| population ecology of the ring-tailed lemur, lemur catta, and the white sifaka, propithecus verreauxi verreauxi, at berenty, madagascar, 1981. | the diurnal lemurs propithecus verreauxi verreauxi and lemur catta at berenty in southern madagascar, have been studied for the last 30 years. the august 1981 census indicates that the population size of l. catta remains stable at 150 adults but that p. v. verreauxi troops have become fragmented and scattered and the population is apparently increasing. eight different vegetation types were classified within the reserve and their influence on the distribution of l. catta and p. v. verreauxi inve ... | 1986 | 3557229 |
| kinetics of leaping primates: influence of substrate orientation and compliance. | our current knowledge about the forces leapers generate and absorb is very limited and based exclusively on rigid force platform measurements. in their natural environments, however, leapers take off and land on branches and tree trunks, and these may be compliant. we evaluated the influence of substrate properties on leaping kinetics in prosimian leapers by using a combined field and laboratory approach. tree sway and the timing of takeoffs relative to the movements of trees were documented for ... | 1995 | 7604894 |
| molecular and morphologic characterization of a cryptosporidium genotype identified in lemurs. | this study reports the molecular and morphologic characterization of a cryptosporidium sp., identified in stools of captive lemurs propithecus verreauxi coquereli. stool samples were collected from seven animals (n=7) presenting episodes of diarrhea. bright-field light microscopy of stool smears stained with modified acid-fast technique revealed the presence of cryptosporidium sp. oocysts in four of the stool samples analyzed. all microscopically positive samples were confirmed by pcr using prim ... | 2003 | 12559709 |
| parasitologic analyses of the sifaka (propithecus verreauxi verreauxi) at beza mahafaly, madagascar. | a cross-sectional parasitologic survey of a population of wild sifaka (propithecus verreauxi verreauxi) was conducted at the beza mahafaly special reserve in southwest madagascar. ninety fecal samples were collected from thirty 1- to 30-yr-old male and female sifakas, and the formalin-preserved and polyvinyl alcohol-preserved specimens were examined using the zinc sulfate flotation and formalin-ethyl acetate sedimentation techniques. no intestinal parasites were recovered, possibly because the s ... | 2003 | 14582790 |
| seasonality, body condition, and timing of reproduction in propithecus verreauxi verreauxi in the kirindy forest. | mammals that live in seasonal environments may adjust their reproductive cycles to cope with fluctuations in food availability. because lemurs in madagascar experience highly seasonal variation in food availability, we examined the effects of fluctuating food availability on body condition and reproduction in one of the larger living species, verreaux's sifaka (propithecus verreauxi verreauxi), in the kirindy forest of western madagascar. seven years of demographic data were combined with an int ... | 2005 | 16287105 |
| are kirindy sifaka capital or income breeders? it depends. | the capital and income breeding framework has only recently been used to explain variation in female reproductive strategies in primates. the application of this framework to primates and other mammals with long reproductive cycles has not been consistent. we evaluated data on verreaux's sifaka (propithecus verreauxi verreauxi) in the kirindy forest of western madagascar to determine whether they are capital or income breeders. we found that verreaux's sifaka can be classified as either capital ... | 2005 | 16287106 |
| biomedical evaluation of two sympatric lemur species (propithecus verreauxi deckeni and eulemur fulvus rufus) in tsiombokibo classified forest, madagascar. | complete medical examinations were performed on 20 wild decken's sifaka (propithecus verreauxi deckeni) and 20 wild red-fronted brown lemurs (eulemurfulvus rufus) from western madagascar. each animal received a complete physical examination, and weight, body temperature, heart rate, and respiratory rate were recorded and ectoparasites collected. blood samples were collected for complete blood cell count, differential white blood cell count, hemoparasite examination, serum biochemical profile, fa ... | 2005 | 17312713 |
| testing for a historical population bottleneck in wild verreaux's sifaka (propithecus verreauxi verreauxi) using microsatellite data. | the degree to which historical human activities negatively impacted past and present lemur species is a long-standing question in primatology. at present, most evidence addressing this issue comes from archaeology, paleontology, and behavioral studies. genetic data provide another source of evidence. in this study, six microsatellite loci, genotyped on more than 360 wild verreaux's sifaka, are used in order to test the hypothesis that this population experienced a population bottleneck in the la ... | 2008 | 18618601 |
| demography of verreaux's sifaka in a stochastic rainfall environment. | in this study, we use deterministic and stochastic models to analyze the demography of verreaux's sifaka (propithecus verreauxi verreauxi) in a fluctuating rainfall environment. the model is based on 16 years of data from beza mahafaly special reserve, southwest madagascar. the parameters in the stage-classified life cycle were estimated using mark-recapture methods. statistical models were evaluated using information-theoretic techniques and multi-model inference. the highest ranking model is t ... | 2009 | 19636591 |
| fitness and extra-group reproduction in male verreaux's sifaka: an analysis of reproductive success from 1989-1999. | adult males in social groups often compete with other male group members for access to adult females. in some primate species, males also seek mating opportunities in neighboring social groups. such extra-group fertilizations (egfs) provide an additional source of variation in male fitness. this additional component of fitness provided by egfs must be incorporated into analyses that investigate sources of variation in male lifetime reproductive success. in this study, a model is analyzed in whic ... | 2007 | 17133430 |
| scent marking in sifaka: no one function explains it all. | various hypotheses to explain possible functions of scent-marking have been put forth and basically fall into five categories: territorial demarcation, ownership of resources, mate attraction, noncombative fighting, and self-advertisement. verreaux's sifaka (propithecus verreauxi verreauxi), like many prosimians, use scent-marking as one form of communication. the goal of this study was to determine the function of scent-marking in sifaka. all-occurrence of scent-marks, scent-mark context, and s ... | 2006 | 16715510 |
