scholarly journals Sympatric Mouse Lemurs in Nort-West Madagascar: A New Rufous Mouse Lemur Species (Microcebus ravelobensis)

1998 ◽  
Vol 69 (2) ◽  
pp. 106-114 ◽  
Author(s):  
Eleke Zimmermann ◽  
Sabine Cepok ◽  
Nasolo Rakotoarison ◽  
Vera Zietemann ◽  
Ute Radespiel
Keyword(s):  
Mouse Lemur ◽  
Mouse Lemurs ◽  
Lemur Species

scholarly journals RADseq data reveal a lack of admixture in a mouse lemur contact zone contrary to previous microsatellite results

2021 ◽  
Author(s):  
Jelmer Wijtze Poelstra ◽  
B. Karina Montero ◽  
Jan Lüdemann ◽  
Ziheng Yang ◽  
S. Jacques Rakotondranary ◽  
...  
Keyword(s):  
Gene Flow ◽  
Contact Zone ◽  
Mouse Lemur ◽  
Biological Processes ◽  
Microsatellite Data ◽  
Ancestral Gene ◽  
Mouse Lemurs ◽  
Low Levels ◽  
Future Work ◽  
Lemur Species

Despite being one of the most fundamental biological processes, the process of speciation remains poorly understood in many groups of organisms. Mouse lemurs are a species-rich genus of small primates endemic to Madagascar, whose diversity has only recently been uncovered using genetic data and is primarily found among morphologically cryptic, allopatric populations. To assess to what extent described species represent reproductively isolated entities, studies are needed in areas where mouse lemur taxa come into contact. Hybridization has previously been reported in a contact zone between two closely related mouse lemur species (Microcebus murinus and M. griseorufus) based on microsatellite data. Here, we revisit this system using RADseq data for populations in, near, and far from the contact zone, including many of the individuals that had previously been identified as hybrids. Surprisingly, we find no evidence for admixed nuclear ancestry in any of the individuals. Re-analyses of microsatellite data and simulations suggest that previously inferred hybrids were false positives and that the program NewHybrids can be particularly sensitive to erroneously inferring hybrid ancestry. Using coalescent-bases analyses, we also show an overall lack of recent gene flow between the two species, and low levels of ancestral gene flow. Combined with evidence for local syntopic occurrence, these data indicate that M. murinus and M. griseorufus are reproductively isolated. Finally, we estimate that they diverged less than a million years ago, suggesting that completion of speciation is relatively rapid in mouse lemurs. Future work should focus on the underpinnings of reproductive isolation in this cryptic primate radiation, which are mostly unknown. Our study also provides a cautionary tale for the inference of hybridization with microsatellite data.

scholarly journals Linking cognition to ecology in wild sympatric mouse lemur species

2021 ◽  
Vol 288 (1963) ◽  
Author(s):  
Johanna Henke-von der Malsburg ◽  
Peter M. Kappeler ◽  
Claudia Fichtel
Keyword(s):  
Environmental Conditions ◽  
Cognitive Abilities ◽  
Environmental Changes ◽  
Social Systems ◽  
Ecological Factors ◽  
Mouse Lemur ◽  
Cognitive Test ◽  
Ecological Adaptations ◽  
Mouse Lemurs ◽  
Lemur Species

Cognitive abilities covary with both social and ecological factors across animal taxa. Ecological generalists have been attributed with enhanced cognitive abilities, but which specific ecological factors may have shaped the evolution of which specific cognitive abilities remains poorly known. To explore these links, we applied a cognitive test battery (two personality, ten cognitive tests; n = 1104 tests) to wild individuals of two sympatric mouse lemur species ( n = 120 Microcebus murinus, n = 34 M. berthae ) varying in ecological adaptations but sharing key features of their social systems. The habitat and dietary generalist grey mouse lemurs were more innovative and exhibited better spatial learning abilities; a cognitive advantage in responding adaptively to dynamic environmental conditions. The more specialized Madame Berthe's mouse lemurs were faster in learning associative reward contingencies, providing relative advantages in stable environmental conditions. Hence, our study revealed key cognitive correlates of ecological adaptations and indicates potential cognitive constraints of specialists that may help explain why they face a greater extinction risk in the context of current environmental changes.

