Publications

intersexual dominance, masculinized genitals and prenatal steroids: comparative data from lemurid primates.	masculinization of female genitalia and female intersexual dominance distinguish spotted hyenas (crocuta crocuta) and malagasy primates (lemuriformes) from most other mammals. an unusual prenatal endocrine environment has been proposed to proximately underlie the development of these traits in hyenas. to examine whether female dominance and genital masculinization are similarly enhanced by the prenatal environment in lemurid primates, we measured androgen and estrogen excretion in pregnant wild ...	2003	12649757
a molecular approach to comparative phylogeography of extant malagasy lemurs.	the lemurs of madagascar provide an excellent model for exploring evolutionary diversification. this study investigates genetic divergence among most extant lemur taxa in relation to potential geographical boundaries to gene flow. for this purpose, approximately 2,400 bp of mitochondrial dna (part of the coiii gene; nd3, nd4l, and nd4 genes; and five trnas) were sequenced in a total of 131 lemurs from 5 families, 12 genera, 25 species, and 18 subspecies to reconstruct phylogenetic relationships ...	2003	12719521
endocrine characterization of female reproductive status in wild redfronted lemurs (eulemur fulvus rufus).	in order to characterize the endocrine changes associated with ovarian function and pregnancy in wild redfronted lemurs (eulemur fulvus rufus), profiles of immunoreactive 5alpha-pregnane-3alpha-ol-20-one (5-p-3oh) and total estrogens (e(t)) in feces were generated during the breeding season and gestation. hplc data confirmed the presence of high amounts of 5-p-3oh in the feces of redfronted lemurs and showed that estrone and estradiol-17beta were the major estrogens excreted into feces, with est ...	2003	12714009
circadian rhythms in diet and habitat use in red ruffed lemurs (varecia rubra) and white-fronted brown lemurs (eulemur fulvus albifrons).	daily variation in niche use among vertebrates is attributed to a variety of factors, including thermoregulatory, reproductive, and nutritional requirements. lemuriform primates exhibit many behavioral and physiological adaptations related to thermoregulation and sharp, seasonal reproduction, yet they have rarely been subjects of a quantitative analysis of circadian (or daily) rhythms in niche use. in this study, i document daily rhythms in diet and microhabitat use over an annual cycle in two s ...	2004	15252863
reciprocal recognition of sifaka ( propithecus verreauxi verreauxi) and redfronted lemur ( eulemur fulvus rufus) alarm calls.	redfronted lemurs ( eulemur fulvus rufus) and verreaux's sifakas ( propithecus verreauxi verreauxi) occur sympatrically in western madagascar. both species exhibit a so-called mixed alarm call system with functionally referential alarm calls for raptors and general alarm calls for carnivores and raptors. general alarm calls also occur in other contexts associated with high arousal, such as inter-group encounters. field playback experiments were conducted to investigate whether interspecific reco ...	2004	12827548
ancestral loss of short wave-sensitive cone visual pigment in lorisiform prosimians, contrasting with its strict conservation in other prosimians.	mammals are basically dichromatic in color vision, possessing middle to long wave-sensitive (m/lws) and the short wave-sensitive (sws) cone opsins in the retina, whereas some nocturnal mammals lack functional sws opsins. prosimians, primitive primates consisting of three extant groups (lorisiformes, lemuriformes, and tarsiiformes), include many nocturnal species. among nocturnal prosimians, a species of lorisiforms, the greater galago (otolemur crassicaudatus), is known to lack a functional sws ...	2004	15045486
use of total dietary fiber across four lemur species (propithecus verreauxi coquereli, hapalemur griseus griseus, varecia variegata, and eulemur fulvus): does fiber type affect digestive efficiency?	in vivo digestibility and transit of two experimental diets were compared across four lemur species for which gastrointestinal morphology and preliminary data on physiology differ:varecia variegata (vv), eulemur fulvus (ef), propithecus verreauxi (pv), and hapalemur griseus (hg). since free-ranging groups consume varied amounts of slowly fermentable insoluble fiber (if) and rapidly fermentable soluble fiber (sf), differences in digestibility may be related to variation in the fiber types consume ...	2004	15538767
tree dispersal strategies in the littoral forest of sainte luce (se-madagascar).	zoochory is the most common mode of seed dispersal for the majority of plant species in the tropics. based on the assumption of tight plant-animal interactions several hypotheses have been developed to investigate the origin of life history traits of plant diaspores and their dispersers, such as species-specific co-evolution, the low/high investment model (low investment in single fruits but massive fruiting to attract many different frugivores versus high investment in single fruits and fruit p ...	2004	15095087
characterizing gastrointestinal transit time in four lemur species using barium-impregnated polyethylene spheres (bips).	differences in dietary profiles and gastrointestinal (gi) morphologies observed across lemur species suggest that there may be variation in patterns of digesta flow through the gi tract related to the method of digesta processing. using radio-opaque barium-impregnated polyethylene spheres (bips), we characterized such patterns in four lemur species: varecia variegata (vv), eulemur fulvus (ef), propithecus verreauxi (pv), and hapalemur griseus (hg) (n = 2 per species). after an initial radiograph ...	2004	15538763
hind limb proportions and kinematics: are small primates different from other small mammals?	similar in body size, locomotor behaviour and morphology to the last common ancestor of primates, living small quadrupedal primates provide a convenient model for investigating the evolution of primate locomotion. in this study, the hind limb kinematics of quadrupedal walking in mouse lemurs, brown lemurs, cotton-top tamarins and squirrel monkeys are analysed using cineradiography. the scaling of hind limb length to body size and the intralimb proportions of the three-segmented hind limb are tak ...	2005	16109897
biomedical evaluation of two sympatric lemur species (propithecus verreauxi deckeni and eulemur fulvus rufus) in tsiombokibo classified forest, madagascar.	complete medical examinations were performed on 20 wild decken's sifaka (propithecus verreauxi deckeni) and 20 wild red-fronted brown lemurs (eulemurfulvus rufus) from western madagascar. each animal received a complete physical examination, and weight, body temperature, heart rate, and respiratory rate were recorded and ectoparasites collected. blood samples were collected for complete blood cell count, differential white blood cell count, hemoparasite examination, serum biochemical profile, fa ...	2005	17312713
