| evidence on primate phylogeny from epsilon-globin gene sequences and flanking regions. | phylogenetic relationships among various primate groups were examined based on sequences of epsilon-globin genes. epsilon-globin genes were sequenced from five species of strepsirhine primates. these sequences were aligned and compared with other known primate epsilon-globin sequences, including data from two additional strepsirhine species, one species of tarsier, 19 species of new world monkeys (representing all extant genera), and five species of catarrhines. in addition, a 2-kb segment upstr ... | 1995 | 7714911 |
| evolution of alanine:glyoxylate aminotransferase 1 peroxisomal and mitochondrial targeting. a survey of its subcellular distribution in the livers of various representatives of the classes mammalia, aves and amphibia. | as part of a wider study on the molecular evolution of alanine:glyoxylate aminotransferase 1 (agt1) intracellular compartmentalization, we have determined the subcellular distribution of immunoreactive agt1, using postembedding protein a-gold immunoelectron microscopy, in the livers of various members of the classes mammalia, aves, and amphibia. as far as organellar distribution is concerned, three categories could be distinguished. in members of the first category (type i), all, or nearly all, ... | 1994 | 7813517 |
| milk composition reflects pattern of maternal care in prosimian primates. | hypothesized relationships between milk composition and life history traits were examined by analyzing mid-lactation milks of seven lemurs (eulemur fulvus, e. macaco, e. rubriventer, e. mongoz, varecia variegata, hapalemur griseus, lemur catta), three bushbabies (otolemur crassicaudatus, o. garnettii, galago moholi), and two lorises (nycticebus coucang, loris tardigradus); partial data were also obtained for the lemuroid cheirogaleus medius. there were no significant differences in milk composit ... | 1997 | 9057965 |
| topographical localization of iron in brains of the aged fat-tailed dwarf lemur (cheirogaleus medius) and gray lesser mouse lemur (microcebus murinus). | iron deposits in the human brain are characteristic of normal aging but have also been implicated in various neurodegenerative diseases. among nonhuman primates, strepsirhines are of particular interest because hemosiderosis has been consistently observed in captive aged animals. in particular, the cheirogaleids, because of their small size, rapid maturity, fecundity, and relatively short life expectancy, are a useful model system for the study of normal and pathological cerebral aging. this stu ... | 1998 | 9651651 |
| topographical localization of lipofuscin pigment in the brain of the aged fat-tailed dwarf lemur (cheirogaleus medius) and grey lesser mouse lemur (microcebus murinus): comparison to iron localization. | the present study was undertaken to explore the distribution of lipofuscin in the brain of cheirogaleids by autofluorescence and compare it to other studies of iron distribution. aged dwarf (cheirogaleus medius) and mouse (microcebus murinus) lemurs provide a reliable model for the study of normal and pathological cerebral aging. accumulation of lipofuscin, an age pigment derived by lipid peroxidation, constitutes the most reliable cytological change correlated with neuronal aging. brain section ... | 1999 | 10466576 |
| aspects of social life in the fat-tailed dwarf lemur (cheirogaleus medius): inferences from body weights and trapping data. | body weight is an important attribute of any animal and influences its biology in many ways. in the case of the fat-tailed dwarf lemur (cheirogaleus medius), this is of special interest because animals of this species store fat to survive extended torpor phases during the austral winter and, as a result, show extreme seasonal variation in body weight. in this paper, i present field data from a 20-month study at the forestry station of ampijoroa in northwestern madagascar on body weights of repea ... | 1999 | 10512544 |
| a preliminary study of spatial distribution and mating system of pygmy mouse lemurs (microcebus cf. myoxinus). | according to current hypotheses on the evolution of life history traits and social systems of malagasy lemurs, nocturnality is associated with a solitary lifestyle and a polygynous or promiscuous mating system. recent studies, however, have indicated that this may not be true of all lemurs. the goal of this study was to investigate the sociality and the mating system of pygmy mouse lemurs (microcebus cf myoxinus), which are the smallest known primates, and which retain characteristics of the mos ... | 2000 | 10811439 |
