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Peter M. Kappeler - One of the best experts on this subject based on the ideXlab platform.
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species discovery and validation in a cryptic radiation of endangered primates coalescent based species delimitation in madagascar s mouse lemurs
Molecular Ecology, 2016Co-Authors: Scott Hotaling, Peter M. Kappeler, Meredith A. Barrett, Marina B. Blanco, Rodin M. Rasoloarison, Mary E Foley, Nicolette M Lawrence, Jose L Bocanegra, Anne D. YoderAbstract:Implementation of the coalescent model in a Bayesian framework is an emerging strength in genetically based species delimitation studies. By providing an objective measure of species diagnosis, these methods represent a quantitative enhancement to the analysis of multilocus data, and complement more traditional methods based on phenotypic and ecological characteristics. Recognized as two species 20 years ago, mouse lemurs (genus Microcebus) now comprise more than 20 species, largely diagnosed from mtDNA sequence data. With each new species description, enthusiasm has been tempered with scientific scepticism. Here, we present a statistically justified and unbiased Bayesian approach towards mouse lemur species delimitation. We perform validation tests using multilocus sequence data and two methodologies: (i) reverse-jump Markov chain Monte Carlo sampling to assess the likelihood of different models defined a priori by a guide tree, and (ii) a Bayes factor delimitation test that compares different species-tree models without a guide tree. We assess the sensitivity of these methods using randomized individual assignments, which has been used in bpp studies, but not with Bayes factor delimitation tests. Our results validate previously diagnosed taxa, as well as new species hypotheses, resulting in support for three new mouse lemur species. As the challenge of multiple researchers using differing criteria to describe diversity is not unique to Microcebus, the methods used here have significant potential for clarifying diversity in other taxonomic groups. We echo previous studies in advocating that multiple lines of evidence, including use of the coalescent model, should be trusted to delimit new species.
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Agent-mediated spatial storage effect in heterogeneous habitat stabilizes competitive mouse lemur coexistence in Menabe Central, Western Madagascar
BMC Ecology, 2015Co-Authors: Livia Schäffler, Joachim Saborowski, Peter M. KappelerAbstract:Background 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 heterogeneities with the specific goal of elucidating the mechanisms stabilizing competitive coexistence of the two mouse lemur species (Microcebus spp.).
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Agent-mediated spatial storage effect in heterogeneous habitat stabilizes competitive mouse lemur coexistence in Menabe Central, Western Madagascar
BMC Ecology, 2015Co-Authors: Livia Schäffler, Joachim Saborowski, Peter M. KappelerAbstract:Background 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 heterogeneities with the specific goal of elucidating the mechanisms stabilizing competitive coexistence of the two mouse lemur species ( Microcebus spp.). Results Interspecific competition between the mouse lemurs was indicated by negative spatial associations in degraded habitat and by habitat partitioning along anthropogenic disturbance gradients during dry seasons with resource scarcity. In non-degraded habitat, intraguild predator M. coquereli , but not C. medius, was negatively associated with M. murinus on the population level, whereas its regional distribution overlapped spatially with that of M. berthae . The species’ interspecific distribution pattern across spatial and temporal heterogeneities corresponded to predictions for agent-mediated coexistence and thus confirmed M. coquereli ’s stabilizing impact on the coexistence of mouse lemurs. Conclusions Interspecific interactions contribute to ecological structure in this cheirogaleid assemblage and determinants vary across spatio-temporal heterogeneities. Coexistence of Microcebus spp. is stabilized by an agent-mediated spatial storage effect: M. coquereli creates refuges from competition for M. berthae in intact habitat, whereas anthropogenic environments provide M. murinus with an escape from resource competition and intraguild predation. Species persistence in the assemblage therefore depends on the conservation of habitat content and context that stabilizing mechanisms rely on. Our large-scale population level approach did not allow for considering all potential functional and stochastic drivers of ecological structure, a key limitation that accounts for the large proportion of unexplained variance in our models.
