Publications
| Title | Abstract | Year(sorted descending) Filter | PMID Filter |
|---|
| somatic variation in living, wild ring-tailed lemurs (lemur catta). | while understanding somatic variability among wild primates can provide insight into natural patterns of developmental plasticity, published data for living populations are rare. here we provide such information for two distinct wild populations of lemur catta. variants observed include microtia, athelia, and female virilization. dental variants observed include individuals with supernumerary teeth, rotated teeth, maxillary incisor agenesis, and severe malocclusion. there was a sex bias in incis ... | 2008 | 17878733 |
| new hand bones of hadropithecus stenognathus: implications for the paleobiology of the archaeolemuridae. | a partial, associated skeleton of hadropithecus stenognathus (aha-i) was discovered in 2003 at andrahomana cave in southeastern madagascar. among the postcranial elements found were the first hand bones (right scaphoid, right hamate, left first metacarpal, and right and left fifth metacarpals) attributed to this rare subfossil lemur. these hand bones were compared to those of extant strepsirrhines and catarrhines in order to infer the positional adaptations of hadropithecus, and they were compar ... | 2008 | 18068213 |
| a comparison of salivary ph in sympatric wild lemurs (lemur catta and propithecus verreauxi) at beza mahafaly special reserve, madagascar. | chemical deterioration of teeth is common among modern humans, and has been suggested for some extinct primates. dental erosion caused by acidic foods may also obscure microwear signals of mechanical food properties. ring-tailed lemurs at the beza mahafaly special reserve (bmsr), madagascar, display frequent severe tooth wear and subsequent tooth loss. in contrast, sympatric verreaux's sifaka display far less tooth wear and infrequent tooth loss, despite both species regularly consuming acidic t ... | 2008 | 18157845 |
| using extant patterns of dental variation to identify species in the primate fossil record: a case study of middle eocene omomys from the bridger basin, southwestern wyoming. | patterns of extant primate dental variation provide important data for interpreting taxonomic boundaries in fossil forms. here i use dental data from several well-known living primates (as well as data from selected eocene forms) to evaluate dental variation in middle eocene omomys, the first north american fossil primate identified by paleontologists. measurements were collected from a sample of 148 omomyid dental specimens recovered from bridger b localities in the bridger basin, wyoming. most ... | 2008 | 18246298 |
| dispersal among male ring-tailed lemurs (lemur catta) on st. catherines island. | male dispersal patterns were analyzed across a nine-year period in a population of ring-tailed lemurs (lemur catta) on st. catherines island (sci), usa, to evaluate two ultimate explanations for male dispersal: inbreeding avoidance and intrasexual mating competition. as part of this analysis, we also compared patterns of dispersal at this site with data from wild populations. overall, we found that patterns of male intertroop movement on sci are similar to the wild with respect to the frequency ... | 2008 | 18478578 |
| the asymmetric scent: ringtailed lemurs (lemur catta) have distinct chemical signatures in left and right brachial glands. | distinctive cues are predicted to evolve when the benefits obtained by the recognition process overcome its costs. when individual recognition is particularly beneficial for both senders and receivers, the expression of strongly distinctive signals is predicted to evolve. on the other hand, it could be predicted that each individual should show a very stable individual signature. in the same perspective, a great stability of the individual signatures could be expected. lemur catta is the first n ... | 2008 | 18542901 |
| seroepidemiology of toxoplasma gondii in zoo animals in selected zoos in the midwestern united states. | toxoplasma gondii infections in zoo animals are of interest because many captive animals die of clinical toxoplasmosis and because of the potential risk of exposure of children and elderly to t. gondii oocysts excreted by cats in the zoos. seroprevalence of t. gondii antibodies in wild zoo felids, highly susceptible zoo species, and feral cats from 8 zoos of the midwestern united states was determined by using the modified agglutination test (mat). a titer of 1:25 was considered indicative of t. ... | 2008 | 18605803 |
| the asymmetric scent: ringtailed lemurs (lemur catta) have distinct chemical signatures in left and right brachial glands. | 2008 | 27518532 | |
| 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 ... | 2008 | 18702079 |
| 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 ... | 2008 | 18564085 |
| 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 ... | 2008 | 18157684 |
| 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 ... | 2007 | 17679512 |
| 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 ... | 2007 | 17644684 |
| 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 ... | 2007 | 17488747 |
| 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 ... | 2007 | 17455284 |
| 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 ... | 2007 | 17427976 |
| 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 ... | 2007 | 17317808 |
| 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 ... | 2007 | 17154374 |
