The behaviour of a social group of mandrills, Mandrillus sphinx

A social group of 37 mandrills, with composition resembling a wild group, maintained in a 5.3 ha enclosure of natural relict gallery forest at CIRMF, Gabon was studied over 29 months. The 14 wild-caught founders (7 adult females, 2 adult and 5 subadult males) were the subjects of detailed behavioural study (15 months, 1200+ hours observation). Mandrills were captured at least annually to obtain blood samples, data on body weight, dental and reproductive status, and testicular volume. Breeding was seasonal, with a 4-month mating season in which 92% of oestrous periods occurred. Oestrus synchrony was evident, with up to 5 females maximally swollen on any one day. Most (92%) copulations occurred at maximum swelling, with ejaculation in a single mount. 'Mate-guarding' of pen-ovulatory females by the alpha male involved sustained proximity to her and 'warning grunts' to other males. No herding behaviour was observed. Spatial, grooming, and agonistic relationships were examined in detail. During anoestrus, males were rarely near females; three males were never recorded allogrooming. The alpha male spent significantly more time close to anoestrous females, grooming with them significantly more than the other males. Females spent time near each other, groomed with their offspring, and gave three-quarters of their grooming to and received nearly all grooming from founder females. During oestrus, male-female proximity increased, females spent more time grooming, groomed with fewer age-sex classes, groomed mostly with male founders, and received more grooming from males. Stable, linear dominance hierarchies existed within each sex. Various aspects of mandrill biology - colouration, scent-marking, vocalisations - were interpreted as adaptations to ecological constraints of living semi-terrestrially in tropical forest. Results were used to assess models of single- and multi-male social organisation and male mating strategies. It was suggested that mandrills form one-male units, different from those of hamadryas and gelada baboons. Instead similarities with an Asian ecological analogue of the mandrill, the pig-tailed macaque, were emphasised

Habituating primates: Processes, techniques, variables and ethics

First paragraph: Field biologists adopted the term habituation from physiology, as the relatively persistent waning of a response as a result of repeated stimulation that is not followed by any kind of reinforcement (Thorpe, 1963). Repeated neutral contacts between non-human primates (hereafter called primates in this chapter) and humans can lead to a reduction in fear, and ultimately to the ignoring of an observer. The techniques and processes involved have only rarely been described (e.g. Schaller, 1963; Kummer, 1995), as habituation has generally been viewed as a means to an end (Tutin & Fernandez, 1991). The few studies that have quantified primate behaviour in relation to habituators describe the process with African great apes (Grieser Johns, 1996; van Krunkelsven et al., 1999; Blom et al., 2001). As we become increasingly aware of the potential effects of observer presence on primate behaviour, and especially the potential risks of close proximity with humans, it behoves us to measure as much as possible about the habituation process

Habituating primates: Processes, techniques, variables and ethics (2nd Edition)

Introduction Field biologists adopted the term habituation from physiology, as the relatively persistent waning of a response as a result of repeated stimulation that is not followed by any kind of reinforcement (Thorpe, 1963). Repeated neutral contacts between primates and humans can lead to a reduction in fear, and ultimately to the ignoring of an observer. Historically, the techniques and processes involved were rarely described, as habituation was generally viewed as a means to an end (Tutin & Fernandez, 1991). As we become increasingly aware of the potential effects of observer presence on primate behaviour, and especially the potential risks of close proximity with humans, it behoves us to measure as much about the habituation process as possible. However, most recent studies that have quantified primate behaviour in relation to habituators have focussed on great apes (see, for example, Ando et al., 2008; Bertolani & Boesch, 2008; Blom et al., 2004; Cipolletta, 2003; Doran-Sheehy et al., 2007; Sommer et al., 2004; Werdenich et al., 2003), with little information available for other primate taxa (but see Jack et al., 2008)

Group differences in feeding and diet composition of wild western gorillas

The ecological-constraints model posits that living in larger groups is associated to higher travel costs and reduced nutritional intake due to within-group feeding competition setting upper group size limits. While this is critical for frugivorous mammals, the model is less ubiquitous for folivores who feed on more abundant and evenly distributed food. The seasonally frugivorous diet of western gorillas (Gorilla gorilla) provides the opportunity to study the ecological-constraints model in the largest primate species. We investigated how two groups of western gorillas of difering sizes (N= 9, N= 15) in Central African Republic, responded to seasonal variation in fruit availability in terms of activity and diet. We used continuous focal animal sampling during periods of high (July–August 2011) and low (October 2011–January 2012) fruit availability, measured by monthly phenological scores. While diet diversity, resting and moving time did not difer between groups, overall the smaller group spent more time feeding than the larger group although this became less evident when fruit was more available. The smaller group was more frugivorous than the larger group. However, the larger group increased more steeply fruit consumption when fruit was more available, and incorporated more insects, young leaves and bark when fruit was less available, when compared to the smaller group. Up to a certain limit, the fexibility of large, seasonal frugivores to survive on a more folivorous diet may bufer the upper limit group size, suggesting deviation from the ecological-constraints model as in some folivores

Bacillus cereus Biovar Anthracis Causing Anthrax in Sub-Saharan Africa—Chromosomal Monophyly and Broad Geographic Distribution

