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beyond the gallery forest: contrasting habitat and diet in lemur catta troops at bezà mahafaly special reserve.ring-tailed lemurs have been studied intensively in the parcel 1 gallery forest of bezà mahafaly special reserve. here, we report on lemur groups in a mixture of deciduous dry forest and spiny forest just 5 km to the west. compared to parcel 1, parcel 2 (p2) has a lower density of tamarindus indica, a major dietary plant species for gallery forest lemurs. recent studies in drier habitats have called into question the association of lemur density and tamarind presence. in order to address this qu ...201526022299
seasonal feeding ecology of ring-tailed lemurs: a comparison of spiny and gallery forest habitats.although lemur catta persists in many habitat types in southern madagascar, its ecology has been primarily studied within gallery forests. we compare plant food selection and properties for ring-tailed lemurs in the spiny and gallery forests over the synchronized lactation period (september to march) that includes both the dry and wet seasons. we found no significant habitat-specific differences in the type of plant part consumed per month (i.e. flower, fruit, leaf) or between the intake of solu ...201526022298
reproductive female feeding strategies in spiny forest-dwelling lemur catta in southern and southwestern madagascar: how do females meet the challenges of reproduction in this harsh habitat?the spiny forest ecoregion of southern and southwestern madagascar is characterized by low annual rainfall, high temperatures, short-stature xeric vegetation and lack of canopy. lemur catta is often the only diurnal primate persisting in this habitat. for reproductive females living in spiny forests, gestation and early-to-mid lactation periods occur during the dry season when food resources are limited. we conducted a between-site comparison of variables important to the feeding ecology of repr ...201526022297
ring-tailed lemurs: a species re-imagined.for over 50 years, ring-tailed lemurs have been studied continuously in the wild. as one of the most long-studied primate species, the length and breadth of their study is comparable to research on japanese macaques, baboons and chimpanzees. they are also one of the most broadly observed of all primates, with comprehensive research conducted on their behaviour, biology, ecology, genetics, palaeobiology and life history. however, over the last decade, a new generation of lemur scholars, working i ...201526022295
patterns of gut bacterial colonization in three primate species.host fitness is impacted by trillions of bacteria in the gastrointestinal tract that facilitate development and are inextricably tied to life history. during development, microbial colonization primes the gut metabolism and physiology, thereby setting the stage for adult nutrition and health. however, the ecological rules governing microbial succession are poorly understood. in this study, we examined the relationship between host lineage, captive diet, and life stage and gut microbiota characte ...201525970595
systemic effects of leucaena leucocephala ingestion on ringtailed lemurs (lemur catta) at berenty reserve, madagascar.leucaena (leucaena leucocephala) is a leguminous tree that is nutritious forage for domestic livestock when ingested in limited amounts. unfortunately, leucaena contains mimosine, a plant amino acid, that can be toxic when ingested at higher concentrations. reported toxic effects include alopecia (fur loss), poor body condition, infertility, low birth weight, thyroid gland dysfunction, and organ toxicity. originally native to mexico and central america, leucaena has been introduced throughout th ...201525809223
baby on board: olfactory cues indicate pregnancy and fetal sex in a non-human primate.olfactory cues play an integral, albeit underappreciated, role in mediating vertebrate social and reproductive behaviour. these cues fluctuate with the signaller's hormonal condition, coincident with and informative about relevant aspects of its reproductive state, such as pubertal onset, change in season and, in females, timing of ovulation. although pregnancy dramatically alters a female's endocrine profiles, which can be further influenced by fetal sex, the relationship between gestation and ...201525716086
a complex sensory organ in the nose skin of the prosimian primate lemur catta.most mammals have nose tips covered by glabrous skin, a labronasal area, or rhinarium. the surface of the rhinarium of lemur catta has a dermatoglyphic pattern consisting of epidermal domes. below the domes, epidermal pegs dip down into the dermis. in and below the tip of the epidermal peg, a complex sensory organ is found. it consists of an association of innervated merkel cells, lamellate (pacini-like) bodies with a central nerve, and a ring of unmyelinated nerve endings in the epidermis. the ...201525645577
the vomeronasal organ of lemur catta.the vomeronasal organ (vno), also known as the jacobson's organ, is a bilateral chemosensory organ found at the base of the nasal cavity specialized for the detection of higher-molecular weight (non-volatile) chemostimuli. it has been linked to pheromone detection. the vno has been well studied in nocturnal lemurs and lorises, but poorly studied in diurnal/cathemeral species despite the large repertoire of olfactory behaviors noted in species such as lemur catta. here, the vno and associated str ...201525220179
male-specific use of the purr in the ring-tailed lemur (lemur catta).in mammals, purring has been described in mostly affiliative contexts. in the ring-tailed lemur (lemur catta), both males and females purr, but only males were observed purring in agonistic contexts. in order to determine whether male ring-tailed lemurs purr as aggressive displays during intrasexual agonistic encounters, 480 h of focal data were collected on 25 adult males from beza mahafaly special reserve, madagascar, from march to july 2010. the male purring rate increased during periods of m ...201425139722
thoracic limb morphology of the ring-tailed lemur (lemur catta) evidenced by gross osteology and radiography.there is limited information available on the morphology of the thoracic limb of the ring-tailed lemur (lemur catta). this study describes the morphology of the thoracic limb of captive ring-tailed lemurs evidenced by gross osteology and radiography as a guide for clinical use. radiographic findings of 12 captive ring-tailed lemurs are correlated with bone specimens of three adult animals. the clavicle is well developed. the scapula has a large area for the origin of the m. teres major. the cora ...201525105809