| costs and potential benefits of parental care in the nocturnal fat-tailed dwarf lemur (cheirogaleus medius). | parental care should evolve only if fitness benefits exceed fitness costs. in cheirogaleus medius, a small nocturnal lemur of western madagascar, we found the peculiar situation of considerable parental care by both sexes, combined with an extremely high rate of extra-pair young (epy). in this paper, we try to elucidate the costs and benefits of parental care in c. medius, and we discuss hypotheses as to why males might actively participate in raising young, especially with regard to the high ra ... | 2003 | 14605471 |
| kinematics of vertical climbing in lorises and cheirogaleus medius. | the type of climbing exhibited by apes and atelines is argued to have been important in the evolution of specialized locomotion, such as suspensory locomotion and bipedalism. however, little is known about the mechanics of climbing in primates. previous work shows that asian apes and atelines use larger joint excursions and longer strides than african apes and the japanese macaque, respectively. this study expands knowledge of climbing mechanics by providing the first quantitative kinematic data ... | 2006 | 16445966 |
| body mass distribution and gait mechanics in fat-tailed dwarf lemurs (cheirogaleus medius) and patas monkeys (erythrocebus patas). | most quadrupeds walk with lateral sequence (ls) gaits, where hind limb touchdowns are followed by ipsilateral forelimb touchdowns. primates, however, typically walk with diagonal sequence (ds) gaits, where hind limb touchdowns are followed by contralateral forelimb touchdowns. because the use of ds gaits is nearly ubiquitous among primates, understanding gait selection in primates is critical to understanding primate locomotor evolution. the support polygon model [tomita, m., 1967. a study on th ... | 2007 | 17512970 |
| neutral versus adaptive genetic variation in parasite resistance: importance of major histocompatibility complex supertypes in a free-ranging primate. | current discussions in evolutionary ecology and conservation genetics focus on the relative importance of using selective neutral markers or markers of coding genes to identify adaptive and evolutionary relevant processes. genetic diversity might be particularly important in immune genes (e.g., in genes of the major histocompatibility complex, mhc), which are influencing pathogen and parasite resistance. we investigated the effects of neutral versus adaptive genetic variation in parasite resista ... | 2007 | 17519969 |
| energetics of tropical hibernation. | in this field study, the energetic properties of tropical hibernation were investigated by measuring oxygen consumption and body temperature of the malagasy primate cheirogaleus medius in their natural hibernacula. these lemurs use tree holes with extremely varying insulation capacities as hibernacula. in poorly insulated tree holes, tree hole temperature and body temperature fluctuated strongly each day (between 12.8 and 34.4 degrees c). the metabolic rate under these conditions also showed lar ... | 2009 | 19048262 |
| functional associations of similar mhc alleles and shared parasite species in two sympatric lemurs. | several recent studies of animals in their natural surroundings found evidence for effects of certain major histocompatibility complex (mhc) immune gene alleles on the parasite load. however, in multi-infected individuals the particular selection pressure exerted by specific parasites has rarely been explored. in this study we took advantage of the parasitological and genetic data of two previously investigated malagasy lemur species (cheirogaleus medius and microcebus murinus). we investigated ... | 2010 | 20363374 |
| gene expression profiling in the hibernating primate, cheirogaleus medius. | hibernation is a complex physiological response that some mammalian species employ to evade energetic demands. previous work in mammalian hibernators suggests that hibernation is activated not by a set of genes unique to hibernators, but by differential expression of genes that are present in all mammals. this question of universal genetic mechanisms requires further investigation and can only be tested through additional investigations of phylogenetically dispersed species. to explore this ques ... | 2016 | 27412611 |
