Gillian Olivieri,
Elke Zimmermann,
Blanchard Randrianambinina,
Solofonirina Rasoloharijaona,
Daniel Rakotondravony,
Katerina Guschanski,
Ute Radespiel
Institute of Zoology, University of Veterinary Medicine Hannover, Bünteweg 17, 30559 Hannover, Germany.
Mouse lemurs (Microcebus spp.) are the world's smallest primates and endemic to Madagascar. Several recent taxonomic revisions resulted in an extraordinary increase of recognized species. What still was considered as being two species at the beginning of the 20th century is currently recognized as 12 taxa. Based on fur coloration pattern, they can be divided into grayish and reddish forms. Two major models have been proposed to explain the extensive speciation events in the Malagasy fauna. The best known suggests that major rivers and mountains combine to act as effective barriers to gene flow and thereby facilitate allopatric speciation processes. A more recent model used an analysis of watersheds in the context of Quaternary climatic shifts to explain the process of explosive speciation on the island. We tested these two models by covering the areas between all major rivers (n=8) in northwestern and northern Madagascar. Mouse lemurs were systematically caught, sampled and morphometrically characterized in 25 sites (with 2-49 individuals per site and species). A complete phylogeny was constructed on the basis of the sequences of three mitochondrial loci (in total 1296bp). The phylogenetic data revealed a previously unknown biodiversity with three new mouse lemur species among the reddish forms, each having a very small distribution, i.e., being restricted to only one Inter-River-System (IRS). Morphometric analyses underlined their distinctiveness and a brief formal species description is provided. In contrast to the reddish forms, grayish forms have a very low species diversity coupled with broad distributions that cover more than one IRS. These differences among the species are discussed as outcome of divergent colonization scenarios. Elements of both biogeographic models are combined in a new hypothesis that aims to explain the speciation process leading to the present distribution of mouse lemurs in Madagascar.
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Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103, Leipzig, Germany, vigilant@eva.mpg.de.
While much can be learned about primates by means of observation, the slow life history of many primates means that even decades of dedicated effort cannot illuminate long-term evolutionary processes. For example, while the size of a contemporary population can be estimated from field censuses, it is often desirable to know whether a population has been constant or changing in size over a time frame of hundreds or thousands of years. Even the nature of "a population" is open to question, and the extent to which individuals successfully disperse among defined populations is also difficult to estimate by using observational methods alone. Researchers have thus turned to genetic methods to examine the size, structure, and evolutionary histories of primate populations. Many results have been gained by study of sequence variation of maternally inherited mitochondrial DNA, but in recent years researchers have been increasingly focusing on analysis of short, highly variable microsatellite segments in the autosomal genome for a high-resolution view of evolutionary processes involving both sexes. In this review we describe some of the insights thus gained, and discuss the likely impact on this field of new technologies such as high-throughput DNA sequencing.
Ute Radespiel,
Gillian Olivieri,
David W Rasolofoson,
Gilbert Rakotondratsimba,
Odon Rakotonirainy,
Solofonirina Rasoloharijaona,
Blanchard Randrianambinina,
Jonah H Ratsimbazafy,
Felix Ratelolahy,
Tahirihasina Randriamboavonjy,
Tovonanahary Rasolofoharivelo,
Mathias Craul,
Lucien Rakotozafy,
Rose M Randrianarison
Institute of Zoology, University of Veterinary Medicine Hannover, Hannover, Germany.
Although the number of described lemur species has increased considerably over the last 20 years, detailed biogeographic data are still lacking from many geographic regions, in particular in the eastern part of Madagascar. This study investigated mouse lemur species diversity in a previously unstudied Inter-River-System in the eastern Makira region. Three sites were visited and 26 individuals were sampled and characterized with 13 external morphometric measurements. Standard phylogenetic analyses were performed on the basis of sequences of three mitochondrial loci by including representatives of all other published mouse lemur species for comparison. The analyses revealed the presence of three mouse lemur species in one study site, two of which were previously undescribed. The two new species are genetically distinct and belong to the larger-bodied mouse lemur species on the island, whereas the third species, Microcebus mittermeieri, belongs to the smaller-bodied mouse lemur species. The study fully describes one of the new species. This study and other lemur inventories suggest that the Makira region is particularly rich in lemur species and the lack of any protected zone in this area should now attract the urgent attention of conservation stakeholders. Am. J. Primatol. 70:1-14, 2008.(c) 2008 Wiley-Liss, Inc.
Mathias Craul,
Ute Radespiel,
David Rasolofoson,
Gilbert Rakotondratsimba,
Odon Rakotonirainy,
Solofonirina Rasoloharijaona,
Blanchard Randrianambinina,
Jonah Ratsimbazafy,
Felix Ratelolahy,
Tahirihasina Randrianamboavaonjy,
Lucien Rakotozafy
Institute of Zoology, University of Veterinary Medicine Hannover, Buenteweg 17, 30559, Hannover, Germany.