sources of tooth wear variation early in life among known-aged wild ring-tailed lemurs (lemur catta) at the bezà mahafaly special reserve, madagascar.ring-tailed lemurs (lemur catta) at the bezà mahafaly special reserve (bmsr), madagascar display a high frequency of individuals with notable and sometimes extreme tooth wear. adult lemurs display a range of tooth wear even among individuals of the same age, but we do not know at what age this variation first appears. this study's goal was to determine whether wear variation occurs in younger wild lemurs. based on the decade-long study of ring-tailed lemur feeding and dental ecology at bmsr, we ...201424953664
relaxed open mouth as a playful signal in wild ring-tailed lemurs.play signals are commonly used by animals to communicate their playful motivation and to limit the risk that rough acts are misunderstood by playmates. the relaxed open mouth is the most common facial expression performed during play in many mammals and represents the ritualized version of the movement anticipating a play bite. the signaling nature of this expression has been proven in many haplorrhine species but never demonstrated in strepsirrhines. our purpose was assessing whether, also in s ...201424810169
the anatomy and ontogeny of the head, neck, pectoral, and upper limb muscles of lemur catta and propithecus coquereli (primates): discussion on the parallelism between ontogeny and phylogeny and implications for evolutionary and developmental biology.most anatomical studies of primates focus on skeletal tissues, but muscular anatomy can provide valuable information about phylogeny, functional specializations, and evolution. herein, we present the first detailed description of the head, neck, pectoral, and upper limb muscles of the fetal lemuriforms lemur catta (lemuridae) and propithecus coquereli (indriidae). these two species belong to the suborder strepsirrhini, which is often presumed to possess some plesiomorphic anatomical features wit ...201424757163
individual recognition through olfactory-auditory matching in lemurs.individual recognition can be facilitated by creating representations of familiar individuals, whereby information from signals in multiple sensory modalities become linked. many vertebrate species use auditory-visual matching to recognize familiar conspecifics and heterospecifics, but we currently do not know whether representations of familiar individuals incorporate information from other modalities. ring-tailed lemurs (lemur catta) are highly visual, but also communicate via scents and vocal ...201424741013
surgical correction of an arteriovenous fistula in a ring-tailed lemur (lemur catta).a 10-y-old ovariohysterectomized ring-tailed lemur (lemur catta) was presented for exacerbation of respiratory signs. the lemur had a history of multiple examinations for various problems, including traumatic lacerations and recurrent perivulvar dermatitis. examination revealed abnormal lung sounds and a femoral arteriovenous fistula with a palpable thrill and auscultable bruit in the right inguinal area. a diagnosis of congestive heart failure was made on the basis of exam findings, radiography ...201424672831
iron deficiency anemia in a ring-tailed lemur (lemur catta) with concurrent chronic renal failure.a 16-year-old vasectomized male ring-tailed lemur (lemur catta) with a history of suspected chronic renal failure was evaluated because of extreme lethargy, hyperpnea, and abscess of the right pectoral scent gland.201424479462
radiographic thoracic anatomy of the ring-tailed lemur (lemur catta).the ring-tailed lemur (lemur catta) is a quadruped arboreal primate primarily distributed in south and south-western madagascar. this study was carried out to describe the normal radiographic thoracic anatomy of the ring-tailed lemur as a reference for clinical use.201424444331
sex ratios provide evidence for monozygotic twinning in the ring-tailed lemur, lemur catta.monozygotic (mz) twinning is generally considered to be rare in species other than human. we inspected sex ratios in european zoo-bred ring-tailed lemurs (lemur catta), revealing a significant excess of same-sex twins. of 94 pairs, 60 (64%) were either both males or both females (p = .004). application of the weinberg differential rule argues that 27% of all twins in this species are mz pairs. in this protected species, where twinning is commonplace (~50% of newborns are twins), the probable exi ...201424384029
victims of infanticide and conspecific bite wounding in a female-dominant primate: a long-term study.the aggression animals receive from conspecifics varies between individuals across their lifetime. as poignantly evidenced by infanticide, for example, aggression can have dramatic fitness consequences. nevertheless, we understand little about the sources of variation in received aggression, particularly in females. using a female-dominant species renowned for aggressivity in both sexes, we tested for potential social, demographic, and genetic patterns in the frequency with which animals were wo ...201324367560
ring-tailed lemurs (lemur catta) exploit information about what others can see but not what they can hear.studies suggest that haplorhine primates are sensitive to what others can see and hear. using two experimental designs, we tested the hypothesis that ring-tailed lemurs (n = 16) are also sensitive to the visual and auditory perception of others. in the first task, we used a go/no-go design that required lemurs to exploit only auditory information. in the second task, we used a forced-choice design where lemurs competed against a human who would prevent them from obtaining food if their approache ...201424218121
squealing rate indicates dominance rank in the male ring-tailed lemur (lemur catta).squeals are sharp and forceful short-range vocalizations used as aggressive and submissive agonistic signals by many mammalian species. the ring-tailed lemur (lemur catta), a female-dominant strepsirhine primate, has a male-specific squeal call with proposed male-male agonistic functions and male-female courtship functions that have never been empirically tested. the goal of my study is to clarify why ring-tailed lemur males squeal at other males and females by applying the handicap hypothesis t ...201323868116