First indications of a highland specialist among mouse lemurs (Microcebus spp.) and evidence for a new mouse lemur species from eastern Madagascar

Primates ◽  
2011 ◽  
Vol 53 (2) ◽  
pp. 157-170 ◽  
Author(s):  
Ute Radespiel ◽  
Jonah H. Ratsimbazafy ◽  
Solofonirina Rasoloharijaona ◽  
Herimalala Raveloson ◽  
Nicole Andriaholinirina ◽  
...  
Keyword(s):  
Mouse Lemur ◽  
Mouse Lemurs ◽  
Lemur Species

scholarly journals Mouse lemurs’ and degraded habitat

2017 ◽  
Author(s):  
Simon Knoop ◽  
Lounès Chikhi ◽  
Jordi Salmona
Keyword(s):  
Habitat Use ◽  
Forest Type ◽  
Conservation Status ◽  
Forest Degradation ◽  
Mouse Lemur ◽  
Degraded Forest ◽  
Forest Types ◽  
Tree Hole ◽  
Mouse Lemurs ◽  
Lemur Species

AbstractMadagascar is known for its unique biodiversity including its endemic primates, the lemurs. This biodiversity is threatened by deforestation, forest degradation and anthropogenic disturbances. Several mouse lemurs (genus Microcebus) have been shown to cope with habitat disturbances and degradation. However, there are 24 recognized mouse lemur species living in very different habitats, and it is not clear whether all these species respond similarly to forest degradation. Here, we review the literature on mouse lemur use of degraded habitat. We further question whether mouse lemurs show variation in degraded habitat use, with respect to forest type, conservation status and distribution range. We show that data on degraded forest (DF) use is available for 14 species and geographically aggregated in a few locations. However, data are scarce for most species, and lacking for almost half of the currently recognized species. Our results however confirm that most mouse lemur species are able to cope with, but do not necessarily respond positively to habitat degradation. We found no variation in degraded habitat use, with respect to forest type, conservation status and distribution range. However, we identified food resources availability, understory structure, predation, and tree hole availability to be the most frequently invoked factors potentially influencing DF use. The relative frequency of these four factors vary among forest types suggesting that differences may exist but still require research efforts for ecological and environmental differences among regions to be fully understood.RESEARCH HIGHLIGHTSLittle differences in the use of degraded forest (DF) between forest types, distribution ranges or conservation status.Varying factors potentially affecting DF use, such as food resources, forest structure, tree hole availability and predation.

Molecular liver fingerprint reflects the seasonal physiology of the grey mouse lemur (Microcebus murinus) during winter

2021 ◽  
Author(s):  
Blandine Chazarin ◽  
Margaux Benhaim-Delarbre ◽  
Charlotte Brun ◽  
Aude Anzeraey ◽  
Fabrice Bertile ◽  
...  
Keyword(s):  
Glucose Intolerance ◽  
Molecular Mechanisms ◽  
Mouse Lemur ◽  
Primate Species ◽  
Whole Body ◽  
Microcebus Murinus ◽  
Late Winter ◽  
Pathological State ◽  
Fat Reserves ◽  
Mouse Lemurs

