Publications

cytoarchitecture and intrafrontal connections of the frontal cortex of the brain of the hamadryas baboon (papio hamadryas).	a study was made of the cytoarchitecture of the lateral and medial frontal cortex in the hamadryas baboon (papio hamadryas). the frontal cortico-cortical connections of areas 46, 8, 6, and 4 were investigated by injection of wheat-germ agglutinine conjugated to horseradish peroxiase (wga-hrp) into different regions of areas 46, 8, and 6. the lateral region of the frontal lobe of the baboon consists of broad areas of motor (area 4), premotor (area 6), and the dorsolateral prefrontal cortex, each ...	1991	1719042
seed-eating by west african cercopithecines, with reference to the possible evolution of bilophodont molars.	data on tooth use in eating fruits and seeds were collected on 12 west african monkeys representing five species of cercopithecines, cercopithecus aethiops, cercopithecus campbelli, cercocebus atys, erythrocebus patas, and papio papio. field observations and information in the published literature were used to select fruits for captive feeding trials. a total of over 27,000 tests were conducted to determine the preferences of the monkeys for 78 fruits. data were collected on the selection of fru ...	1988	3364545
[social behavior of lowe's guenon (cercopithecus campbelli lowei)].		1972	4624173
secnidazole vs. paromomycin: comparative antiprotozoan treatment in captive primates.	the antiprotozoan activity of secnidazole was studied in cercocebus t. torquatus, cercopithecus campbelli, erythrocebus patas (cercopithecidae), and gorilla gorilla (pongidae) compared with that of paromomycin in cercocebus t. lunulatus (cercopithecidae), e. patas, and g. gorilla (pongidae) by coprological analysis. the antiprotozoan activity of both drugs depended on the parasite species and the host species. the drugs acted in a similar way on entamoeba coli parasitising c. t. torquatus, and e ...	1998	9606042
"rodent-like" and "primate-like" types of astroglial architecture in the adult cerebral cortex of mammals: a comparative study.	previous observations disclosed that astroglia with interlaminar processes were present in the cerebral cortex of adult new and old world monkeys, but not in the rat, and scarcely in the prosimian microcebus murinus. the present report is a more systematic and comprehensive comparative analysis of the occurrence of such processes in the cerebral cortex of several mammalian species. brain samples were obtained from adult individuals from the following orders: carnivora (canine), rodentia (rat and ...	2000	10672363
interspecies semantic communication in two forest primates.	west african diana monkeys (cercopithecus diana) and campbell's monkeys (cercopithecus campbelli) frequently form mixed-species associations. males of both species produce acoustically distinct alarm calls to crowned eagles (stephanoaetus coronalus) and leopards (panthera pardus), two of their main predators. field playback experiments were conducted to investigate whether diana monkeys respond to campbell's alarm calls and whether they understand the calls' semantic content. diana monkeys respo ...	2000	10821618
vocal similarities and social bonds in campbell's monkey (cercopithecus campbelli).	this study examined variations of social call structures in female campbell's monkeys. the comparison of frequency modulations using a similarity index revealed that each individual presented one to three variants. some variants were shared by two to several individuals, often associated with play. on the contrary, vocal divergence was observed in a socially isolated animal and a negative correlation appeared between similarity index and the frequency of avoidance. this preliminary study gives t ...	2003	14746273
patterns of vocal sharing and social dynamics in a captive group of campbell's monkeys (cercopithecus campbelli campbelli).	although vocal sharing is widespread at several phylogenetic levels, few descriptions concerned primates. the present study involved the dynamics of vocal structures and social organization in a captive group of campbell's monkeys (cercopithecus campbelli campbelli) at 3-year periods, using precise sound recording and comparison. the authors focused on combined harmonic 6 calls, often involved in vocal exchanges and associated with approaches. each female produced 1 to 4 variants, shared, or not ...	2004	15482063
socially meaningful vocal plasticity in adult campbell's monkeys (cercopithecus campbelli).	campbell's monkeys (cercopithecus campbelli) frequently exchange vocalizations, the combined-harmonic calls, with individuals responding to one another's calls. previous work has shown that these calls can be grouped into several structural variants. adult females differ in their variant repertoires, which may change during their adult life, particularly after changes in the group composition. playback of females' currently produced variants triggered vocal responses from other group members, wh ...	2005	15982165