osteology and radiographic anatomy of the pelvis and hind limb of healthy ring-tailed lemurs (lemur catta).in family lemuridae, anatomical variations exist. considering its conservation status (near threatened) and presence of similarities between strepsirrhines and primitive animals, it was thought to be beneficial to describe the gross osteology and radiographic anatomy of the pelvis and hind limb of ring-tailed lemurs (lemur catta) as a reference for clinical use and species identification. radiography was performed in 14 captive adult ring-tailed lemurs. the radiographic findings were correlated ...201423651234
the estimated mechanical advantage of the prosimian ankle joint musculature, and implications for locomotor adaptation.in this study we compared the power arm lengths and mechanical advantages attributed to 12 lower leg muscles across three prosimian species. the origins and insertions of the lower leg muscles in garnett's galago, the ring-tailed lemur, and the slow loris were quantified and correlated with positional behaviour. the ankle joint of the galago has a speed-oriented mechanical system, in contrast to that of the slow loris, which exhibits more power-oriented mechanics. the lemur ankle joint exhibited ...201323489408
the ranging behavior of lemur catta in the region of cap sainte-marie, madagascar.large home ranges and extreme flexibility in ranging behaviors characterize most subarid dwelling haplorhines. however, the most comparable extant strepsirhine, lemur catta, is characterized as having small home ranges with consistent boundaries. since ranging studies on this species have been limited to gallery forest habitat, the author's goal is to identify ecological factors that affect range use of l. catta in one of the most resource-limited environments of its distribution. to conduct thi ...201323180618
(un-)expected nocturnal activity in "diurnal" lemur catta supports cathemerality as one of the key adaptations of the lemurid radiation.the ability to operate during the day and at night (i.e., cathemerality) is common among mammals but has rarely been identified in primates. adaptive hypotheses assume that cathemerality represents a stable adaptation in primates, while nonadaptive hypotheses propose that it is the result of an evolutionary disequilibrium arising from human impacts on natural habitats. madagascar offers a unique opportunity to study the evolution of activity patterns as there we find a monophyletic primate radia ...201323180596
gait-specific metabolic costs and preferred speeds in ring-tailed lemurs (lemur catta), with implications for the scaling of locomotor costs.metabolic costs of resting and locomotion have been used to gain novel insights into the behavioral ecology and evolution of a wide range of primates; however, most previous studies have not considered gait-specific effects. here, metabolic costs of ring-tailed lemurs (lemur catta) walking, cantering and galloping are used to test for gait-specific effects and a potential correspondence between costs and preferred speeds. metabolic costs, including the net cost of locomotion (col) and net cost o ...201222976581
sight or scent: lemur sensory reliance in detecting food quality varies with feeding ecology.visual and olfactory cues provide important information to foragers, yet we know little about species differences in sensory reliance during food selection. in a series of experimental foraging studies, we examined the relative reliance on vision versus olfaction in three diurnal, primate species with diverse feeding ecologies, including folivorous coquerel's sifakas (propithecus coquereli), frugivorous ruffed lemurs (varecia variegata spp), and generalist ring-tailed lemurs (lemur catta). we us ...201222870229
well-differentiated hepatocellular carcinoma in a ring-tailed lemur (lemur catta).a 16-year-old male ring-tailed lemur (lemur catta) was presented with severe cachexia and an abdominal mass. the encapsulated, multilobular mass replaced the right medial lobe of the liver and compressed the adjacent gall bladder. multiple haemorrhages and necrotic foci were found within the mass. microscopically, neoplastic cells formed cords of moderately pleomorphic, polygonal cells with mild to moderate anaplasia. immunohistochemical markers used for diagnosis of hepatocellular carcinomas in ...201322819017
the impact of dental impairment on ring-tailed lemur food processing performance.during mastication, foods are reduced into particles suitable for swallowing and digestion. smaller particles possess a greater surface area per unit of volume on which digestive enzymes and bacteria may work than relatively larger particles, and are thus more readily digested. as dental morphology facilitates the breakdown of diets with specific mechanical properties, extensive dental wear and/or tooth loss may impede an individual's ability to break down and exploit foods. we present data demo ...201222610899
interpreting food processing through dietary mechanical properties: a lemur catta case study.knowledge of dietary mechanical properties can be informative about physical consequences to consumers during ingestion and mastication. in this article, we examine how tamarindus indica fruits can affect dental morphology in a population of ring-tailed lemurs (lemur catta) at beza mahafaly special reserve in southwestern madagascar. ring-tailed lemurs in tamarind dominated gallery forests exhibit extreme wear and tooth loss on their postcanine dentition that has been related to processing t. in ...201222610896
nanoindentation of lemur enamel: an ecological investigation of mechanical property variations within and between sympatric species.the common morphological metrics of size, shape, and enamel thickness of teeth are believed to reflect the functional requirements of a primate's diet. however, the mechanical and material properties of enamel also contribute to tooth function, yet are rarely studied. substantial wear and tooth loss previously documented in lemur catta at the beza mahafaly special reserve suggests that their dental morphology, structure, and possibly their enamel are not adapted for their current fallback food ( ...201222610894
what is dental ecology?teeth have long been used as indicators of primate ecology. early work focused on the links between dental morphology, diet, and behavior, with more recent years emphasizing dental wear, microstructure, development, and biogeochemistry, to understand primate ecology. our study of lemur catta at the beza mahafaly special reserve, madagascar, has revealed an unusual pattern of severe tooth wear and frequent tooth loss, primarily the result of consuming a fallback food for which these primates are ...201222610892