| a comparative analysis of serial ordering in ring-tailed lemurs (lemur catta). | research over the last 25 years has demonstrated that animals are able to organize sequences in memory and retrieve ordered sequences without language. qualitative differences have been found between the serial organization of behavior in pigeons and monkeys. here the authors test serial ordering abilities in ring-tailed lemurs, a strepsirrhine primate whose ancestral lineage diverged from that of monkeys, apes, and humans approximately 63 million years ago. lemurs' accuracy and response times w ... | 2007 | 18085919 |
| seroprevalence of toxoplasma gondii, sarcocystis neurona, and encephalitozoon cuniculi in three species of lemurs from st. catherines island, ga, usa. | in the current study, we determined the seroprevalence of toxoplasma gondii, sarcocystis neurona, and encephalitozoon cuniculi in three species of lemurs from st. catherines island, georgia. serum samples were tested from 52 ring-tailed lemurs (lemur catta), six blue-eyed black lemurs (eulemur macaco flavifrons), and four black and white ruffed lemurs (varecia variegata variegata) using an agglutination assay. three ring-tailed lemurs (5.8%) were positive for t. gondii (titer of 1:50); one ring- ... | 2007 | 17052854 |
| lateral bias to the leading limb in an olfactory social signal by male ring-tailed lemurs. | because ring-tailed lemurs (lemur catta) show handedness during feeding, i investigated whether they also show lateral preference in the limbs used by males during scent marking. during a bout of marking, a male alternates a variable number of shoulder rubs and arm marks. it is a complex social signal that has both olfactory and visual components and is frequently part of intrasexual agonistic interactions. i used all-occurrences behavior sampling, manually recorded all totally visible bouts, an ... | 2007 | 17245755 |
| coprophagy by wild ring-tailed lemurs (lemur catta) in human-disturbed locations adjacent to the beza mahafaly special reserve, madagascar. | coprophagy occurs in a number of animal species, including nonhuman primates. during the 2003-2004 dry seasons at the beza mahafaly special reserve, madagascar, we observed wild ring-tailed lemurs (lemur catta) consuming dried fecal matter from three different species. ring-tailed lemurs consumed human feces on 12 occasions, cattle feces twice, and feral dog feces once. coprophagy in this population may be a behavioral adaptation that provides animals access to energy and nutrients and may be an ... | 2007 | 17253614 |
| 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 |
| assessing flavivirus, lentivirus, and herpesvirus exposure in free-ranging ring-tailed lemurs in southwestern madagascar. | the ring-tailed lemur (lemur catta) is an endangered species found in southwestern madagascar, and understanding infectious disease susceptibility is an essential step towards the preservation of wild and captive lemur populations. lemurs are primates that are widely dispersed throughout the island of madagascar and may serve as hosts or reservoirs for zoonotic infections. the aim of this study was to determine the prevalence of antibodies to west nile virus (wnv), simian immunodeficiency virus ... | 2007 | 17347392 |
| trypanosoma cruzi prevalence and epidemiologic trends in lemurs on st. catherines island, georgia. | lemurs on st. catherines island, georgia were tested for trypanosoma cruzi infection to develop a better understanding of the epizootiology of the parasite in nonhuman primates in the southeastern united states. fifty-six ring-tailed (lemur catta), blue-eyed black (eulemur macaco flavifrons), and black-and-white ruffed (varecia variegata variegata) lemurs were tested by hemoculture and serology to determine the prevalence of t. cruzi in the population. of those tested 3 (5%) were identified as c ... | 2007 | 17436947 |
| biomedical evaluation of free-ranging ring-tailed lemurs (lemur catta) in three habitats at the beza mahafaly special reserve, madagascar. | complete physical examinations and biomedical sample collection were performed on 70 free-ranging ring-tailed lemurs (lemur catta) from three different habitats in the beza mahfaly special reserve (bmsr), in southern madagascar, to assess the impact of humans and habitat on lemur health. lemurs were chemically immobilized with ketamine and diazepam administered via blow darts for concurrent biomedical, morphometric, and behavioral studies. subsets of the animals had blood analyzed for hematology ... | 2007 | 17679503 |
| female dominance in lemur catta: more than just female feeding priority? | 2007 | 2227726 | |
| [blastocystis from primates]. | a new species, blastocystis lemuri sp. n., was found in the lemur catta. size of blastocysts in a culture is 10.25-35.25 mkm, the number of nuclei varies from 1 to 2. the optimum temperature for cultivation is +39 degrees. | 2007 | 9479381 |
| sex and seasonal differences in aggression and steroid secretion in lemur catta: are socially dominant females hormonally 'masculinized'? | female social dominance characterizes many strepsirrhine primates endemic to madagascar, but currently there is no comprehensive explanation for how or why female lemurs routinely dominate males. reconstructing the evolutionary pressures that may have shaped female dominance depends on better understanding the mechanism of inheritance, variation in trait expression, and correlating variables. indeed, relative to males, many female lemurs also display delayed puberty, size monomorphism, and 'masc ... | 2007 | 17382329 |
