Roseline Beudels-Jamar

The Role of Anthropic, Ecological, and Social Factors in Sleeping Site Choice by Long‐Tailed Macaques (Macaca fascicularis)

When choosing their sleeping sites, primates make adaptive trade‐offs between various biotic and abiotic constraints. In human‐modified environments, anthropic factors may play a role. We assessed the influence of ecological (predation), social (intergroup competition), and anthropic (proximity to human settlements) factors in sleeping site choice by long‐tailed macaques (Macaca fascicularis) occupying a habitat at the interface of natural forests and human‐modified zones in Bali Barat National Park, Indonesia. Over the course of 56 nights, we collected data relating to physical features of sleeping trees, patterns of the use of sleeping sites within the home range, pre‐sleep behavior, diurnal ranging patterns and availability of natural and human food. Overall, the macaques used 17 sleeping sites with 37 sleeping trees. When the monkeys slept in forest zones, they selected sleeping trees that had larger trunks but were not significantly taller than surrounding trees. Though the macaques rarely re‐used sleeping sites on consecutive nights, they frequently re‐used four sites over the study period. The group favored sleeping within the core area of its home range, despite the occurrence of frequent agonistic intergroup encounters there. Macaques preferentially selected sleeping trees located within or near human‐modified zones, especially when human food was abundant and natural food was scarce. These results partially support the hypothesis that long‐tailed macaques choose their sleeping sites to avoid predation; proximity to human settlements appears to be the primary factor influencing sleeping site choice in this primate species. Our results reflect the strong influence that anthropic factors have on primates, which subsist in increasingly human‐dominated landscapes. Am. J. Primatol. 76:1140–1150, 2014.

Intergroup variation in robbing and bartering by long-tailed macaques at Uluwatu Temple (Bali, Indonesia)

Robbing and bartering (RB) is a behavioral practice anecdotally reported in free-ranging commensal macaques. It usually occurs in two steps: after taking inedible objects (e.g., glasses) from humans, the macaques appear to use them as tokens, returning them to humans in exchange for food. While extensively studied in captivity, our research is the first to investigate the object/food exchange between humans and primates in a natural setting. During a 4-month study in 2010, we used both focal and event sampling to record 201 RB events in a population of long-tailed macaques (Macaca fascicularis), including four neighboring groups ranging freely around Uluwatu Temple, Bali (Indonesia). In each group, we documented the RB frequency, prevalence and outcome, and tested the underpinning anthropogenic and demographic determinants. In line with the environmental opportunity hypothesis, we found a positive qualitative relation at the group level between time spent in tourist zones and RB frequency or prevalence. For two of the four groups, RB events were significantly more frequent when humans were more present in the environment. We also found qualitative partial support for the male-biased sex ratio hypothesis [i.e., RB was more frequent and prevalent in groups with higher ratios of (sub)adult males], whereas the group density hypothesis was not supported. This preliminary study showed that RB is a spontaneous, customary (in some groups), and enduring population-specific practice characterized by intergroup variation in Balinese macaques. As such, RB is a candidate for a new behavioral tradition in this species.

Bonobo nest site selection and the importance of predictor scales in primate ecology

The role of spatial scale in ecological pattern formation such as the geographical distribution of species has been a major theme in research for decades. Much progress has been made on identifying spatial scales of habitat influence on species distribution. Generally, the effect of a predictor variable on a response is evaluated over multiple, discrete spatial scales to identify an optimal scale of influence. However, the idea to identify one optimal scale of predictor influence is misleading. Species‐environment relationships across scales are usually sigmoid increasing or decreasing rather than humped‐shaped, because environmental conditions are generally highly autocorrelated. Here, we use nest count data on bonobos (Pan paniscus) to build distribution models which simultaneously evaluate the influence of several predictors at multiple spatial scales. More specifically, we used forest structure, availability of fruit trees and terrestrial herbaceous vegetation (THV) to reflect environmental constraints on bonobo ranging, feeding and nesting behaviour, respectively. A large number of models fitted the data equally well and revealed sigmoidal shapes for bonobo‐environment relationships across scales. The influence of forest structure increased with distance and became particularly important, when including a neighbourhood of at least 750 m around observation points; for fruit availability and THV, predictor influence decreased with increasing distance and was mainly influential below 600 and 300 m, respectively. There was almost no difference in model fit, when weighing predictor values within the extraction neighbourhood by distance compared to simply taking the arithmetic mean of predictor values. The spatial scale models provide information on bonobo nesting preferences and are useful for the understanding of bonobo ecology and conservation, such as in the context of mitigating the impact of logging. The proposed approach is flexible and easily applicable to a wide range of species, response and predictor variables and over diverse spatial scales and ecological settings.