Sportive lemurs constitute a highly diverse endemic lemur family (24 species) for which many biogeographic boundaries are not yet clarified. Based on recent phylogeographic models, this study aims to determine the importance of two large rivers (the Antainambalana and Rantanabe) in northeastern Madagascar as species barriers for Lepilemur seali. The Antainambalana River was previously assumed to act as the southern border of its distribution. A total of 1,038 bp of the mtDNA of four individuals stemming from two adjacent inter-river systems south of the Antainambalana River was sequenced and compared to sequences of 22 described Lepilemur species. The phylogenetic reconstruction did not find support for either of the two rivers as species barrier for Lepilemur, as all captured individuals clustered closely with and therefore belonged to L. seali. However, a previously published sequence of an individual from a site south of our study sites belongs to a separate species. The southern boundary of L. seali must therefore be one of two large rivers further south of our study sites. The results suggest that L. seali may possess a relatively large altitudinal range that enabled this species to migrate around the headwaters of the Antainambalana and Rantanabe Rivers. Previous phylogeographic models need to be refined in order to incorporate these findings, and more species-specific altitudinal range data are urgently needed in order to fully understand the biogeographic patterns of lemurs on Madagascar.
Abteilung Verhaltensökologie & Soziobiologie, Deutsches Primatenzentrum, Kellnerweg 4, 37077, Göttingen, Germany, mdammha@gwdg.de.
Understanding the co-occurrence of ecologically similar species remains a puzzling issue in community ecology. The species-rich mouse lemurs (Microcebus spec.) are distributed over nearly all remaining forest areas of Madagascar with a high variability in species distribution patterns. Locally, many congeneric species pairs seem to co-occur, but only little detailed information on spatial patterns is available. Here, we present the results of an intensive capture-mark-recapture study of sympatric Microcebus berthae and M. murinus populations that revealed small-scale mutual spatial exclusion. Nearest neighbour analysis indicated a spatial aggregation in Microcebus murinus but not in M. berthae. Although the diet of both species differed in proportions of food categories, they used the same food sources and had high feeding niche overlap. Also, forest structure related to the spatial distribution of main food sources did not explain spatial segregation because parts used by each species exclusively did not differ in density of trees, dead wood and lianas. We propose that life history trade-offs that result in species aggregation and a relative increase in the strength of intra-specific over inter-specific competition best explain the observed pattern of co-occurrence of ecologically similar congeneric Microcebus species.
Maria Méndez-Cárdenas,
Blanchard Randrianambinina,
Andriatahiana Rabesandratana,
Solofonirina Rasoloharijaona,
Elke Zimmermann
Institute of Zoology, University of Veterinary Medicine Hannover, Hannover, Germany.
Bioacoustical studies in nonhuman primates have shown that loud calls can be reliably used as a noninvasive diagnostic tool for discriminating cryptic taxa, for their monitoring in the field as well as for the reconstruction of their phylogeny. To date, it is unknown, whether loud calls can be used for these purposes in sportive lemurs, for which current genetic studies suggest the existence of at least 24 cryptic species. The aim of this study was to compare the structure of loud calls of populations of sportive lemurs to characterize informative acoustic traits for taxa discrimination and to establish a phylogenetic tree based on acoustic structure. We have based our study on Inter-River-Systems (IRSs) as operational taxonomic units. Samples were collected from nine different localities of four IRSs along a transect from northwestern to northern Madagascar. Two call types, the ouah and the high-pitched call, were present in almost all IRSs. Six temporal and eight spectral parameters were measured in 196 calls of the best quality given by 21 different males. Variation within and between IRSs was assessed by multivariate statistics. Loud calls differed significantly among the different IRSs. The IRSs varied most in spectral parameters, whereas temporal parameters were less variable. Phylogenetic analysis using parsimony yielded 11 out of 17 acoustic characters as phylogenetically informative. The acoustic tree had an average branch support of 78%. Its topology coincided less with geographic distances than with genetic tree topology. Altogether our findings revealed that loud calls separated geographically isolated populations of sportive lemurs specifically. Based on these results, noninvasive tools for diagnosis and monitoring of cryptic species in nature can be developed for conservation management. Am. J. Primatol. 70:1-11, 2008.(c) 2008 Wiley-Liss, Inc.
C Gilbert,
S Goodman,
V Soarimalala,
L Olson,
P O'Brien,
F Elder,
F Yang,
M Ferguson-Smith,
T Robinson
Tenrecs (Tenrecidae) are a widely diversified assemblage of small eutherian mammals that occur in Madagascar and Western and Central Africa. With the exception of a few early karyotypic descriptions based on conventional staining, nothing is known about the chromosomal evolution of this family. We present a detailed analysis of G-banded and molecularly defined chromosomes based on fluorescence in situ hybridization (FISH) that allows a comprehensive comparison between the karyotypes of 11 species of two closely related Malagasy genera, Microgale (10 species) and Oryzorictes (one species), of the subfamily Oryzorictinae. The karyotypes of Microgale taiva and M. parvula (2n = 32) were found to be identical to that of O. hova (2n = 32) most likely reflecting the ancestral karyotypes of both genera, as well as that of the Oryzorictinae. Parsimony analysis of chromosomal rearrangements that could have arisen following Whole Arm Reciprocal Translocations (WARTs) showed, however, that these are more likely to be the result of Robertsonian translocations. A single most parsimonious tree was obtained that provides strong support for three species associations within Microgale, all of which are consistent with previous molecular and morphological investigations. By expanding on a recently published molecular clock for the Tenrecidae we were able to place our findings in a temporal framework that shows strong chromosomal rate heterogeneity within the Oryzorictinae. We use these data to critically examine the possible role of chromosomal rearrangements in speciation within Microgale.