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mhc class ii variation in a rare and ecological specialist mouse lemur reveals lower allelic richness and contrasting selection patterns compared to a generalist and widespread sympatric congener
Immunogenetics, 2015Co-Authors: Eva Pechouskova, Peter M. Kappeler, Melanie Dammhahn, Claudia Fichtel, Markus Brameier, Elise HuchardAbstract:The polymorphism of immunogenes of the major histocompatibility complex (MHC) is thought to influence the functional plasticity of immune responses and, consequently, the fitness of populations facing heterogeneous pathogenic pressures. Here, we evaluated MHC variation (allelic richness and divergence) and patterns of selection acting on the two highly polymorphic MHC class II loci (DRB and DQB) in the endangered primate Madame Berthe’s mouse lemur (Microcebus berthae). Using 454 pyrosequencing, we examined MHC variation in a total of 100 individuals sampled over 9 years in Kirindy Forest, Western Madagascar, and compared our findings with data obtained previously for its sympatric congener, the grey mouse lemur (Microcebus murinus). These species exhibit a contrasting ecology and demography that were expected to affect MHC variation and molecular signatures of selection. We found a lower allelic richness concordant with its low population density, but a similar level of allelic divergence and signals of historical selection in the rare feeding specialist M. berthae compared to the widespread generalist M. murinus. These findings suggest that demographic factors may exert a stronger influence than pathogen-driven selection on current levels of allelic richness in M. berthae. Despite a high sequence similarity between the two congeners, contrasting selection patterns detected at DQB suggest its potential functional divergence. This study represents a first step toward unravelling factors influencing the adaptive divergence of MHC genes between closely related but ecologically differentiated sympatric lemurs and opens new questions regarding potential functional discrepancy that would explain contrasting selection patterns detected at DQB.
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females go where the food is does the socio ecological model explain variation in social organisation of solitary foragers
Behavioral Ecology and Sociobiology, 2009Co-Authors: Melanie Dammhahn, Peter M. KappelerAbstract:The socio-ecological model (SEM) links ecological factors with characteristics of social systems and allows predictions about the relationships between resource distribution, type of competition and social organisation. It has been mainly applied to group-living species but ought to explain variation in social organisation of solitary species as well. The aim of this study was to test basic predictions of the SEM in two solitary primates, which differ in two characteristics of female association patterns: (1) spatial ranging and (2) sleeping associations. Beginning in August 2002, we regularly (re-)captured and marked individuals of sympatric populations of Madame Berthe's and grey mouse lemurs (Microcebus berthae, Microcebus murinus) in Kirindy Forest (Madagascar). We recorded data on spatial patterns, feeding and social behaviour by means of direct observation of radio-collared females. The major food sources of M. berthae occurred in small dispersed patches leading to strong within-group scramble competition and over-dispersed females with a low potential for female associations. In contrast, M. murinus additionally used patchily distributed, high-quality (large) resources facilitating within-group contest competition. The combined influence of less strong within-group scramble and contest as well as between-group contest over non-food resources allowed females of this species to cluster in space. Additionally, we experimentally manipulated the spatial distribution of food sources and found that females adjusted their spatial patterns to food resource distribution. Thus, our results support basic predictions of the SEM and demonstrated that it can also explain variation in social organisation of solitary foragers.
Ute Radespiel - One of the best experts on this subject based on the ideXlab platform.