expectations about numerical events in four lemur species (eulemur fulvus, eulemur mongoz, lemur catta and varecia rubra).	although much is known about how some primates--in particular, monkeys and apes--represent and enumerate different numbers of objects, very little is known about the numerical abilities of prosimian primates. here, we explore how four lemur species (eulemur fulvus, e. mongoz, lemur catta, and varecia rubra) represent small numbers of objects. specifically, we presented lemurs with three expectancy violation looking time experiments aimed at exploring their expectations about a simple 1+1 additio ...	2005	15729569
external forces on the limbs of jumping lemurs at takeoff and landing.	ground reaction forces were recorded for jumps of three individuals each of lemur catta and eulemur fulvus. animals jumped back and forth between a ground-mounted force plate and a 0.5-m elevated platform, covering horizontal distances of 0.5-2 m. in total, 190 takeoffs and 263 landings were collected. animals typically jumped from a run up and into a run out, during which they gained or into which they carried horizontal impulse. correspondingly, vertical impulses dominated takeoffs and landing ...	2005	15810009
how prosimian primates represent tools: experiments with two lemur species (eulemur fulvus and lemur catta).	the authors examined how 2 lemur species (eulemur fulvus and lemur catta) reason about tools. experiment 1 allowed subjects to use 1 of 2 canes to retrieve an inaccessible food reward. lemurs learned to solve this problem as quickly as other primates. experiment 2 then presented subjects with novel tools differing from the originals along one featural dimension. subjects attended more to tools' sizes than to their colors and made no distinction between tools' shapes and textures. experiments 3 a ...	2005	16366773
feeding behavior of lactating brown lemur females (eulemur fulvus) in mayotte: influence of infant age and plant phenology.	altmann [baboon mothers and infants, university of chicago press, 1980] and dunbar and dunbar [animal behavior 36:970-980, 1988] provided a model that predicts the amount of time spent feeding by lactating baboon females, as related to infant age. dunbar's model further suggests that food quality affects the amount of time that females devote to feeding activity, and is predictable from rainfall and temperature data. in this study the model was tested with data recorded from births of the mayott ...	2006	16900506
predation by eulemur fulvus fulvus on eggs of ploceus sakalava sakalava (aves: ploceidae) in ankarafantsika, madagascar.		2006	15583420
cathemerality in the mayotte brown lemur (eulemur fulvus): seasonality and food quality.	in past decades, cathemerality--as defined by tattersall [1987]--has been documented in two primate families: cebidae and lemuridae. in the lemuridae, in particular the genus eulemur, cathemeral activity seems to be a regular behavioural trait. nevertheless, ultimate and proximate determinants responsible for this behaviour remain unclear. in this study, in a dry and deciduous forest on mayotte (comoro archipelago), activities of 4 female brown lemurs (eulemur fulvus fulvus) were recorded by foc ...	2006	16415584
a note on the activity cycle of captive white-fronted lemurs (eulemur fulvus albifrons).	we studied the activity cycle of captive-born white-fronted lemurs (eulemur fulvus albifrons) at zurich zoo with the aim to discuss current hypotheses on the evolution of cathemerality in lemurs. in contrast to their relatives in the wild, these lemurs were active exclusively during the day. if cathemerality is a strategy to increase food intake or to avoid predators, then nocturnal activity is not essential for captive animals and may be suppressed simply due to the absence of stimuli. this sug ...	2006	16415582
chronobiological background to cathemerality: circadian rhythms in eulemur fulvus albifrons (prosimii) and aotus azarai boliviensis (anthropoidea).	cathemeral activity, in which the animals' motor activity is almost evenly distributed throughout the dark and the light portion of the day, has been described in various lemur genera (eulemur, hapalemur) and in the owl monkey aotus azarai of the argentinean chaco. proximate and ultimate factors responsible for this behaviour are still being debated. however, the chronobiological background of the behaviour has largely been ignored. we studied e. fulvus albifrons and a. a. boliviensis under cont ...	2006	16415579
influence of abiotic factors on cathemeral activity: the case of eulemur fulvus collaris in the littoral forest of madagascar.	the role environmental factors play in influencing circadian rhythms in natural habitats is still poorly described in primates, especially for those taxa with an activity cycle extended over the 24-hour cycle. in this paper, we elucidate the importance of abiotic factors in entraining the activity of cathemeral primates, focussing on results from a long-term study of eulemur fulvus collaris (collared brown lemur) in south-eastern malagasy littoral forest. two groups of lemurs were followed for 6 ...	2006	16415580
the concept of cathemerality: history and definition.	during a field study in 1974 it was noticed, and further fieldwork in 1977 and 1980 confirmed, that the activity of the mayotte lemur, eulemur fulvus fulvus, is distributed fairly evenly throughout the daily 24-hour cycle: by a very crude approximation the daytime activity:rest ratio averages 0.271, while the night-time ratio averages 0.283. in 1978 i proposed the new word 'cathemeral', compounded from the greek roots kappaalphataualpha (through) and etamuepsilonrhoalpha (the day), to describe t ...	2006	16415574
edge effects and their influence on lemur density and distribution in southeast madagascar.	edge effects are caused by the penetration of abiotic and biotic conditions from the matrix into forest interiors. although edge effects influence the biogeography of many tropical organisms, they have not been studied directly in primates. edge effects are particularly relevant to lemurs due to the loss of 80-90% of forests in madagascar. in this study, data are presented on how biotic edge effects influenced the distribution and density of lemurs in the vohibola iii classified forest in southe ...	2006	16323178
spatial variations in eulemur fulvus rufus and lepilemur mustelinus densities in madagascar.	i present data on variations in eulemur fulvus rufus and lepilemur mustelinus densities as well as tree characteristics (height, diameter and stem frequency) between edge and interior forest habitats in southeastern madagascar. line transect surveys were conducted from june 2003 to november 2005 in edge and interior forest habitats in the vohibola iii classified forest. although e. f. rufus densities were significantly lower in edge habitats than in interior habitats, density estimates for l. mu ...	2007	17170556