Suitable sleeping sites as potentially restricted resources are suggested to shape sociality in primates. We investigated sleeping site ecology of a rain-forest dwelling sportive lemur in eastern Madagascar for the first time. Using radiotelemetry, we characterized the type, quality and usage of sleeping sites as well as social sleeping habits of 11 focal individuals of the weasel sportive lemur (Lepilemur mustelinus) during the dry and the onset of the rainy season. Morphometric measurements provided additional information. The sexes showed an unusual sexual dimorphism for primates. Males and females did not differ in body length, but females surpassed males in body mass suggesting female dominance. Both sexes used dense vegetation and holes in hollow trees high above the ground as shelters for sleeping during the day. No sex difference in the quality of tree holes was found, but focal individuals used tree holes more often than open sleeping sites in dense vegetation. Both sexes showed high sleeping site fidelity limited to two to six different sites that they used primarily solitarily. The results imply that suitable sleeping sites are limited and survival of this species will strongly depend on the availability of mature rain forests with suitable hollow trees. Furthermore, these findings provide evidence of a solitary sleeping and ranging system in this rain-forest dwelling sportive lemur with suitable sleeping sites as defendable resources. Am. J. Primatol. 69:1-11, 2007.(c) 2007 Wiley-Liss, Inc.
Other papers by authors:
Ute Radespiel,
Gillian Olivieri,
David W Rasolofoson,
Gilbert Rakotondratsimba,
Odon Rakotonirainy,
Solofonirina Rasoloharijaona,
Blanchard Randrianambinina,
Jonah H Ratsimbazafy,
Felix Ratelolahy,
Tahirihasina Randriamboavonjy,
Tovonanahary Rasolofoharivelo,
Mathias Craul,
Lucien Rakotozafy,
Rose M Randrianarison
Institute of Zoology, University of Veterinary Medicine Hannover, Hannover, Germany.
Although the number of described lemur species has increased considerably over the last 20 years, detailed biogeographic data are still lacking from many geographic regions, in particular in the eastern part of Madagascar. This study investigated mouse lemur species diversity in a previously unstudied Inter-River-System in the eastern Makira region. Three sites were visited and 26 individuals were sampled and characterized with 13 external morphometric measurements. Standard phylogenetic analyses were performed on the basis of sequences of three mitochondrial loci by including representatives of all other published mouse lemur species for comparison. The analyses revealed the presence of three mouse lemur species in one study site, two of which were previously undescribed. The two new species are genetically distinct and belong to the larger-bodied mouse lemur species on the island, whereas the third species, Microcebus mittermeieri, belongs to the smaller-bodied mouse lemur species. The study fully describes one of the new species. This study and other lemur inventories suggest that the Makira region is particularly rich in lemur species and the lack of any protected zone in this area should now attract the urgent attention of conservation stakeholders. Am. J. Primatol. 70:1-14, 2008.(c) 2008 Wiley-Liss, Inc.
Institut für Zoologie, Tierärztliche Hochschule Hannover, Bünteweg 17, 30559 Hannover, Germany.
To investigate for the first time the relationship between contrasting patterns of seasonal changes of the environment and activity, body mass and reproduction for small nocturnal primates in nature, we compared a population of golden brown mouse lemur ( Microcebus ravelobensis) in a dry deciduous forest of northwestern Madagascar and of the brown mouse lemur ( Microcebus rufus) in an evergreen rain forest of eastern Madagascar. Both species live under similar photoperiodic conditions. Golden brown mouse lemurs (GBML) were active during the whole period (May to December) irrespective of changing environmental conditions. In contrast, a part of the population of brown mouse lemurs (BML) showed prolonged seasonal torpor, related to body mass during periods of short day length and low ambient temperatures. Differences between species might be due to differences in ambient temperature and food supply. Body weight and tail thickness (adipose tissue reserve) did not show prominent differences between short and long photoperiods in GBML, whereas both differ significantly in BML, suggesting species-specific differences in the photoperiodically driven control of metabolism. Both species showed a seasonal reproduction. The rate of growth and size of the testes were similar and preceded estrous onset in both species suggesting a photoperiodic control of reproduction in males. The estrous onset in females occurred earlier in GBML than in BML. Estrous females were observed over at least 4 months in the former, but in only 1 month in the latter species. Intraspecific variation of estrous onset in GBML may be explained by body mass. Interspecific variation of female reproduction indicates species-specific differences in the control of reproduction. Thus, environmentally related differences in annual rhythms between closely related small nocturnal lemurs emerged that allow them to cope with contrasting patterns of seasonal changes in their habitats.
