Publications

TitleAbstractYear
Filter
PMID
Filter
ecological correlates to social structure in two lemur species in madagascar.in this study, i tested two hypotheses regarding the relationship of ecological variables (size, density, and distribution of patches) and infant developmental patterns to lemur social structure using two prosimian primates in ranomafana, madagascar: the rufous lemur (eulemur fulvus rufus) and the red-bellied lemur (eulemur rubriventer). three predictions regarding the general effects of patch size and subgroup size on lemur feeding rates were supported: (1) rufous lemurs used large patches; red ...19968842323
special relationships instead of female dominance for redfronted lemurs, eulemur fulvus rufus.most lemurs yet studied in detail exhibit some mode of adult female social dominance over males. the known exception, a brown lemur subspecies known as rufous or redfronted lemurs (eulemur fulvus rufus), forms multimale-multifemale social groups within which unambiguous dominance relations are not observed among adults. resting groups of redfronted lemurs consistently include huddling adult male-female pairs whose males selectively scentmark and rub their heads in the scentmarks of their female ...19979359967
are eulemur species pair-bonded? social organization and mating strategies in eulemur fulvus rufus from 1988-1995 in southeast madagascar.strong social relationships have been reported between adult male and female prosimian primates in the genera eulemur and varecia and have been referred to as "pair-bonding." it has been hypothesized that females benefit from these affiliative relationships with an adult male by having protection against infanticidal males, implying that the male member of the dyad also is the father of her offspring. i evaluated this hypothesis and whether or not the term pair-bond was appropriate by using fiel ...19989511911
seed handling by three prosimian primates in southeastern madagascar: implications for seed dispersal.in this paper, we studied three species of prosimian primate (propithecus diadema edwardsi, eulemur fulvus rufus, and eulemur rubriventer) from june-july 1995 at the ranomafana national park to answer three questions: 1) how they handle and process seeds, 2) how the physical properties of seeds influence seed handling and seed fate, and 3) whether handling and processing patterns influence seed dispersal. seeds from five plant species were collected from feces and examined for external damage (p ...19989573443
the primates of the baly bay area, north-western madagascar.primate surveys were conducted in isolated primary west malagasy decidous forest blocks around baly bay, north-western madagascar. eight species of primate were found, including microcebus c.f. myoxinus, hapalemur griseus occidentalis and phaner furcifer. two species were found only in namoroka strict nature reserve, which may mean that other forest blocks in the area have experienced primate extinctions. the record of m. c.f. myoxinus came from mangrove, the first confirmed record of a lemur fr ...19989885334
life history of eulemur fulvus rufus from 1988-1998 in southeastern madagascar.in this study, we compare the life-history patterns of male and female eulemur fulvus rufus based on longitudinal data collected on individuals from two study groups from 1988-1998 in southeastern madagascar. mean group size was 9.5 individuals, and groups either contained more adult males than females or equal numbers of both sexes. females reproduced for the first time between 2 and 4 years of age and reproduced each year, although the mean interbirth interval between surviving offspring was 2 ...199910096681
nocturnal activity in the cathemeral red-fronted lemur (eulemur fulvus rufus), with observations during a lunar eclipse.several ecological and physiological factors have been suggested to structure circadian activity in cathemeral primates, i.e., those that are regularly active both day and night, but their relative importance remains controversial. we studied the nocturnal activity of a group of cathemeral redfronted lemurs (eulemur fulvus rufus) in kirindy forest in western madagascar to examine its relationship with one environmental factor, ambient light levels, in detail. to this end, nightly travel distance ...200111170168
genetic assessment of a white-collared x red-fronted lemur hybrid zone at andringitra, madagascar.we examined a purported lemur (eulemur fulvus rufusxe. albocollaris) hybrid zone at andringitra, madagascar, using sequences from five genes (one mitochondrial gene (d-loop) and four nuclear introns (hemopexin, malic enzyme, ceruloplasmin, and microsatellite 26 flanking region)), from 60 individuals (e. albocollaris (n = 16), e.f. rufus (n = 14), e. collaris (n = 9), and purported hybrids from andringitra (n = 21)). diagnostic (d-loop and microsatellite 26) and private sites (all other genes) we ...200212111681