habitat use and social structure of a brown lemur hybrid population in the berenty reserve, madagascar.	the population of brown lemurs has rapidly grown since their founders were introduced to the berenty reserve. the founders consist of two species (eulemur fulvus rufus and e. collaris). to characterize the behavior of the population and to examine whether these characteristics affect population growth, i investigated the habitat use and social structure of the population of brown lemurs at berenty (berenty eulemur). behavior data were collected focusing on horizontal and vertical habitat use, ac ...	2007	17294429
transfer of self-control in black (eulemur macaco) and brown (eulemur fulvus) lemurs: choice of a less preferred food item under a reverse-reward contingency.	when presented a choice between two food-type arrays of equivalent size under a reverse-reward contingency, black (eulemur macaco) and brown (eulemur fulvus) lemurs transposed their self-control abilities, acquired in a previous experiment, to significantly select the less-desired food item in order to gain access to the more desired one. however, when presented with the choice between two different food-type arrays in which the amount of the less desired food array was larger than the more desi ...	2007	18085918
splice: a technique for generating in vitro spliced coding sequences from genomic dna.	we describe a rapid and cost-effective technique for the in vitro removal of introns and other unwanted regions from genomic dna to generate a single sequence of continuous coding capacity, where tissues required for rna extraction and complementary dna synthesis are unavailable. based on an overlapping fusion-pcr strategy, we name this procedure splice (for swift pcr for ligating in vitro constructed exons). as proof-of-principle, we used splice successfully to generate a single piece of dna co ...	2007	18251255
the influence of social organisation on leadership in brown lemurs (eulemur fulvus fulvus) in a controlled environment.	studies on leadership during group movements in several lemur species showed that females were responsible for the travelling choices concerning time and direction. interestingly, in these species females are dominant over males. we investigated the influence of social organisation upon leadership processes by studying a lemur species in which social organisation is characterized by the absence of female dominance: the brown lemur (eulemur fulvus fulvus). the study was conducted on a semi-free r ...	2008	18586413
population demography and social structure changes in eulemur fulvus rufus from 1988 to 2003.	eulemur fulvus rufus has been described as having stable multi-male/multi-female groups, a male-biased sex ratio, and female philopatry. however, in a 16-year study of this subspecies we documented a great deal of demographic change as several groups permanently fissioned, some groups disappeared, and new groups formed. we split the dataset into two periods, 1988 to 1993 and 1994 to 2003, which coincided with the first disappearance of a study group (in august 1994) and the first permanent group ...	2008	18257015
can brown lemurs (eulemur fulvus) learn to deceive a human competitor?	in the present study we asked whether lemurs could learn to manipulate information in order to deceive a human competitive trainer. four brown lemurs were trained to communicate about the location of a hidden reward to a cooperative trainer, who rewarded the subject if he indicated the baited bowl. next, a competitive trainer was introduced who kept the reward for himself if the subject indicated the baited bowl. in a first experiment, sessions were randomly assigned to be with either the cooper ...	2008	17876614
spatial memory during foraging in prosimian primates: propithecus edwardsi and eulemur fulvus rufus.	a variety of anthropoids travel efficiently from one food source to another, although there is disagreement over how this is accomplished over large-scale space. mental maps, for example, require that animals internally represent space, geometrically locate landmarks, use true distance and direction, and generate novel shortcuts to resources. alternately, topological or route-based maps are based on a network of fixed points, landmarks and routes so that one food patch can be linked with another ...	2008	18176079
forelimb proportions and kinematics: how are small primates different from other small mammals?	the crouched limb posture of small mammals enables them to react to unexpected irregularities in the support. small arboreal primates would benefit from these kinematics in their arboreal habitat but it has been demonstrated that primates display certain differences in forelimb kinematics to other mammals. the objective of this paper is to find out whether these changes in forelimb kinematics are related to changes in body size and limb proportions. as primates descended from small ancestors, a ...	2008	19043050
does eulemur cinereiceps exist? preliminary evidence from genetics and ground surveys in southeastern madagascar.	although appearing in the literature as early as 1890, the brown lemur form eulemur cinereiceps has recently resurfaced as a potentially valid taxon, distinct from neighboring, presumably closely related species such as white-collared lemurs (eulemur albocollaris). we propose two scenarios for the potential separation of e. cinereiceps and e. albocollaris: (1) coastal and interior populations represent two distinct taxa and (2) the coastal population north of the manampatrana river (the locality ...	2008	18027864
androgen and glucocorticoid levels reflect seasonally occurring social challenges in male redfronted lemurs (eulemur fulvus rufus).	intense reproductive competition and social instability are assumed to increase concentrations of glucocorticoids and androgens in vertebrates, as a means of coping with these challenges. in seasonally breeding redfronted lemurs (eulemur fulvus rufus), the mating and the birth season and the associated increased male competition are predicted to pose such reproductive challenges. in this paper, we investigate seasonal variation in hormone excretion in male redfronted lemurs, and examine whether ...	2008	19816530
social thermoregulation in redfronted lemurs (eulemur fulvus rufus).	pronounced seasonality, with temperatures dropping as low as 5 degrees c during the dry season, has led to the hypothesis that malagasy lemurs face cold stress and respond to this by inactivity and social thermoregulation, i.e. resting in tight body contact with conspecifics. compared to anthropoids, lemur groups are comprised of an unusually high number of males, leading to an even or slightly male-biased adult sex ratio. according to one hypothesis, females may benefit from these surplus males ...	2008	12399657