| retrospective evaluation of the incidence and severity of hemosiderosis in a large captive lemur population. | significant concern has been generated about the susceptibility of captive lemurs to iron storage disease, which has led some researchers to propose husbandry changes regarding dietary iron. in the current study we sought to determine the history, severity, and prevalence of iron storage disease within a large captive lemur population. iron concentration and hemosiderin accumulation in a target organ, the liver, were assessed in necropsy specimens from 15 different species (n=153) of lemurs over ... | 2006 | 16534809 |
| anatomy of the hand and arm in daubentonia madagascariensis : a functional and phylogenetic outlook. | the aye-aye (daubentonia madagascariensis) is easily the most enigmatic of living primates. it sports a unique combination of derived characters, including continuously growing incisors, functional claws, the largest hand of any primate and a highly modified middle finger. the specialised middle finger is no longer used in locomotion and serves as a probe-like instrument for investigating, locating and extracting xylophagous (wood-boring) larvae as well as other food items. its phalanges can be ... | 2006 | 16230860 |
| effects of three food enrichment items on the behavior of black lemurs (eulemur macaco macaco) and ringtail lemurs (lemur catta) at the henson robinson zoo, springfield, illinois. | this study tested 3 food enrichment items mentioned in a laboratory primate newsletter with 6 adult eulemur macaco and 3 adult lemur catta to examine whether the items would affect the behavior of the lemurs. the results suggest that food enrichment item 3 (a wire box filled with whole grapes, apples, or both hidden in straw hung from a branch within the enclosure) caused a significant decrease in the incidence of resting and a significant increase in the incidences of playing and grooming, with ... | 2006 | 16956316 |
| the evolution of cathemerality in primates and other mammals: a comparative and chronoecological approach. | non-primate mammalian activity cycles are highly variable across and within taxonomic groups. in contrast, the order primates has historically been recognized as displaying a diurnal-nocturnal dichotomy that mapped, for the most part, onto the taxonomic division between haplorhines and strepsirhines. however, it has become clear over the past two decades that activity cycles in primates are not quite so clear cut. some primate species--like many large herbivorous mammals, mustelids, microtine ro ... | 2006 | 16415585 |
| troop fission in wild ring-tailed lemurs (lemur catta) at berenty, madagascar. | a detailed fission process in a wild ring-tailed lemur (lemur catta) troop was observed at berenty reserve, madagascar. the troop fission occurred as follows: 1) during the birth season in 2000, two adult females (mother and daughter) were evicted as a result of "targeted aggression" (i.e., intense and persistent aggressive behavior toward particular individuals). 2) two adult and three immature females in the same kin group as the evicted females spontaneously immigrated into the new group. 3) ... | 2006 | 16419123 |
| cutting corners: the dynamics of turning behaviors in two primate species. | in an attempt to characterize more fully the variation in substrate reaction forces in the locomotor repertoire of primates, we recorded the forces involved in directional changes for two species. these are the first records of turning forces for vertebrate quadrupeds, much less primates. three ring-tailed lemurs and two patas monkeys performed turns of approximately 30 degrees as they crossed a force platform. the ring-tailed lemurs also turned on a horizontal branch-like support with a segment ... | 2006 | 16481581 |
| ancient positive selection on cd155 as a possible cause for susceptibility to poliovirus infection in simians. | poliovirus is the etiological agent of poliomyelitis. from the observations that only simians are susceptible to poliovirus infection and that 37 amino acid sites (the poliovirus-binding associated [pba] sites) in the domain d1 of cd155 are involved in the binding to poliovirus, it is considered that the susceptibility to poliovirus infection evolved through amino acid substitutions that occurred at the pba sites on the ancestral branch of simians. here it is shown that positive selection has op ... | 2006 | 16500041 |
| the value of small size: loss of forest patches and ecological thresholds in southern madagascar. | many services generated by forest ecosystems provide essential support for human well-being. however, the vulnerability of these services to environmental change such as forest fragmentation are still poorly understood. we present spatial modeling of the generation of ecosystem services in a human-dominated landscape where forest habitat patches, protected by local taboos, are located in a matrix of cultivated land in southern madagascar. two ecosystem services dependent on the forest habitats w ... | 2006 | 16711035 |
| olfactory signals and the mhc: a review and a case study in lemur catta. | the major histocompatibility complex (mhc) is the most polymorphic genetic system known in vertebrates. decades of research demonstrate that it plays a critical role in immune response and disease resistance. it has also been suggested that mhc genes influence social behavior and reproductive phenomena. studies in laboratory mice and rats report that kin recognition and mate choice are influenced by olfactory cues determined at least in part by an individual's mhc genes. this issue has stimulate ... | 2006 | 16715507 |
