Association for the Study of Animal Behaviour.
Abstract.
2011
Hockings KJ (2011). Behavioural flexibility and division of roles in chimpanzee road-crossing. In Matsuzawa T, Humle T, Sugiyama Y (Eds.) The chimpanzees of Bossou and Nimba, Tokyo: Springer-Verlag, 221-229.
Hockings KJ (2011). The crop-raiders of the sacred hill. In Matsuzawa T, Humle T, Sugiyama Y (Eds.) The chimpanzees of Bossou and Nimba, Tokyo: Springer-Verlag, 211-220.
2010
Hockings KJ, Yamakoshi G, Kabasawa A, Matsuzawa T (2010). Attacks on local persons by chimpanzees in Bossou, Republic of Guinea: Long-term perspectives.
American Journal of Primatology,
72(10), 887-896.
Abstract:
Attacks on local persons by chimpanzees in Bossou, Republic of Guinea: Long-term perspectives
Attacks on humans by nonhuman primates are one of the most serious causes of human-primate conflict, and strongly influence people's perceptions and tolerance of nonhuman primates. Despite their importance, systematic and extensive records of such attacks are rare. Here, we report the attacks that occurred on local persons by chimpanzees (Pan troglodytes verus) at Bossou, Republic of Guinea, from 1995 to 2009. There have been a total of 11 attacks during this period, the majority of which were directed toward children. They varied in their severity, but all were nonfatal. Attacks took place on a road and narrow paths that bordered the forest or in cultivated fields and orchards where opportunities for human-chimpanzee contact are high. Attacks occurred between the months of March and October, coinciding with wild fruit scarcity, increased levels of crop-raiding, and periods of human cultivation with likely increased human usage of paths. Although the families of attack victims felt angry and fearful toward chimpanzees after attacks, some drew on their traditional beliefs to explain why chimpanzees were respected, protected, and could not hurt them, even when attacks occurred. We provide suggestions for reducing future nonhuman primate attacks on humans in an effort to mitigate human-primate conflict situations. © 2009 Wiley-Liss, Inc.
Abstract.
Hockings KJ, Anderson JR, Matsuzawa T (2010). Flexible feeding on cultivated underground storage organs by rainforest-dwelling chimpanzees at Bossou, West Africa.
Journal of Human Evolution,
58(3), 227-233.
Abstract:
Flexible feeding on cultivated underground storage organs by rainforest-dwelling chimpanzees at Bossou, West Africa
It has been proposed that exploitation of underground storage organs (USOs) played an important role in the evolution of the genus Homo, these items serving as 'fallback foods' during periods of low food availability. The use of USOs as food by wild chimpanzees is infrequent and seen mostly in populations inhabiting relatively arid environments, such as the savanna. Here, we specifically test the hypothesis that chimpanzees (Pan troglodytes verus) inhabiting tropical wet forest at Bossou (Republic of Guinea, West Africa) exploit USOs as a fallback food during periods of fruit scarcity. Chimpanzees were never observed feeding on wild USOs, that is, those that were never cultivated, and rarely on other underground plant parts. However, direct observations revealed regular consumption of the USOs of cultivated cassava (Manihot esculenta), a spatially abundant and continuously available plant, although the chimpanzees did not use tools when acquiring and feeding on cassava. In agreement with the fallback foods hypothesis, our results show that chimpanzees exploited cassava USOs more frequently when both wild and cultivated fruits were scarce, and consumption patterns of cassava paralleled those of wild fallback foods. These seasonal extractive USO foraging strategies by chimpanzees can strengthen attempts to construct a clearer picture of the importance of USO feeding in hominoid evolution. © 2009 Elsevier Ltd. All rights reserved.
Abstract.
Hockings KJ (2010). Human-chimpanzee competition and conflict in Africa: a case study of coexistence in Bossou, Republic of Guinea. In Lonsdorf E, Ross S, Matsuzawa T (Eds.) The Mind of the Chimpanzee: Ecological and Experimental Perspectives, Chicago and London: the University of Chicago Press, 347-360.
Fuentes A, Hockings KJ (2010). The ethnoprimatological approach in primatology.
American Journal of Primatology,
72(10), 841-847.
Abstract:
The ethnoprimatological approach in primatology
Recent and long-term sympatries between humans and nonhuman primates (hereafter primates) are central to the behavioral ecology, conservation, and evolutionary trajectories of numerous primate species. Ethnoprimatology emphasizes that interconnections between humans and primates should be viewed as more than just disruptions of a "natural" state, and instead anthropogenic contexts must be considered as potential drivers for specific primate behavioral patterns. Rather than focusing solely on the behavior and ecology of the primate species at hand, as in traditional primatology, or on the symbolic meanings and uses of primates, as in socio-cultural anthropology, ethnoprimatology attempts to merge these perspectives into a more integrative approach. As human pressures on environments continue to increase and primate habitats become smaller and more fragmented, the need for a primatology that considers the impact of human attitudes and behavior on all aspects of primate lives and survival is imperative. In this special issue, we present both data-driven examples and more general discussions that describe how ethnoprimatological approaches can be both a contribution to the core theory and practice of primatology and a powerful tool in our goal of conservation action. © 2010 Wiley-Liss, Inc.