evidence that displacement activities facilitate behavioural transitions in ring-tailed lemurs.displacement activities are behavioural patterns defined by their apparent irrelevance to an animal's ongoing actions. despite being identified in diverse taxa, their function remains poorly understood. one hypothesis posits that displacement activities facilitate transitions between different behaviours by mediating changes in animals' motivational state. under this hypothesis, it is predicted that displacement activities will occur more frequently around changes in behaviour than at other time ...201222561968
the gaits of primates: center of mass mechanics in walking, cantering and galloping ring-tailed lemurs, lemur catta.most primates, including lemurs, have a broad range of locomotor capabilities, yet much of the time, they walk at slow speeds and amble, canter or gallop at intermediate and fast speeds. although numerous studies have investigated limb function during primate quadrupedalism, how the center of mass (com) moves is not well understood. here, we examined com energy, work and power during walking, cantering and galloping in ring-tailed lemurs, lemur catta (n=5), over a broad speed range (0.43-2.91 m ...201222539740
scratching around mating: factors affecting anxiety in wild lemur catta.scratching has been successfully used to detect anxiety, a proxy for stress, in primates, from strepsirrhines to homo sapiens. here, we investigated the fluctuation of scratching in lemur catta during the mating season. in particular we evaluated whether scratching (1) varied according to sex and rank differences, (2) increased in the period of maximum stress (around the mating days), and (3) was reduced by grooming. at berenty (south madagascar), we followed two lemur groups (23 adult/subadult ...201222278710
evaluation of modified techniques for immobilization of wild ring-tailed lemurs (lemur catta).wild ring-tailed lemurs (lemur catta) can be anesthetized with telazol via blow dart, but improved techniques are needed so that each lemur is reliably induced with a single dart. medetomidine-butorphanol (mb) is a good supplemental protocol to be administered once the lemurs are captured, but other protocols may provide longer periods of sedation and immobility. one possible way of increasing the efficacy of each dart is to increase the time it is retained in the leg. in this investigation, a " ...201122204057
nocturnal ranging by a diurnal primate: are ring-tailed lemurs (lemur catta) cathemeral?cathemerality, an activity pattern comprised of distinct periods of diurnal and nocturnal activity, is a trait found among several of the malagasy strepsirhines and one species of aotus. because occasional anecdotal reports suggest that some diurnal primates can be active at night, i investigated the possibility of nocturnal ranging behavior in the ring-tailed lemur (lemur catta) by using global positioning system (gps) collars programmed to collect data across a 24-h period. five individuals in ...201121717291
numerical rule-learning in ring-tailed lemurs (lemur catta).we investigated numerical discrimination and numerical rule-learning in ring-tailed lemurs (lemur catta). two ring-tailed lemurs were trained to respond to two visual arrays, each of which contained between one and four elements, in numerically ascending order. in experiment 1, lemurs were trained with 36 exemplars of each of the numerosities 1-4 and then showed positive transfer to trial-unique novel exemplars of the values 1-4. in experiments 2a and 2b, lemurs were tested on their ability to t ...201121713071
can zoo records help answer behavioral research questions? the case of the left-handed lemurs (lemur catta).most zoos keep comprehensive records, which potentially form a database for use in answering some research questions, such as in veterinary and population management research. they have not, however, been widely used to answer questions about animal behavior and welfare. here we try to assess the usefulness to behavioral research of two sorts of zoo records (arks, the animal records keeping system, and student dissertations held on file) to test the hypothesis that ring-tailed lemurs with a left ...201221674604
functional and evolutionary significance of the recruitment and firing patterns of the jaw adductors during chewing in verreaux's sifaka (propithecus verreauxi).jaw-muscle electromyographic (emg) patterns indicate that compared with thick-tailed galagos and ring-tailed lemurs, anthropoids recruit more relative emg from their balancing-side deep masseter, and that this muscle peaks late in the power stroke. these recruitment and firing patterns in anthropoids are thought to cause the mandibular symphysis to wishbone (lateral transverse bending), resulting in relatively high symphyseal stresses. we test the hypothesis that living strepsirrhines with robus ...201121590749
feeding behavior and nutrient intake in spiny forest-dwelling ring-tailed lemurs (lemur catta) during early gestation and early to mid-lactation periods: compensating in a harsh environment.strong resource seasonality in madagascar has led to the evolution of female feeding priority and weaning synchrony in most lemur species. for these taxa, pregnancy/early lactation periods coincide with low food availability, and weaning of infants is timed with increased resources at the onset of the rainy season. reproductive females experience high metabolic requirements, which they must accommodate, particularly when food resources are scarce. female ring-tailed lemurs (lemur catta) residing ...201121541932
structural analysis of a repetitive protein sequence motif in strepsirrhine primate amelogenin.strepsirrhines are members of a primate suborder that has a distinctive set of features associated with the development of the dentition. amelogenin (amel), the better known of the enamel matrix proteins, forms 90% of the secreted organic matrix during amelogenesis. although amel has been sequenced in numerous mammalian lineages, the only reported strepsirrhine amel sequences are those of the ring-tailed lemur and galago, which contain a set of additional proline-rich tandem repeats absent in al ...201121437261
field anesthesia of wild ring-tailed lemurs (lemur catta) using tiletamine-zolazepam, medetomidine, and butorphanol.telazol has been commonly used for field anesthesia of wild lemurs, including ring-tailed lemurs (lemur catta). telazol alone provides good induction, but doesn't cause adequate muscle relaxation and sedation for collecting consistent somatic measurements and high-quality dental impressions that are sometimes needed. variability in induction response has been seen between individuals that have received similar dosages, with young lemurs seeming to need more anesthetic than mature lemurs. this in ...201122946374