| evidence of early butchery of giant lemurs in madagascar. | we report here definitive evidence of butchery, most probably associated with hunting, of giant extinct lemurs by early human settlers in madagascar. specimens of palaeopropithecus ingens and pachylemur insignis from two sites in southwestern madagascar, taolambiby and tsirave, show classic signs of butchering. we compared these to the bones (also from taolambiby) of butchered propithecus verreauxi, a lemur still living in the region. the characteristics of the tool-induced extinct-lemur bone al ... | 2005 | 16225904 |
| sex differences in scent-marking in sifaka: mating conflict or male services? | male and female interests can either be in conflict or serve as a basis for exchange. communication is thus an important aspect of intersexual relationships. verreaux's sifaka (propithecus verreauxi verreauxi), like many prosimians, uses chemical signals as one form of communication. the goals of this study were to determine 1) if males and females exhibit sex differences in their scent-marking behavior, and 2) if scent-marking is an example of mating conflict or cooperation. all occurrences of ... | 2005 | 15795894 |
| use of total dietary fiber across four lemur species (propithecus verreauxi coquereli, hapalemur griseus griseus, varecia variegata, and eulemur fulvus): does fiber type affect digestive efficiency? | in vivo digestibility and transit of two experimental diets were compared across four lemur species for which gastrointestinal morphology and preliminary data on physiology differ:varecia variegata (vv), eulemur fulvus (ef), propithecus verreauxi (pv), and hapalemur griseus (hg). since free-ranging groups consume varied amounts of slowly fermentable insoluble fiber (if) and rapidly fermentable soluble fiber (sf), differences in digestibility may be related to variation in the fiber types consume ... | 2004 | 15538767 |
| pair-bonding, female aggression and the evolution of lemur societies. | lemur societies have been described as convergent with those of anthropoids, including papio-like female-bonded multi-male groups. recent research, however, shows at least 5 pair-bonded species among the lemuridae and indriidae. three more, eulemur mongoz, eulemur fulvus and varecia variegata, have societies combining aspects of pairing with aspects of troop life. the best-known female-bonded societies, those of lemur catta, propithecus diadema edwardsi and propithecus verreauxi, may be assembla ... | 1998 | 9595685 |
| characterizing gastrointestinal transit time in four lemur species using barium-impregnated polyethylene spheres (bips). | differences in dietary profiles and gastrointestinal (gi) morphologies observed across lemur species suggest that there may be variation in patterns of digesta flow through the gi tract related to the method of digesta processing. using radio-opaque barium-impregnated polyethylene spheres (bips), we characterized such patterns in four lemur species: varecia variegata (vv), eulemur fulvus (ef), propithecus verreauxi (pv), and hapalemur griseus (hg) (n = 2 per species). after an initial radiograph ... | 2004 | 15538763 |
| genetic population structure of the white sifaka (propithecus verreauxi verreauxi) at beza mahafaly special reserve, southwest madagascar (1992-2001). | gene flow within and between social groups is contingent on behaviourally mediated patterns of mating and dispersal. to understand how these patterns affect the genetic structure of primate populations, long-term data are required. in this study, we analyse 10 years of demographic and genetic data from a wild lemur population (propithecus verreauxi verreauxi) at beza mahafaly special reserve, southwest madagascar. our goal is to specify how patterns of mating and dispersal determine kinship and ... | 2003 | 12919470 |
| observed infanticide in a seasonal breeding prosimian (propithecus verreauxi verreauxi) in kirindy forest, madagascar. | | 2003 | 12778920 |
| 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 |
| reproduction in free-ranging male propithecus verreauxi: the hormonal correlates of mating and aggression. | endocrine studies of captive strepsirrhine primates suggest that physical environment and social factors mediate inter-individual variations in testicular function and serum testosterone (st) in males. while these studies have made major contributions to our understanding of the individual proximate mechanisms influencing androgen activity in male strepsirrhines, none have investigated how these mechanisms work coincidentally in free-ranging populations. in this study we used fecal steroid analy ... | 1998 | 9511910 |
| functional morphology of the lemuriform wrist joints and the relationship between wrist morphology and positional behavior in arboreal primates. | a comparative study of carpal joint structure and function in six malagasy lemuriforms was undertaken to test predicted morphoclines in carpal joint morphology between pronograde and orthograde arboreal primates. patterns of movement at the wrist during locomotion were observed and described for the lemuriform species lemur fulvus and propithecus verreauxi. lemur fulvus, which assumes a pronograde posture during locomotion, extends and pronates the wrist during the support phase of quadrupedal w ... | 1996 | 8967331 |
| relative growth of the limbs and trunk in sifakas: heterochronic, ecological, and functional considerations. | limb, trunk, and body weight measurements were obtained for growth series of milne-edwards's diademed sifaka, propithecus diadema edwardsi, and the golden-crowned sifaka, propithecus tattersalli. similar measures were obtained also for primarily adults of two subspecies of the western sifaka: propithecus verreauxi coquereli, coquerel's sifaka, and propithecus verreauxi verreauxi, verreaux's sifaka. ontogenetic series for the larger-bodied p. d. edwardsi and the smaller-bodied p. tattersalli were ... | 1993 | 8296878 |
| propithecus verreauxi population and ranging at berenty, madagascar, 1975 and 1980. | propithecus verreauxi have been repeatedly censused in parts of the 200-ha reserve at berenty between 1963 and 1975. troop rearrangements in 1963 and 1975 showed that both males and females can change troop outside the breeding season. group sex ratio varies from 0.3 female/male to 5.0 female/male. usually, at berenty, groups defend highly exclusive territories, in contrast to ranging patterns elsewhere. in 1980 troops were censused during 2 weeks in november at a different season from earlier s ... | 1982 | 7141349 |
| troop continuity and troop spacing in propithecus verreauxi and lemur catta at berenty (madagascar). | | 1972 | 4673322 |
| intra-specific variation in the social organization and ecology of propithecus verreauxi. | | 1974 | 4474117 |