cheek pouch use in relation to interspecific competition and predator risk for three guenon monkeys (cercopithecus spp.).	forest guenons (cercopithecus spp.) are often found in polyspecific associations that may decrease predator risk while increasing interspecific competition for food. cheek pouch use may mitigate interspecific competition and predator risk by reducing the time spent in areas of high competition/predator risk. i investigated these ideas in three forest guenons: campbell's monkey (cercopithecus campbelli), spot-nosed monkey (c. petaurista), and diana monkey (c. diana). i present 13 months of scan s ...	2006	16645704
manual laterality in campbell's monkeys (cercopithecus c. campbelli) in spontaneous and experimental actions.	behavioural asymmetries, once thought to be exclusively human, appear to be widespread in vertebrates. a population-level bias should stem from natural selection and reflect a cerebral dominance, while individual preferences might be linked to individual characteristics. manual laterality has been extensively investigated in non-human primates. however, despite a strong data base, no general patterns have emerged, resulting in a few explanatory theories and little consensus. this study was inter ...	2006	16919818
female social relationships in a captive group of campbell's monkeys (cercopithecus campbelli campbelli).	a study group of campbell's monkeys (cercopithecus c. campbelli) provided data on affiliative and agonistic relationships between females. over a period of two years (involving 111 hr), we conducted observations of a captive group which had a composition similar to wild groups. we were able to identify a monitor-adjust social system with frequent affiliative interactions, directed gazing and avoidances rather than aggressive acts. we described long-term differentiated affiliative bonds: adult fe ...	2006	17096425
lateralization for visual processes: eye preference in campbell's monkeys (cercopithecus c. campbelli).	brain lateralization has been the matter of extensive research over the last centuries, but it remains an unsolved issue. while hand preferences have been extensively studied, very few studies have investigated laterality of eye use in non-human primates. we examined eye preference in 14 campbell's monkeys (cercopithecus c. campbelli). we assessed eye preference to look at a seed placed inside a tube using monocular vision. eye use was recorded for 100 independent and non-rewarded trials per ind ...	2009	18575907
dental topography and diets of four old world monkey species.	dental topographic analysis allows comparisons of variably worn teeth within and between species to infer relationships between dental form and diet in living primates, with implications for reconstructing feeding adaptations of fossil forms. although analyses to date have been limited mainly to the m(2)s of a few primate taxa, these suggest that dental topographic analysis holds considerable promise. still, larger samples including a greater range of species and different tooth types are needed ...	2009	19367586
social and emotional values of sounds influence human (homo sapiens) and non-human primate (cercopithecus campbelli) auditory laterality.	the last decades evidenced auditory laterality in vertebrates, offering new important insights for the understanding of the origin of human language. factors such as the social (e.g. specificity, familiarity) and emotional value of sounds have been proved to influence hemispheric specialization. however, little is known about the crossed effect of these two factors in animals. in addition, human-animal comparative studies, using the same methodology, are rare. in our study, we adapted the head t ...	2009	19609434
campbell's monkeys use affixation to alter call meaning.	human language has evolved on a biological substrate with phylogenetic roots deep in the primate lineage. here, we describe a functional analogy to a common morphological process in human speech, affixation, in the alarm calls of free-ranging adult campbell's monkeys (cercopithecus campbelli campbelli). we found that male alarm calls are composed of an acoustically variable stem, which can be followed by an acoustically invariable suffix. using long-term observations and predator simulation expe ...	2009	19915663
campbell's monkeys concatenate vocalizations into context-specific call sequences.	primate vocal behavior is often considered irrelevant in modeling human language evolution, mainly because of the caller's limited vocal control and apparent lack of intentional signaling. here, we present the results of a long-term study on campbell's monkeys, which has revealed an unrivaled degree of vocal complexity. adult males produced six different loud call types, which they combined into various sequences in highly context-specific ways. we found stereotyped sequences that were strongly ...	2009	20007377