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forest edges affect ectoparasite infestation patterns of small mammalian hosts in fragmented forests in madagascar
International Journal for Parasitology, 2020Co-Authors: Frederik Kiene, Ute Radespiel, Bertrand Andriatsitohaina, Malcolm S Ramsay, Herinjatovo Rakotondramanana, Romule Rakotondravony, Christina StrubeAbstract:Habitat loss and fragmentation drive the worldwide depletion of biodiversity. Although it is known that anthropogenic disturbances severely affect host and ecosystem integrity, effects on parasites are largely understudied. This study aims to investigate if and how habitat fragmentation affects the composition of ectoparasite communities on small mammalian hosts in two networks of dry deciduous forest fragments in northwestern Madagascar. Forest sites differing in size, proportion of edge habitat and host density were studied in the Ankarafantsika National Park and in the Mariarano region. A total of 924 individuals of two mouse lemur species, Microcebus murinus (n = 200) and Microcebus ravelobensis (n = 426), and two rodent species, endemic Eliurus myoxinus (n = 114) and introduced Rattus rattus (n = 184), were captured to assess ectoparasite infestations. Ectoparasite prevalence and ectoparasite species richness were statistically related to nine ecological variables applying generalized linear mixed models. Hosts harbored ticks (Haemaphysalis microcebi), mites (Schoutedenichia microcebi, Listrophoroides spp., Laelaptidae gen. spp.) and sucking lice (Lemurpediculus spp., Polyplax sp., Hoplopleuridae gen. sp.). Parasite prevalence differed significantly between host species for all detected parasite taxa. Proximity to the forest edge led to a significant reduction in ectoparasites. Parasite-specific edge effects were observed up to a distance of 750 m from the forest edge. The obtained results imply that habitat fragmentation impacts ectoparasite communities, in particular by negatively affecting temporary parasite species. The results are best explained by an interplay of parasite life cycles, responses to changes in abiotic factors induced by edges and host-specific responses to habitat fragmentation. The negative responses of most studied ectoparasite taxa to forest edges and habitat fragmentation demonstrate their ecological vulnerability that may eventually threaten the integrity of ecosystems and potentially impact ectoparasite biodiversity worldwide.
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a new species of schoutedenichia jadin vercammen grandjean 1954 from madagascar and a re description of s dutoiti radford 1948 from south africa acariformes trombiculidae
Systematic Parasitology, 2019Co-Authors: Alexandr A Stekolnikov, Sharon E Kessler, Alida F Hasiniaina, Ute Radespiel, Elke Zimmermann, Sonja Matthee, Lance A DurdenAbstract:A new chigger mite species, Schoutedenichia microcebi n. sp. is described from the grey mouse lemur Microcebus murinus (J.F. Miller) from Madagascar. The new species is closely related to S. dutoiti (Radford, 1948), a species described from a single specimen collected on a rodent in South Africa. Examination of the holotype and new material on S. dutoiti from South Africa enabled us to re-describe this species and provide new data on its hosts and geographical distribution.
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a new species of sucking louse phthiraptera anoplura polyplacidae from the gray mouse lemur Microcebus murinus primates cheirogaleidae in madagascar
Journal of Medical Entomology, 2018Co-Authors: Lance A Durden, Sharon E Kessler, Alida F Hasiniaina, Ute Radespiel, Elke Zimmermann, Sarah ZohdyAbstract:Lemurpediculus madagascariensis sp. nov. (Phthiraptera: Anoplura: Polyplacidae) is described from the Gray Mouse lemur, Microcebus murinus (J. F. Miller) (Primates: Cheirogaleidae), from Ankarafantsika National Park, Madagascar. Lemurs were trapped using Sherman Live Traps and visually inspected for lice, which were preserved in 90% ethanol. Adults of both sexes and the third-instar nymph of the new species are illustrated and distinguished from the four previously known species of Lemurpediculus: L. verruculosus (Ward); L. petterorum Paulian; L. claytoni Durden, Blanco, and Seabolt; and L. robbinsi Durden, Blanco, and Seabolt. It is not known if the new species of louse is a vector of any pathogens or parasites.
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characterisation of urinary wfdc12 in small nocturnal basal primates mouse lemurs Microcebus spp
Scientific Reports, 2017Co-Authors: Jennifer Unsworth, Elke Zimmermann, Grace M Loxley, Amanda J Davidson, Jane L Hurst, Guadalupe Gomezbaena, Nicholas I Mundy, Robert J Beynon, Ute RadespielAbstract:Mouse lemurs are basal primates that rely on chemo- and acoustic signalling for social interactions in their dispersed social systems. We examined the urinary protein content of two mouse lemurs species, within and outside the breeding season, to assess candidates used in species discrimination, reproductive or competitive communication. Urine from Microcebus murinus and Microcebus lehilahytsara contain a predominant 10 kDa protein, expressed in both species by some, but not all, males during the breeding season, but at very low levels by females. Mass spectrometry of the intact proteins confirmed the protein mass and revealed a 30 Da mass difference between proteins from the two species. Tandem mass spectrometry after digestion with three proteases and sequencing de novo defined the complete protein sequence and located an Ala/Thr difference between the two species that explained the 30 Da mass difference. The protein (mature form: 87 amino acids) is an atypical member of the whey acidic protein family (WFDC12). Seasonal excretion of this protein, species difference and male-specific expression during the breeding season suggest that it may have a function in intra- and/or intersexual chemical signalling in the context of reproduction, and could be a cue for sexual selection and species recognition.