| codominant autosomal inheritance of polymorphic red cell acid phosphates of lemurs and some properties of the enzymes. | red cell acid phosphatase phenotypes of 207 captive animals of the genera lemur, hapalemur, and prophithecus were determined by starch gel electrophoresis and phosphatase-specific staining. in lemur fulvus, three phenotypes, designated a, b, and ab, were observed. in each of the species l. catta, l. macaco, l. mongoz, and l. variegatus, a single phenotype was observed, in hapalemur griseus, three phenotypes were found: a,b, and ab. in propithecus verreauxi, a single phenotype was found. examinat ... | 1977 | 406895 |
| [cranial and mandibular morphology of the indrinae. contribution of procrustes methods and fourier analysis]. | although it is universally accepted that the indridae family is monophyletic, there is no such unanimity about how the extant species of the indrinae sub-family are related. cranium and mandible disparity among indri indri, propithecus diadema, propithecus verreauxi and avahi laniger is analysed by geometrical morphometric methods and interpreted in adaptive terms. we compare results obtained by two techniques: procrustes superimpositions for skulls and elliptical fourier analysis for jawbones. ... | 2000 | 10923214 |
| 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 |
| social structure and escherichia coli sharing in a group-living wild primate, verreaux's sifaka. | epidemiological models often use information on host social contacts to predict the potential impact of infectious diseases on host populations and the efficiency of control measures. it can be difficult, however, to determine whether social contacts are actually meaningful predictors of transmission. we investigated the role of host social structure in the transmission of escherichia coli in a wild population of primates, verreaux's sifakas (propithecus verreauxi). using multilocus sequence typ ... | 2016 | 26868261 |
| red cell acid phosphatases of propithecus verreauxi: evidence for a high-activity allele. | | 2001 | 114163 |
| comparing chromosomal and mitochondrial phylogenies of the indriidae (primates, lemuriformes). | the malagasy primate family indriidae comprises three genera with up to 19 species. cytogenetic and molecular phylogenies of the indriidae have been performed with special attention to the genus propithecus. comparative r-banding and fish with human paints were applied to karyotypes of representatives of all three genera and confirmed most of the earlier r-banding results. however, additional chromosomal rearrangements were detected. a reticulated and a cladistic phylogeny, the latter including ... | 2011 | 21336668 |
| even adult sex ratios in lemurs: potential costs and benefits of subordinate males in verreaux's sifaka (propithecus verreauxi) in the kirindy forest cfpf, madagascar. | optimal group size and composition are determined by both the costs and benefits of group living for the group's members. verreaux's sifakas (propithecus verreauxi), a diurnal lemur, form multimale multifemale groups with the tendency toward even adult sex ratios despite a small average number of females per group. the unexpected presence of multiple adult males may be explained by tolerance of other group members if subordinate males provide benefits to the group that outweigh the costs associa ... | 2009 | 19425098 |
| birth season glucocorticoids are related to the presence of infants in sifaka (propithecus verreauxi). | the responses of plural breeding mammals to environmental stressors are little understood in free-ranging populations, but recent studies of singular breeders suggest that ecological factors and social milieu influence the variable physiological stress responses observed among individuals. our previous studies examining faecal glucocorticoid (fgc)-behaviour interactions in plural breeding male sifaka (propithecus verreauxi) show that fgc elevations coincide with specific dispersal events, partic ... | 2009 | 19324777 |
| 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 |
| ontogeny of conspecific and heterospecific alarm call recognition in wild verreaux's sifakas (propithecus verreauxi verreauxi). | the production of vocalizations in nonhuman primates is predominantly innate, whereas learning influences the usage and comprehension of vocalizations. in this study, i examined the development of alarm call recognition in free-ranging infant verreaux's sifakas. specifically, i investigated their ability to recognize conspecific alarm calls as well as those of sympatric redfronted lemurs (eulemur fulvus rufus) in kirindy forest, western madagascar. both species have functionally referential alar ... | 2008 | 17705223 |
| chromosomal evolution in malagasy lemurs. vii. phylogenic relationships between propithecus, avahi (indridae), microcebus (cheirogaleidae), and lemur (lemuridae). | a chromosomal banding study was carried out on propithecus verreauxi verreauxi, p. verreauxi deckeni, and avahi laniger laniger. comparison of their karyotypes with those of microcebus murinus and lemur fulvus led to reconstruction of the ancestral lemuriform karyotype and a determination that the branch leading to the indridae was isolated very early, before the separation of the lemuridae from the cheirogaleidae. the karyotype of avahi remained highly ancestral, whereas that of p. verreauxi wa ... | 1983 | 6641285 |
| female and male life tables for seven wild primate species. | we provide male and female census count data, age-specific survivorship, and female age-specific fertility estimates for populations of seven wild primates that have been continuously monitored for at least 29 years: sifaka (propithecus verreauxi) in madagascar; muriqui (brachyteles hypoxanthus) in brazil; capuchin (cebus capucinus) in costa rica; baboon (papio cynocephalus) and blue monkey (cercopithecus mitis) in kenya; chimpanzee (pan troglodytes) in tanzania; and gorilla (gorilla beringei) i ... | 2016 | 26928014 |
| reciprocal recognition of sifaka ( propithecus verreauxi verreauxi) and redfronted lemur ( eulemur fulvus rufus) alarm calls. | redfronted lemurs ( eulemur fulvus rufus) and verreaux's sifakas ( propithecus verreauxi verreauxi) occur sympatrically in western madagascar. both species exhibit a so-called mixed alarm call system with functionally referential alarm calls for raptors and general alarm calls for carnivores and raptors. general alarm calls also occur in other contexts associated with high arousal, such as inter-group encounters. field playback experiments were conducted to investigate whether interspecific reco ... | 2004 | 12827548 |
| 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 |
| the socio-matrix reloaded: from hierarchy to dominance profile in wild lemurs. | dominance hierarchy influences the life quality of social animals, and its definition should in principle be based on the outcome of agonistic interactions. however, defining and comparing the dominance profile of social groups is difficult due to the different dominance measures used and because no one measure explains it all. we applied different analytical methods to winner-loser sociomatrices to determine the dominance profile of five groups of wild lemurs (species: lemur catta, propithecus ... | 2015 | 25653908 |