| root sepsis associated with insect-dwelling sebaldella termitidis in a lesser dwarf lemur (cheirogaleus medius). | sebaldella termitidis is a rare fastidious microorganism of the leptotrichiaceae family. a variety of closely related species are associated with severe and even life-threatening disease in humans and animals, such as streptobacillus moniliformis, the etiological organism of rat-bite fever as well as members of leptotrichia spp. and sneathia sanguinegens, which have been reported from cases of septicaemia. in contrast, since its description some 50 years ago, s. ermitidis has so far never been r ... | 2015 | 26377576 |
| diversity of photoreceptor arrangements in nocturnal, cathemeral and diurnal malagasy lemurs. | the lemurs of madagascar (primates: lemuriformes) are a monophyletic group that has lived in isolation from other primates for about 50 million years. lemurs have diversified into species with diverse daily activity patterns and correspondingly different visual adaptations. we assessed the arrangements of retinal cone and rod photoreceptors in six nocturnal, three cathemeral and two diurnal lemur species and quantified different parameters in six of the species. the analysis revealed lower cone ... | 2017 | 28054342 |
| molecular phylogeny of the lemur family cheirogaleidae (primates) based on mitochondrial dna sequences. | cheirogaleidae currently comprises five genera whose relationships remain contentious. the taxonomic status and phylogenetic position of both mirza coquereli and allocebus trichotis are still unclear. the taxonomic status of the recently discovered microcebus ravelobensis (a sympatric sibling species of microcebus murinus) and its phylogenetic position also require further examination. a approximately 2.4-kb mitochondrial dna sequence including part of the coiii gene, complete nd3, nd4l, and nd4 ... | 2001 | 11286490 |
| distribution of olfactory epithelium in the primate nasal cavity: are microsmia and macrosmia valid morphological concepts? | the terms "microsmatic" and "macrosmatic" are used to compare species with greater versus lesser olfactory capabilities, such as carnivores compared to certain primates. these categories have been morphologically defined based on the size of olfactory bulb and surface area of olfactory epithelium in the nasal fossa. the present study examines assumptions regarding the morphological relationship of bony elements to the olfactory mucosa, the utility of olfactory epithelial surface area as a compar ... | 2004 | 15472902 |
| heterothermy in afrotropical mammals and birds: a review. | recent years have seen a rapid increase in the number of afrotropical endotherms known to avoid mismatches between energy supply and demand by using daily torpor and/or hibernation. among mammals, heterothermy has been reported in 40 species in six orders, namely macroscelidea, afrosoricida, rodentia, eulipotyphla, primates and chiroptera. these species span a range in body mass of 7-770 g, with minimum heterothermic body temperatures ranging from 1-27°c and bout length varying from 1 h to 70 da ... | 2011 | 21705792 |
| first direct evidence of hibernation in an eastern dwarf lemur species (cheirogaleus crossleyi) from the high-altitude forest of tsinjoarivo, central-eastern madagascar. | the nocturnal dwarf lemurs of madagascar (genus cheirogaleus) are the only primates known to be obligate hibernators. although the physiology of hibernation has been studied widely in the western, small-bodied species, cheirogaleus medius, no direct evidence of hibernation, i.e., body temperature recordings, has been reported for any of the three recognized eastern dwarf lemur species. we present skin temperature data collected by external collar transmitters from two eastern dwarf lemur individ ... | 2010 | 20835697 |
| hibernation in a primate: does sleep occur? | during hibernation, critical physiological processes are downregulated and thermogenically induced arousals are presumably needed periodically to fulfil those physiological demands. among the processes incompatible with a hypome tabolic state is sleep. however, one hibernating primate, the dwarf lemur cheirogaleus medius, experiences rapid eye movement (rem)-like states during hibernation, whenever passively reaching temperatures above 30°c, as occurs when it hibernates in poorly insulated tree ... | 2016 | 27853604 |