ontogeny of conspecific and heterospecific alarm call recognition in wild verreaux's sifakas (propithecus verreauxi verreauxi).	the production of vocalizations in nonhuman primates is predominantly innate, whereas learning influences the usage and comprehension of vocalizations. in this study, i examined the development of alarm call recognition in free-ranging infant verreaux's sifakas. specifically, i investigated their ability to recognize conspecific alarm calls as well as those of sympatric redfronted lemurs (eulemur fulvus rufus) in kirindy forest, western madagascar. both species have functionally referential alar ...	2008	17705223
comparison of biomedical evaluation for white-fronted brown lemurs (eulemur fulvus albifrons) from four sites in madagascar.	health and nutritional assessments of wildlife are important management tools and can provide a means to evaluate ecosystem health. such examinations were performed on 37 white-fronted brown lemurs (eulemur fulvus albifrons) from four sites in madagascar. comparison of health parameters between sites revealed statistically significant differences in body weight, body temperature, respiratory rate, hematology parameters (white cell count, hematocrit, segmented neutrophil count, and lymphocyte cou ...	2008	19110698
genetic analysis of hybridization and introgression between wild mongoose and brown lemurs.	hybrid zones generally represent areas of secondary contact after speciation. the nature of the interaction between genes of individuals in a hybrid zone is of interest in the study of evolutionary processes. in this study, data from nuclear microsatellites and mitochondrial dna sequences were used to genetically characterize hybridization between wild mongoose lemurs (eulemur mongoz) and brown lemurs (e. fulvus) at anjamena in west madagascar.	2009	19196458
anatomy and ultrasonography of the normal kidney in brown lemurs: eulemur fulvus.	the purpose of this study is to describe the anatomy and obtain echographic measurements of normal kidneys in brown lemurs (eulemur fulvus). the anatomical findings show that brown lemur kidneys are comparable to those of rats except for an elongated papilla. the kidneys of 16 (7 females and 9 males) lemurs were examined with two-dimensional and power doppler ultrasonography under general anesthesia. morphometrically, the left and right kidney surface areas are comparable (3.29 and 3.51 cm(2)). ...	2009	19466749
enumeration of objects and substances in non-human primates: experiments with brown lemurs (eulemur fulvus).	both human infants and adult non-human primates share the capacity to track small numbers of objects across time and occlusion. the question now facing developmental and comparative psychologists is whether similar mechanisms give rise to this capacity across the two populations. here, we explore whether non-human primates' object tracking abilities are subject to the same constraints as those of human infants. in particular, we examine whether one primate species, the brown lemur (eulemur fulvu ...	2009	19840047
gaze following and gaze priming in lemurs.	although primates have often been found to co-orient visually with other individuals, members of these same species have usually failed to use co-orientation to find hidden food in object-choice experiments. this presents an evolutionary puzzle: what is the function of co-orientation if it is not used for a function as basic as locating resources? co-orientation responses have not been systematically investigated in object-choice experiments, and requiring co-orientation with humans (as is typic ...	2009	19107531
what is it going to be? pattern and potential function of natal coat change in sexually dichromatic redfronted lemurs (eulemur fulvus rufus).	in some primate species, pelage colorations at birth contrast with adult colorations. the intensity of natal coats and their phylogenetic distribution is highly variable within primates. natal coat coloration seems to change to adult coloration in most species when infants become independent from their mothers, but an accepted functional explanation for natal coats is not available. here we describe pelage coloration change in sexually dichromatic redfronted lemurs (eulemur fulvus rufus) in kiri ...	2009	18615575
object permanence in lemurs.	object permanence, the ability to mentally represent objects that have disappeared from view, should be advantageous to animals in their interaction with the natural world. the objective of this study was to examine whether lemurs possess object permanence. thirteen adult subjects representing four species of diurnal lemur (eulemur fulvus rufus, eulemur mongoz, lemur catta and hapalemur griseus) were presented with seven standard piagetian visible and invisible object displacement tests, plus on ...	2009	18936991
individual facial coloration in male eulemur fulvus rufus: a condition-dependent ornament?	researchers studying individual variation in conspicuous skin coloration in primates have suggested that color indicates male quality. although primate fur color can also be flamboyant, the potential condition dependence and thus signaling function of fur remains poorly studied. we studied sources of variation in sexually dichromatic facial hair coloration in red-fronted lemurs (eulemur fulvus rufus). we collected data on 13 adult males in kirindy forest, madagascar, during two study periods in ...	2009	19946601
costs and benefits of multi-male associations in redfronted lemurs (eulemur fulvus rufus).	the evolution of group-living has fascinated but also puzzled researchers from the inception of behavioural ecology. we use a simple optimality approach to examine some of the costs and benefits of group-living in redfronted lemurs (eulemur fulvus rufus). we show that dominant males profit from accepting subordinates within their groups, as the latter significantly decrease the likelihood that the group is taken over by intruders. this benefit is large enough to outweigh the costs of reproductiv ...	2010	20236969
gastro-intestinal parasites of red-fronted lemurs in kirindy forest, western madagascar.	although parasites are important regulatory factors in animal populations, basic knowledge on their fauna in many vertebrate taxa is lacking. in particular, parasite infections of primate species have gained little attention. here, i present data on the gastro-intestinal fauna of a population of wild red-fronted lemurs ( eulemur fulvus rufus; primates: lemuriformes) monitored over a total of 8 mo during 2 consecutive field seasons in 2006 and 2007 in kirindy forest, western madagascar. using fec ...	2010	19954263