Feeding ecology of bonobos living in forest-savannah mosaics: Diet seasonal variation and importance of fallback foods.

Primates along with many other animal taxa are forced to cope with large shifts in basic ecological conditions because of rapid anthropogenically induced changes of their habitats. One of the coping strategies for primates is to adjust their diet to these changes, and several studies have demonstrated the importance of fallback resources for this. Bonobos, like chimpanzees, might be particularly vulnerable to habitat fragmentation because of their high dependence on fruit availability. Little is known, however, about bonobo feeding ecology in fragmented habitats and their use of fallback resources. In this study, we investigate diet seasonal variation and the exploitation of preferred and fallback foods in a bonobo population living in forest‐savannah mosaics. Results show that bonobos have adapted to this fragmented habitat by feeding on only a few fruit species, including an important number of non‐tree species (liana, herb and savannah shrub), in comparison to populations living in dense forests. These non‐tree plants have been defined as fallback and non‐preferred foods, which are most probably consumed to maintain high frugivory. Interestingly, we identified that preferred foods are all typical of mature forests while fallback resources are mainly found in forest edges or disturbed areas. This finding indicates that bonobos prefer to use mature forests when feeding, as they do for nesting, but extend their range use to forest areas in close proximity to humans when the availability of preferred fruits is low. Finally, we show that bonobo diet relies heavily on two abundant fallback fruits: Musanga cecropioides and Marantochloa leucantha. Other studies have demonstrated that the selection of abundant fallback resources enables primates to subsist at high densities and to maintain cohesive groups, as observed at this study site. Our findings suggest that bonobos living in forest‐savannah mosaics can be considered as staple fallback food consumers. Am. J. Primatol. 77:948–962, 2015.

Using Zero-Inflated Models to Predict the Relative Distribution and Abundance of Roe Deer Over Very Large Spatial Scales

In Norway, recovering populations of large carnivores commonly prey on roe deer (Capreolus capreolus). Understanding predator habitat use and ecology requires fine-scaled information on prey distribution and abundance. However, the massive spatial scales at which large carnivores use the landscape presents many practical and statistical challenges for developing functional prey distribution models. Pellet-count data from > 1000 km of transects gathered across southeastern Norway between 2005 and 2011 were used to derive a map of the relative prey abundance for roe deer. These data were modeled using zero-inflated hurdle models using both environmental and anthropogenic variables. Snow depth and agricultural fields were the most significant variables in explaining both presence and abundance. Internal k-cross validation of the model showed medium accuracy (Spearmans r = 0.35), whereas external evaluation carried out on the basis of independently collected snow-tracking data (Spearmans r = 0.37) and hunting statistics (Spearmans r = 0.88) showed higher accuracy. The map generated can facilitate both the study of broad scale processes linking predators and prey as well as roe deer management in southeastern Norway.

Changes in Activity Patterns and Intergroup Relationships After a Significant Mortality Event in Commensal Long-Tailed Macaques (Macaca Fascicularis) in Bali, Indonesia

Little is known regarding behavioral and social responses of free-ranging primates to demographic changes emerging from significant mortality events. Here, we report on the activity patterns and intergroup sociospatial relationships in a commensal population of long-tailed macaques (Macaca fascicularis) in Bali, Indonesia, that underwent a significant mortality event in summer 2012. During the period of interest, we noted heightened mortality in three of the five social groups present in this population, with adult females and juveniles experiencing higher mortality rates than adult and subadult males. Limited diagnostic data regarding pathogen identification and a lack of any conclusive etiology of the deaths prevent our ascertainment of the agent(s) responsible for the observed mortality, but given the characteristics of the event we assume it was caused by a transmissible disease outbreak. Comparing the pre- and post-mortality event periods, we found significant differences in activity patterns, including a decreased proportion of affiliation in adult females. This result is likely indicative of enhanced social instability induced by the high mortality of adult females that constitute the stable core of macaque social structure. A higher social tension between groups after the mortality event was indicated by more frequent and intense agonistic intergroup encounters. Intergroup conflict success was inversely proportional to the rate of mortality a group suffered. Our results illustrate how changes in demographic structure caused by significant mortality events may have substantial consequences on behavior and social dynamics in primate groups and at the level of a population.