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Additional file 1: of Population genetics of mouse lemur vomeronasal receptors: current versus past selection and demographic inference
2017Co-Authors: Philipp Hohenbrink, Nicholas Mundy, Ute RadespielAbstract:IDs of the sampled individuals; the table contains the IDs of all males and females that were used for sequencing 17 VR loci in the two mouse lemur species Microcebus murinus (n = 20) and M. ravelobensis (n = 20) in the study site JBA. (DOCX 14 kb
Elke Zimmermann - One of the best experts on this subject based on the ideXlab platform.
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a new species of schoutedenichia jadin vercammen grandjean 1954 from madagascar and a re description of s dutoiti radford 1948 from south africa acariformes trombiculidae
Systematic Parasitology, 2019Co-Authors: Alexandr A Stekolnikov, Sharon E Kessler, Alida F Hasiniaina, Ute Radespiel, Elke Zimmermann, Sonja Matthee, Lance A DurdenAbstract:A new chigger mite species, Schoutedenichia microcebi n. sp. is described from the grey mouse lemur Microcebus murinus (J.F. Miller) from Madagascar. The new species is closely related to S. dutoiti (Radford, 1948), a species described from a single specimen collected on a rodent in South Africa. Examination of the holotype and new material on S. dutoiti from South Africa enabled us to re-describe this species and provide new data on its hosts and geographical distribution.
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a new species of sucking louse phthiraptera anoplura polyplacidae from the gray mouse lemur Microcebus murinus primates cheirogaleidae in madagascar
Journal of Medical Entomology, 2018Co-Authors: Lance A Durden, Sharon E Kessler, Alida F Hasiniaina, Ute Radespiel, Elke Zimmermann, Sarah ZohdyAbstract:Lemurpediculus madagascariensis sp. nov. (Phthiraptera: Anoplura: Polyplacidae) is described from the Gray Mouse lemur, Microcebus murinus (J. F. Miller) (Primates: Cheirogaleidae), from Ankarafantsika National Park, Madagascar. Lemurs were trapped using Sherman Live Traps and visually inspected for lice, which were preserved in 90% ethanol. Adults of both sexes and the third-instar nymph of the new species are illustrated and distinguished from the four previously known species of Lemurpediculus: L. verruculosus (Ward); L. petterorum Paulian; L. claytoni Durden, Blanco, and Seabolt; and L. robbinsi Durden, Blanco, and Seabolt. It is not known if the new species of louse is a vector of any pathogens or parasites.
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characterisation of urinary wfdc12 in small nocturnal basal primates mouse lemurs Microcebus spp
Scientific Reports, 2017Co-Authors: Jennifer Unsworth, Elke Zimmermann, Grace M Loxley, Amanda J Davidson, Jane L Hurst, Guadalupe Gomezbaena, Nicholas I Mundy, Robert J Beynon, Ute RadespielAbstract:Mouse lemurs are basal primates that rely on chemo- and acoustic signalling for social interactions in their dispersed social systems. We examined the urinary protein content of two mouse lemurs species, within and outside the breeding season, to assess candidates used in species discrimination, reproductive or competitive communication. Urine from Microcebus murinus and Microcebus lehilahytsara contain a predominant 10 kDa protein, expressed in both species by some, but not all, males during the breeding season, but at very low levels by females. Mass spectrometry of the intact proteins confirmed the protein mass and revealed a 30 Da mass difference between proteins from the two species. Tandem mass spectrometry after digestion with three proteases and sequencing de novo defined the complete protein sequence and located an Ala/Thr difference between the two species that explained the 30 Da mass difference. The protein (mature form: 87 amino acids) is an atypical member of the whey acidic protein family (WFDC12). Seasonal excretion of this protein, species difference and male-specific expression during the breeding season suggest that it may have a function in intra- and/or intersexual chemical signalling in the context of reproduction, and could be a cue for sexual selection and species recognition.