lemurs in a complex landscape: mapping species density in subtropical dry forests of southwestern madagascar using data at multiple levels.the study of southern dry forest lemurs has been largely restricted to small reserves; yet, the majority of the region's lemur populations reside outside protected areas. lemur catta and propithecus verreauxi occupy the same forests but have different dietary preferences. this study assessed l. catta and p. verreauxi population densities across a 3-km dry forest gradient (1,539 ha) in southern madagascar. the study was designed to allow lemur densities to be related to particular forest types. a ...201120954249
variation in dental wear and tooth loss among known-aged, older ring-tailed lemurs (lemur catta): a comparison between wild and captive individuals.tooth wear is generally an age-related phenomenon, often assumed to occur at similar rates within populations of primates and other mammals, and has been suggested as a correlate of reduced offspring survival among wild lemurs. few long-term wild studies have combined detailed study of primate behavior and ecology with dental analyses. here, we present data on dental wear and tooth loss in older (>10 years old) wild and captive ring-tailed lemurs (lemur catta). among older ring-tailed lemurs at ...201020872788
evaluation of male inter-troop transfer as a mating strategy among ring-tailed lemurs on st. catherines island, usa.one commonly cited function of dispersal is to increase mating opportunities. in this study, i evaluated the hypothesis that male inter-troop transfer is used as a mating strategy in ring-tailed lemurs, lemur catta, on st. catherines island (sci), ga., usa. i measured male mating success and inter-troop transfer behavior across 5 years in a population consisting of 4 lemur groups on sci. data strongly supported dispersal as a successful mating strategy of natal males, because these males did not ...201020720432
smelling wrong: hormonal contraception in lemurs alters critical female odour cues.animals, including humans, use olfaction to assess potential social and sexual partners. although hormones modulate olfactory cues, we know little about whether contraception affects semiochemical signals and, ultimately, mate choice. we examined the effects of a common contraceptive, medroxyprogesterone acetate (mpa), on the olfactory cues of female ring-tailed lemurs (lemur catta), and the behavioural response these cues generated in male conspecifics. the genital odorants of contracepted fema ...201120667870
evidence for social learning in wild lemurs (lemur catta).interest in social learning has been fueled by claims of culture in wild animals. these remain controversial because alternative explanations to social learning, such as asocial learning or ecological differences, remain difficult to refute. compared with laboratory-based research, the study of social learning in natural contexts is in its infancy. here, for the first time, we apply two new statistical methods, option-bias analysis and network-based diffusion analysis, to data from the wild, com ...201020628161
effects of food, proximity, and kinship on social behavior in ringtailed lemurs.efforts to understand the variation in primate social systems and their underlying interaction patterns have focused on both intrinsic and extrinsic factors. in the socioecological model, food distribution and abundance have been argued to be the primary influences on the social behavior of primate species. we examined the relationship of food resources and two intrinsic factors-kinship and proximity-with patterns of affiliative and agonistic relationships in two semi-free ranging ringtailed lem ...201020549762
making progress in genetic kin recognition among vertebrates.a recent study in bmc evolutionary biology has shown that genetically similar individual ring-tailed lemurs are also more similar in their scent composition, suggesting a possible mechanism of kin recognition. theoretical and experimental studies reveal challenges ahead in achieving a true systems-level understanding of this process and its outcomes.201020236486
decoding an olfactory mechanism of kin recognition and inbreeding avoidance in a primate.like other vertebrates, primates recognize their relatives, primarily to minimize inbreeding, but also to facilitate nepotism. although associative, social learning is typically credited for discrimination of familiar kin, discrimination of unfamiliar kin remains unexplained. as sex-biased dispersal in long-lived species cannot consistently prevent encounters between unfamiliar kin, inbreeding remains a threat and mechanisms to avoid it beg explanation. using a molecular approach that combined a ...200919958525
a comparison of auditory brainstem responses and behavioral estimates of hearing sensitivity in lemur catta and nycticebus coucang.primates depend on acoustic signals and cues to avoid predators, locate food, and share information. accordingly, the structure and function of acoustic stimuli have long been emphasized in studies of primate behavioral and cognitive ecology. yet, few studies have addressed how well primates hear such stimuli; indeed, the auditory thresholds of most primate species are unknown. this empirical void is due in part to the logistic and economic challenges attendant on traditional behavioral testing ...201019938053
seasonality, sociality, and reproduction: long-term stressors of ring-tailed lemurs (lemur catta).fecal glucocorticoid (fgc) concentrations are reliable, non-invasive indices of physiological stress that provide insight into an animal's energetic and social demands. to better characterize the long-term stressors in adult members of a female-dominant, seasonally breeding species - the ring-tailed lemur (lemur catta) - we first validated fecal samples against serum samples and then examined the relationship between fgc concentrations and seasonal, social, demographic, genetic, and reproductive ...201019804779
adult play fighting and potential role of tail signals in ringtailed lemurs (lemur catta).adult strepsirrhines have been completely neglected in the study of animal play. i focused on adult play fighting and the role of tail-play as a signal in ringtailed lemurs (lemur catta). tail-play is performed during play fighting, when lemurs anoint or, more rarely, wave their tails toward the playmate. during the prereproductive period, male and female lemurs engaged in play fighting with comparable frequencies, as was expected to occur in monomorphic species such as l. catta. the dyads showi ...200919236139