attention to elders' voice in non-human primates.	the observed respect and attention to elders' speech in traditional cultures appears to have a 'universal' component which questions its possible biological bases. animals present differential attention to the vocalizations of other individuals according to their characteristics but little is known about the potential propensity to pay more attention to vocalizations of elders. on the basis of several hundreds of vocal exchanges recorded, here we show that aged female campbell's monkeys (cercopi ...	2010	20053662
cross-amplified polymorphic microsatellites for campbell's monkey.	population genetic analyses are of considerable importance for conservation strategies to protect endangered primates. we tested microsatellites of human origin with an aim to understand the genetic diversity of a west african forest guenon, campbell's monkey, cercopithecus campbelli. twelve markers amplified successfully, were polymorphic and were inherited in a mendelian fashion in a group of 4 individuals kept in captivity. these 12 markers were further amplified from 35 faecal samples collec ...	2010	20197664
polyspecific associations of cercopithecus campbelli and c. petaurista with c. diana: what are the costs and benefits?	polyspecific associations (psa) are common in many african primate communities, including the diurnal primates at taï forest, côte d'ivoire. in this paper i use data on the psa of two forest guenons, campbell's (cercopithecus campbelli) and lesser spot-nosed monkeys (c. petaurista), with diana monkeys (c. diana) and other primates to clarify interspecific relationships during 17 months including a 3-month low-fruit period. i analyzed association in relation to fruit availability and measured for ...	2010	20535628
speed of call delivery is related to context and caller identity in campbell's monkey males.	call rate can be a salient feature in animal communication. depending on the species, different psychological variables appear to influence call rates but the exact nature of these relationships remains poorly explored. here, we demonstrate for free-ranging campbell's monkeys that the call rates of four different alarm series (termed h, k, k(+), and b series) vary systematically as a function of context, associated behaviour, and identity of the caller. k(+) series were given more rapidly to pre ...	2010	20848074
acoustic variability and social significance of calls in female campbell's monkeys (cercopithecus campbelli campbelli).	although the vocal repertoire of nonhuman primates is strongly constrained by genetic, a growing number of studies evidence socially determined flexibility. according to snowdon et al. [social influences on vocal development (university press, cambridge, 1997), pp. 234-248], calls with a higher social function (affiliative or agonistic) would be expected to show more flexibility than lesser social calls. owren and rendall [evol. anthropol., 10, 58-71 (2001)] nuanced this by defending a structure ...	2011	21568434
Social learning of vocal structure in a nonhuman primate?	ABSTRACT: BACKGROUND: Non-human primate communication is thought to be fundamentally different from human speech, mainly due to vast differences in vocal control. The lack of these abilities in non-human primates is especially striking if compared to some marine mammals and bird species, which has generated somewhat of an evolutionary conundrum. What are the biological roots and underlying evolutionary pressures of the human ability to voluntarily control sound production and learn the vocal ut ...	2011	22177339
hunting, law enforcement, and african primate conservation.	primates are regularly hunted for bushmeat in tropical forests, and systematic ecological monitoring can help determine the effect hunting has on these and other hunted species. monitoring can also be used to inform law enforcement and managers of where hunting is concentrated. we evaluated the effects of law enforcement informed by monitoring data on density and spatial distribution of 8 monkey species in taï national park, côte d'ivoire. we conducted intensive surveys of monkeys and looked for ...	2012	22394275
visual recognition of age class and preference for infantile features: implications for species-specific vs universal cognitive traits in primates.	despite not knowing the exact age of individuals, humans can estimate their rough age using age-related physical features. nonhuman primates show some age-related physical features; however, the cognitive traits underlying their recognition of age class have not been revealed. here, we tested the ability of two species of old world monkey, japanese macaques (jm) and campbell's monkeys (cm), to spontaneously discriminate age classes using visual paired comparison (vpc) tasks based on the two dist ...	2012	22685529
hand preference and its flexibility according to the position of the object: a study in cercopithecines examining spontaneous behaviour and an experimental task (the bishop qhp task).	the extant literature on manual laterality in non-human primates is inconclusive, plagued by inconsistent or contradictory findings and by disturbing methodological issues (e.g. uncontrolled influential factors, comparability issues). the present study examined hand preference and its flexibility in 15 red-capped mangabeys (c. t. torquatus) and 13 campbell's monkeys (c. c. campbelli), two species that differ in their degree of arboreality. we investigated the influence of the spatial position of ...	2012	22718414