| non-human primates avoid the detrimental effects of prenatal androgen exposure in mixed-sex litters: combined demographic, behavioral, and genetic analyses. | producing single versus multiple births has important life history trade-offs, including the potential benefits and risks of sharing a common in utero environment. sex hormones can diffuse through amniotic fluid and fetal membranes, and females with male littermates risk exposure to high levels of fetal testosterone, which are shown to have masculinizing effects and negative fitness consequences in many mammals. whereas most primates give birth to single offspring, several new world monkey and s ... | 2016 | 27434275 |
| does habitat disturbance affect stress, body condition and parasitism in two sympatric lemurs? | understanding how animals react to human-induced changes in their environment is a key question in conservation biology. owing to their potential correlation with fitness, several physiological parameters are commonly used to assess the effect of habitat disturbance on animals' general health status. here, we studied how two lemur species, the fat-tailed dwarf lemur (cheirogaleus medius) and the grey mouse lemur (microcebus murinus), respond to changing environmental conditions by comparing thei ... | 2016 | 27656285 |
| agent-mediated spatial storage effect in heterogeneous habitat stabilizes competitive mouse lemur coexistence in menabe central, western madagascar. | spatio-temporal distribution patterns of species in response to natural and anthropogenic drivers provide insight into the ecological processes that determine community composition. we investigated determinants of ecological structure in a species assemblage of 4 closely related primate species of the family cheirogaleidae (microcebus berthae, microcebus murinus, cheirogaleus medius, mirza coquereli) in western madagascar by extensive line transect surveys across spatial and temporal heterogenei ... | 2015 | 25888023 |
| functional and evolutionary aspects of axial stability in euarchontans and other mammals. | the presence of a stable thoracolumbar region, found in many arboreal mammals, is considered advantageous for bridging and cantilevering between discontinuous branches. however, no study has directly explored the link between osteological features cited as enhancing axial stability and the frequency of cantilevering and bridging behaviors in a terminal branch environment. to fill this gap, we collected metric data on costal and vertebral morphology of primate and nonprimate mammals known to cant ... | 2014 | 24288155 |
| distinct types of lipofuscin pigment in the hippocampus and cerebellum of aged cheirogaleid primates. | the formation of autofluorescent lipopigment or lipofuscin is a highly consistent and reliable cytological change that correlates with cellular aging in postmitotic cells. one causal factor of lipofuscinogenesis involves free radical-induced lipid peroxidation. in mammals, dentate gyrus neurons and purkinje cells are usually affected widely. in this study, we investigated the ultrastructure of lipofuscin deposits in large neurons of the dentate gyrus and in purkinje cells of aged fat-tailed dwar ... | 2013 | 24124014 |
| the relationship of sleep with temperature and metabolic rate in a hibernating primate. | it has long been suspected that sleep is important for regulating body temperature and metabolic-rate. hibernation, a state of acute hypothermia and reduced metabolic-rate, offers a promising system for investigating those relationships. prior studies in hibernating ground squirrels report that, although sleep occurs during hibernation, it manifests only as non-rem sleep, and only at relatively high temperatures. in our study, we report data on sleep during hibernation in a lemuriform primate, c ... | 2013 | 24023713 |
| nocturnal light environments influence color vision and signatures of selection on the opn1sw opsin gene in nocturnal lemurs. | although loss of short-wavelength-sensitive (sws) cones and dichromatic color vision in mammals has traditionally been linked to a nocturnal lifestyle, recent studies have identified variation in selective pressure for the maintenance of the opn1sw opsin gene (and thus, potentially dichromacy) among nocturnal mammalian lineages. these studies hypothesize that purifying selection to retain sws cones may be associated with a selective advantage for nocturnal color vision under certain ecological c ... | 2013 | 23519316 |