host intrinsic determinants and potential consequences of parasite infection in free-ranging red-fronted lemurs (eulemur fulvus rufus).	parasites and infectious diseases represent ecological forces shaping animal social evolution. although empirical studies supporting this link abound in various vertebrate orders, both the study of the dynamics and impact of parasite infections and infectious diseases in strepsirrhine primates have received little empirical attention. we conducted a longitudinal parasitological study on four groups of wild red-fronted lemurs (eulemur fulvus rufus) at kirindy forest, madagascar, during two field ...	2010	20091843
a 12-month survey of gastrointestinal helminth infections of lemurs kept in two zoos in madagascar.	infections with gastrointestinal parasites may be a major threat to lemurs kept in captivity, as they are a common cause of diarrhea. in this study, fecal egg count patterns and clinical signs associated with gastrointestinal nematodes were assessed for 12 mo in 40 lemurs kept under different husbandry and climatic conditions at two sites in madagascar. involved species were black-and-white ruffed lemurs (varecia variegata), eastern grey bamboo lemurs (hapalemur griseus), greater bamboo lemurs ( ...	2010	21370644
total energy expenditure and body composition in two free-living sympatric lemurs.	evolutionary theories that account for the unusual socio-ecological traits and life history features of group-living prosimians, compared with other primates, predict behavioral and physiological mechanisms to conserve energy. low energy output and possible fattening mechanisms are expected, as either an adaptive response to drastic seasonal fluctuations of food supplies in madagascar, or persisting traits from previously nocturnal hypometabolic ancestors. free ranging ring-tailed lemurs (lemur ...	2010	20360848
morphological characterization of a brown lemur hybrid zone (eulemur rufifrons × e. cinereiceps).	hybridization has recently been identified as a pervasive force in the evolution of primates. in this study, we characterized a hybrid zone between two species of brown lemur (eulemur rufifrons and e. cinereiceps) in the andringitra region of southeastern madagascar using morphological traits. we immobilized animals along a north-south transect (∼80 km), scored them for their degree of hybridity using pelage traits and measured standard morphometric variables. results from our study suggest that ...	2011	21312177
scratching around stress: hierarchy and reconciliation make the difference in wild brown lemurs (eulemur fulvus).	the scratching-stress linkage has been demonstrated in monkeys and apes but never in strepsirrhines, either in the wild or in captivity. we analysed data collected on a 14-animal group of eulemur fulvus in the berenty forest (south madagascar, march-july 2008). we applied a protocol (same weather conditions, time slot, social/activity context, forest quadrat, and subgroup formation) involving four conditions, under which we recorded the scratching response: predation attempt, reconciled conflict ...	2011	20666657
experimental evidence for olfactory predator recognition in wild mouse lemurs.	although primates have remarkable olfactory capabilities, their ability for olfactory predator recognition is still understudied. we investigated this cognitive ability in wild gray and golden-brown mouse lemurs (microcebus murinus and m. ravelobensis) that were confronted with four different olfactory stimuli, derived from two malagasy predators (fossa and barn owl) and two local nonpredator species (brown lemur and sifaka). the predator response was tested (1) in a systematic cage setup and (2 ...	2011	21557286
Brown (Eulemur fulvus) and Ring-Tailed Lemurs (Lemur catta) Use Human Head Orientation as a Cue to Gaze Direction in a Food Choice Task.	Whilst the ability to follow human gaze has been demonstrated in monkeys and apes, there is little evidence that prosimians share this ability. The current study used a food choice paradigm to assess whether captive brown (Eulemur fulvus) and ring-tailed lemurs (Lemur catta) use human gaze direction as a cue when choosing between an attending or non-attending human. Four experiments assessed the use of body, head and eye cues by the lemurs. In experiment 1, the non-attending human stood with her ...	2011	22123170
genetic regulation of parasite infection: empirical evidence of the functional significance of an il4 gene snp on nematode infections in wild primates.	susceptibility to parasite infection affects fitness-related processes, such as mate choice and survival, yet its genetic regulation remains poorly understood. interleukin-4 (il4) plays a central role in the humoral immune defence against nematode parasite infections, inducing ige switch and regulation of worm expulsion from the intestines. the evolutionary and functional significance of single nucleotide polymorphisms (snps) in il4-genes is known, yet empirical information on the effect of il4 ...	2011	21501512
can lemurs (eulemur fulvus and e. macaco) use abstract representations of quantities to master the reverse-reward contingency task?	in previous studies we demonstrated that brown and black lemurs (eulemur fulvus and e. macaco) showed self-control abilities under a reverse-reward contingency. they were able to significantly select the smaller quantity of food to be rewarded with the larger one and to generalize this ability when presented with two rewards that differed in quality. in the present study, previously trained subjects had to choose between graphic representations of two different quantities of food under the rever ...	2011	21394424
testing brown lemurs (eulemur fulvus) on the reverse-reward contingency task without a modified procedure.	a common paradigm used to study inhibitory control is the reverse-reward contingency task in which the subject is presented with a choice between two different quantities of food and is rewarded with the non-chosen item. most animals have problems inhibiting their impulsive choice towards the larger quantity, and need correction procedures to master the reverse-reward task. recent studies have nonetheless shown that rhesus macaques and white crowned mangabeys were able to master the task without ...	2011	21044665
the instantaneous center of rotation of the mandible in nonhuman primates.	kinematic analyses of mandibular movement in humans demonstrate that the mandibular instantaneous center of rotation (icor) is commonly located near the level of the occlusal plane and varies in its position during a chewing sequence. few data are available regarding the location of the icor in nonhuman primates and it remains unclear how the position of the icor varies in association with mastication and/or gape behaviors. icor was quantified throughout the gape cycle in five species of nonhuma ...	2011	21622946