| evolution of an intronic microsatellite polymorphism in toll-like receptor 2 among primates. | nonhuman primates express varying responses to mycobacterium tuberculosis: new world monkeys appear to be resistant to tuberculosis (tb) while old world monkeys seem to be particularly susceptible. the aim of this study was to elucidate the presence of the regulatory guanine-thymine (gt) repeat polymorphisms in intron 2 of toll-like receptor 2 (tlr2) associated with the development of tb in humans and to determine any variations in these microsatellite polymorphisms in primates. we sequenced the ... | 2006 | 16912902 |
| severe wear and tooth loss in wild ring-tailed lemurs (lemur catta): a function of feeding ecology, dental structure, and individual life history. | the ring-tailed lemurs at beza mahafaly special reserve, madagascar, exhibit a high frequency of severe wear and antemortem tooth loss. as part of a long-term study, we collected dental data on 83 living adult ring-tailed lemurs during 2003 and 2004. among these individuals, 192 teeth were scored as absent. the most frequently missing tooth position is m1 (24%). as m1 is the first tooth to erupt, its high frequency of absence (primarily a result of wear) is not remarkable. however, the remaining ... | 2006 | 16962643 |
| 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 ... | 2006 | 16715509 |
| 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 ... | 2006 | 16645705 |
| 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 ... | 2006 | 16547195 |
| 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 ... | 2006 | 16431130 |
| 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 ... | 2006 | 16345068 |
| 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 ... | 2006 | 16345065 |
| 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 ... | 2006 | 17361082 |
| scent marking and contact call production in ring-tailed lemurs (lemur catta). | 2006 | 10085520 | |
| social behavior and aggression among ringtailed lemurs. | 2006 | 12861973 | |
| individual distinctiveness of the contact calls of ring-tailed lemurs. | 2006 | 12207060 | |
| maternal recognition of infant calls in ring-tailed lemurs. | 2006 | 10828691 | |
| 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 ... | 2005 | 17148128 |
| temporalis function in anthropoids and strepsirrhines: an emg study. | the major purpose of this study is to analyze anterior and posterior temporalis muscle force recruitment and firing patterns in various anthropoid and strepsirrhine primates. there are two specific goals for this project. first, we test the hypothesis that in addition to transversely directed muscle force, the evolution of symphyseal fusion in primates may also be linked to vertically directed balancing-side muscle force during chewing (hylander et al. [2000] am. j. phys. anthropol. 112:469-492) ... | 2005 | 15714512 |
| 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 |
| does female dominance facilitate feeding priority in black-and-white ruffed lemurs (varecia variegata) in southeastern madagascar? | although many malagasy lemurs are thought to be female dominant and to have female feeding priority, to date the relationship between these behaviors has been rigorously established only in lemur catta, and other ways that females might achieve feeding priority have not been examined closely. erhart and overdorff [international journal of primatology 20:927-940, 1999] suggested that one way female primates achieve feeding priority is to initiate and lead groups to food, thereby gaining access to ... | 2005 | 15898069 |
| long-term changes in dominance ranks among ring-tailed lemurs at berenty reserve, madagascar. | a study was conducted between 1989 and 2001 to monitor changes in the dominance ranks among adult ring-tailed lemurs (lemur catta) at berenty reserve, madagascar. adult females were observed to be dominant over adult males. their rank fluctuated greatly. however, in some troops, female rank orders were fairly stable over a period of several years. in general, male ranks were more unstable than female ranks. most young females aged 3 years occupied the lowest ranks among adult females. however, s ... | 2005 | 16142423 |
| effects of reproductive and social variables on fecal glucocorticoid levels in a sample of adult male ring-tailed lemurs (lemur catta) at the beza mahafaly reserve, madagascar. | glucocorticoids, a group of adrenal hormones, are secreted in response to stress. in male primates, variables such as breeding seasonality, dominance hierarchy stability, and aggressive and affiliative interactions can affect glucocorticoid levels. in this study, we examined interindividual differences in mean fecal glucocorticoid (fgc) levels among males in three groups of wild ring-tailed lemurs to better understand the physiological costs of group living for males in a female-dominant species ... | 2005 | 16163722 |
| attacks on a wild infant ring-tailed lemur (lemur catta) by immigrant males at berenty, madagascar: interpreting infanticide by males. | an orphaned infant ring-tailed lemur (lemur catta) was attacked persistently by immigrant males and disappeared with severe wounds at berenty reserve, madagascar. prior to the attacks, two troop members disappeared. on 20 november 1998, the only resident male in troop c2b disappeared suddenly. after the disappearance, nine males from three neighboring troops approached, but only six males continued to shadow the troop. of the females, the one lactating female attacked the males the most frequent ... | 2005 | 16229008 |