| hemoparasites in a wild primate: infection patterns suggest interaction of plasmodium and babesia in a lemur species. | hemoparasites can cause serious morbidity in humans and animals and often involve wildlife reservoirs. understanding patterns of hemoparasite infections in natural populations can therefore inform about emerging disease risks, especially in the light of climate change and human disruption of natural ecosystems. we investigated the effects of host age, sex, host group size and season on infection patterns of plasmodium sp., babesia sp. and filarial nematodes in a population of wild malagasy prima ... | 2015 | 26767166 |
| biomedical evaluation of verreaux's sifaka (propithecus verreauxi) from kirindy mitea national park in madagascar. | evaluation of the health, prevalence, and incidence of diseases in wild populations is a critical component of wildlife management. in addition, the establishment of reference physiologic parameters can verreaux's sifaka (propithecus verreauxi) from kirindy mitea national park, madagascar, during two field captures incontribute to the assessment of population risks. complete medical evaluations were performed on 33 wild june 2010 and june 2011. each animal received a complete physical examinatio ... | 2014 | 25000684 |
| locomotor ecology of propithecus verreauxi in kirindy mitea national park. | the locomotor behaviour of 2 groups of propithecus verreauxi (verreaux's sifaka) was studied over an 8-month period in kirindy mitea national park (kmnp), madagascar. this paper assesses the major characteristics of their locomotion, focusing on the extent that seasonal variation in climate and habitat, and local variation in habitat, is reflected in changes in locomotor behaviour. p. verreauxi is a committed leaper with a strong preference for vertical and angled supports. we found clear betwee ... | 2015 | 26111555 |
| reach and posture hand preferences during arboreal feeding in sifakas (propithecus sp.): a test of the postural origins theory of behavioral lateralization. | sixteen sifakas (11 propithecus verreauxi coquereli, 2 propithecus verreauxi verreauxi form majori, and 3 propithecus tattersalli) were videotaped as they fed on leaves in an arboreal context. the hand used to feed and the hand used to maintain postural stability was coded. for each subject, the lateral bias of the hand used to feed was opposite the hand used in postural support. seven sifakas displayed no bias for feeding or posture-related hand use, 7 sifakas displayed significant feeding-rela ... | 2005 | 16366776 |
| anatomy is important, but need not be destiny: novel uses of the thumb in aye-ayes compared to other lemurs. | aye-ayes (daubentonia madagascerensis) have highly specialized hands with long digits, especially the thin middle one (d3), which is used for extracting food, such as beetle larvae, under bark. due to the elongation of their fingers, including the thumb, it is presumed that aye-ayes have a rather limited capacity for delicate manipulation of objects. however, studies have reported independent movement of digits d3 and d4, and one report noted a seemingly independent thumb (d1) movement in holdin ... | 2012 | 21924295 |
| functional morphology of indrid lumbar vertebrae. | indrids are primarily vertical clingers and leapers but also engage to various extents in climbing, suspensory postures, bimanual movement, bipedal hopping, and quadrupedalism. it has been demonstrated that these behaviors are well reflected in the appendicular anatomy of these primates, while indrid vertebral anatomy has received relatively little attention. in this morphometric study, biomechanically relevant aspects of the lumbar vertebrae of indri indri, propithecus diadema, and propithecus ... | 1995 | 8572156 |
| testing yawning hypotheses in wild populations of two strepsirrhine species: propithecus verreauxi and lemur catta. | yawning, although easily recognized, is difficult to explain. traditional explanations stressed physiological mechanisms, but more recently, behavioral processes have received increasing attention. this is the first study to test a range of hypotheses on yawning in wild primate populations. we studied two sympatric strepsirrhine species, lemur catta, and propithecus verreauxi, of the ankoba forest (24.99°s, 46.29°e, berenty reserve) in southern madagascar. sexual dimorphism is lacking in both sp ... | 2015 | 26317594 |
| the gut microbiome of wild lemurs: a comparison of sympatric lemur catta and propithecus verreauxi. | mammalian gut microbes are invaluable to the host's metabolism, but few researchers have examined gut microbial dynamics under natural conditions in wild mammals. this study aims to help fill this knowledge gap with a survey of the natural variation of the gut microbiome in 2 wild lemur species, lemur catta and propithecus verreauxi. the wild l. catta were also compared to a captive population to discern the effect of habitat within a species. gut microbial dna was extracted from fecal samples c ... | 2015 | 26022304 |
| 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 ... | 2011 | 21590749 |
| prins analysis of the telomeric sequence in seven lemurs. | we examined the chromosomal localization of the telomeric sequence, (ttaggg)n, in seven species of the lemurs and one greater galago, as an outgroup, using the primed in-situ labeling (prins) technique. as expected, the telomeric sequence was identified at both ends of all chromosomes of the eight prosimians. however, six species showed a signal at some pericentromeric regions involving constitutive heterochromatin as well. the pericentromeric region of chromosome 1 of verreaux's sifaka (propith ... | 2000 | 10730589 |
| variation in the meaning of alarm calls in verreaux's and coquerel's sifakas (propithecus verreauxi, p. coquereli). | the comprehension and usage of primate alarm calls appear to be influenced by social learning. thus, alarm calls provide flexible behavioral mechanisms that may allow animals to develop appropriate responses to locally present predators. to study this potential flexibility, we compared the usage and function of 3 alarm calls common to 2 closely related sifaka species (propithecus verreauxi and p. coquereli), in each of 2 different populations with different sets of predators. playback studies re ... | 2011 | 21475394 |