Grey mouse lemurs (Microcebus murinus) are a primate species exhibiting strong physiological seasonality in response to environmental energetic constraint. They notably store large amounts of lipids during early winter (EW), which are thereafter mobilized during late winter (LW), when food availability is low. In addition, they develop glucose intolerance in LW only. To decipher how the hepatic mechanisms may support such metabolic flexibility, we analyzed the liver proteome of adult captive male mouse lemurs, which seasonal regulations of metabolism and reproduction are comparable to their wild counterparts, during the phases of either constitution or use of fat reserves. We highlight profound changes that reflect fat accretion in EW at the whole-body level, however, without triggering an ectopic storage of fat in the liver. Moreover, molecular regulations would be in line with the lowering of liver glucose utilization in LW, and thus with reduced tolerance to glucose. However, no major regulation was seen in insulin signaling/resistance pathways, which suggests that glucose intolerance does not reach a pathological stage. Finally, fat mobilization in LW appeared possibly linked to reactivation of the reproductive system and enhanced liver detoxification may reflect an anticipation to return to summer levels of food intake. Altogether, these results show that the physiology of mouse lemurs during winter relies on solid molecular foundations in liver processes to adapt fuel partitioning while avoiding reaching a pathological state despite large lipid fluxes. This work emphasizes how the mouse lemur is of primary interest for identifying molecular mechanisms relevant to biomedical field.

scholarly journals The effects of a national highway on the Endangered golden-brown mouse lemur Microcebus ravelobensis in Ankarafantsika National Park, Madagascar

Oryx ◽  
2017 ◽  
Vol 53 (4) ◽  
pp. 727-731 ◽  
Author(s):  
Malcolm S. Ramsay ◽  
Andriamahery Razafindrakoto ◽  
Shawn M. Lehman
Keyword(s):  
National Park ◽  
Mouse Lemur ◽  
Population Subdivision ◽  
Empirical Testing ◽  
Future Studies ◽  
North West ◽  
Mouse Lemurs ◽  
Interior Forest ◽  
Males And Females ◽  
Dispersal Events

AbstractAlthough roads are often assumed to be barriers to the dispersal of arboreal species, there has been little empirical testing of this assumption. If arboreal animals are unable to cross roads, population subdivision may occur, or resources may become inaccessible. We tested the hypothesis that Route Nationale 4 (RN4), a paved highway, was a barrier to movement and dispersal of the Endangered golden-brown mouse lemur Microcebus ravelobensis in Ankarafantsika National Park, in north-west Madagascar. During June–August 2015 we conducted a capture–mark–recapture study at three sites: two adjacent to RN4 and one within intact forest without a potential barrier. During 2,294 trap nights we captured 120 golden-brown mouse lemurs 1,032 times. In roadside habitats we captured significantly more males than females, whereas the opposite was the case in interior forest habitat. We detected eighteen crossings of highway transects by nine individuals; however, all potential dispersal events involved males. In roadside habitat, movement was significantly inhibited in both males and females. We present some of the first data on the effects of roads on movement patterns in arboreal Malagasy mammals, showing species- and sex-biased effects of roads as dispersal barriers. Our findings indicate that roads may not be complete barriers to dispersal in lemurs. We recommend that conservation managers and scientists examine explicitly the effects of roads and natural arboreal bridges in Madagascar in future studies.

Enter the Matrix: Use of Secondary Matrix by Mouse Lemurs

2020 ◽  
pp. 1-11
Author(s):  
Travis S. Steffens ◽  
Malcolm S. Ramsay ◽  
Bertrand Andriatsitohaina ◽  
Ute Radespiel ◽  
Shawn M. Lehman
Keyword(s):  
Relative Abundance ◽  
Mouse Lemur ◽  
Primate Species ◽  
Forest Loss ◽  
Fragmented Landscape ◽  
Forest Fragments ◽  
Matrix Elements ◽  
Fragmented Forest ◽  
Mouse Lemurs ◽  
The Matrix