| hip anatomy and ontogeny of lower limb musculature in three species of nonhuman primates. | the hip region is examined to determine what aspects of musculoskeletal anatomy are precociously developed in primate species with highly specialized modes of locomotion. muscles of the hind limb were removed and weighed in each specimen, and the hip joint of selected specimens was studied in stained serial sections. no perinatal differences among species are evident, but in adults, the hip joint of galago moholi (a leaping specialist) appears to have proportionally thick articular cartilage (re ... | 2011 | 22567295 |
| shouldering the burdens of locomotion and posture: glenohumeral joint structure in prosimians. | despite its importance in movement of the upper limb, the soft-tissue morphology of the shoulder joint complex (the acromioclavicular, coracoclavicular, and glenohumeral joints) across primates is poorly understood. this study compares soft-tissue morphology of these three shoulder joint components among broad phylogenetic, locomotor, and postural behavior ranges in prosimian primates. two adult specimens of galago moholi (a vertical clinger and leaper) were dissected for study, along with one a ... | 2010 | 20235324 |
| visual acuity in the cathemeral strepsirrhine eulemur macaco flavifrons. | studies of visual acuity in primates have shown that diurnal haplorhines have higher acuity (30-75 cycles per degree (c/deg)) than most other mammals. however, relatively little is known about visual acuity in non-haplorhine primates, and published estimates are only available for four strepsirrhine genera (microcebus, otolemur, galago, and lemur). we present here the first measurements of visual acuity in a cathemeral strepsirrhine species, the blue-eyed black lemur (eulemur macaco flavifrons). ... | 2009 | 19180555 |
| 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 |
| hibernation in the tropics: lessons from a primate. | the malagasy primate cheirogaleus medius hibernates in tree holes for 7 months, although ambient temperatures during hibernation rise above 30 degrees c in their natural environment. in a field study we show that during hibernation the body temperature of most lemurs fluctuates between about 10 degrees c and 30 degrees c, closely tracking the diurnal fluctuations of ambient temperature passively. these lemurs do not interrupt hibernation by spontaneous arousals, previously thought to be obligato ... | 2005 | 15682314 |
| physiology: hibernation in a tropical primate. | the madagascan fat-tailed dwarf lemur, cheirogaleus medius, hibernates in tree holes for seven months of the year, even though winter temperatures rise to over 30 degrees c. here we show that this tropical primate relies on a flexible thermal response that depends on the properties of its tree hole: if the hole is poorly insulated, body temperature fluctuates widely, passively following the ambient temperature; if well insulated, body temperature stays fairly constant and the animal undergoes re ... | 2004 | 15215852 |
| seasonal variation in body mass and locomotor kinetics of the fat-tailed dwarf lemur (cheirogaleus medius). | the fat-tailed dwarf lemur (cheirogaleus medius) is unusual among primates in storing large amounts of fat subcutaneously prior to hibernating during the winter months. in doing so, it increases its body mass by more than 50%, with a substantial weight gain in the tail. this seasonal increase in mass provides a unique natural experiment to examine how changes in body mass affect substrate reaction forces during locomotion. as body mass increases, it is expected that the limbs of the fat-tailed d ... | 2004 | 15052597 |
| white adipose tissue composition in the free-ranging fat-tailed dwarf lemur (cheirogaleus medius; primates), a tropical hibernator. | in temperate species, hibernation is enhanced by high levels of essential fatty acids in white adipose tissue. essential fatty acids cannot be synthesized by mammals, thus nutritional ecology should play a key role in physiological adaptations to hibernation. tropical hibernators are exposed to different physiological demands than hibernators in temperate regions and are expected to be subject to different constraints. the aims of this study were to assess whether or not the tropical hibernator ... | 2003 | 12592437 |
| lateral bending of the lumbar spine during quadrupedalism in strepsirhines. | much research has been devoted to spinal kinematics of nonmammalian vertebrates, while comparatively little is known about the locomotor role of spinal movements in mammals, especially primates. this study, conducted at the duke university primate center, examines the function of lateral spinal bending during quadrupedal walking among a diverse sample of strepsirhines. the taxa studied include loris tardigradus (1), nycticebus coucang (1), n. pygmaeus (1), cheirogaleus medius (2), varecia varieg ... | 2001 | 11180987 |