Mathias Craul,
Ute Radespiel,
David Rasolofoson,
Gilbert Rakotondratsimba,
Odon Rakotonirainy,
Solofonirina Rasoloharijaona,
Blanchard Randrianambinina,
Jonah Ratsimbazafy,
Felix Ratelolahy,
Tahirihasina Randrianamboavaonjy,
Lucien Rakotozafy
Institute of Zoology, University of Veterinary Medicine Hannover, Buenteweg 17, 30559, Hannover, Germany.
Sportive lemurs constitute a highly diverse endemic lemur family (24 species) for which many biogeographic boundaries are not yet clarified. Based on recent phylogeographic models, this study aims to determine the importance of two large rivers (the Antainambalana and Rantanabe) in northeastern Madagascar as species barriers for Lepilemur seali. The Antainambalana River was previously assumed to act as the southern border of its distribution. A total of 1,038 bp of the mtDNA of four individuals stemming from two adjacent inter-river systems south of the Antainambalana River was sequenced and compared to sequences of 22 described Lepilemur species. The phylogenetic reconstruction did not find support for either of the two rivers as species barrier for Lepilemur, as all captured individuals clustered closely with and therefore belonged to L. seali. However, a previously published sequence of an individual from a site south of our study sites belongs to a separate species. The southern boundary of L. seali must therefore be one of two large rivers further south of our study sites. The results suggest that L. seali may possess a relatively large altitudinal range that enabled this species to migrate around the headwaters of the Antainambalana and Rantanabe Rivers. Previous phylogeographic models need to be refined in order to incorporate these findings, and more species-specific altitudinal range data are urgently needed in order to fully understand the biogeographic patterns of lemurs on Madagascar.
Maria Méndez-Cárdenas,
Blanchard Randrianambinina,
Andriatahiana Rabesandratana,
Solofonirina Rasoloharijaona,
Elke Zimmermann
Institute of Zoology, University of Veterinary Medicine Hannover, Hannover, Germany.
Bioacoustical studies in nonhuman primates have shown that loud calls can be reliably used as a noninvasive diagnostic tool for discriminating cryptic taxa, for their monitoring in the field as well as for the reconstruction of their phylogeny. To date, it is unknown, whether loud calls can be used for these purposes in sportive lemurs, for which current genetic studies suggest the existence of at least 24 cryptic species. The aim of this study was to compare the structure of loud calls of populations of sportive lemurs to characterize informative acoustic traits for taxa discrimination and to establish a phylogenetic tree based on acoustic structure. We have based our study on Inter-River-Systems (IRSs) as operational taxonomic units. Samples were collected from nine different localities of four IRSs along a transect from northwestern to northern Madagascar. Two call types, the ouah and the high-pitched call, were present in almost all IRSs. Six temporal and eight spectral parameters were measured in 196 calls of the best quality given by 21 different males. Variation within and between IRSs was assessed by multivariate statistics. Loud calls differed significantly among the different IRSs. The IRSs varied most in spectral parameters, whereas temporal parameters were less variable. Phylogenetic analysis using parsimony yielded 11 out of 17 acoustic characters as phylogenetically informative. The acoustic tree had an average branch support of 78%. Its topology coincided less with geographic distances than with genetic tree topology. Altogether our findings revealed that loud calls separated geographically isolated populations of sportive lemurs specifically. Based on these results, noninvasive tools for diagnosis and monitoring of cryptic species in nature can be developed for conservation management. Am. J. Primatol. 70:1-11, 2008.(c) 2008 Wiley-Liss, Inc.
Suitable sleeping sites as potentially restricted resources are suggested to shape sociality in primates. We investigated sleeping site ecology of a rain-forest dwelling sportive lemur in eastern Madagascar for the first time. Using radiotelemetry, we characterized the type, quality and usage of sleeping sites as well as social sleeping habits of 11 focal individuals of the weasel sportive lemur (Lepilemur mustelinus) during the dry and the onset of the rainy season. Morphometric measurements provided additional information. The sexes showed an unusual sexual dimorphism for primates. Males and females did not differ in body length, but females surpassed males in body mass suggesting female dominance. Both sexes used dense vegetation and holes in hollow trees high above the ground as shelters for sleeping during the day. No sex difference in the quality of tree holes was found, but focal individuals used tree holes more often than open sleeping sites in dense vegetation. Both sexes showed high sleeping site fidelity limited to two to six different sites that they used primarily solitarily. The results imply that suitable sleeping sites are limited and survival of this species will strongly depend on the availability of mature rain forests with suitable hollow trees. Furthermore, these findings provide evidence of a solitary sleeping and ranging system in this rain-forest dwelling sportive lemur with suitable sleeping sites as defendable resources. Am. J. Primatol. 69:1-11, 2007.(c) 2007 Wiley-Liss, Inc.