brown lemurs (eulemur fulvus) can master the qualitative version of the reverse-reward contingency.	behavioral flexibility that requires behavioral inhibition has important fitness consequences. one task commonly used to assess behavioral inhibition is the reverse-reward task in which the subject is rewarded by the non selected items. lemurs were tested for their ability to solve the qualitative version of the reverse-reward task with the choice between identical quantities of different food items instead of different quantities of the same food. two of four subjects mastered the task without ...	2012	23118998
inferences about the location of food in lemurs (eulemur macaco and eulemur fulvus): a comparison with apes and monkeys.	the ability of black and brown lemurs (eulemur macaco and eulemur fulvus) to make inferences about hidden food was tested using the same paradigm as in call's (j comp psycol 118:232-241, 2004) cup task experiment. when provided with either visual or auditory information about the content of two boxes (one empty, one baited), lemurs performed better in the auditory condition than in the visual one. when provided with visual or auditory information only about the empty box, one subject out of four ...	2012	22806271
normal nasal cavity and paranasal sinuses in brown lemurs eulemur fulvus: computed tomography and cross-sectional anatomy.	far less is known about the normal anatomy of the nasal cavity of eulemur fulvus; no computed tomography (ct) scan has ever been published.	2012	22671517
diurnal resting in brown lemurs in a dry deciduous forest, northwestern madagascar: implications for seasonal thermoregulation.	decreased activity has been reported in both nocturnal and diurnal primates during the prolonged dry season in western madagascar, and this has been interpreted as a reaction to the severe environment, with its food scarcity and/or thermal stress. several day-active lemurs rest more as trees defoliate, although the reason for this is unclear. to understand the mechanism underpinning the diurnal resting of lemurs in seasonal deciduous forests, i observed common brown lemurs (eulemur fulvus fulvus ...	2012	22388421
habitat shifting by the common brown lemur (eulemur fulvus fulvus): a response to food scarcity.	during periods of food scarcity, most primates display behavioral responses, such as dietary switching or adjustment of traveling and foraging efforts, within home ranges. in rare cases, several primate species leave their home ranges for other remote habitats to seek alternative resources; this migration-like behavior is termed "habitat shifting." reports of habitat shifting have concentrated on platyrrhines, but this behavior has rarely been observed among prosimians. during 1 year of observat ...	2013	23591642
brief communication: effect of size biases in the coefficient of variation on assessing intraspecific variability in the prosimian skeleton.	this study examines the effect of a measurement size bias in coefficients of variation on the evaluation of intraspecific skeletal variability in a sample of eight prosimian species (eulemur fulvus, hapalemur griseus, lemur catta, varecia variegata, galago senegalensis, otolemur crassicaudatus, nycticebus coucang, and tarsius syrichta). measurements with smaller means were expected to have higher coefficients of variation (cvs) due to the impact of instrumental precision on the ability to assess ...	2013	23900852
clinal variation in a brown lemur (eulemur spp.) hybrid zone: combining morphological, genetic and climatic data to examine stability.	studies of hybrid zones can inform our understanding of reproductive isolation and speciation. two species of brown lemur (eulemur rufifrons and e. cinereiceps) form an apparently stable hybrid zone in the andringitra region of southeastern madagascar. the aim of this study was to identify factors that contribute to this stability. we sampled animals at 11 sites along a 90-km transect through the hybrid zone and examined variation in 26 microsatellites, the d-loop region of mitochondrial dna, si ...	2013	23865455
true lemurs…true species - species delimitation using multiple data sources in the brown lemur complex.	species are the fundamental units in evolutionary biology. however, defining them as evolutionary independent lineages requires integration of several independent sources of information in order to develop robust hypotheses for taxonomic classification. here, we exemplarily propose an integrative framework for species delimitation in the "brown lemur complex" (blc) of madagascar, which consists of seven allopatric populations of the genus eulemur (primates: lemuridae), which were sampled extensi ...	2013	24159931
phylogeographic analysis of the true lemurs (genus eulemur) underlines the role of river catchments for the evolution of micro-endemism in madagascar.	due to its remarkable species diversity and micro-endemism, madagascar has recently been suggested to serve as a biogeographic model region. however, hypothesis-based tests of various diversification mechanisms that have been proposed for the evolution of the island's micro-endemic lineages are still limited. here, we test the fit of several diversification hypotheses with new data on the broadly distributed genus eulemur using coalescent-based phylogeographic analyses.	2013	24228694
habitat degradation and seasonality affect physiological stress levels of eulemur collaris in littoral forest fragments.	the littoral forest on sandy soil is among the most threatened habitats in madagascar and, as such, it represents a hot-spot within a conservation hot-spot. assessing the health of the resident lemur fauna is not only critical for the long-term viability of these populations, but also necessary for the future re-habilitation of this unique habitat. since the endangered collared brown lemur, eulemur collaris, is the largest seed disperser of the malagasy south-eastern littoral forest its survival ...	2014	25229944
fibre type composition in the lumbar perivertebral muscles of primates: implications for the evolution of orthogrady in hominoids.	the axial musculoskeletal system is important for the static and dynamic control of the body during both locomotor and non-locomotor behaviour. as a consequence, major evolutionary changes in the positional habits of a species are reflected by morpho-functional adaptations of the axial system. because of the remarkable phenotypic plasticity of muscle tissue, a close relationship exists between muscle morphology and function. one way to explore major evolutionary transitions in muscle function is ...	2014	24433382