food procurement and tooth use in two sympatric lemur species.this study of two lemur species (lemur catta and propithecus v. verreauxi) in madagascar combines observations of food procurement and initial food placement in the mouth with comparisons to food toughness and external properties. food toughness was hypothesized to play a decisive role in determining food placement during ingestion. it was found that tougher foods are generally ingested on the postcanines for all foods eaten. however, when leaves and fruits are analyzed separately, food size and ...200312740956
social behavior and aggression among ringtailed lemurs. 200612861973
comparison of the efficacy and cardiorespiratory effects of medetomidine-based anesthetic protocols in ring-tailed lemurs (lemur catta).the relative efficacies and cardiorespiratory effects of three injectable anesthetic combinations containing medetomidine were evaluated in ring-tailed lemurs (lemur catta). in addition, the direct effects of medetomidine on heart rate and blood pressure were evaluated in lemurs anesthetized with isoflurane. for injectable anesthesia, captive adult ring-tailed lemurs were anesthetized with medetomidine and ketamine (0.04-0.06 mg/kg, i.m. and 3 mg/kg, i.m., respectively), medetomidine, butorphano ...200312885134
tooth loss, survival, and resource use in wild ring-tailed lemurs (lemur catta): implications for inferring conspecific care in fossil hominids. 200415120269
anogenital gland secretions of lemur catta and propithecus verreauxi coquereli: a preliminary chemical examination.although prosimians are greatly olfaction-oriented, little is known about the specifics of how they use scent to communicate. in this preliminary study we attempted to delineate intra- and interspecific differences among the anogenital gland secretions of two lemur species (lemur catta and propithecus verreauxi coquereli) using gas chromatography-mass spectrometry (gc-ms). the results indicate that the two species are discernible through scent. furthermore, we were able to identify reproductive ...200415195327
high-resolution x-ray computed tomography scanning of primate copulatory plugs.in this study, high-resolution computed tomography x-ray scanning was used to scan ring-tailed lemur (lemur catta) copulatory plugs. this method produced accurate measures of plug volume and surface area, but was not useful for visualizing plug internal structure. copulatory plug size was of interest because it may relate to male fertilization success. copulatory plugs form from coagulated ejaculate, and are routinely displaced in this species by the penis of a subsequent mate during copulation ...200616345065
masseter electromyography during chewing in ring-tailed lemurs (lemur catta).we examined masseter recruitment and firing patterns during chewing in four adult ring-tailed lemurs (lemur catta), using electromyography (emg). during chewing of tougher foods, the working-side superficial masseter tends to show, on average, 1.7 times more scaled emg activity than the balancing-side superficial masseter. the working-side deep masseter exhibits, on average, 2.4 times the scaled emg activity of the balancing-side deep masseter. the relatively larger activity in the working-side ...200616345068
maternal recognition of infant calls in ring-tailed lemurs. 200610828691
noninvasive telemetric gaze tracking in freely moving socially housed prosimian primates.behavioral and neurophysiological studies strongly suggest that visual orienting reflects the integration of sensory, motor, and motivational variables. relatively little is known, however, regarding the goals that govern visual orienting of animals in their natural environments. field observations suggest that most nonhuman primates orient to features of their natural environments whose salience is dictated by the visual demands of foraging, locomotion, and social interaction. this hypothesis i ...200616431130
beyond odor discrimination: demonstrating individual recognition by scent in lemur catta.the current study demonstrates, for the first time, the occurrence of olfactory individual recognition in a nonhuman primate species. the empirical demonstration of recognition systems requires 1) a set of cues produced by the sender (expression component), 2) the perception of these cues by the receiver (perception component), and 3) a functional response by the receiver (action component). on the basis of this framework, we analyzed by gas chromatography 35 brachial secretions collected from 1 ...200616547195
scent marking and contact call production in ring-tailed lemurs (lemur catta). 200610085520
influence of group size on reproductive success of female ring-tailed lemurs: distinguishing between igfc and pfc hypotheses.based on data obtained over a period of 11 years from female ring-tailed lemurs (lemur catta), we analyzed the correlation between group size and female reproductive parameters. the birth rate and mean number of surviving infants 1 year after birth per adult female generated an inverted u-shaped curve when plotted against group size (although not significant) and number of adult female members. infant mortality rate did not have a consistent correlation with group size and number of adult female ...200616645705
scent marking as resource defense by female lemur catta.because ring-tailed lemurs (lemur catta) are a female-dominant, female-philopatric species in which the females provide the majority of parental care and troop defense, resource defense is a possible function of female lemur scent marking. to test this hypothesis, i conducted three studies. first, i presented captive, individually housed females with a series of samples of female scent, each from a different female, to determine whether they would respond to those samples and discriminate betwee ...200616715509
analysis of lateralized components of feeding behavior in the ring-tailed lemur (lemur catta).twenty-one ring-tailed lemurs (lemur catta) were videotaped during feeding. they had previously been classified as left-, right- or ambipreferent on the basis of the hand used to reach for food. the feeding sequences provided duration-based measures of manipulation, hand and mouth lateralization, and posture during feeding sequences with 2 types of food. hand preference for reaching and holding was stable over time and across measurement conditions. as a group, the lemurs grasped fruit bimanuall ...19957705057