| 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 |
| 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 |
| disseminated toxoplasmosis in a captive ring-tailed lemur (lemur catta). | a 3-yr-old secundiparous female ring-tailed lemur presented to the auburn university small animal clinic with signs of dyspnea, lethargy, and anorexia. the animal died before she could be examined, and a full necropsy was immediately performed. provisional necropsy findings included moderate pneumonia and hepatopathy. acute interstitial pneumonia and focal hepatocellular necrosis were confirmed histologically. lung impression smears, histopathology, electron microscopy, immunohistochemistry, and ... | 2004 | 15357101 |
| molecular and serologic evidence of tick-borne ehrlichiae in three species of lemurs from st. catherines island, georgia, usa. | in recent years, several species of ehrlichiae have been recognized as tick-borne disease agents of veterinary and medical importance. clinically normal free-ranging or previously free-ranging lemurs, including 46 ring-tailed lemurs (lemur catta), six blue-eyed black lemurs (eulemur macaco flavifrons), and four black and white ruffed lemurs (varecia variegata variegata) from st. catherines island, georgia, were tested for evidence of exposure to tick-borne ehrlichiae. all 52 adult lemurs were se ... | 2004 | 15732591 |
| 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 ... | 2004 | 15195327 |
| tooth loss, survival, and resource use in wild ring-tailed lemurs (lemur catta): implications for inferring conspecific care in fossil hominids. | 2004 | 15120269 | |
| 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 ... | 2003 | 12885134 |
| host range of poliovirus is restricted to simians because of a rapid sequence change of the poliovirus receptor gene during evolution. | the host range of most poliovirus (pv) strains is restricted to simians. this host range specificity is believed to be determined by the interaction between pv and its receptor molecule. to elucidate the molecular basis of this species-specific infection of pv, we cloned orthologs of the pv receptor (pvr) gene ( pvr) as well as those of pv receptor-related genes 1 and 2 ( prr1 and prr2) from various mammalian species. these three genes are widely present in mammalian genomes including those of n ... | 2003 | 12536294 |
| demographic and life-history patterns in a population of ring-tailed lemurs (lemur catta) at beza mahafaly reserve, madagascar: a 15-year perspective. | over 15 field seasons (1987-2001), we collected census and life-history data on a population of individually identified ring-tailed lemurs at the beza mahafaly reserve, madagascar. no significant difference was found in population size over the study period, though a marked decline in the population occurred following a 2-year drought. the population rebounded rapidly after the immediate postdrought period. there was nearly a complete replacement of individuals over the study period. average gro ... | 2003 | 12541335 |
| seasonal variation in the testicular volume of capuchin monkeys (cebus apella) in captivity. | the study of the reproductive strategy developed by different species in order to adapt to their environmental conditions and their meaning in an evolutionary perspective is essential for understanding the mechanisms involved in the process of reproduction. non-human primates are very interesting models for this purpose. some species show a typical seasonal reproductive pattern, such as rhesus macaques (macaca mulatta) [sade, 1964; conaway and sade, 1965] and ring-tailed lemurs (lemur catta) [zu ... | 2003 | 12606852 |
| biomedical evaluation of free-ranging ring-tailed lemurs (lemur catta) in tsimanampetsotsa strict nature reserve, madagascar. | complete health assessments were performed on 20 adult ring-tailed lemurs (lemur catta), 10 males and 10 females, free ranging within the tsimanampetsotsa strict nature reserve in southwest madagascar. each animal was anesthetized using tiletamine and zolazepam, weighed, and given a thorough physical examination. blood was collected for hematology, determination of plasma total protein concentration, serum chemistry, determination of fat-soluble vitamin and trace mineral concentrations, assessme ... | 2003 | 12723796 |
| diurnality and cone photopigment polymorphism in strepsirrhines: examination of linkage in lemur catta. | trichromatic color vision is routine among catarrhine primates, but occurs only as a variant form of color vision in some individuals in most platyrrhine genera. this arises from a fundamental difference in the organization of x-chromosome cone opsin genes in these two lineages: catarrhines have two opsin genes specifying middle- and long-wavelength-sensitive cone pigments, while platyrrhines have only a single gene. some female platyrrhine monkeys achieve trichromacy because of a species polymo ... | 2003 | 12923905 |
| 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 ... | 2003 | 12740956 |
| 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 ... | 2003 | 12614647 |