dietary modification by common brown lemurs (eulemur fulvus) during seasonal drought conditions in western madagascar.	primates often modify dietary composition in relation to seasonal changes in food availability or climate conditions. we studied the feeding patterns of a troop of common brown lemurs (eulemur fulvus), a semi-frugivorous strepsirhine, in a dry forest in northwestern madagascar. to understand the mechanism of dietary modification, we recorded daily feeding times of diet items during 101 full-day observations over 1 year, and then conducted a linear model analysis to examine the effects of fruitin ...	2014	24217743
isolation and characterization of faecal bifidobacteria and lactobacilli isolated from dogs and primates.	although bifidobacteria and lactobacilli have been suggested beneficial for the host and are components of many probiotics and competitive exclusion mixtures, the knowledge on abundance, metabolic and probiotic characteristics in isolates from dogs and monkeys is still limited. the present study was aimed to isolate bifidobacterium and lactobacillus strains (faeces of 22 dogs and of 5 primates: cebus apella, eulemur fulvus, erythrocebus patas, macaca fascicularis, papio hamadryas) with the maldi ...	2014	24239978
transitive inference in two lemur species (eulemur macaco and eulemur fulvus).	when confronted with tasks involving reasoning instead of simple learning through trial and error, lemurs appeared to be less competent than simians. our study aims to investigate lemurs' capability for transitive inference, a form of deductive reasoning in which the subject deduces logical conclusions from preliminary information. transitive inference may have an adaptative function, especially in species living in large, complex social groups and is proposed to play a major role in rank estima ...	2015	25328141
effect of ph and anions on functional properties of hemoglobin from lemur fulvus fulvus.		2016	4833745
illegal captive lemurs in madagascar: comparing the use of online and in-person data collection methods.	although it is illegal to capture, sell, and trade lemurs, the live capture of lemurs in madagascar is ongoing and may have impacted over 28,000 lemurs between 2010 and 2013. only one study has examined this trade and did so using in-person interviews in northern madagascar. the current study sought to expand this existing dataset and examine the comparability of online surveys to more traditional on-location data collection methods. in this study, we collected data through a web-based survey re ...	2016	26927567
gastrointestinal parasites of captive and free-living lemurs and domestic carnivores in eastern madagascar.	fecal samples from captive and free-living lemurs at ivoloina zoological park (izp) and domestic carnivores from six villages surrounding izp were evaluated between july and august 2012. free-living lemurs from betampona natural reserve (bnr), a relatively pristine rainforest fragment 40 km away, were also evaluated in november 2013. all 33 dogs sampled (100%) and 16 of 22 cats sampled (72.7%) were parasitized, predominantly with nematodes (strongyles, ascarids, and spirurids) as well as cestode ...	2016	27010275
diet and effects of sanford's brown lemur (eulemur sanfordi, archbold 1932) gut-passage on the germination of plant species in amber forest, madagascar.	kaloantsimo sarah chen, jun qing li, jean rasoarahona, fousseni folega, and christophe manjaribe (2016)eulemur sanfordi belongs to a group of endemic lemur species in amber mountain national park, madagascar. the diet of e. sanfordi and the effects of gut-passage on the germination of seeds were studied to determine how the feeding activities of this lemur affect the integrity of this forest ecosystem. a specific group of e. sanfordi was observed and monitored during 396 hours from the end of th ...	2016	31966166
anatomy, histology, and ultrasonography of the normal adrenal gland in brown lemur: eulemur fulvus.	the medical care currently to brown lemurs (eulemur fulvus) is limited by a lack of knowledge of their anatomy. the aim of this study was to describe the anatomy and histology and obtain ultrasonographic measurements of normal adrenal glands in these animals.	2017	28295350
absence of evidence of rift valley fever infection in eulemur fulvus (brown lemur) in mayotte during an interepidemic period.	the potential role of eulemur fulvus (brown lemur) in the epidemiology of rift valley fever (rvf) in mayotte, during an interepidemic period, was explored. in february and march 2016, 72 animals were blood sampled and tested for rvf. no evidence of rvf genome or antibodies was found in the samples. the role of other wild mammals on the island should, however, be further investigated.	2017	28437185
stuck in fragments: population genetics of the endangered collared brown lemur eulemur collaris in the malagasy littoral forest.	the endangered collared brown lemur (eulemur collaris) is the largest primate living in the littoral forest of southeastern madagascar, a top priority habitat for biodiversity conservation on the island. because this lemur is a key seed-disperser, an evaluation of the structure and connectivity of the populations surviving in the forest fragments is urgently needed to guide conservation plans.	2017	28429848
evaluating the triplet hypothesis during rhythmic mastication in primates.	mammalian mastication involves precise jaw movements including transverse movement of the mandible during the power stroke. jaw elevation and transverse movement are driven by asymmetrical jaw elevator muscle activity, which is thought to include a phylogenetically primitive and conserved triplet motor pattern consisting of: triplet i (balancing side: superficial masseter and medial pterygoid; working side: posterior temporalis), which reaches onset, peak and offset first; and triplet ii (workin ...	2018	29133297
assessment of environmental enrichment for different primate species under low budget: a case study.	the 2011 european union zoo inquiry presented evidence that most zoos fail to achieve adequate levels of nonhuman animal welfare. appropriate environmental enrichment (ee) can play a role in the promotion of welfare. however, financial and staff constraints frequently make it challenging to implement ee on a daily basis. the aim of this study was to test how individuals of three different nonhuman primate species at the maia zoo in portugal (white-handed gibbons, hylobates lar; mona monkeys, cer ...	2018	29299937
the role of facial pattern variation for species recognition in red-fronted lemurs (eulemur rufifrons).	species recognition, i.e., the ability to distinguish conspecifics from heterospecifics, plays an essential role in reproduction. the role of facial cues for species recognition has been investigated in several non-human primate species except for lemurs. we therefore investigated the role of facial cues for species recognition in wild red-fronted lemurs (eulemur rufifrons) at kirindy forest. we presented adult red-fronted lemurs pictures of male faces from five species including red-fronted lem ...	2018	29433448