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fo e
2016Co-Authors: Heike Lutermann, Ute Radespiel, Barthel Schmelting, Elke ZimmermannAbstract:The role of survival for the evolution of female philopatry in a solitary forager, the grey mouse lemur (Microcebus murinus
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context specific calls signal infants needs in a strepsirrhine primate the gray mouse lemur Microcebus murinus
Developmental Psychobiology, 2007Co-Authors: Marina Scheumann, Elke Zimmermann, Guntram DeichselAbstract:The presence of context-specific communication sounds, structurally different call types related to particular situations and potentially expressing distinct emotions of the caller, were not systematically studied in infants of strepsirrhine primates. We exposed suckling's of gray mouse lemurs (Microcebus murinus) in an infant separation paradigm to three distinct contexts (isolation, threat-induced, grooming). An audio–videographic analysis of sound-correlated infant behaviors and a simultaneous multiparametric sound analysis revealed context-specific calls. Peak frequency predicted their acoustic classification best. Findings provided first evidence for a strepsirrhine primate that infant communication sounds may express distinct contexts and thereby infant's need reliably. © 2007 Wiley Periodicals, Inc. Dev Psychobiol 49: 708–718, 2007.
Jorg U Ganzhorn - One of the best experts on this subject based on the ideXlab platform.
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seasonal variations in gastrointestinal parasites excreted by the gray mouse lemur Microcebus murinus in madagascar
Endangered Species Research, 2010Co-Authors: Brigitte M Raharivololona, Jorg U GanzhornAbstract:We describe seasonal variations in gastrointestinal parasites found in feces of the gray mouse lemur Microcebus murinus. Our study was carried out in the evergreen littoral forest of Mandena, Madagascar. Fecal samples from M. murinus caught during monthly trapping sessions were screened for eggs and larvae of intestinal parasites. Gastrointestinal parasite infection of M. murinus was charac- terized by parasite species richness, the prevalence of parasites, and the intensity of infection expressed as the number of parasite eggs, larvae, and cysts per g feces. We used a modification of the McMaster flotation egg counting technique to quantify parasite egg shedding. Parasite excretions changed season- ally when analyzed on the level of individual hosts. The number of parasite species and the abundance of parasite eggs and larvae in Microcebus feces were higher during the hot season than during the cold season. Reduced parasite excretion during the cold season could be due to environmental factors or to the ability of M. murinus to enter torpor and hibernation during the cold season, which might lead to re- duced metabolism of intestinal parasites and might thus result in reduced shedding of eggs. No such variation was found when the analyses were based on samples of unknown origin.
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gastrointestinal parasite infection of the gray mouse lemur Microcebus murinus in the littoral forest of mandena madagascar effects of forest fragmentation and degradation
Madagascar Conservation & Development, 2009Co-Authors: Brigitte M Raharivololona, Jorg U GanzhornAbstract:Faecal material from 169 individuals of Microcebus murinus living in five littoral forest fragments was analyzed for gastrointestinal parasites. The fragments differed in size and forest quality. Gastrointestinal parasite infection of M. murinus was characterised using parasite species richness, the prevalence of parasites, and the intensity of infection expressed as the number of parasite eggs, larvae and cysts per gram of faeces. For this, a modification of the McMaster flotation egg counting technique was applied to analyze egg shedding. We recorded nine gastrointestinal parasite species in faecal samples of Microcebus murinus . In good quality forest lemurs from a smaller fragment had higher prevalences and intensities of infection of gastrointestinal nematodes and protozoans than animals from a larger forest fragment. In large forests, excretion of eggs from Ascarididae and tapeworms was higher in a degraded forest fragment than in a good quality forest fragment. This situation was reversed in small forest fragments with fewer eggs of Suburula nematodes and protozoans shed by lemurs in the degraded fragment than by lemurs from the good quality fragment. Our analyses are hampered by the fact that we had only one forest fragment per type of treatment. Keeping this limitation in mind, the results are consistent with other studies and indicate that forest degradation and fragmentation have marked effects on the level of parasitism of Madagascar’s