ABSTRACT: BACKGROUND: The lemurs of Madagascar provide an excellent mammalian radiation to explore mechanisms and processes favouring species diversity and evolution. Species diversity, in particular of nocturnal species, increased considerably during the last decade. However, the factors contributing to this high diversity are not well understood. We tested predictions derived from two existing biogeographic models by exploring the genetic and morphological divergence among populations of a widely distributed lemur genus, the sportive lemur (Lepilemur ssp.) along a 560 km long transect from western to northern Madagascar. RESULTS: By using the phylogenetic analyses of mtDNA sequence data, molecular diagnostic sites and phenotypic morphometric traits, we uncovered two previously undetected species whose distributions contradict the two existing biogeographic models. Brief species descriptions are provided and a new biogeographic model is proposed (the 'large river model'). CONCLUSIONS: According to the 'large river model', large rivers in north and northwestern Madagascar acted as geographical barriers for gene flow and facilitated speciation events on a much smaller spatial scale than previously thought. Thereby, this study does not only show that species diversity in nocturnal Malagasy primates is continuously underestimated but aims to emphasize the need for conservation actions if those species with small ranges shall not face extinction in the near future.
Faculté des Sciences, Université d'Antananarivo, Antananrivo 101, Madagascar.
Dispersed pair-living primates provide a unique model for illuminating the evolution of mechanisms regulating spacing and cohesiveness in permanently cohesive groups. We present for the first time data on the spatiotemporal distribution and loud-calling behavior of the Milne Edwards' sportive lemur, known to forage solitarily during the night, but to form stable male-female sleeping groups during the day. Data include radio-tracking observations of sleeping associations, and focal follows of pair partners during dispersal in the evenings and reunions in the mornings. Male-female pairs forming stable sleeping associations during the day were pair-bonded. They used sleeping sites and home ranges exclusively, and exchanged loud calls at potentially restricted resources during dispersal in the evenings and during reunion in the mornings. Direct agonistic conflicts between pairs and others were rare. The acoustic analysis of loud calls revealed nine major call types. They carry signatures for sex and pair identity, and provide the substrate for signaling and the potential for recognizing pair ownership. Thus, pairs use loud call exchanges as a vocal display for signaling territory ownership, thus limiting direct aggressive encounters between neighbors and strangers. Altogether, our findings provide the first empirical evidence for the hypothesis that loud calling has evolved as a key mechanism for regulating space use and cohesiveness in dispersed pair-living primates. Am J Phys Anthropol, 2006.(c) 2005 Wiley-Liss, Inc.
Institute of Zoology and Anthropology, University of Göttingen, 37073 Göttingen, Germany.
Our study provides the first data on the social organization of the golden brown mouse lemur, a nocturnal primate discovered in northwestern Madagascar in 1994. The study was carried out in two 6-month field periods during the dry season, covering time before and during the mating season. The spatial and temporal distributions of the sexes in the population were investigated by mark/recapture and radiotelemetry. Focal observations and the determination of sleeping associations provided further insights into the sociality of this solitary forager. High intra- and intersexual home-range overlaps occurred throughout the study. In general, individuals of both sexes had spatial access to more than one conspecific of the same and the opposite sex. We found no indication for spatial monopolization of females by certain males. These results suggest a dispersed multimale/multifemale system with a promiscuous mating pattern. Individuals showed temporal stability in their home range locations and interacted regularly with conspecifics. Five sleeping groups were identified during the study period: one female group and four mixed-sex groups. Even though sleeping sites were changed frequently, sleeping-group compositions remained stable over time. Thermoregulatory constraints are the most likely explanation for sleeping-group composition with members of both sexes in this species. Mixed-sex sleeping groups can be described as the basic social unit within this dispersed multimale/multifemale society. Am J Phys Anthropol, 2003.
Institut für Zoologie, Tierärztliche Hochschule Hannover, 30559 Hannover, Germany.
Safe sleeping sites may be a limited resource crucial for survival. In order to investigate their potential significance for social organization in nocturnal primates, we analyzed the spatial distribution of daily sleeping sites, their characteristics, their usage, and sleeping group compositions in the nocturnal Milne Edwards' sportive lemur during a 6-month field study in the dry deciduous forest of northwestern Madagascar. Sexes did not differ either in body size or in body mass. Sleeping sites were used almost exclusively by adult male-female pairs. Individuals showed a high sleeping-site fidelity limited to 2-3 different sleeping sites in close vicinity during the whole study period. Most females showed a higher fidelity to one distinct sleeping site than their male partners. Sleeping groups consisted of one adult male and one adult female and remained stable in composition over the whole study period. Exclusive pair-specific usage of sleeping sites suggests sleeping site related territoriality of male-female pairs, perhaps influenced by inter- and intrasexual resource competition. Results give first insights into the distribution patterns and social organization of this species. They imply dispersed monogamy for the Milne Edwards' sportive lemur, with sleeping sites as a potentially restricted and defendable resource.
Clinical Neurobiology Laboratory, German Primate Center, Göttingen 37077, Germany.