energy (im-)balance in frugivorous lemurs in southern madagascar: a preliminary study in lemur catta and eulemur rufifrons × collaris.	the reproductive cycle of several lemur species is synchronized by photoperiodic changes and it is attuned to the seasonal fluctuations in food supply. nevertheless, irregular periods of food shortage occur in madagascar, which can result in a negative energy balance and reduced fitness, especially in frugivorous species. here, we tested whether ring-tailed lemurs (lemur catta) and brown lemurs (eulemur rufifrons × collaris) use fat stores to maintain their energy balance in a gallery forest of ...	2018	30286458
lemur species-specific metapopulation responses to habitat loss and fragmentation.	determining what factors affect species occurrence is vital to the study of primate biogeography. we investigated the metapopulation dynamics of a lemur community consisting of eight species (avahi occidentalis, propithecus coquereli, microcebus murinus, microcebus ravelobensis, lepilemur edwardsi, cheirogaleus medius, eulemur mongoz, and eulemur fulvus) within fragmented tropical dry deciduous forest habitat in ankarafantsika national park, madagascar. we measured fragment size and isolation of ...	2018	29742108
occupancy strongly influences faecal microbial composition of wild lemurs.	the microbiota of the mammalian gut is a complex ecosystem, the composition of which is greatly influenced by host genetics and environmental factors. in this study, we aim to investigate the influence of occupancy (a geographical area of habitation), species, age and sex on intestinal microbiota composition of the three lemur species: eulemur fulvus, e. rubriventer and e. rufifrons. faecal samples were collected from a total of 138 wild lemurs across madagascar, and microbial composition was de ...	2018	29415151
local habitat, not phylogenetic relatedness, predicts gut microbiota better within folivorous than frugivorous lemur lineages.	both host phylogenetic placement and feeding strategy influence the structure of the gut microbiome (gmb); however, parsing their relative contributions presents a challenge. to meet this challenge, we compared gmb structure in two genera of lemurs characterized by different dietary specializations, the frugivorous brown lemurs ( eulemur spp.) and the folivorous sifakas ( propithecus spp.). these genera sympatrically occupy similar habitats (dry forests and rainforests) and diverged over similar ...	2019	31185820
pitch control and speed limitation during overground deceleration in lemurid primates.	an animal's fitness is influenced by the ability to move safely through its environment. recent models have shown that aspects of body geometry, for example, limb length and center of mass (com) position, appear to set limits for pitch control in cursorial quadrupeds. models of pitch control predict that the body shape of these and certain other primates, with short forelimbs and posteriorly positioned com, should allow them to decelerate rapidly while minimizing the risk of pitching forward. we ...	2019	30653715
context-specific response inhibition and differential impact of a learning bias in a lizard.	response inhibition (inhibiting prepotent responses) is needed for reaching a more favourable goal in situations where reacting automatically would be detrimental. inhibiting prepotent responses to resist the temptation of a stimulus in certain situations, such as a novel food item, can directly affect an animal's survival. in humans and dogs, response inhibition varies between contexts and between individuals. we used two contextually different experiments to investigate response inhibition in ...	2019	30707367
biomedical evaluation of a brown lemur (eulemur fulvus spp.) population from mbouzi islet, mayotte island.	the brown lemur population (eulemur fulvus spp.) in mbouzi islet is not native, and was introduced in 1997. since then, the population has grown. in 2012 the national council for protection of nature of mayotte requested to remove this population of lemurs from mbouzi, as they were suspected to be a threat to the protected endemic flora of the islet. the association francophone des vétérinaires de parcs zoologiques (french-speaking zoo veterinarians association, afvpz) was asked to conduct a bio ...	2019	33517635
jaw elevator muscle coordination during rhythmic mastication in primates: are triplets units of motor control?	the activity of mammal jaw elevator muscles during chewing has often been described using the concept of the triplet motor pattern, in which triplet i (balancing side superficial masseter and medial pterygoid; working side posterior temporalis) is consistently activated before triplet ii (working side superficial masseter and medial pterygoid; balancing side posterior temporalis), and each triplet of muscles is recruited and modulated as a unit. here, new measures of unison, synchrony, and coord ...	2020	31821998
abiotic factors affecting the cathemeral activity of eulemur fulvus in the dry deciduous forest of north-western madagascar.	cathemeral primates perform significant amounts of activity during the daylight and dark portions of the 24-h cycle. most brown lemurs have been reported to be cathemeral. a previous study reported that brown lemurs in ankarafantsika national park (anp) shift their activity pattern from being cathemeral in the dry season to being diurnal in the wet season. from july 2015 to march 2016, we collected data on active behaviour of brown lemurs over 46 full-day and 33 full-night observations, distribu ...	2020	32155623
life in a fragment: evolution of foraging strategies of translocated collared brown lemurs, eulemur collaris, over an 18-year period.	while the drivers of primate persistence in forest fragments have been often considered at the population level, the strategies to persist in these habitats have been little investigated at the individual or group level. considering the rapid variation of fragment characteristics over time, longitudinal data on primates living in fragmented habitats are necessary to understand the key elements for their persistence. since translocated animals have to cope with unfamiliar areas and face unknown f ...	2020	32072654
comparison of the glucocorticoid concentrations between three species of lemuridae kept in a temporary housing facility.	we compared the glucocorticoid concentrations in response to various types of potential stressors present during standard operation of a temporary housing facility between three species, namely, ring-tailed lemurs, collared brown lemurs and white-headed lemurs. the levels of faecal glucocorticoid metabolites (fgms) were measured non-invasively on a daily basis during a 30-day period. a total of 510 faecal samples were collected. concentrations of immunoreactive glucocorticoid hormone metabolites ...	2020	32532091