lemurs. RESUME Des matieres fecales de 169 individus de Microcebus murinus vivant dans cinq fragments de foret littorale du sud de Madagascar ont ete analysees par la methode modifiee de flottaison de McMaster. Ces animaux avaient ete captures entre avril 2003 et octobre 2005. Les fragments de foret different entre eux par la taille et le degre de degradation. Pour etudier l’impact de la fragmentation et de la degradation de la foret sur l’infestation parasitaire de cette espece de lemurien, trois criteres ont ete evalues qui sont le nombre d’especes de parasite, la prevalence et l’intensite de l’infestation. Les fragments ayant des tailles differentes mais montrant un meme type de degradation ont fait l’objet d’une comparaison au meme titre que des fragments presentant un meme degre de degradation mais de memes tailles. Neuf especes de parasites gastro-intestinaux ont ete recensees chez Microcebus murinus de la foret de Mandena dont six nematodes avec une espece non-identifiee de la famille des Ascarididae et de l’ordre des Strongylida, Trichuris sp., deux especes d’Oxyuridae dont l’une est du genre Lemuricola et une autre qui n’est pas encore identifiee, Subulura sp., deux cestodes appartenant au genre Hymenolepis et un protozoaire de l’ordre des Coccidia. La fragmentation et la degradation de la foret de Mandena affectent le parasitisme de cette espece de lemurien. Les deux tendances qui ressortent de cette etude sont, d’une part, une augmentation de l’intensite et de la prevalence des parasites gastro-intestinaux de Microcebus murinus dans les plus petits fragments forestiers et d’autre part, une augmentation qui semble etre en relation avec le degre de degradation de la foret dans les plus grands fragments. L’augmentation du nombre d’especes de parasites avec la taille des fragments peut etre une consequence de la taille des fragments ou du nombre d’animaux echantillonnes. Dans les grands fragments, les microcebes sont plus souvent infestes par les deux especes de cestode lorsqu’ils sont dans des forets degradees que dans les fragments plus ou moins intacts. Dans les plus grandes parcelles forestieres, la prevalence et l’intensite de l’infestation parasitaire sont plus elevees chez les microcebes vivant dans les fragments tres degrades. Ce fait pourrait etre du a la reduction ou la perte de l’habitat associee a l’organisation sociale de l’animal car M. murinus dort en groupe pendant le jour, de sorte qu’une reduction de son habitat pourrait favoriser une augmentation des contacts interindividuels et la transmission de parasites, bien que l’infestation des microcebes n’etait pas liee a la densite des hotes d’une maniere significative. En connaissant l’effet nefaste des parasites, cette etude contribuerait a l’amelioration de la conservation de la biodiversite en relation avec les risques et les benefices des activites d’exploitation et de gestion de l’ecosysteme.
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Sensory Basis of Food Detection in Wild Microcebus murinus
International Journal of Primatology, 2007Co-Authors: Björn M. Siemers, Holger R. Goerlitz, Eric Robsomanitrandrasana, Marcus Piep, Jean-baptiste Ramanamanjato, Daniel Rakotondravony, Olga Ramilijaona, Jorg U GanzhornAbstract:Very little is known about how nocturnal primates find their food. Here we studied the sensory basis of food perception in wild-caught gray mouse lemurs (Microcebus murinus) in Madagascar. Mouse lemurs feed primarily on fruit and arthropods. We established a set of behavioral experiments to assess food detection in wild-born, field-experienced mouse lemurs in short-term captivity. Specifically, we investigated whether they use visual, auditory, and motion cues to find and to localize prey arthropods and further whether olfactory cues are sufficient for finding fruit. Visual cues from motionless arthropod dummies were not sufficient to allow reliable detection of prey in choice experiments, nor did they trigger prey capture behavior when presented on the feeding platform. In contrast, visual motion cues from moving prey dummies attracted their attention. Behavioral observations and experiments with live and recorded insect rustling sounds indicated that the lemurs make use of prey-generated acoustic cues for foraging. Both visual motion cues and acoustic prey stimuli on their own were sufficient to trigger approach and capture behavior in the mouse lemurs. For the detection of fruit, choice experiments showed that olfactory information was sufficient for mouse lemurs to find a piece of banana. Our study provides the first experimental data on the sensory ecology of food detection in mouse lemurs. Further research is necessary to address the role of sensory ecology for food selection and possibly for niche differentiation between sympatric Microcebus species.