Male mating tactics can vary according to the potential for scramble or contest competition but also as a consequence of individual characteristics, such as body condition and previous experience. The influence of experience, i.e., residency, on male recapture rates and reproductive success was studied in a population of free-living grey mouse lemurs. Long-term capture data from 320 individuals revealed that both sexes had very low recapture probabilities within their first year in the study population, but recapture rates declined less sharply during the following years. Capture results and telemetric analyses on 12 focal males revealed that resident males had larger body mass and larger home ranges than new males. Home range size correlated with the number of accessible females, indicating that resident males had higher probabilities to meet mates than new males. The reproductive success of 132 candidate fathers, representing both resident and new males, was determined by means of molecular genotyping. Paternity determination was successful in 38 cases (success rate: 19%). Sixteen resident males and seventeen new males sired offspring. However, in relation to the number of candidate fathers being present in the mating season, resident males were twice as likely to reproduce successfully as new males. These findings suggest experience-dependent reproductive tactics that most likely correspond to a differential spatial knowledge of resources, mates and potential threats. The results generally agree with the predictions made for a scramble competition regime and demonstrate substantial behavioral plasticity in a nocturnal primate species with a dispersed multi-male/multi-female mating system. Am J Phys Anthropol, 2007.(c) 2007 Wiley-Liss, Inc.
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School of Human Evolution and Social Change, Arizona State University, Tempe, AZ 85287.
Studies of primate life history variation are constrained by the fact that all large-bodied extant primates are haplorhines. However, large-bodied strepsirrhines recently existed. If we can extract life history information from their skeletons, these species can contribute to our understanding of primate life history variation. This is particularly important in light of new critiques of the classic "fast-slow continuum" as a descriptor of variation in life history profiles across mammals in general. We use established dental histological methods to estimate gestation length and age at weaning for five extinct lemur species. On the basis of these estimates, we reconstruct minimum interbirth intervals and maximum reproductive rates. We utilize principal components analysis to create a multivariate "life history space" that captures the relationships among reproductive parameters and brain and body size in extinct and extant lemurs. Our data show that, whereas large-bodied extinct lemurs can be described as "slow" in some fashion, they also varied greatly in their life history profiles. Those with relatively large brains also weaned their offspring late and had long interbirth intervals. These were not the largest of extinct lemurs. Thus, we distinguish size-related life history variation from variation that linked more strongly to ecological factors. Because all lemur species larger than 10 kg, regardless of life history profile, succumbed to extinction after humans arrived in Madagascar, we argue that large body size increased the probability of extinction independently of reproductive rate. We also provide some evidence that, among lemurs, brain size predicts reproductive rate better than body size. Am J Phys Anthropol, 2010.(c) 2010 Wiley-Liss, Inc.
Department of Earth Sciences, University of Hong Kong, Pokfulam Road, Hong Kong, China.
Madagascar hosts one of the world's most unusual, endemic, diverse and threatened concentrations of fauna. To explain its unique, imbalanced biological diversity, G. G. Simpson proposed the 'sweepstakes hypothesis', according to which the ancestors of Madagascar's present-day mammal stock rafted there from Africa. This is an important hypothesis in biogeography and evolutionary theory for how animals colonize new frontiers, but its validity is questioned. Studies suggest that currents were inconsistent with rafting to Madagascar and that land bridges provided the migrants' passage. Here we show that currents could have transported the animals to the island and highlight evidence inconsistent with the land-bridge hypothesis. Using palaeogeographic reconstructions and palaeo-oceanographic modelling, we find that strong surface currents flowed from northeast Mozambique and Tanzania eastward towards Madagascar during the Palaeogene period, exactly as required by the 'sweepstakes process'. Subsequently, Madagascar advanced north towards the equatorial gyre and the regional current system evolved into its modern configuration with flows westward from Madagascar to Africa. This may explain why no fully non-aquatic land mammals have colonized Madagascar since the arrival of the rodents and carnivorans during the early-Miocene epoch. One implication is that rafting may be the dominant means of overseas dispersal in the Cenozoic era when palaeocurrent directions are properly considered.
Jing-Wen Li,
Carol K L Yeung,
Pi-Wen Tsai,
Rong-Chien Lin,
Chia-Fen Yeh,
Cheng-Te Yao,
Lianxian Han,
LE Manh Hung,
Ping Ding,
Qishan Wang,
Shou-Hsien Li
Department of Life Science, National Taiwan Normal University, Taipei 116 Taiwan.
Abstract Allopatry is conventionally considered the geographical mode of speciation for continental island organisms. However, strictly allopatric speciation models that assume the lack of postdivergence gene flow seem oversimplified given the recurrence of land bridges during glacial periods since the late Pliocene. Here, to evaluate whether a continental island endemic, the Taiwan hwamei (Leucodioptron taewanus, Passeriformes Timaliidae) speciated in strict allopatry, we used weighted-regression-based approximate Bayesian computation (ABC) to analyse the genetic polymorphism of 18 neutral nuclear loci (total length: 8500 bp) in Taiwan hwamei and its continental sister species, the Chinese hwamei (L. canorum canorum). The nonallopatry model was found to fit better with observed genetic polymorphism of the two hwamei species (posterior possibility = 0.82). We also recovered unambiguous signals of nontrivial bidirectional postdivergence gene flow (N(e)m >> 1) between Chinese hwamei and Taiwan hwamei until 0.5 Ma. Divergence time was estimated to be 3.5 to 2 million years earlier than that estimated from mitochondrial cytochrome b sequences. Finally, using the inferred nonallopatry model to simulate genetic variation at 24 nuclear genes examined showed that the adiponectin receptor 1 gene may be under divergent adaptation. Our findings imply that the role of geographical barrier may be less prominent for the speciation of continental island endemics, and suggest a shift in speciation studies from simply correlating geographical barrier and genetic divergence to examining factors that facilitate and maintain divergence, e.g. differential selection and sexual selection, especially in the face of interpopulation gene flow.