intersexual dominance, masculinized genitals and prenatal steroids: comparative data from lemurid primates.masculinization of female genitalia and female intersexual dominance distinguish spotted hyenas (crocuta crocuta) and malagasy primates (lemuriformes) from most other mammals. an unusual prenatal endocrine environment has been proposed to proximately underlie the development of these traits in hyenas. to examine whether female dominance and genital masculinization are similarly enhanced by the prenatal environment in lemurid primates, we measured androgen and estrogen excretion in pregnant wild ...200312649757
edge effects and their influence on lemur density and distribution in southeast madagascar.edge effects are caused by the penetration of abiotic and biotic conditions from the matrix into forest interiors. although edge effects influence the biogeography of many tropical organisms, they have not been studied directly in primates. edge effects are particularly relevant to lemurs due to the loss of 80-90% of forests in madagascar. in this study, data are presented on how biotic edge effects influenced the distribution and density of lemurs in the vohibola iii classified forest in southe ...200616323178
spatial variations in eulemur fulvus rufus and lepilemur mustelinus densities in madagascar.i present data on variations in eulemur fulvus rufus and lepilemur mustelinus densities as well as tree characteristics (height, diameter and stem frequency) between edge and interior forest habitats in southeastern madagascar. line transect surveys were conducted from june 2003 to november 2005 in edge and interior forest habitats in the vohibola iii classified forest. although e. f. rufus densities were significantly lower in edge habitats than in interior habitats, density estimates for l. mu ...200717170556
habitat use and social structure of a brown lemur hybrid population in the berenty reserve, madagascar.the population of brown lemurs has rapidly grown since their founders were introduced to the berenty reserve. the founders consist of two species (eulemur fulvus rufus and e. collaris). to characterize the behavior of the population and to examine whether these characteristics affect population growth, i investigated the habitat use and social structure of the population of brown lemurs at berenty (berenty eulemur). behavior data were collected focusing on horizontal and vertical habitat use, ac ...200717294429
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 ...200517312713
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 ...200817705223
spatial memory during foraging in prosimian primates: propithecus edwardsi and eulemur fulvus rufus.a variety of anthropoids travel efficiently from one food source to another, although there is disagreement over how this is accomplished over large-scale space. mental maps, for example, require that animals internally represent space, geometrically locate landmarks, use true distance and direction, and generate novel shortcuts to resources. alternately, topological or route-based maps are based on a network of fixed points, landmarks and routes so that one food patch can be linked with another ...200818176079
what is it going to be? pattern and potential function of natal coat change in sexually dichromatic redfronted lemurs (eulemur fulvus rufus).in some primate species, pelage colorations at birth contrast with adult colorations. the intensity of natal coats and their phylogenetic distribution is highly variable within primates. natal coat coloration seems to change to adult coloration in most species when infants become independent from their mothers, but an accepted functional explanation for natal coats is not available. here we describe pelage coloration change in sexually dichromatic redfronted lemurs (eulemur fulvus rufus) in kiri ...200918615575
object permanence in lemurs.object permanence, the ability to mentally represent objects that have disappeared from view, should be advantageous to animals in their interaction with the natural world. the objective of this study was to examine whether lemurs possess object permanence. thirteen adult subjects representing four species of diurnal lemur (eulemur fulvus rufus, eulemur mongoz, lemur catta and hapalemur griseus) were presented with seven standard piagetian visible and invisible object displacement tests, plus on ...200918936991
gastro-intestinal parasites of red-fronted lemurs in kirindy forest, western madagascar.although parasites are important regulatory factors in animal populations, basic knowledge on their fauna in many vertebrate taxa is lacking. in particular, parasite infections of primate species have gained little attention. here, i present data on the gastro-intestinal fauna of a population of wild red-fronted lemurs ( eulemur fulvus rufus; primates: lemuriformes) monitored over a total of 8 mo during 2 consecutive field seasons in 2006 and 2007 in kirindy forest, western madagascar. using fec ...201019954263