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Taxonomic Revision of Mouse Lemurs (Microcebus) in the Western Portions of Madagascar
International Journal of Primatology, 2000Co-Authors: Rodin M. Rasolooarison, Steven M. Goodman, Jorg U GanzhornAbstract:The genus Microcebus (mouse lemurs) are the smallest extant primates. Until recently, they were considered to comprise two different species: Microcebus murinus, confined largely to dry forests on the western portion of Madagascar, and M. rufus, occurring in humid forest formations of eastern Madagascar. Specimens and recent field observations document rufous individuals in the west. However, the current taxonomy is entangled due to a lack of comparative material to quantify intrapopulation and intraspecific morphological variation. On the basis of recently collected specimens of Microcebus from 12 localities in portions of western Madagascar, from Ankarana in the north to Beza Mahafaly in the south, we present a revision using external, cranial, and dental characters. We recognize seven species of Microcebus from western Madagascar. We name and describe 3 spp., resurrect a previously synonymized species, and amend diagnoses for Microcebus murinus (J. F. Miller, 1777), M. myoxinus Peters, 1852, and M. ravelobensis Zimmermann et al., 1998.
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Remarkable species diversity in Malagasy mouse lemurs (primates, Microcebus)
Proceedings of the National Academy of Sciences of the United States of America, 2000Co-Authors: Anne D. Yoder, Steven M. Goodman, Sylvia Atsalis, Rodin M. Rasoloarison, Jodi A. Irwin, Matthew J. Ravosa, Jorg U GanzhornAbstract:Phylogenetic analysis of mtDNA sequence data confirms the observation that species diversity in the world's smallest living primate (genus Microcebus) has been greatly underestimated. The description of three species new to science, and the resurrection of two others from synonymy, has been justified on morphological grounds and is supported by evidence of reproductive isolation in sympatry. This taxonomic revision doubles the number of recognized mouse lemur species. The molecular data and phylogenetic analyses presented here verify the revision and add a historical framework for understanding mouse lemur species diversity. Phylogenetic analysis revises established hypotheses of ecogeographic constraint for the maintenance of species boundaries in these endemic Malagasy primates. Mouse lemur clades also show conspicuous patterns of regional endemism, thereby emphasizing the threat of local deforestation to Madagascar's unique biodiversity.
Fabienne Aujard - One of the best experts on this subject based on the ideXlab platform.
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the ontogeny of masticatory muscle architecture in Microcebus murinus
Anatomical Record-advances in Integrative Anatomy and Evolutionary Biology, 2020Co-Authors: Kaitlyn C Leonard, Edwin Dickinson, Fabienne Aujard, Anthony Herrel, Marissa L Boettcher, Neha Malhotra, Adam HartstoneroseAbstract:The masticatory apparatus has been the focus of many studies in comparative anatomy-especially analyses of skulls and teeth, but also of the mandibular adductor muscles which are responsible for the production of bite force and the movements of the mandible during food processing and transport. The fiber architecture of these muscles has been correlated to specific diets (e.g., prey size in felids) and modes of foraging (e.g., tree gouging in marmosets). Despite the well-elucidated functional implications of this architecture, little is known about its ontogeny. To characterize age-related myological changes, we studied the masticatory muscles in a large (n = 33) intraspecific sample of a small, Malagasy primate, Microcebus murinus including neonatal through geriatric individuals. We removed each of the mandibular adductors and recorded its mass as well as other linear measurements. We then chemically dissected each muscle to study its architecture-fascicle length and physiological cross-sectional area (PCSA) which relate to stretch (gape) and force capabilities, respectively. We observed PCSA and muscle mass to increase rapidly and plateau in adulthood through senescence. Fascicle lengths remained relatively constant once maximal length was reached, which occurred early in life, suggesting that subsequent changes in PCSA are driven by changes in muscle mass. Quadratic curvilinear models of each of the architectural variables of all adductors combined as well as individual muscles regressed against age were all significant. Anat Rec, 303:1364-1373, 2020. © 2019 American Association for Anatomy.