| population and social dynamics changes in ring-tailed lemur troops at berenty, madagascar between 1989 - 1999. | in the present study, we recorded all births, immigrations, deaths, and emigrations for a population of ring-tailed lemurs at berenty reserve, madagascar, between september 1989 and august 1999. in september 1989, three troops (c, b, and t) inhabited the study area of 14.2 ha. during the 10-year period, eight troop divisions, six evictions of females, and three troop takeovers of ranges by other troops occurred in and around the study area. consequently, in august 1999, the number of troops in t ... | 2002 | 12426464 |
| dental and general health in a population of wild ring-tailed lemurs: a life history approach. | data are presented on dental and general health for seven groups of wild ring-tailed lemurs, lemur catta, from the beza mahafaly reserve, in southern madagascar. as part of a study of population demography, adults were captured, collared, and tagged, and biometric measurements, dental casts, and analyses of dental and general health were made. results indicate that patterns of dental health vary by individual, age, sex, and habitat. prime adults show more dental attrition than young adults. prim ... | 2002 | 11815947 |
| telomere biology and cellular aging in nonhuman primate cells. | to determine how cellular aging is conserved among primates, we analyzed the replicative potential and telomere shortening in skin fibroblasts of anthropoids and prosimians. the average telomere length of the new world primates ateles geoffroyi (spider monkey) and saimiri sciureus (squirrel monkey) and the old world primates macaca mulatta (rhesus monkey), pongo pygmaeus (orangutan), and pan paniscus (pigmy chimpanzee) ranged from 4 to 16 kb. we found that telomere shortening limits the replicat ... | 2002 | 11777339 |
| [primate foot evolution: a new approach to the old problem]. | functional reasons for specific changes in mammal foot skeleton occurring in course of formation and progressive evolution of locomotion on the parasagittal extremities are formulated for the first time. the paper establishes the base of the study of highly parasagittal forms (terrestrial catarhine monkeys, man and his ancestors), that evolved in primate history much later then their counterparts in other orders. the foot of primitive primate (lemur catta) is scrutinized as a model of a primitiv ... | 2002 | 12298178 |
| analysis of chromosome conservation in lemur catta studied by chromosome paints and bac/pac probes. | a panel of human chromosome painting probes and bacterial and p1 artificial chromosome (bac/pac) clones were used in fluorescence in situ hybridization (fish) experiments to investigate the chromosome conservation of the ring-tailed lemur (lemur catta, lca) with respect to human. whole chromosome paints specific for human chromosomes 7, 9, 11, 13, 14, 17, 18, 20, 21, and x were found to identify a single chromosome or an uninterrupted chromosomal region in lca. a large set of partial chromosome ... | 2002 | 12474064 |
| characterization and phylogenetic relationship of prosimian mhc class i genes. | mhc class i cdna sequences from the most divergent primate group of extant primates compared to human, the suborder strepsirrhini (prosimians), are described. the sequences are derived from the gray mouse lemur (microcebus murinus) and the ring-tailed lemur (lemur catta), which are members of the malagasy lemuriformes, as well as from the pygmy slow loris (nycticebus pygmaeus), a prosimian from east asia. the m. murinus sequences have been analyzed in detail. analysis of the expression level, g/ ... | 2002 | 12486535 |
| naturally occurring ehrlichia chaffeensis infection in two prosimian primate species: ring-tailed lemurs (lemur catta) and ruffed lemurs (varecia variegata). | a naturally occurring infection of ehrlichia chaffeensis in lemurs is described. dna of ehrlichia chaffeensis was identified by polymerase chain reaction in peripheral blood from six of eight clinically ill lemurs. organisms were cultured from the blood of one lemur exhibiting clinical and hematologic abnormalities similar to those of humans infected with e. chaffeensis. | 2002 | 12498671 |
| localization of a new highly repeated dna sequence of lemur cafta (lemuridae, strepsirhini). | we have isolated and cloned an 800-bp highly repeated dna (hrdna) sequence from lemur catta (lca) and described its localization on lca chromosomes. lemur catta hrdna sequences were localized by performing fish experiments on standard and elongated metaphasic chromosomes using an lca hrdna probe (lcasat). a complex hybridization pattern was detected. a strong pericentromeric hybridization signal was observed on most lca chromosomes. chromosomes 7 and 13 were lit in pericentromeric regions, as we ... | 2002 | 12416631 |
| adaptive and phylogenetic significance of ontogenetic sequences in archaeolemur, subfossil lemur from madagascar. | among the best known of recently extinct malagasy lemurs is archaeolemur, which is represented by many hundreds of specimens. the phylogenetic affinities of this taxon are unclear, especially in light of recent preliminary analysis of ancient dna which does not support its previously accepted close relationship with the living indridae. we examined the nearly complete skeletons of two adults and one juvenile and other less complete specimens to reconstruct aspects of the ontogeny of archaeolemur ... | 2001 | 11782109 |