host intrinsic determinants and potential consequences of parasite infection in free-ranging red-fronted lemurs (eulemur fulvus rufus).parasites and infectious diseases represent ecological forces shaping animal social evolution. although empirical studies supporting this link abound in various vertebrate orders, both the study of the dynamics and impact of parasite infections and infectious diseases in strepsirrhine primates have received little empirical attention. we conducted a longitudinal parasitological study on four groups of wild red-fronted lemurs (eulemur fulvus rufus) at kirindy forest, madagascar, during two field ...201020091843
genetic regulation of parasite infection: empirical evidence of the functional significance of an il4 gene snp on nematode infections in wild primates.susceptibility to parasite infection affects fitness-related processes, such as mate choice and survival, yet its genetic regulation remains poorly understood. interleukin-4 (il4) plays a central role in the humoral immune defence against nematode parasite infections, inducing ige switch and regulation of worm expulsion from the intestines. the evolutionary and functional significance of single nucleotide polymorphisms (snps) in il4-genes is known, yet empirical information on the effect of il4 ...201121501512
costs and benefits of multi-male associations in redfronted lemurs (eulemur fulvus rufus).the evolution of group-living has fascinated but also puzzled researchers from the inception of behavioural ecology. we use a simple optimality approach to examine some of the costs and benefits of group-living in redfronted lemurs (eulemur fulvus rufus). we show that dominant males profit from accepting subordinates within their groups, as the latter significantly decrease the likelihood that the group is taken over by intruders. this benefit is large enough to outweigh the costs of reproductiv ...201020236969
individual facial coloration in male eulemur fulvus rufus: a condition-dependent ornament?researchers studying individual variation in conspicuous skin coloration in primates have suggested that color indicates male quality. although primate fur color can also be flamboyant, the potential condition dependence and thus signaling function of fur remains poorly studied. we studied sources of variation in sexually dichromatic facial hair coloration in red-fronted lemurs (eulemur fulvus rufus). we collected data on 13 adult males in kirindy forest, madagascar, during two study periods in ...200919946601
population demography and social structure changes in eulemur fulvus rufus from 1988 to 2003.eulemur fulvus rufus has been described as having stable multi-male/multi-female groups, a male-biased sex ratio, and female philopatry. however, in a 16-year study of this subspecies we documented a great deal of demographic change as several groups permanently fissioned, some groups disappeared, and new groups formed. we split the dataset into two periods, 1988 to 1993 and 1994 to 2003, which coincided with the first disappearance of a study group (in august 1994) and the first permanent group ...200818257015
androgen and glucocorticoid levels reflect seasonally occurring social challenges in male redfronted lemurs (eulemur fulvus rufus).intense reproductive competition and social instability are assumed to increase concentrations of glucocorticoids and androgens in vertebrates, as a means of coping with these challenges. in seasonally breeding redfronted lemurs (eulemur fulvus rufus), the mating and the birth season and the associated increased male competition are predicted to pose such reproductive challenges. in this paper, we investigate seasonal variation in hormone excretion in male redfronted lemurs, and examine whether ...200819816530
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 ...200412827548
endocrine characterization of female reproductive status in wild redfronted lemurs (eulemur fulvus rufus).in order to characterize the endocrine changes associated with ovarian function and pregnancy in wild redfronted lemurs (eulemur fulvus rufus), profiles of immunoreactive 5alpha-pregnane-3alpha-ol-20-one (5-p-3oh) and total estrogens (e(t)) in feces were generated during the breeding season and gestation. hplc data confirmed the presence of high amounts of 5-p-3oh in the feces of redfronted lemurs and showed that estrone and estradiol-17beta were the major estrogens excreted into feces, with est ...200312714009
social thermoregulation in redfronted lemurs (eulemur fulvus rufus).pronounced seasonality, with temperatures dropping as low as 5 degrees c during the dry season, has led to the hypothesis that malagasy lemurs face cold stress and respond to this by inactivity and social thermoregulation, i.e. resting in tight body contact with conspecifics. compared to anthropoids, lemur groups are comprised of an unusually high number of males, leading to an even or slightly male-biased adult sex ratio. according to one hypothesis, females may benefit from these surplus males ...200812399657