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Drivers of in vivo bite performance in wild brown mouse lemurs and a comparison with the grey mouse lemur
Journal of Zoology, 2018Co-Authors: P. B. Zablocki Thomas, Emmanuelle Pouydebat, Fabienne Aujard, Caitlin J Karanewsky, J. L. Pendleton, Anthony HerrelAbstract:Physical performance is crucial for animal survival and fitness. In this context, greater bite forces can provide advantages and may allow an individual to gain access to reproductive partners and/or different food resources. Here, we explored the determinants of bite force in a wild population of the brown mouse lemur (Microcebus rufus). Our objectives were to elucidate (1) if sex, head width, heart rate (as an indicator of overall physical fitness) and body condition drive variation in bite force in this population of wild mouse lemurs; and (2) the relative importance of the ecological niche in determining bite force by comparing results from this wild population with previously published results on bite force, body mass and head width from a laboratory colony of the grey mouse lemur (Microcebus murinus). We captured 32 wild brown mouse lemurs at night in the Ranomafana National Park in Madagascar during the beginning of the rainy season from 1st to 31st October 2016. We measured bite force, heart rate, body mass and head width of all individuals, and assigned sex and body condition (estimated as the unstandardized residual of a regression of body mass against head size). Although maximum bite force was positively correlated with body mass, it was not correlated with body condition. Residual bite force was highly correlated with residual head width and heart rate. The mean bite force of wild brown mouse lemurs was much lower than that of grey mouse lemurs in captivity, but showed similar relationships to head dimension and body mass. Even when corrected by body condition, grey mouse lemurs bit significantly harder than brown mouse lemurs. The difference in bite force between species could be explained by differences in head size and niche divergence with brown mouse lemurs eating mostly soft fruits and grey mouse lemurs eating more hard insects.
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metabolic and genomic adaptations to winter fattening in a primate species the grey mouse lemur Microcebus murinus
International Journal of Obesity, 2018Co-Authors: Jérémy Terrien, M Gaudubois, Delphine Champeval, V Zaninotto, L Roger, Jeanfrancois Riou, Fabienne AujardAbstract:Metabolic and genomic adaptations to winter fattening in a primate species, the grey mouse lemur ( Microcebus murinus )
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complete mitochondrial genome of the gray mouse lemur Microcebus murinus primates cheirogaleidae
Mitochondrial DNA, 2016Co-Authors: Emilie Lecompte, Brigitte Crouauroy, Helene Holota, Fabienne Aujard, Jerome MurienneAbstract:AbstractWe report the high-coverage complete mitochondrial genome sequence of the gray mouse lemur Microcebus murinus. The sequencing has been performed on an Illumina Hiseq 2500 platform, with a genome skimming strategy. The total length of this mitogenome is 16 963 bp, containing 13 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes and 1 non-coding region (D-loop region). The genome organization, nucleotide composition and codon usage are similar to those reported from other primate’s mitochondrial genomes. The complete mitochondrial genome sequence reported here will be useful for comparative genomics studies in primates.
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sexual dimorphism in bite force in the grey mouse lemur
Journal of Zoology, 2015Co-Authors: Emmanuelle Pouydebat, Fabienne Aujard, Anthony Herrel, Callum F Ross, Pauline Thomas, Isabelle HardyAbstract:Sexual dimorphism is thought to be the result of sexual selection, food competition and/or niche differentiation, or simply the result of differential growth between the sexes. Despite the fact that sexual dimorphism is common among primates, lemurs are thought to be largely monomorphic. Yet, females of the species Microcebus are known to be larger than males. Here, we investigate if dimorphism in head dimensions is present in a colony of captive grey mouse lemurs Microcebus murinus. Moreover, we test whether any observed shape dimorphism is associated with differences in bite force between the sexes. Our results show that male and female grey mouse lemurs are indeed sexually dimorphic in head dimensions, with females having taller and wider heads than males. Moreover, we confirm previous observations that females are heavier than males. Bite force was principally determined by head dimensions and age in our dataset, and differed between sexes, with females biting harder than males. These data suggest a potential role for niche dimorphism in driving the observed shape and performance dimorphism as female reproductive output may depend upon the ability of animals to obtain resources that are difficult to ingest.