| feeding ecology of the hibernating primate cheirogaleus medius: how does it get so fat? | the fat-tailed dwarf lemur (cheirogaleus medius; cheirogaleidae) lives in the tropical forests of madagascar. it is exceptional among primates, because this small nocturnal lemur hibernates during the dry season from the end of april until october. this field study was carried out to assess seasonal changes in body mass and behavioral traits (locomotor activity, feeding ecology) of c. medius that enable this species to accumulate large quantities of fat within weeks. feeding observations of 36 r ... | 1999 | 28308555 |
| cytochrome oxidase 'blobs' and other characteristics of primary visual cortex in a lemuroid primate, cheirogaleus medius. | we recently obtained the brain of a rare lemuroid primate, cheirogaleus medius. the brain was not perfused before death, but rather fixed by immersion shortly thereafter. in both flat-mounted and transversely sectioned tissue, we were able to clearly demonstrate periodic zones of high cytochrome oxidase (co) activity in the primary visual cortex, resembling the so-called 'blobs' described in many other primate species. our results contrast with a previous report indicating that blobs are absent ... | 1996 | 8866707 |
| banded chromosomes of galago crassicaudatus monteiri, g. c. garnetti, and a subspecific hybrid. | in this report the karyotypes of galago crassicaudatus monteiri and g. c. garnetti are described using g-banding, q-banding, silver staining for nucleolus organizer regions and synaptonemal complex analysis. the banded chromosomes of the two subspecies are compared with each other and with a hybrid between the two subspecies. allowing for pericentric inversions of seven autosomal pairs, the banded chromosomes of the two subspecies are indistinguishable. comparisons with the karyotype of cheiroga ... | 1982 | 7160231 |
| reproduction in cheirogaleus medius. | the reproductive behavior of 20 captive cheirogaleus medius was studied over two breeding seasons in 1980 and 1981. seasonality, estrous cycle, sexual behavior, sexual maturity, and postpartum estrus are described. reproduction of the different species of the family cheirogaleidae as well as that of the galaginae and lemuridae is compared. | 1982 | 7141351 |
| seasonal and daily activity changes in captive cheirogaleus medius. | seasonal and daily variation in locomotor activity are recorded in 11 animals over 17 weeks, covering the last 8 weeks of the inactive season and the ensuing breeding season. the results are compared with changes in body weight and with the onset, duration and frequency of reproductive activity. these and some behavioral observations are related to the conclusions of previous publications. | 1982 | 7129255 |
| chromosomes of lemuriformes. v. a comparison of the karyotypes of cheirogaleus medius and lemur fulvus fulvus. | in this report we compare the karyotype of lemus fulvus fulvus (2n=60) with that of cheirogaleus medius (2n=66), a species thought to retain the ancestral lemur karyotype. a culture technique was designed specifically for lemur lymphocytes to facilitate description of the complete karyotypes using g--banding, c-banding, and ag-as staining for nucleolus organizer regions (nor's). different g-banding patterns in three chromosome pairs and different nor-bearing chromosomes between the two species, ... | 1979 | 113177 |
| underground hibernation in a primate. | hibernation in mammals is a remarkable state of heterothermy wherein metabolic rates are reduced, core body temperatures reach ambient levels, and key physiological functions are suspended. typically, hibernation is observed in cold-adapted mammals, though it has also been documented in tropical species and even primates, such as the dwarf lemurs of madagascar. western fat-tailed dwarf lemurs are known to hibernate for seven months per year inside tree holes. here, we report for the first time t ... | 2013 | 23636180 |
| captive dwarf and mouse lemurs have variable fur growth. | researchers typically assume constant fur and hair growth for primates, but the few studies that have investigated growth explicitly suggest this may not be the case. instead, growth may vary considerably among individuals and across seasons. one might expect this variability to be most pronounced for species that have seasonally variable activity patterns (e.g., madagascar's cheiorogaleidae). in particular, dwarf lemurs (cheirogaleus spp.) undergo considerable changes in their daily activity le ... | 2020 | 32731532 |