cross-taxa similarities in affect-induced changes of vocal behavior and voice in arboreal monkeys.	measuring the affective state of an individual across species with comparable non-invasive methods is a current challenge in animal communication research. this study aims to explore to which extent affect intensity is conveyed in the vocal behaviours of three nonhuman primate species (campbell's monkeys, de brazza's monkeys, red-capped mangabeys), which vary in body size, ecological niche and social system. similarly in the three species, we experimentally induced a change in captive social gro ...	2012	22984618
validation of an auditory sensory reinforcement paradigm: campbell's monkeys (cercopithecus campbelli) do not prefer consonant over dissonant sounds.	the central position and universality of music in human societies raises the question of its phylogenetic origin. one of the most important properties of music involves harmonic musical intervals, in response to which humans show a spontaneous preference for consonant over dissonant sounds starting from early human infancy. comparative studies conducted with organisms at different levels of the primate lineage are needed to understand the evolutionary scenario under which this phenomenon emerged ...	2013	23566027
voice discrimination in four primates.	one accepted function of vocalisations is to convey information about the signaller, such as its age-sex class, motivation, or relationship with the recipient. yet, in natural habitats individuals not only interact with conspecifics but also with members of other species. this is well documented for african forest monkeys, which form semi-permanent mixed-species groups that can persist for decades. although members of such groups interact with each other on a daily basis, both physically and voc ...	2013	23800631
social complexity parallels vocal complexity: a comparison of three non-human primate species.	social factors play a key role in the structuring of vocal repertoires at the individual level, notably in non-human primates. some authors suggested that, at the species level too, social life may have driven the evolution of communicative complexity, but this has rarely been empirically tested. here, we use a comparative approach to address this issue. we investigated vocal variability, at both the call type and the repertoire levels, in three forest-dwelling species of cercopithecinae present ...	2013	23847565
diversity and prevalence of gastrointestinal parasites in seven non-human primates of the taï national park, côte d'ivoire.	parasites and infectious diseases are well-known threats to primate populations. the main objective of this study was to provide baseline data on fecal parasites in the cercopithecid monkeys inhabiting côte d'ivoire's taï national park. seven of eight cercopithecid species present in the park were sampled: cercopithecus diana, cercopithecus campbelli, cercopithecus petaurista, procolobus badius, procolobus verus, colobus polykomos, and cercocebus atys. we collected 3142 monkey stool samples betw ...	2015	25619957
suffixation influences receivers' behaviour in non-human primates.	compared to humans, non-human primates have very little control over their vocal production. nonetheless, some primates produce various call combinations, which may partially offset their lack of acoustic flexibility. a relevant example is male campbell's monkeys (cercopithecus campbelli), which give one call type ('krak') to leopards, while the suffixed version of the same call stem ('krak-oo') is given to unspecific danger. to test whether recipients attend to this suffixation pattern, we carr ...	2015	25925101
factors of influence and social correlates of parturition in captive campbell's monkeys: case study and breeding data.	how nonhuman primates deal with birth, at the moment of delivery, and during the following days, remains poorly explored because of the unpredictability of this event, particularly for forest-dwelling arboreal species. available studies highlight intra- and interspecific variation which suggest flexibility of the timing of delivery, of behavior associated with labor contractions and parturition, and the social context and ambient noise surrounding delivery. here, we present the findings of a two ...	2017	28196398
cytomegaloviruses in a community of wild nonhuman primates in taï national park, côte d'ivoire.	cytomegaloviruses (cmvs) are known to infect many mammals, including a number of nonhuman primates (nhps). however, most data available arose from studies led on captive individuals and little is known about cmv diversity in wild nhps. here, we analyzed a community of wild nonhuman primates (seven species) in taï national park (tnp), côte d'ivoire, with two pcr systems targeting betaherpesviruses. cmv dna was detected in 17/87 primates (4/7 species). six novel cmvs were identified in sooty manga ...	2017	29286318