| dietary and dental variations in the genus lemur, with comments concerning dietary-dental correlations among malagasy primates. | field studies of feeding in the lemur subspecies lemur fulvus rufus and l. f. mayottensis have revealed that feeding patterns within a single species can be markedly different, both regionally and seasonally. thus l. f. rufus is a dietary specialist (3 plant species accounting for 80-90% of feeding time), and is highly folivorous, especially during the dry season (90% of feeding time spent eating leaves during the dry season, and 53% during the wet season). on the other hand, l. f. mayottensis i ... | 2001 | 98050 |
| analysis of dentition of a living wild population of ring-tailed lemurs (lemur catta) from beza mahafaly, madagascar. | detailed descriptions of the dentition of many strepsirhine primate taxa are rare, despite their importance in understanding primate evolutionary biology. while several researchers have provided detailed morphological descriptions of ring-tailed lemur dentition (e.g., schwartz and tattersall [1985] am. mus. nat. hist. anthropol. pap. 60:1-100; tattersall and schwartz [1991] am. mus. nat. hist. anthropol. pap. 69:2-18), there are few studies (e.g., eaglen [1986] am. j. phys. anthropol. 71:185-201 ... | 2001 | 11241187 |
| centromere emergence in evolution. | evolutionary centromere repositioning is a paradox we have recently discovered while studying the conservation of the phylogenetic chromosome ix in primates. two explanations were proposed: a conservative hypothesis assuming sequential pericentric inversions, and a more challenging assumption involving centromere emergence during evolution. the complex evolutionary history showed by chromosome ix did not allow us to clearly distinguish between these two hypotheses. here we report comparative stu ... | 2001 | 11282974 |
| t-cell-rich b-cell lymphoma in a ring-tailed lemur (lemur catta). | a 13-yr-old ring-tailed lemur (lemur catta) was evaluated for depression, anorexia, polyuria, and polydipsia. the lemur was in poor body condition and was anemic, hypoalbuminemic, and hyponatremic. cytologic examination of aspirates of the spleen, liver, and bone marrow and histopathologic examination of liver and bone marrow biopsies revealed a disseminated round cell tumor. after euthanasia, necropsy revealed hepatomegaly, splenomegaly, and mesenteric lymphadenomegaly. neoplastic cells were pr ... | 2000 | 11558462 |
| microsatellite structures in the context of human evolution. | six microsatellite - or short tandem repeat (str) - systems with uniform repetitive sequences (humth01, humcd4, humfes/fps, humf13b, humtpo, humlpl) and three compound repeat systems (humvwa, humfibra, d21s11) were used, including data from the literature, to determine genetic distances among eight populations worldwide. the th01- and vwa homologous loci in nonhuman primates (chimpanzees, gorillas, orangutans, rhesus monkeys, ring-tailed lemurs) were compared and found to be shorter than in huma ... | 2000 | 10768773 |
| description of the gastrointestinal tract of five lemur species: propithecus tattersalli, propithecus verreauxi coquereli, varecia variegata, hapalemur griseus, and lemur catta. | the objective of this project was to better define the similarities and differences in gastrointestinal morphology present in lemur species. measurements of the gastrointestinal tract of lemurs were obtained at necropsy from the captive population at duke university primate center. measurements of body length and weight, as well as gastrointestinal length, were recorded from five prosimian species: propithecus tattersalli, propithecus verreauxi, varecia variegata, hapalemur griseus, and lemur ca ... | 2000 | 11078027 |
| exogenous estradiol and sexual receptivity in photoinhibited female lemur catta. | 2000 | 105365 | |
| androgen levels and female social dominance in lemur catta. | morphological and behavioural traits which improve agonistic power are subject to intrasexual selection and, at the proximate level, are influenced by circulating androgens. because intrasexual selection in mammals is more intense among males, they typically dominate females. female social dominance is therefore unexpected and, indeed, rare. ring-tailed lemurs (lemur catta) are sexually monomorphic primates in which all adult females dominate all males. the goal of our study was to test the pred ... | 2000 | 11007329 |
| mating season aggression and fecal testosterone levels in male ring-tailed lemurs (lemur catta). | the challenge hypothesis (j. c. wingfield, r. e. hegner, b. g. ball, and a. m. duffy, 1990, am. nat. 136, 829-846) proposes that in birds, reptiles, and fish, "the frequency or intensity of reproductive aggression as an effect of t[estosterone] is strongest in situations of social instability, such as during the formation of dominance relationships, the establishment of territorial boundaries, or challenges by a conspecific male for a territory or access to mates" (p. 833). to determine the exte ... | 2000 | 10868488 |
| adoption of a wild orphaned ringtailed lemur infant by natal group members: adaptive explanations. | in december 1992 an infant ringtailed lemur, approximately 7 weeks of age, was orphaned in one of the regularly-censused social groups at the beza-mahafaly reserve, southwestern madagascar. the infant was initially adopted by a subadult (2 yr-old) male from the group. continuous-time focal animal data were collected for a 12-hr period, from the time that the infant was retrieved by the young male, in order to document the adoption process. ten members of the infant's social group (total group nu ... | 2000 | 30545205 |