the vocal repertoire of the ringtailed lemur (lemur catta).the vocal repertoire of the ringtailed lemur (lemur catta) is described quantitatively and spectrographically. structure, usage and inferred function of the vocalizations of adults and immatures are examined and discussed. the size, acoustic variability and development of the ringtailed lemur's vocal repertoire are compared to prior assessments for this species as well as for other primates. with up to 22 different adult call types, the ringtailed lemur has a moderately large vocal repertoire fo ...19937959437
high faecal glucocorticoid levels predict mortality in ring-tailed lemurs (lemur catta).glucocorticoid levels are commonly used as measures of stress in wild animal populations, but their relevance to individual fitness in a wild population has not been demonstrated. in this study i followed 93 ring-tailed lemurs (lemur catta) at berenty reserve in madagascar, collecting 1089 faecal samples from individually recognized animals, and recording their survival over a 2 year period. i evaluated faecal glucocorticoid levels as predictors of individual survival to the end of the study. an ...200517148128
female dominance and feeding priority in a prosimian primate: experimental manipulation of feeding competition.female dominance and feeding priority are considered unique behavioral strategies in many malagasy lemuriformes, particularly lemur catta. two hypotheses have been introduced to explain these behavior patterns: 1) females are agonistically dominant over males to mitigate female-male food competition so that females can compensate for high energy demands and inefficient reproductive physiology, and 2) males defer to females when feeding as a reproductive strategy. we tested these hypotheses by co ...200717154374
olfactory demarcation of territorial but not home range boundaries by lemur catta.over 350 h of observations were collected using focal animal sampling of scent-marking behavior by 2 troops of ring-tailed lemurs (lemur catta) in the field in madagascar. although they did not mark any branch species preferentially, they did have preferred marking sites. significantly more scent marks were deposited in the area of home range overlap between troops than in the area of exclusive use. however, few marks were deposited at the periphery of the area of overlap. instead, the majority ...19883240911
coccidioidomycosis in a ring-tailed lemur. 19863505988
inter-troop transfer of lemur catta males at berenty, madagascar.lemur catta male exchange occurred throughout the reserve at berenty and affected change in the composition of most, if not all, of the twelve troops in the reserve. males migrate into troops with which they are already familiar. inter-troop encounters may serve to increase a male's knowledge of a potential new home. extensive overlap in home ranges may facilitate this process. an important result of migration in l. catta is the avoidance of inbreeding in a species whose females form stable grou ...19836862323
a mixed epithelial and stromal tumor of the kidney in a ringtail lemur (lemur catta).primary renal tumors are rare neoplasms in nonhuman primates. this report describes a mixed epithelial and stromal tumor of the kidney (mestk) in a 14.5-year-old female ringtail lemur. the well-demarcated, solid, and cystic mass was located in the pelvis of the left kidney and consisted histologically of both epithelial and mesenchymal components. the mesenchymal cells were arranged in fascicles around cysts lined by a well-differentiated epithelium. neither the mesenchymal nor the epithelial pa ...200717317808
density of muscle spindles in prosimian shoulder muscles reflects locomotor adaptation.we examined the correlation between the density of muscle spindles in shoulder muscles and the locomotor mode in three species of prosimian primates: the slow loris (nycticebus coucang), garnett's galago (otolemur garnettii), and the ring-tailed lemur (lemur catta). the shoulder muscles (supraspinatus, infraspinatus, teres major, teres minor, and subscapularis) were embedded in celloidin and cut into transverse serial thin sections (40 microm); then, every tenth section was stained using the aza ...200617361082
variation in fecal testosterone levels, inter-male aggression, dominance rank and age during mating and post-mating periods in wild adult male ring-tailed lemurs (lemur catta).in primate species exhibiting seasonal reproduction, patterns of testosterone excretion in adult males are variable: in some species, peaks correlate with female receptivity periods and heightened male-male aggression over access to estrous females, in others, neither heightened aggression nor marked elevations in testosterone have been noted. in this study, we examined mean fecal testosterone ( f t) levels and intermale aggression in wild adult male ring-tailed lemurs residing in three groups a ...200717427976
induction of estrus in intact lemur catta under photoinhibition of ovarian cycles. 1977408831
diurnal variations of plasma testosterone in two prosimian primates (galago crassicaudatus crassicaudatus and lemur catta). 1976823984
composition of lemur milk.the average composition of 8 samples of milk from lemur catta, l. fulvus, l. macaco and a hybrid lemur was (in g/100 mt): lipids, 2.3; protein, 2.7; lactose, 6.4; and ash, 0.35. the fatty acids and major minerals were also quantified. the results did not support classification of l. fulvus and l. macao within the same species.1976827483
olfactory and visual cues in social interactions of lemur catta.the relationship between visual and olfactory cues and their relative importance in interactions between pairs of adult male ring-tailed lemurs was determined. visual and olfactory contact was controlled. when visualcontact was prevented. little behavior occurred. when visual contact was permitted, olfactory cues altered behavior.1976821832
hydatid disease in four nonhuman primates.hydatid disease was detected in 4 nonhuman primates (galago crassicaudatus, lemur catta, and 2 macaca mulatta) at the oregon regional primate research center. involvement extended from 2 1/2 to 7 1/2 years. a 6-cm cyst was surgically removed from the thoracic cavity of 1 macaque; 6 years later multiple cysts were found in its abdominal cavity. lesions found in the primates at necropsy included compression or displacement of the lungs, hydroureter and hydronephrosis, and distension of the abdomen ...1975809387
primate breeding season: photoperiodic regulation in captive lemur catta.under natural light in portland, oreg., captive ring-tailed lemurs (lemur catta) experience a breeding season that differs by nearly half a year from the season in madagascar. a series of experimental day length changes from 1971 to 1974 demonstrated the ability of both temperate and tropical photoperiod cycles to induce estrous cycles in quiescent animals. after photoperiodic activation, most impregnated females failed to resume estrous cycles even after infant separations unless they received ...1975809326