| opsin gene and photopigment polymorphism in a prosimian primate. | a recent genetic investigation found some species of prosimian to have an opsin gene polymorphism [nature 402 (1999) 36]. in the present study the functional implications of this finding were explored in a correlated investigation of opsin genes and spectral sensitivity measurements of a diurnal prosimian, coquerel's sifaka (propithecus verreauxi coquereli). spectra recorded using electroretinogram (erg) flicker photometry reveal a cone photopigment polymorphism paralleling an opsin gene polymor ... | 2002 | 11804627 |
| the birth and early development of a captive sifaka, propithecus verreauxi coquereli. | we report here our observations on parturition and infant development up to five months in a captive sifaka, propithecus verreauxi coquereli. comparisons are made with other reports of propithecus. in describing the acquisition of developmental landmarks, a distinction is made between the first sighting of a behavior pattern and its regular occurrence in the infant's repertoire. we describe the development of locomotor abilities, grooming, feeding, play, and social interactions. in general, matu ... | 1978 | 102572 |
| patterns of seasonality and group membership characterize the gut microbiota in a longitudinal study of wild verreaux's sifakas (propithecus verreauxi). | the intestinal microbiota plays a major role in host development, metabolism, and health. to date, few longitudinal studies have investigated the causes and consequences of microbiota variation in wildlife, although such studies provide a comparative context for interpreting the adaptive significance of findings from studies on humans or captive animals. here, we investigate the impact of seasonality, diet, group membership, sex, age, and reproductive state on gut microbiota composition in a wil ... | 2017 | 28808547 |
| the dynamics of transmission and the dynamics of networks. | a toy example depicted here highlighting the results of a study in this issue of the journal of animal ecology that investigates the impact of network dynamics on potential disease outbreaks. infections (stars) that spread by contact only (left) reduce the predicted outbreak size compared to situations where individuals can become infected by moving through areas that previously contained infected individuals (right). this is potentially important in species where individuals, or in this case gr ... | 2017 | 28394028 |
| dynamic vs. static social networks in models of parasite transmission: predicting cryptosporidium spread in wild lemurs. | social networks provide an established tool to implement heterogeneous contact structures in epidemiological models. dynamic temporal changes in contact structure and ranging behaviour of wildlife may impact disease dynamics. a consensus has yet to emerge, however, concerning the conditions in which network dynamics impact model outcomes, as compared to static approximations that average contact rates over longer time periods. furthermore, as many pathogens can be transmitted both environmentall ... | 2017 | 27973681 |
| group benefit associated with polymorphic trichromacy in a malagasy primate (propithecus verreauxi). | in some primate lineages, polymorphisms in the x-linked m/lws opsin gene have produced intraspecific variation in color vision. in these species, heterozygous females exhibit trichromacy, while males and homozygous females exhibit dichromacy. the evolutionary persistence of these polymorphisms suggests that balancing selection maintains color vision variation, possibly through a 'trichromat advantage' in detecting yellow/orange/red foods against foliage. we identified genetic evidence of polymor ... | 2016 | 27910919 |
| sex and seasonal differences in diet and nutrient intake in verreaux's sifakas (propithecus verreauxi). | fluctuations in food availability are a major challenge faced by primates living in seasonal climates. variation in food availability can be especially challenging for females, because of the high energetic costs of reproduction. therefore, females must adapt the particular demands of the different reproductive stages to the seasonal availability of resources. madagascar has a highly seasonal climate, where food availability can be extremely variable. we investigated the seasonal changes in diet ... | 2017 | 27781287 |
| the role of the residence-effect on the outcome of intergroup encounters in verreaux's sifakas. | intergroup competition has an important impact on the survival and fitness of individuals in group-living species. however, factors influencing the probability of winning an encounter are not fully understood. we studied the influence of numerical advantage and location of the encounter on the chances of winning in eight neighboring groups of verreaux's sifakas (propithecus verreauxi), in kirindy forest, western madagascar. intergroup encounters were inferred from spatial data collected via gps ... | 2016 | 27328940 |
| intergroup encounters in verreaux's sifakas (propithecus verreauxi): who fights and why? | individuals living in groups have to achieve collective action for successful territorial defense. because conflicts between neighboring groups always involve risks and costs, individuals must base their decision to participate in a given conflict on an evaluation of the trade-off between potential costs and benefits. since group members may differ in motivation to engage in group encounters, they exhibit different levels of participation in conflicts. in this study, we investigated factors infl ... | 2017 | 27194822 |
| sequence characterization and phylogeny analysis of the complete mitochondrial genome of verreaux's sifaka, propithecus verreauxi (primates: indriidae). | the verreaux's sifaka, propithecus verreauxi, is a medium-sized lemur that inhabits in tropical dry lowland and montane forest. here, we reported the complete mitochondrial genome sequence of this species. the mitogenome of p. verreauxi is 17 106 bp in length and composed of 13 protein-coding genes (pcgs), 2 ribosomal rna genes, 22 transfer rna genes and a control region. the structure about gene order and composition is identical to that of the other lemur species and related genera. the overal ... | 2016 | 26406276 |
| comparison of three short-term immobilization regimes in wild verreaux's sifakas (propithecus verreauxi): ketamine-xylazine, ketamine-xylazine-atropine, and tiletamine-zolazepam. | although research on lemurid primates in madagascar has been ongoing for several decades, reports on different drug regimes to immobilize wild lemurs are limited. this study compares the efficacy, reliability, and side effects of ketamine-xylazine, ketamine-xylazine-atropine, and tiletamine-zolazepam immobilization in wild verreaux's sifakas (propithecus verreauxi). in the course of a long-term study in kirindy forest, western madagascar, eight animals each received a mixture of ketamine (5.32±1 ... | 2015 | 26352951 |