Optimizing scale search in species distribution models

DOI: 10.1159/000354129 298 5th Congress of the European Federation for Primatology researchers usually argue that one of the distinguishing features of non-human primates’ gestures is their high degree of flexibility, which can be considered in different ways: (1) ‘means-end dissociation’, which refers to the use of a particular gesture in different functional contexts and/or several gestures for one specific context, and (2) gesture sequences which consist of combinations of two or more gestural signals. Both strategies enable non-human primates to adjust their gesture use to their partner’s behaviour and to increase the range of potential meanings that can be conveyed by combining the components of a more or less limited gestural repertoire. Because of their flexible use, however, very few gestures have a specific meaning, but their meaning is defined by the context in which they occur. Thus, in contrast to many vocalizations of non-human primates, their gestures are (1) less context-specific and do not represent functionally referential signals and, related to this, (2) gesture sequences do not represent meaningful combinations used for other functions than their single components. Therefore, I will first provide an overview of recent research on the flexible use of gestures in great apes to demonstrate how they create meaning in their interactions with others. I will then discuss how these findings relate to evidence from vocal studies with the aim to identify ‘blind spots’ and biases that currently constrain a fruitful debate about the origins of human language.Comparative studies of primate grasping and manipulative behaviours in captivity are numerous but there has been little research on hand use in the wild. Hand use during wild non-locomotor behaviours may reveal increased ranges of joint mobility or manipulative behaviours that have been previously ignored or underestimated. Manipulative behaviours in apes can strongly correlate with different habitats at the species and population level. Chimpanzees more often use tools in the wild and thus are thought to be more manipulative than gorillas. However, captive studies have demonstrated high dexterity in both taxa. We investigate hand use during manipulation (e.g. food processing, tool-use) in wild mountain gorillas (Gorilla beringei, Bwindi Impenetrable National Park, Uganda) and wild chimpanzees (Pan troglodytes verus, Tai National Park, Cote d’Ivoire). We used video data collected in the wild that included 32 gorilla (n=9 individuals) and 53 chimpanzee (n=11 individuals) instances of manipulative tasks. Digital images were extracted and analysed frame by frame. Preliminary results show that hand grips are similar between gorillas and chimpanzees during the manipulation of common food objects, such as long plant stems or branches. During the manipulation of species-specific food objects, gorillas use variable thumb-index grips during the manipulation of thistles and small plant stems, while chimpanzees use similar grips during nut-cracking. These preliminary results suggest that Bwindi mountain gorillas have similarly high dexterity as that of Tai chimpanzees despite not being tool-users. Gorillas frequently use precision grasping more to obtain small rather than large food items, which is similar to chimpanzees and other non-human primates.Previous studies have shown a positive relationship between proximity to humans or habitat fragmentation and parasitic levels in non-human primates (NHPs). However, to date few have explicitly explored links between parasite load and stress conditions. To better understand the links between parasite prevalence and NHP immune system efficiency and stress levels, faecal samples of Alouatta palliata and the critically endangered Ateles geoffroyi geoffroyi were non-invasively collected in northern Costa Rica. We investigated whether the presence of gastrointestinal parasites was related to the abundance of hormones (cortisol and testosterone). Samples were gathered across three areas differing in the frequency and diversity of human presence, i.e. around the Cano Palma Biological Station, near villages and at ecotourism sites. Two grams of each faecal sample were stored in a sugar saturated solution with 10% formalin to conserve the parasites; the remaining matter was dried to preserve DNA and steroid hormones. The samples enabled the quantification of parasites as well as testosterone and cortisol levels using ELISA as proxies of general health status and stress levels. Data on parasite abundance and hormone levels were contrasted across the two species and the three different sampling areas. Furthermore, we assessed the genetic exchange among the different groups of primates sampled. We genetically analysed the samples using 12 microsatellites previously validated by the University of Costa Rica. We verified whether transmission of parasites among the groups could be possible concomitant to the genetic exchange. This study aimed to better understand and assess the impact of human factors on NHP health and across NHPs with different socio-ecological characteristics.DOI: 10.1159/000354129 290 5th Congress of the European Federation for Primatology considerably between species for any given body size. Numerous hypotheses have been put forward to explain this variation. In recent years, we have tested predictions that flow from a framework focusing on the energetic aspects of having a large amount of the metabolically expensive brain tissue. In this talk, I will give an overview of our findings from broad comparative phylogenetic studies in mammals, and their implications for our understanding of non-human and human primate evolution. In sum, we found evidence for two pathways to increase relative brain size compared to the ancestral state. First, a species may change its lifestyle to allow for a stable increase in its total energy budget, e.g. by changing its diet. Alternatively, or in combination with the first pathway, a species may allocate more energy to the brain and less to other expensive functions such as offspring production. Ultimately, this option results in very low population growth rates even in good conditions, as found in great apes. A further increase in brain size would not be compatible with demographically viable populations in these large-brained primates. However, using comparative evidence from mammals, we demonstrate that help from non-mothers can alleviate this trade-off between reproductive effort and brain size. Nevertheless, the energetic constraints on brain size evolution will only be overcome in species that can actually benefit from enhanced cognitive abilities. While such benefits are potentially ubiquitous, we would expect them to be undermined by unavoidable mortality in some socioecological conditions, and by the difficulty of transferring knowledge across generations in some social systems. A combined test of all these considerations remains a challenge, largely due to the shortcomings of the distinct datasets, but I will present the newest data and results from our current projects.Throughout their range across Africa, chimpanzees (Pan troglodytes) are threatened with extinction due to habitat destruction, disease and unsustainable levels of hunting and capture, in spite of being protected by national and international laws. In recent years, the bush meat and the pet trade have resulted in a significant increase in the number confiscated orphan chimpanzees. The Chimpanzee Conservation Centre (CCC), located in the High Niger National Park (HNNP), is the only Pan African Sanctuary Alliance (PASA)-accredited sanctuary caring for chimpanzee orphans in Guinea, West Africa. This sanctuary has been rehabilitating confiscated chimpanzees since 1997. With the aim of reinforcing the wild chimpanzee population of the HNNP and to enhance park protection, the CCC, in 2008, released a first group of 12 chimpanzees into the Mafou core area of the park. Five of those individuals have since settled at the release site and continue to be monitored. In August 2011, the CCC was able to re-enforce this resident group with the successful addition of 2 adult females. Post-release monitoring of these individuals involved distance monitoring using simple VHF and/or ARGOS and GPS store-on-board radio collars. Here, we present data downloaded in 2011–2012 from the GPS store-on-board collars of 2 adult males and these 2 additional adult females. These data allowed us to analyse their social dynamics, party composition, habitat preferences, day range and home range use. Our results indicate that these females integrated successfully into the resident group and that the behaviour of these wild-born released orphan chimpanzees mirrors that of wild counterparts inhabiting similar savannah dominated landscapes, suggesting that they have adapted appropriately to their release conditions.