Francine L Dolins,
Alison Jolly,
Hantanirina Rasamimanana,
Jonah Ratsimbazafy,
Anna T C Feistner,
Florent Ravoavy
Department of Behavioral Sciences, University of Michigan, Dearborn, Michigan.
Few Malagasy children and adults are aware of the rare and unique fauna and flora indigenous to their island-continent, including flagship lemur species. Even the Malagasy ancestral proverbs never mentioned lemurs, but these same proverbs talked about the now extinct hippopotamus. Madagascar's geography, history, and economic constraints contribute to severe biodiversity loss. Deforestation on Madagascar is reported to be over 100,000 ha/year, with only 10-15% of the island retaining natural forest [Green & Sussman, 1990]. Educating children, teacher-training, and community projects about environmental and conservation efforts to protect the remaining natural habitats of endangered lemur species provide a basis for long-term changes in attitudes and practices. Case studies of three conservation education projects located in different geographical regions of Madagascar, Centre ValBio, Madagacar Wildlife Conservation Alaotra Comic Book Project, and The Ako Book Project, are presented together with their ongoing stages of development, assessment, and outcomes. We argue that while nongovernmental organizational efforts are and will be very important, the Ministry of Education urgently needs to incorporate biodiversity education in the curriculum at all levels, from primary school to university. Am. J. Primatol. 71:1-16, 2009.(c) 2009 Wiley-Liss, Inc.
Michael K Schwartz,
Jeffrey P Copeland,
Neil J Anderson,
John R Squires,
Robert M Inman,
Kevin S McKelvey,
Kristy L Pilgrim,
Lisette P Waits,
Samuel A Cushman
USDA Forest Service Rocky Mountain Research Station, 800 East Beckwith, Missoula, Montana 59801, USA. mkschwartz@fs.fed.us
Wolverines (Gulo gulo) are one of the rarest carnivores in the contiguous United States. Effective population sizes in Montana, Idaho, and Wyoming, where most of the wolverines in the contiguous United States exist, were calculated to be 35 (credible limits, 28 52) suggesting low abundance. Landscape features that influence wolverine population substructure and gene flow are largely unknown. Recent work has identified strong associations between areas with persistent spring snow and wolverine presence and range. We tested whether a dispersal model in which wolverines prefer to disperse through areas characterized by persistent spring snow cover produced least-cost paths among all individuals that correlated with genetic distance among individuals. Models simulating large preferences for dispersing within areas characterized by persistent spring snow explained the data better than a model based on Euclidean distance. Partial Mantel tests separating Euclidean distance from spring snow-cover-based effects indicated that Euclidean distance was not significant in describing patterns of genetic distance. Because these models indicated that successful dispersal paths followed areas characterized by spring snow cover, we used these understandings to derive empirically based least-cost corridor maps in the U.S. Rocky Mountains. These corridor maps largely explain previously published population subdivision patterns based on mitochondrial DNA and indicate that natural colonization of the southern Rocky Mountains by wolverines will be difficult but not impossible.
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 fecal samples for parasite analyses, I identified 10 parasite species, including 6 nematodes (Lemuricola vauceli, Trichuris sp., 2 species of Callistoura, 1 trichostrongylid, and 1 strongyloid), 1 anoplocephalid cestode, a dicrocoeliid trematode as well as 2 protozoans (Entamoeba sp. and Balantidium coli). The population in Kirindy Forest had the highest prevalence and number of parasite species ever recorded for species of lemurs. Additionally, prevalence of some parasite species differed between the social groups studied. These findings lead to 2 conclusions: First, it is important to extend a parasitological study to several social groups of a host population as groups may differ in parasite fauna due to minor microclimatic or habitat parameters, and, second, short-term assessments of lemur health might underestimate the real parasite burden.
ABSTRACT: BACKGROUND: Molecular tools may help to uncover closely related and still diverging species from a wide variety of taxa and provide insight into the mechanisms, pace and geography of marine speciation. There is a certain controversy on the phylogeography and speciation modes of species-groups with an Eastern Atlantic-Western Indian Ocean distribution, with previous studies suggesting that older events (Miocene) and/or more recent (Pleistocene) oceanographic processes could have influenced the phylogeny of marine taxa. The spiny lobster genus Palinurus allows for testing among speciation hypotheses, since it has a particular distribution with two groups of three species each in the Northeastern Atlantic (P. elephas, P. mauritanicus and P. charlestoni) and Southeastern Atlantic and Southwestern Indian Oceans (P. gilchristi, P. delagoae and P. barbarae). In the present study, we obtain a more complete understanding of the phylogenetic relationships among these species through a combined dataset with both nuclear and mitochondrial markers, by testing alternative hypotheses on both the mutation rate and tree topology under the recently developed approximate Bayesian computation (ABC) methods. RESULTS: Our analyses support a North-to-South speciation pattern in Palinurus with all the South-African species forming a monophyletic clade nested within the Northern Hemisphere species. Coalescent-based ABC methods allowed us to reject the previously proposed hypothesis of a Middle Miocene speciation event related with the closure of the Tethyan Seaway. Instead, divergence times obtained for Palinurus species using the combined mtDNA-microsatellite dataset and standard mutation rates for mtDNA agree with known glaciation-related processes occurring during the last 2 my. CONCLUSIONS: The Palinurus speciation pattern is a typical example of a series of rapid speciation events occurring within a group, with very short branches separating different species. Our results support the hypothesis that recent climate change-related oceanographic processes have influenced the phylogeny of marine taxa, with most Palinurus species originating during the last two million years. The present study highlights the value of new coalescent-based statistical methods such as ABC for testing different speciation hypotheses using molecular data.