| patterns of male dispersal in verreaux's sifaka (propithecus verreauxi) at kirindy mitea national park. | males of many group-living mammals emigrate from their social groups to improve mating opportunities. to help mitigate the social and locational costs of dispersal and to increase reproductive benefits, they may immigrate seasonally, immigrate alongside a partner, and/or replace the alpha male (versus entering a group as a subordinate). verreaux's sifaka (propithecus verreauxi) are highly seasonally breeding primates characterized by male-biased dispersal. we hypothesized that (i) males time imm ... | 2017 | 26255992 |
| single-limb force data for two lemur species while vertically clinging. | vertical clinging and climbing have been integral to hypotheses about primate origins, yet little is known about how an animal with nails instead of claws resists gravity while on large, vertical, and cylindrical substrates. here we test models of how force is applied to maintain posture, predicting (1) the shear component force (fs ) at the hands will be higher than the feet; (2) the normal component force (fn ) at the feet will be relatively high compared to the hands; (3) the component force ... | 2015 | 26174130 |
| jaw elevator muscle coordination during rhythmic mastication in primates: are triplets units of motor control? | the activity of mammal jaw elevator muscles during chewing has often been described using the concept of the triplet motor pattern, in which triplet i (balancing side superficial masseter and medial pterygoid; working side posterior temporalis) is consistently activated before triplet ii (working side superficial masseter and medial pterygoid; balancing side posterior temporalis), and each triplet of muscles is recruited and modulated as a unit. here, new measures of unison, synchrony, and coord ... | 2020 | 31821998 |
| dynamics of locomotor transitions from arboreal to terrestrial substrates in verreaux's sifaka (propithecus verreauxi). | most primates are able to move with equal facility on the ground and in trees, but most use the same quadrupedal gaits in both environments. a few specialized primates, however, use a suspensory or leaping mode of locomotion when in the trees but a bipedal gait while on the ground. this is a rare behavioral pattern among mammals, and the extent to which the bipedal gaits of these primates converge and are constrained by the anatomical and neurological adaptations associated with arboreal locomot ... | 2014 | 25237138 |
| stranger to familiar: wild strepsirhines manage xenophobia by playing. | the power of play in limiting xenophobia is a well-known phenomenon in humans. yet, the evidence in social animals remains meager. here, we aim to determine whether play promotes social tolerance toward strangers in one of the most basal group of primates, the strepsirhines. we observed two groups of wild lemurs (propithecus verreauxi, verreaux's sifaka) during the mating season. data were also collected on nine visiting, outgroup males. we compared the distribution of play, grooming, and aggres ... | 2010 | 20949052 |
| grooming patterns in verreaux's sifaka. | lemur grooming has received very little attention in the literature. nevertheless, allogrooming in lemurs has been suggested to be fundamentally different from the grooming of anthropoids. one reason is that lemurs generally rely on oral rather than manual grooming. lemur allogrooming has also been suggested to serve less of a social function than has been attributed to anthropoid grooming. i analyzed the allogrooming behaviors of 29 verreaux's sifaka (propithecus verreauxi) living in five socia ... | 2010 | 19998391 |
| 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 ... | 2011 | 20954249 |
| 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 |
| the responses of verreaux's sifakas to anti-predator alarm calls given by sympatric ring-tailed lemurs. | | 1998 | 9885336 |
| chest staining variation as a signal of testosterone levels in male verreaux's sifaka. | male verreaux's sifaka (propithecus verreauxi) exhibit variation in the staining of chest hair in association with the activity of the sternal gland. scent-marking behavior and social relationships have been shown to vary with the state of chest staining. research on other mammals suggests that sternal gland activity is modulated by testosterone. the goal of this study was to examine the relationship among fecal testosterone, testes mass, and chest staining in sifaka. i predicted that for sifaka ... | 2009 | 19162056 |
| intergroup relations and home range use in verreaux's sifaka (propithecus verreauxi). | relationships between neighboring groups feature prominently in socioecological theory, but few empirical studies have focused on the effects of neighbors on the behavior of primates. interactions between neighboring groups are most conspicuous during intergroup encounters, but the likelihood of encounters with neighbors can also affect ranging and activity patterns indirectly, and, as a result, behavioral patterns in areas of exclusive use may differ from those in overlap areas of adjacent home ... | 2008 | 18613007 |
| morphological integration and natural selection in the postcranium of wild verreaux's sifaka (propithecus verreauxi verreauxi). | morphological integration manifests as strong phenotypic covariation among interacting traits. in this study, a graph-theory approach is used to analyze patterns of morphological integration in a wild population of verreaux's sifaka (propithecus verreauxi verreauxi). the motivation for this study is to determine the relative roles of development versus function in shaping patterns of morphological integration in the sifaka postcranium. a developmental and a functional hypothesis of integration a ... | 2008 | 18322916 |
| influence of reproductive season and rank on fecal glucocorticoid levels in free-ranging male verreaux's sifakas (propithecus verreauxi). | studies in anthropoid primates and other mammals suggest that reproductive season, rank, reproductive skew, aggression received, and social support are the major factors influencing glucocorticoid output. in which way these are also affecting adrenal function in lemurid primates has been studied rarely. here, we examine the influence of reproductive season and rank on glucocorticoid output in male sifakas (propithecus verreauxi), a species characterized by high breeding seasonality, a hierarchy ... | 2007 | 17448474 |
| sifaka positional behavior: ontogenetic and quantitative genetic approaches. | in many primate species, hands and feet are large relative to neonatal body weight, and they subsequently exhibit negative allometric growth during ontogeny. here, data are presented showing that this pattern holds for a wild population of lemur, verreaux's sifaka (propithecus verreauxi verreauxi). using morphometric data collected on this population, it is shown that younger animals possess relatively large hands and feet. this ontogenetic pattern suggests a simple behavioral test: do juvenile ... | 2006 | 16596593 |