The Role of Megafauna Restoration in Dryland, Natural and Cultural Heritage Conservation

Eurasia and North Africa are traversed by the world’s largest continuous belt of drylands. It has harboured the earliest manifestation of many endeavours of mankind and most major domestication events. Deserts and the challenges they provide have generated extraordinarily elaborate responses by biological evolution and by human technological and cultural development. The achievements of these processes can still be admired today in species of unique emblematic value and in manifestations of cultural know-how. This inestimable cultural and natural heritage is gravely threatened, in part by ignorance of its significance. Deserts have a negative image in dominant socio-economic models. The value of their biological diversity resides in beta-diversity, so that they escape the attention of many actors of conservation, focused on centres of species richness. Identifying conservation processes for their distinctive species and communities is thus urgent. The megafauna is a determinant factor of these efforts. Its constitutive species are key components of dryland ecosystems. They are an essential source of inspiration for cultural traditions, extensively represented since earliest times in art and myths of the region. They have an unparalleled attraction potential, extending well beyond the generation of tourism as a source of cultural, scientific and recreational interest in the land. They can be flagship species, guaranteeing sustainability of conservation efforts. Linking major archaeological and historical sites, in which the region is exceptionally rich, with natural sites of unique quality, through the theme of the great mammals, is a particularly promising approach to the revalorisation of the resources of drylands.