[cytogenetic study of lemur catta]. 19704990837
[the role of testosterone in the determinism of the brachial and antebrachial glands of the lemur catta]. 19684238211
[some studies on the behavior of lemur catta]. 19674386897
fine structure of the sweat glands of the antebrachial organ of lemur catta. 19665986740
the skin of primates. x. the skin of the ring-tailed lemur (lemur catta). 196214475446
a sarcoma of bone in a ring-tailed lemur (lemur catta). 195114874165
intraspecific variation in hair delta(13)c and delta(15)n values of ring-tailed lemurs (lemur catta) with known individual histories, behavior, and feeding ecology.stable carbon and nitrogen isotope compositions were analyzed from hair samples of 30 sympatric ring-tailed lemurs (lemur catta) inhabiting the beza mahafaly special reserve, madagascar. all lemurs were known individuals involved in a longitudinal study, which allowed us to explore the degree to which group membership, sex, health status, and migration influenced their stable isotope compositions. the differences in delta(13)c and delta(15)n values between groups were small (<1.5 per thousand) b ...200717455284
chemical composition of scent marks in the ringtailed lemur (lemur catta): glandular differences, seasonal variation, and individual signatures.the apocrine and sebaceous scent glands of ringtailed lemurs (lemur catta) appear to serve different social functions. in behavioral experiments, lemurs modulate their responses to scent marks based on the type of odorant, their own physiological state, the signaler's physiological state, and prior social experience. to examine variation in odorant chemistry relative to olfactory behavior, we used gas chromatography and mass spectrometry to analyze over 86 samples of glandular secretion collecte ...200717488747
females do it better. individual recognition experiments reveal sexual dimorphism in lemur catta (linnaeus 1758) olfactory motivation and territorial defence.in this paper, we aim at demonstrating individual recognition of female genital marking in lemur catta. by gas chromatography and behavioural trials we verified the occurrence of the three components of recognition systems. we showed that each female has a unique chemical signature (expression component), and males and females perceive female individuality (perception component). to verify the presence of the action component (the last component of recognition systems), we designed a bioassay ba ...200717644684
prevention of urethral blockage following semen collection in two species of lemur, varecia variegata variegata and lemur catta.lemurs are a diverse group of primates comprised of five families, all of which are found only on madagascar and the comoro islands. of the 60 known species, 17 are endangered and 5 of these are considered critically endangered. the effects of inbreeding on population health and viability have been well described; though negative inbreeding effects can be ameliorated through the introduction of new genetic material. introduction of new individuals into a population can be extremely challenging b ...200717679512
the relationship between female rank and reproductive parameters of the ringtailed lemur: a preliminary analysis.we used data from a 13-year field study of wild ringtailed lemurs to analyze the relationship between female rank and reproductive parameters. in medium and small groups there were no significant differences in birth rate, infant mortality rate, and the number of surviving infants between the female rank categories. on the other hand, in large sized groups low-ranked females had a smaller number of surviving infants than middle-ranked females. this suggests that in large sized groups, within-gro ...200818157684
scent and the single male: ring-tailed lemurs produce honest signals.in mating systems that involve competing males and choosy females, males are expected to advertise their genetic quality to discriminating females. most examples have focused on visual or acoustic signals, such as ornamentation or song; yet arguably, olfactory communication may be more important to the majority of vertebrates with the possible exception of birds. fortunately, attention has begun to shift to the role of odours in mate choice, with most of that attention being directed at the majo ...200818564085
male aggression during mating: evidence for sexual coercion in a female dominant primate?in this article we document male sexual coercion of a lemur catta female on st. catherines island (sci), usa. data presented in this paper were collected on one free-ranging l. catta group during october-november 2002 using all-occurrences sampling for agonism and reproductive behavior. we observed a male forcefully attempting to mate with a year-old estrous female. despite the fact that we observed this female to present to the male during her estrus, throughout the episode the male employed th ...200818702079
the asymmetric scent: ringtailed lemurs (lemur catta) have distinct chemical signatures in left and right brachial glands. 200827518532
a scoring system for coat and tail condition in ringtailed lemurs, lemur catta.coat condition can be influenced by a wide variety of disorders and thus provides a useful tool for noninvasive health and welfare assessments in wild and captive animals. using lemur catta as an exemplar, we offer a 6-step scoring system for coat and tail condition, ranging from perfectly fluffy to half or more of body and tail being hairless. the categories are described in detail and illustrated with sample pictures from a wild population in berenty reserve, madagascar. furthermore, we elabor ...200919142988
female dominance status and fecal corticoids in a cooperative breeder with low reproductive skew: ring-tailed lemurs (lemur catta).many studies have shown that low dominance status within a social group is associated with elevated glucocorticoid hormone production, a common index of physiological stress. however, the reverse may be true among cooperatively breeding female mammals with high reproductive skew; that is, high dominance status is associated with elevated glucocorticoid levels. elevated glucocorticoid levels in these dominant females may be a product of their being the only breeder within a group or may result fr ...200312614647
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