| intrasexual selection in verreaux's sifaka (propithecus verreauxi verreauxi). | studies of sexual selection show that both female choice and male-male competition can influence the evolution and expression of male phenotypes. in this regard, it is important to determine the functional basis through which male traits influence variation in male reproductive success. in this study, we estimate the strength and type of sexual selection acting on adult males in a population of wild lemur, verreaux's sifaka (propithecus verreauxi verreauxi). the data used in this study were coll ... | 2005 | 15737393 |
| polyboroides radiatus predation attempts on propithecus verreauxi. | | 2003 | 12778907 |
| increase in tannin consumption by sifaka ( propithecus verreauxi verreauxi) females during the birth season: a case for self-medication in prosimians? | in this study we report preliminary data on the consumption of tannin-rich plants by sifakas (propithecus verreauxi verreauxi) living in the kirindy forest, western madagascar. sifakas spent most of their time feeding on only a few plant species. the tannin intake during the period between the pregnancy and birth season was significantly higher in pregnant females or females with lactating infants than in non-reproductive females and males. these periparturient females secured a larger proportio ... | 2003 | 12548335 |
| characterization and screening of microsatellite loci in a wild lemur population (propithecus verreauxi verreauxi). | sixteen dinucleotide microsatellite loci were isolated from the genome of propithecus verreauxi verreauxi. all loci were polymorphic when genotyped on a minimum of 16 animals. the number of alleles across these loci ranges from two to 11. additionally, seven of these loci were genotyped across a minimum of 200 animals in order to estimate heterozygosity and their potential for parentage assignment in this population. using these seven loci, the mean heterozygosity in this population is 0.705, an ... | 2001 | 11748696 |
| mass change, environmental variability and female fertility in wild propithecus verreauxi. | accurate estimates of mass and size are important in a wide range of research questions in population and evolutionary biology, and yet such data are still rare for wild primates. this study presents detailed longitudinal data from a large population of wild indriids, and demonstrates links between fluctuations in body mass, environmental cycles, and reproduction. understanding these links is a necessary step toward explaining the function and evolution of distinctive features of lemur biology a ... | 2000 | 11006047 |
| physiological suppression of sexual function of subordinate males: a subtle form of intrasexual competition among male sifakas (propithecus verreauxi)? | in contrast to most anthropoid primates, sifakas (propithecus verreauxi), like many group-living lemurs, exhibit a number of features that deviate from predictions of sexual selection theory. despite a promiscuous mating system, they lack sexual dimorphism, suggesting that physical combat plays only a minor role in intrasexual competition for receptive females. in this study, we investigated the hypothesis that socioendocrinological mechanisms contribute to suppression of reproductive function o ... | 1999 | 10405114 |
| reproduction in free-ranging propithecus verreauxi: estrus and the relationship between multiple partner matings and fertilization. | female sifaka mate selectively with one or more resident and/or non-resident males during the breeding season. various adaptive explanations have been advanced to explain why female primates mate with multiple males including that 1) females seek to confuse paternity and thereby forestall male infanticide and/or ensure male infant care or 2) females seek to ensure fertilization. assessing the power of fertilization insurance to explain mating patterns in females requires information on the tempo ... | 1996 | 8859954 |
| olfactory demarcation of territorial boundaries by a primate--propithecus verreauxi. | field observations of a troop of sifaka revealed that they scent mark the boundary areas of their territory far more than they do the interior, both during normal daily movements and during battles between adjacent troops. they are active throughout the territory but spend more time and have a higher frequency of marking at the periphery. | 1979 | 118908 |
| a possible role of plantations for primate conservation in madagascar. | the utilization of eucalyptus plantations by seven sympatric species of prosimians was studied in the eastern rainforest of madagascar. the species were avahi laniger, cheirogaleus major, hapalemur griseus, indri indri, lemur fulvus, lepilemur mustelinus, and microcebus rufus. none of the lemurs was ever found in young eucalyptus plantations with little undergrowth. this was mainly due to the lack of travel opportunities within the shrub layer and between the shrubs and the canopy. food (mainly ... | 1987 | 31973503 |
| leaf chemistry as a predictor of primate biomass and the mediating role of food selection: a case study in a folivorous lemur (propithecus verreauxi). | folivorous primate biomass has been shown to positively correlate with the average protein-to-fiber ratio in mature leaves of tropical forests. however, studies have failed to explain the mismatch between dietary selection and the role of the protein-to-fiber ratio on primate biomass; why do not folivores always favor mature leaves or leaves with the highest protein-to-fiber ratio? we examined the effect of leaf chemical characteristics and plant abundance (using transect censuses; 0.37 ha, 233 ... | 2014 | 24310981 |
| sexual signalling in propithecus verreauxi: male "chest badge" and female mate choice. | communication, an essential prerequisite for sociality, involves the transmission of signals. a signal can be defined as any action or trait produced by one animal, the sender, that produces a change in the behaviour of another animal, the receiver. secondary sexual signals are often used for mate choice because they may inform on a potential partner's quality. verreaux's sifaka (propithecus verreauxi) is characterized by the presence of two different morphs of males (bimorphism), which can show ... | 2012 | 22615982 |
| dynamics and determinants of glucocorticoid metabolite concentrations in wild verreaux's sifakas. | glucocorticoids have wide-ranging effects on animals' behaviour, but many of these effects remain poorly understood because numerous confounding factors have often been neglected in previous studies. here, we present data from a 2-year study of 7 groups of wild verreaux's sifakas (propithecus verreauxi), in which we examined concentrations of faecal glucocorticoid metabolites (fgcms, n = 2350 samples) simultaneously in relation to ambient temperatures, food intake, rank, reproduction, adult sex ... | 2020 | 32330550 |