Madagascar is home to many threatened and endemic primate species, yet this island has seen dramatic declines in lemur habitat due to forest loss. This forest loss has resulted in an increasingly fragmented forest landscape, with fragments isolated from each other by grasslands (i.e., matrix). The grassland matrix is not entirely homogeneous containing matrix elements such as isolated trees and shrubs and linear features such as drainage lines. Because most lemurs are predominantly arboreal, they may preferentially use matrix elements to facilitate dispersal between fragments for access to mates or reduce feeding competition, allowing gene flow between fragments of habitat. Therefore, it is important to understand to what degree they use the matrix. We investigated matrix use in two mouse lemurs, the grey mouse lemur (<i>Microcebus murinus</i>) and the golden-brown mouse lemur (<i>Microcebus ravelobensis</i>) in a fragmented landscape in northwest Madagascar. We tested the predictions that: (1) lemurs use matrix less often than forest fragments, (2) if they use the matrix, then they will preferentially use matrix elements compared to grassland, and (3) <i>M. murinus</i> will disperse into the matrix further than <i>M. ravelobensis</i>. In 2011, we visually surveyed line transects in four areas containing matrix elements and four adjacent forest fragments during nocturnal walks. In 2017, we set up traplines in four areas of the matrix containing matrix elements, three areas that were grassland, and six traplines in adjacent fragments. We compared the relative abundance of mouse lemurs in matrix transects to fragmented forest transects, and the relative abundance of captured lemurs in matrix elements, grassland, and fragment traplines. We found that encounter rates of mouse lemurs did not significantly differ between the matrix and fragmented forest transects or traplines. Our sample size was too low to determine if the mean distance from the forest was greater for either <i>Microcebus</i> spp. Our study highlights that mouse lemurs do use matrix elements and there may be interspecific differences in use. Further research is needed to confirm species-specific matrix use, why mouse lemurs use matrix, and how much matrix elements facilitate movement for each species in fragmented landscapes.

scholarly journals Photoperiodic regime influences onset of lens opacities in a non-human primate

2017 ◽  
Author(s):  
Marko Dubicanac ◽  
Julia Strueve ◽  
Nadine Mestre-Frances ◽  
Jean-Michel Verdier ◽  
Elke Zimmermann ◽  
...  
Keyword(s):  
Age At Onset ◽  
Mouse Lemur ◽  
Chronological Age ◽  
Seasonal Cycles ◽  
Photoperiod Regime ◽  
Age Related ◽  
Mouse Lemurs ◽  
Photoperiodic Regime ◽  
Lens Opacities ◽  
Human Primate

Background. Opacities of the lens are typical age related phenomena which have high influence on photoreception and consequently circadian rhythm. In mouse lemurs, a small bodied non-human primate, a high incidence (more than 50% when > 7 years) of cataract has been previously described during aging. Previous studies showed that photoperiodical induced accelerated annual rhythms alter some of mouse lemurs’ life history traits. Whether a modification of photoperiod also affects the onset of age dependent lens opacities has not been investigated so far. The aim of this study was therefore to characterize the type of opacity and the mouse lemurs’ age at its onset in two colonies with different photoperiodic regimen. Methods. Two of the largest mouse lemur colonies in Europe have been investigated; Colony 1 with a natural annual photoperiodic regime and Colony 2 with an induced accelerated annual cycle. A Slit-lamp was used to determine opacities in the lens and a subset of all animals which showed no opacities in the lens nucleus in the first examination but developed first changes in the following examination were further used to estimate the age at onset of opacities. In total 387 animals were examined and 57 represent the subset for age at onset estimation. Results. The first and most common observable opacity in the lens was nuclear sclerosis. Mouse lemurs from Colony 1 showed a delayed onset of nuclear sclerosis compared to mouse lemurs of Colony 2 (4.35 ± 1.50 years vs. 2.75 ± 0.99 years). For colony 1, the chronological age was equivalent to the number of seasonal cycles experienced by the mouse lemurs. For colony 2, in which seasonal cycles are accelerated by factor 1.5, mouse lemurs had experienced 4.13 ± 1.50 seasonal cycles in 2.75 ± 0.99 chronological years. Discussion. Our study showed clear differences in the age at the onset of nuclear sclerosis formation between lemurs kept under different photoperiodic regimes. Instead of measuring the chronological age, the number of seasonal cycles (N = 4) experienced by a mouse lemur can be used as an estimation for risk of beginning NS formation. Ophthalmological investigations should be taken into account when animals older than 5 - 6 seasonal cycles are used for experiments in which unrestricted visual ability has to be ensured. This study is the first to assess and demonstrate the influence of annual photoperiod regime on the incidence of lens opacities in a non-human primate.

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