| do ringtailed lemurs (lemur catta) reconcile in the hour post-conflict?: a pilot study. | a previous study bykappeler (1993) showed that no reconciliation occurred in the ringtailed lemur (lemur catta). like the majority of studies dealing with reconciliation, the post-conflict period lasted 10 minutes. an identical study using a 70-min post-conflict period was conducted on one of the same semi-free ranging group studied six years earlier bykappeler. results showed that individuals who never interacted within 10 min did engage in friendly interactions in the longer lasting postconfli ... | 2000 | 30545174 |
| phylogeny and character behavior in the family lemuridae. | a phylogenetic analysis of the family lemuridae was accomplished using multiple gene partitions and morphological characters. the results of the study suggest that several nodes in the lemurid phylogeny can be robustly resolved; however, the relationships of the species within the genus eulemur are problematically nonrobust. the genus varecia is strongly supported as the basal genus in the family. hapalemur and lemur catta are strongly supported as sister taxa and together are the sister group t ... | 2000 | 10764540 |
| intra-troop affiliative relationships of females with newborn infants in wild ring-tailed lemurs (lemur catta). | to determine how the birth and development of infants influence their mothers' social relationships with other adult troop members, we observed two free-ranging troops of ring-tailed lemurs (lemur catta) at the berenty reserve, madagascar. the number of acts of affiliative contact that the mothers received from other adult troop members during the first and second months of infant life were significantly higher than those before they gave birth, and the values during the third month were as low ... | 2000 | 10711533 |
| preventing dental calculus formation in lemurs (lemur catta, eulemur fulvus collaris) and baboons (papio cynocephalus). | the prevention of calculus accumulation in exotic animals is a relatively unexplored topic. a 6-mo study in ring-tailed lemurs (lemur catta) and collared lemurs (eulemur fulvus collaris) and two studies in baboons (papio cynocephalus) (7.5 wks and 6.5 mo) tested the benefits of a primate diet coated with 0.6% sodium hexametaphosphate (hmp) in controlling calculus in these species using a sequential crossover design. the control regimen was an identical, but non-hmp-coated, dry primate chow. at s ... | 1999 | 10572860 |
| nails and claws in primate evolution. | the issue of whether nails or claws were present on the digits of the last common ancestor of living primates is central to the understanding of the ecological context in which the order originated. two lines of evidence are available, the shape (claw, nail, toilet-claw) and the histological structure (one or two horny strata). here we review the existing data regarding the shape and histological structure of cheirideal appendages in primates and present new information from a wide range of livi ... | 1999 | 9924135 |
| changes in behavior in free-ranging lemur catta following release in a natural habitat. | the adjustment of captive-reared and developmentally deprived ringtailed lemurs (lemur catta) to supported release on st. catherine's island, georgia, was studied over 7 years to examine if these animals developed behavior comparable to wild populations. initial changes after release included decreased obesity and increased agility as well as foraging for appropriate novel plants. ranging, daily behavior cycles, and vocalizations developed more slowly over 1-3 years, but eventually the behavior ... | 1999 | 9888718 |
| genetically engineered mengo virus vaccination of multiple captive wildlife species. | encephalomyocarditis virus (emcv), has caused the deaths of many species of animals in zoological parks and research institutions. the audubon park zoo, (new orleans, louisiana, usa) attempted vaccination of several species with a killed emcv vaccine with mixed results. this paper reports an attempt at vaccination against emcv using a genetically engineered, live attenuated mengo virus (vmc0) at the audubon park zoo and miami metro zoo, (miami, florida, usa) from december 1996 to june 1997. seve ... | 1999 | 10231768 |
| takeoff and landing forces of leaping strepsirhine primates. | knowledge of the forces animals generate and are exposed to during locomotion is an important prerequisite for understanding the musculoskeletal correlates of locomotor modes. we recorded takeoff and landing forces for 14 animals representing seven species of strepsirhine primates with a compliant force pole. our sample included both specialized vertical clingers and leapers and more generalized species. takeoff forces are higher than landing forces. peak forces during acceleration for takeoff r ... | 1999 | 10444353 |
| behavioural patterns associated with faecal cortisol levels in free-ranging female ring-tailed lemurs, lemur catta. | the study of physiological stress and its context in free-ranging animals provides a means for understanding the challenges found in the natural habitat. patterns of physiological stress in free-ranging animals have yet to be well characterized. methodological difficulties in measuring physiological responses in the natural habitat have limited this area of research. in this research, physiological stress in free-ranging ring-tailed lemurs, lemur catta, was estimated using a steroid-extraction m ... | 1999 | 10202101 |