| subordination signals improve the quality of social relationships in verreaux's sifaka: implications for the evolution of power structures and social complexity. | unidirectional dominance-related signals can be used to communicate submission (an immediate behavioral response) or subordination (the status of an established relationship). subordination signals are defined as emitted during peaceful interactions and are hypothesized to be critical for the evolution of social complexity and robust power structures because they reduce uncertainty in social relationships. the chatter vocalization in verreaux's sifaka (propithecus verreauxi) is a unidirectional ... | 2019 | 31211415 |
| infanticide following male takeover event in verreaux's sifaka (propithecus verreauxi verreauxi). | two infanticides occurred after a male takeover in a population of verreaux's sifaka (propithecus verreauxi verreauxi) at beza mahafaly special reserve, madagascar. the first infant was found dying from wounds received to the chest and groin after three adult males had immigrated into the group. the second infanticide was directly observed 2 weeks later when one of the immigrant males targeted and attacked the infant after it was separated from its mother. the directed nature of the attack sugge ... | 2010 | 19655219 |
| mating first, mating more: biological market fluctuation in a wild prosimian. | in biology, economics, and politics, distributive power is the key for understanding asymmetrical relationships and it can be obtained by force (dominance) or trading (leverage). whenever males cannot use force, they largely depend on females for breeding opportunities and the balance of power tilts in favour of females. thus, males are expected not only to compete within their sex-class but also to exchange services with the opposite sex. does this mating market, described for humans and apes, ... | 2009 | 19262737 |
| hierarchical social networks shape gut microbial composition in wild verreaux's sifaka. | in wild primates, social behaviour influences exposure to environmentally acquired and directly transmitted microorganisms. prior studies indicate that gut microbiota reflect pairwise social interactions among chimpanzee and baboon hosts. here, we demonstrate that higher-order social network structure-beyond just pairwise interactions-drives gut bacterial composition in wild lemurs, which live in smaller and more cohesive groups than previously studied anthropoid species. using 16s rrna gene seq ... | 2017 | 29212730 |
| application of fecal steroid techniques to the reproductive endocrinology of female verreaux's sifaka (propithecus verreauxi). | solid phase extraction, high performance liquid chromatography, and radioimmunoassay were used to test the validity of fecal steroid analysis for assessing ovarian function in sifaka (propithecus verreauxi). daily fecal samples were collected over a 4 month period from two cycling female sifaka, and single samples were collected from females during normal gestation and males while housed at the duke university primate center. tests of radioimmunoassay validity indicated that solid phase extracti ... | 1995 | 31924099 |
| social relations in semi-free-ranging sifakas (propithecus verreauxi coquereli) and the question of female dominance. | female social dominance over males is thought to characterize most of the prosimian primates of madagascar. it has been reported in propithecus verreauxi coquereli in the wild but intersexual relations were not fully characterized. in this paper we examine female-male spatial and agonistic relations in semi-free-ranging p. v. coquereli in order to evaluate intersexual social dominance and related behavioral asymmetries. two hundred hours of focal sampling were conducted on two pairs of p. v. coq ... | 1992 | 31941220 |
| chromosomal evolution in malagasy lemurs: x. chromosomal banding studies of propithecus diadema edwardsi and indri indri and phylogenic relationships between all the species of the indriidae. | the r-banded karyotypes of two indriidae, propithecus diadema and indri indri, are described and compared with each other and with those of the other species of this family, previously reported, avahi laniger and propithecus verreauxi. these comparisons show that 30 chromosomal rearrangements, including 21 robertsonian translocations and eight pericentric inversions, differentiate these karyotypes. a phylogenic diagram is proposed, showing the early separation of avahi and the relatively late di ... | 1988 | 31968877 |
| female social dominance and basal metabolism in a malagasy primate, propithecus verreauxi. | tight energetic constraints on reproductively active females are hypothesized to be an important determinant of the phenomenon of female dominance in propithecus verreauxi, a primate endemic to madagascar. five wild sifakas were captured in the beza mahafaly special reserve in southern madagascar, and resting metabolic rates (rmr) were measured. levels were low, as predicted, with the exception of a possibly pregnant female.; although the data were not conclusive, they were consistent with the h ... | 1987 | 31973498 |
| evaluating the triplet hypothesis during rhythmic mastication in primates. | mammalian mastication involves precise jaw movements including transverse movement of the mandible during the power stroke. jaw elevation and transverse movement are driven by asymmetrical jaw elevator muscle activity, which is thought to include a phylogenetically primitive and conserved triplet motor pattern consisting of: triplet i (balancing side: superficial masseter and medial pterygoid; working side: posterior temporalis), which reaches onset, peak and offset first; and triplet ii (workin ... | 2018 | 29133297 |
| [diurnal activity pattern and seasonal variations of captive papio hamadryas.] | activity rhythms and time budgets are two important components of ecological influences on animal individual behaviors. we collected data on activity pattern using instantaneous scan sampling on captive hamadryas baboons (papio hamadryas) in hangzhou wild animal zoo in zhejiang, china from november 2012 to october 2013. the results showed that: 1) in the activity time allocation, the main activities (frequency percentage was more than or equal to 5%) included resting (42.5%), traveling (16.2%), ... | 2016 | 29696873 |
| dispersal by propithecus verreauxi at beza mahafaly, madagascar: 1984-1991. | from 1984 to 1991, 126 males and females were marked and monitored in a wild population of propithecus verreauxi in southwest madagascar. animals were assigned birth years, based on known birth date or degree of dental wear calibrated by recapture data. twenty-one of 27 groups identified in 1984 persisted within stable home range boundaries, 6 groups disappeared, and 6 new groups formed. only males transferred between existing groups, although individuals of both sexes left groups to form new gr ... | 1993 | 31941176 |