| occurrence of lemurs in landscapes and their species-specific scale responses to habitat loss. | studies on the impact of habitat loss on species occurrence consistently find that the amount of habitat (measured as patch area) is a major determinant of species occurrence at a patch-level. however, patch-level research may fail to detect important patterns and processes only observable at a landscape-level. a landscape-level approach that incorporates species-specific scale responses is needed to better understand what drives species occurrence. our aim was to determine the landscape-level s ... | 2020 | 32083335 |
| conservation genomic analysis reveals ancient introgression and declining levels of genetic diversity in madagascar's hibernating dwarf lemurs. | madagascar's biodiversity is notoriously threatened by deforestation and climate change. many of these organisms are rare, cryptic, and severely threatened, making population-level sampling unrealistic. such is the case with madagascar's dwarf lemurs (genus cheirogaleus), the only obligate hibernating primate. we here apply comparative genomic approaches to generate the first genome-wide estimates of genetic diversity within dwarf lemurs. we generate a reference genome for the fat-tailed dwarf l ... | 2020 | 31435007 |
| navigation strategies in three nocturnal lemur species: diet predicts heuristic use and degree of exploratory behavior. | humans generally solve multi-destination routes with simple rules-of-thumb. animals may do the same, but strong evidence is limited to a few species. we examined whether strepsirrhines, who diverged from haplorhines more than 58 mya, would demonstrate the use of three heuristics used by humans and supported in vervets, the nearest neighbor rule, the convex hull, and a cluster strategy, when solving a multi-destination route. we hypothesized that the evolution of these strategies may depend on a ... | 2019 | 30758804 |
| lemur species-specific metapopulation responses to habitat loss and fragmentation. | determining what factors affect species occurrence is vital to the study of primate biogeography. we investigated the metapopulation dynamics of a lemur community consisting of eight species (avahi occidentalis, propithecus coquereli, microcebus murinus, microcebus ravelobensis, lepilemur edwardsi, cheirogaleus medius, eulemur mongoz, and eulemur fulvus) within fragmented tropical dry deciduous forest habitat in ankarafantsika national park, madagascar. we measured fragment size and isolation of ... | 2018 | 29742108 |
| xanthogranuloma of the choroid plexus in the fat-tailed dwarf lemur (cheirogaleus medius). | this report documents the death of two fat-tailed dwarf lemurs (cheirogaleus medius) maintained over 6 years each in our laboratory. postmortem studies revealed xanthogranuloma of the choroid plexus, a mass replete with stored lipids, including cholesterol crystals. six months prior to their deaths, both animals developed a peculiar head tilt and signs suggestive of neurological dysfunction. at autopsy, each had masses projecting into the lateral and ivth ventricles and an associated obstructive ... | 1996 | 31918485 |
| reproduction in coquerel's dwarf lemur (mirza coquereli). | most nocturnal malagasy primates, as well as many diurnal species, are highly endangered in their natural habitat. captive breeding programs have been established for many species, but detailed information on reproduction is only available for three nocturnal taxa: the mouse lemur (microcebus murinus), the dwarf lemur (cheirogaleus medius), and the greater dwarf lemur (cheirogaleus major). in this study, we present data for another nocturnal malagasy primate, coquerel's dwarf lemur (mirza coquer ... | 1995 | 31924095 |
| description of ultrasonic vocalizations of the mouse lemur (microcebus murinus) and the fat-tailed dwarf lemur (cheirogaleus medius). | ultrasonic (>20 khz) vocalizations were recorded from two species of prosimian primates, microcebus murinus and cheirogaleus medius. three types of ultrasonic calls were emitted by isolated or paired m. murinus: 1) "chirps," short-duration (30 msec) calls with a sharp onset at 40 khz followed by rapid and steep declines in frequency and intensity; 2) "twitters," characterized by a brief pulse at 25 khz prior to the onset of repeating, frequency-modulated units; and 3) "long whistles," monotone s ... | 1987 | 31973475 |