Department of Anthropology, University of Southern California, Los Angeles, California.
Three sympatric Hapalemur species (H. g. griseus, H. aureus, and H.(Prolemur) simus) in Ranomafana National Park, Madagascar are known to eat bamboo food parts that contain cyanide. How these lemurs avoid cyanide poisoning remains unknown. In this study, we tested for the presence/absence of cyanide in bamboo lemur foods and excreta to (1) document patterns of cyanide consumption among species with respect to diet,(2) identify routes of elimination of cyanide from the gastrointestinal tract, and (3) determine whether cyanide is absorbed from the diet. We tested 102 food, urine, and fecal samples for hydrogen cyanide (HCN) during two "pre-dry" seasons (April 2006, May 2007) using commercially available Cyantesmo test strips. The test strips changed color in the presence of HCN, and we recorded color change on a scale of 0 (no change) to 5 (cobalt) at preset intervals with a final score taken at 24 hr. We detected cyanide in bamboo food parts and urine of all three Hapalemur species. Time to color change of the test strips ranged from almost instantaneous to >12 hr incubation. Of the foods tested, only bamboo contained cyanide, but results differed among bamboo species and plant parts of the same species. Specifically, branch shoot and culm pith of the giant bamboo produced strong, immediate reactions to the test paper, whereas parts of liana bamboos produced either weak or no color change. Cyanide was present in almost all urine samples but rarely in fecal samples. This suggests that dietary cyanide is absorbed in the gastrointestinal tract of the Hapalemur species and excreted, at least in part, by the kidneys. Samples from H. griseus exhibited lower, though still detectable, cyanide levels compared with H. simus and H. aureus. Differences among lemur species appear to be related to the specific bamboo parts consumed. Am. J. Primatol. 71:1-6, 2009.(c) 2009 Wiley-Liss, Inc.
Instituto de Ecología y Sistemática, Ciudad de la Habana, Cuba.
We studied phylogenetic relationships of the Eleutherodactylus auriculatus species group to infer colonization and diversification patterns in this endemic radiation of terrestrial frogs of the genus Eleutherodactylus in the largest of the Greater Antilles, Cuba. An initial screening of genetic diversity based on partial sequences of the 16S rRNA gene in almost 100 individuals of all species of the group and covering the complete known geographic range of their occurrence found most species endemic to small ranges in the eastern Cuban mountains while a single species was widespread over most of Cuba. Our molecular phylogeny, based on 3,815 bp of four mitochondrial and one nuclear gene, suggests that most cladogenetic events within the group occurred among clades restricted to the eastern mountains, which acted as refugia and facilitated the diversification in this group. Our results reveal two separate colonization events of Central and Western Cuba and allow inferring the timing of the subsequent diversification events that occurred between 11-2 Mya. Because populations previously assigned to E. auriculatus represent four genetically strongly divergent lineages that also differ in their advertisement calls, we propose that E. auriculatus as currently recognized comprises four species. The difficulties in assigning the name auriculatus to any of these four species, and the fact that E. principalis is nested within one of them, stresses the need for a thorough taxonomic revision of this group.
Faculté des Sciences, Université de Mahajanga, Mahajanga, Madagascar.
The coexistence of closely related species is not easily understood on the basis of ecological theories. This study investigates the extent of coexistence of two congeneric species of Microcebus murinus (MUR) and M. ravelobensis (RAV) in northwestern Madagascar. Their presence and local relative population densities were determined by capturing and nocturnal transect counts and compared at 22 study sites in the Ankarafantsika National Park. All sites were characterized with regard to their altitude, access to surface water, and 19 structural vegetation characteristics. RAV and MUR were not equally distributed over this regional scale. RAV occurred in more sites and at higher maximum densities than MUR. The relative population densities of both species were significantly and negatively correlated with each other. Whereas the relative population densities of MUR increased with altitude and were highest in dry habitats far from surface water, the relative population densities of RAV generally decreased with altitude and were highest in low altitude habitats close to surface water. The results of the vegetation characteristics also reflect these general trends. The divergent pattern of local and regional coexistence of these two species is discussed and can be best explained either by the existence of a spatially heterogeneous competitive environment or by independent evolutionary pathways in different historic environments. Am. J. Primatol. 71:1-11, 2009.(c) 2009 Wiley-Liss, Inc.