Abstract.
2009
Hockings KJ, Humle T (2009). Best practice guidelines for the prevention and mitigation of conflict between humans and great apes. Gland, Switzerland, IUCN/SSC Primate Specialist Group.
Hockings KJ (2009). Living at the interface: Human-chimpanzee competition, coexistence and conflict in Africa.
Interaction Studies,
10(2), 183-205.
Abstract:
Living at the interface: Human-chimpanzee competition, coexistence and conflict in Africa
Human-wildlife interactions have existed for thousands of years, however as human populations increase and human impact on natural ecosystems becomes more intensive, both parties are increasingly being forced to compete for resources vital to both. Humans can value wildlife in many contexts promoting coexistence, while in other situations, such as crop-raiding, wildlife conflicts with the interests of people. As our closest phylogenetic relatives, chimpanzees (Pantroglodytes) in particular occupy a special importance in terms of their complex social and cultural relationship with humans. A case study is presented that focuses on the Bossou chimpanzees' (Pan troglodytes verus) perspective of their habitat in the Republic of Guinea, West Africa, by highlighting the risks and opportunities presented by a human-dominated landscape, and detailing their day-to-day coexistence with humans. Understanding how rural people perceive chimpanzees and how chimpanzees adapt to living in anthropogenic environments will enhance our understanding of how people-wildlife interactions develop into situations of conflict and therefore can generate sustainable solutions to prevent or mitigate situations of conflict. © John Benjamins Publishing Company.
Abstract.
Hockings KJ, Anderson JR, Matsuzawa T (2009). Use of wild and cultivated foods by Chimpanzees at Bossou, Republic of Guinea: Feeding dynamics in a human-influenced environment.
American Journal of Primatology,
71(8), 636-646.
Abstract:
Use of wild and cultivated foods by Chimpanzees at Bossou, Republic of Guinea: Feeding dynamics in a human-influenced environment
Increased human population growth and more conversions of natural habitat to agricultural land have resulted in greater proximity between humans and nonhuman primate species. Consequent increases in resource competition including crop-raiding are a by-product of both natural resources becoming less available and the nutritional benefits of cultivated foods becoming more known to the nonhuman primates. Chimpanzees at Bossou in the Republic of Guinea, West Africa, consume 17 different types of cultivated foods that are grown extensively throughout their small, fragmented home range. Direct observations of feeding behavior conducted over an 18-month period revealed that during specific months crops account for up to one quarter of chimpanzee feeding time, with higher overall cropraiding levels throughout the periods of wild fruit scarcity. Some cultivated foods, especially sugar fruits, are mostly fallback foods, whereas others, such as rice pith (Oryza sp.) and maize (Zea mays), are consumed according to their availability even when wild foods are abundant. These findings highlight the importance of both crop choice by farmers and a thorough understanding of the ecology of resident primate species when establishing land management techniques for alleviating human-primate conflict. Am. J. Primatol. 71:636-646, 2009. © 2009 Wiley-Liss, Inc.
Abstract.
2007
Hockings KJ, Humle T, Anderson JR, Biro D, Sousa C, Ohashi G, Matsuzawa T (2007). Chimpanzees share forbidden fruit.
PLoS ONE,
2(9).
Abstract:
Chimpanzees share forbidden fruit
The sharing of wild plant foods is infrequent in chimpanzees, but in chimpanzee communities that engage in hunting, meat is frequently used as a 'social tool' for nurturing alliances and social bonds. Here we report the only recorded example of regular sharing of plant foods by unrelated, non-provisioned wild chimpanzees, and the contexts in which these sharing behaviours occur. From direct observations, adult chimpanzees at Bossou (Republic of Guinea, West Africa) very rarely transferred wild plant foods; in contrast, they shared cultivated plant foods much more frequently (58 out of 59 food sharing events). Sharing primarily consists of adult males allowing reproductively cycling females to take food that the possess. We propose that hypotheses focusing on 'food-for-sex and -grooming' and 'showing-off strategies plausibly account for observed sharing behaviours. A changing human-dominated landscape presents chimpanzees with fresh challenges, and our observation suggest that crop-raiding provides, adult male chimpanzees at Bossou with highly desirable food commodities that may be traded for other currencies. © 2007 Hockings et al.
Abstract.
2006
Hockings KJ, Anderson JR, Matsuzawa T (2006). Road crossing in chimpanzees: a risky business. Current Biology, 16(17).