central males instead of multiple pairs in redfronted lemurs, eulemur fulvus rufus (primates, lemuridae)?in group-living malagasy primates (lemuriformes), certain demographic and morphological traits deviate both from theoretical expectations derived from sexual selection theory and from patterns in better-known anthropoid primates. lemurs lack sexual dimorphism in body and canine size and live in relatively small multimale-multifemale groups with, on average, even adult sex ratios, despite a polygynous mating system. in addition, the majority of gregarious lemurs are cathemeral, that is, they are ...199910564609
coordination of group movements in wild red-fronted lemurs (eulemur rufifrons): processes and influence of ecological and reproductive seasonality.group-living species have to coordinate collective actions to maintain cohesion. in primates, spatial movements represent a meaningful model to study group coordination processes across different socio-ecological contexts. we studied 4 groups of red-fronted lemurs (eulemur rufifrons) in kirindy forest, madagascar, between 2008 and 2010 across different ecological and reproductive seasons. we collected data on ranging patterns using gps collars and observational data on different predefined param ...201122207771
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 ...201525653908
should i stay or should i go? individual movement decisions during group departures in red-fronted lemurs.collective movements are essential for maintaining group cohesion. however, group members can have different optimal departure times, depending on individual, social and contextual factors whose relative importance remains poorly known. we, therefore, studied collective departures in four groups of red-fronted lemurs (eulemur rufifrons) in kirindy forest, madagascar, to investigate the influence of an individual's age, sex, their affiliative relationships and their proximity to other group membe ...201931031989
determining mhc-drb profiles in wild populations of three congeneric true lemur species by noninvasive methods.the major histocompatibility complex (mhc) is a highly polymorphic and polygenic genomic region that plays a crucial role in immune-related diseases. given the need for comparative studies on the variability of immunologically important genes among wild populations and species, we investigated the allelic variation of mhc class ii drb among three congeneric true lemur species: the red-fronted lemur (eulemur rufifrons), red-bellied lemur (eulemur rubriventer), and black lemur (eulemur macaco). we ...201930324236
potential self-medication using millipede secretions in red-fronted lemurs: combining anointment and ingestion for a joint action against gastrointestinal parasites?self-anointing, referring to the behaviour of rubbing a material object or foreign substance over different parts of the body, has been observed in several vertebrate species, including primates. several functions, such as detoxifying a rich food source, social communication and protection against ectoparasites, have been proposed to explain this behaviour. here, we report observations of six wild red-fronted lemurs (eulemur rufifrons) of both sexes and different age classes anointing their peri ...201830058024
the role of facial pattern variation for species recognition in red-fronted lemurs (eulemur rufifrons).species recognition, i.e., the ability to distinguish conspecifics from heterospecifics, plays an essential role in reproduction. the role of facial cues for species recognition has been investigated in several non-human primate species except for lemurs. we therefore investigated the role of facial cues for species recognition in wild red-fronted lemurs (eulemur rufifrons) at kirindy forest. we presented adult red-fronted lemurs pictures of male faces from five species including red-fronted lem ...201829433448
ecological correlates to activity and habitat use of two prosimian primates: eulemur rubriventer and eulemur fulvus rufus in madagascar.in this paper, i provide data on the possible effects of group size and seasonal changes in food availability on the activity and habitat use patterns of two species of prosimian primate: the rufous lemur (eulemur fulvus rufus) and the red-bellied lemur (eulemur rubriventer). general and subtle seasonal differences were observed between lemur species in (1) group size and composition, (2) activity profiles, and (3) habitat use. rufous lemur groups were larger (mean = 8 individuals) and contained ...199631918523
differential patterns in flower feeding by eulemur fulvus rufus and eulemur rubriventer in madagascar.in this paper, i describe the differential patterns of flower feeding observed in rufous lemurs (eulemur fulvus rufus) and red-bellied lemurs (e. rubriventer) in the ranomafana national park, madagascar. red-bellied lemurs licked nectar from flowers while rufous lemurs ate all flower parts from the same flower species. several hypotheses are examined to explain the significance of flower feeding in these two species. in many primate species, flower feeding functions as a keystone resource and/or ...199231941214
Displaying items 1 - 36 of 36