Through full genome analyses of four atypical Bacillus cereus isolates, designated B. cereus biovar anthracis, we describe a distinct clade within the B. cereus group that presents with anthrax-like disease, carrying virulence plasmids similar to those of classic Bacillus anthracis. We have isolated members of this clade from different mammals (wild chimpanzees, gorillas, an elephant and goats) in West and Central Africa (Côte d’Ivoire, Cameroon, Central African Republic and Democratic Republic of Congo). The isolates shared several phenotypic features of both B. anthracis and B. cereus, but differed amongst each other in motility and their resistance or sensitivity to penicillin. They all possessed the same mutation in the regulator gene plcR, different from the one found in B. anthracis, and in addition, carry genes which enable them to produce a second capsule composed of hyaluronic acid. Our findings show the existence of a discrete clade of the B. cereus group capable of causing anthrax-like disease, found in areas of high biodiversity, which are possibly also the origin of the worldwide distributed B. anthracis. Establishing the impact of these pathogenic bacteria on threatened wildlife species will require systematic investigation. Furthermore, the consumption of wildlife found dead by the local population and presence in a domestic animal reveal potential sources of exposure to humans

Mycorrhizal feedbacks influence global forest structure and diversity

One mechanism proposed to explain high species diversity in tropical systems is strong negative conspecific density dependence (CDD), which reduces recruitment of juveniles in proximity to conspecific adult plants. Although evidence shows that plant-specific soil pathogens can drive negative CDD, trees also form key mutualisms with mycorrhizal fungi, which may counteract these effects. Across 43 large-scale forest plots worldwide, we tested whether ectomycorrhizal tree species exhibit weaker negative CDD than arbuscular mycorrhizal tree species. We further tested for conmycorrhizal density dependence (CMDD) to test for benefit from shared mutualists. We found that the strength of CDD varies systematically with mycorrhizal type, with ectomycorrhizal tree species exhibiting higher sapling densities with increasing adult densities than arbuscular mycorrhizal tree species. Moreover, we found evidence of positive CMDD for tree species of both mycorrhizal types. Collectively, these findings indicate that mycorrhizal interactions likely play a foundational role in global forest diversity patterns and structure

Mycorrhizal feedbacks influence global forest structure and diversity

One mechanism proposed to explain high species diversity in tropical systems is strong negative conspecific density dependence (CDD), which reduces recruitment of juveniles in proximity to conspecific adult plants. Although evidence shows that plant-specific soil pathogens can drive negative CDD, trees also form key mutualisms with mycorrhizal fungi, which may counteract these effects. Across 43 large-scale forest plots worldwide, we tested whether ectomycorrhizal tree species exhibit weaker negative CDD than arbuscular mycorrhizal tree species. We further tested for conmycorrhizal density dependence (CMDD) to test for benefit from shared mutualists. We found that the strength of CDD varies systematically with mycorrhizal type, with ectomycorrhizal tree species exhibiting higher sapling densities with increasing adult densities than arbuscular mycorrhizal tree species. Moreover, we found evidence of positive CMDD for tree species of both mycorrhizal types. Collectively, these findings indicate that mycorrhizal interactions likely play a foundational role in global forest diversity patterns and structure

The Primate Habituation Programme, Dzanga Sangha Protected Areas, Central African Republic: An overview

Dzanga Sangha Protected Areas (DSPA), including Dzanga-Ndoki National Park (DNNP), are located in SW Central African Republic (CAR) and are managed by the government and WWF. DSPA is CAR’s largest remaining nearly intact forest block and known for its outstanding biodiversity, including most of CAR's gorillas (G. g. gorilla). In 2012, DNNP, and its neighbouring NPs, were designated a World Heritage Site, the Sangha Tri-National complex (TNS) – classified as an exceptional priority area for western lowland gorilla and central chimpanzee (Pan t. troglodytes) conservation in the IUCN Regional Action Plan. The Primate Habituation Programme (PHP) was established in 1997 and plays a key role in DSPA’s conservation management strategy, generating significant revenue for the programme and tangible local community benefits. Now recognized as the most successful western lowland gorilla tourism and research programme, it has successfully habituated three groups, with another two undergoing habituation, and developed a controlled tourism programme. The habituated gorillas are regularly visited by tourists and are subjects of numerous scientific articles and film documentaries that have greatly contributed to our knowledge of this elusive species. Strong measures are in place to combat habitat loss and poaching in DSPA, but increased tourism, while providing income, can also negatively impact gorilla population health. Added to potential emerging diseases, human contact may increase stress and expose gorillas to human-borne pathogens, to which they may have little immunity. A PHP priority is to develop the programme into a model of sustainable best-practice with reduced risk of negative impacts from tourism/research. Current IUCN great ape tourism best practices (PHP is partly/fully compliant on ~90% of 156 criteria) include ongoing observational gorilla health monitoring, prohibiting visitors who are/have recently been ill and regular staff screening. However, disease risk, especially from asymptomatic pathogens, is a real threat and in order to monitor and mitigate these risks, the PHP set up a Wildlife Health Laboratory (WHL) in 2012. The main aim of this presentation is to give an overview of the PHP’s past, present and future activities (including habituation, research, tourism, and WHL), most of which continue despite the current political instability in CAR