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  • Print publication year: 2016
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26 - Can behavioral ecology help to understand the divergent geographic range sizes of mouse lemurs?

from Part V - Cheirogaleidae: conservation biogeography



The understanding of the size, shape, overlap, and constraints of geographic ranges of organisms forms one important foundation of the very active field of biogeography, and is tightly connected to the understanding of evolutionary processes that give rise to the diverse distribution patterns that can be found today throughout all terrestrial and aquatic biomes (Cox and Moore, 2010; Lomolino et al., 2010). Madagascar is well known for its hypervariable environments (Dewar and Richard, 2007) and its extraordinary diversity in fauna and flora, most of which evolved endemically during the long period of isolation of Madagascar from other landmasses (Yoder et al., 1996; Poux et al., 2005; Crottini et al., 2012; Samonds et al., 2012). Some meta-analyses and reviews have recently aimed to investigate the evolutionary processes that led to the endemic radiations in Malagasy vertebrates and emphasized the role of climatic factors and physical barriers as drivers of allopatric speciation (e.g., Goodman and Ganzhorn, 2004; Yoder and Nowak, 2006; Wilmé et al., 2006; Pearson and Raxworthy, 2009; Vences et al., 2009). In particular, the role of large rivers and mountain ranges in disrupting gene flow and thereby leading to the evolution of local and regional endemics has been emphasized for various vertebrate clades (e.g., Wilmé & Goodman, 2003; Olson et al., 2004; Wilmé et al., 2006; Olivieri et al., 2007; Townsend et al., 2009). It should be mentioned that many geographic range sizes of Malagasy lemurs are only inferred from a rather small amount of point location data rather than known from extensive survey work which is known to limit the power of testing biogeographic hypotheses (Gaston, 1994). Nevertheless, none of the available biogeographic models for Madagascar can explain why some phylogenetic lineages contain closely related species with quite variable geographic range sizes. Mouse lemurs (Microcebus spp.) form one such lineage among lemurs and it shall be explored in this chapter whether ecological and behavioral traits may explain the existence of such divergent distribution patterns within a single genus.

Mouse lemurs comprise a total of 21 described species (Mittermeier et al., 2010; Radespiel et al., 2012; Rasoloarison et al., 2013) and can be found in all forest habitats of the island.

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Allnutt, TF, Ferrier, S, Manion, G, et al. 2008. A method for quantifying biodiversity loss and its application to a 50-year record of deforestation across Madagascar. Conservation Letters 1:173–181.
Anthony, NM, Johnson-Bawe, M, Jeffery, K, et al. 2007. The role of Pleistocene refugia and rivers in shaping gorilla genetic diversity in central Africa. Proceedings of the National Academy of Sciences of the United States of America 104:20432–20436.
Atsalis, S. 1999. Seasonal fluctuations in body fat and activity levels in a rain-forest species of mouse lemur, Microcebus rufus. International Journal of Primatology 20:883–910.
Blair, C, Heckman, KL, Russell, AL, Yoder, AD. 2014. Multilocus coalescent analyses reveal the demographic history and speciation patterns of mouse lemur sister species. BMC Evolutionary Biology 14:57.
Blanco, MB. 2008. Reproductive schedules of female Microcebus rufus at Ranomafana National Park, Madagascar. International Journal of Primatology 29:323–338.
Blanco, MB. 2011. Timely estrus in wild brown mouse lemur females at Ranomafana National Park, southeastern Madagascar. American Journal of Physical Anthropology 145:311–317.
Blanco, MB, Meyer, JS. 2009. Assessing reproductive profiles in female brown mouse lemurs (Microcebus rufus) from Ranomafana National Park, southeast Madagascar, using fecal hormone analysis. American Journal of Primatology 71:439–446.
Bohr, YE-MB, Giertz, P, Ratovonamana, YR, Ganzhorn, JU. 2011. Gray-brown mouse lemurs (Microcebus griseorufus) as an example of distributional constraints through increasing desertification. International Journal of Primatology 32:901–913.
Brown, JH. 1984. On the relationship between abundance and distribution of species. American Naturalist 124:255–279.
Brown, JH. 1995. Macroecology. University of Chicago Press, Chicago.
Busch, J, Dave, R, Hannah, L, et al. 2012. Climate change and the cost of conserving species in Madagascar. Conservation Biology 26:408–419.
Case, TJ, Holt, RD, McPeek, MA, Keitt, TH. 2005. The community context of species' borders: ecological and evolutionary perspectives. Oikos 108:28–46.
Chanu, L, Goetze, D, Rajeriarison, C, et al. 2012. Can differences in floristic composition explain variation in the abundance of two sympatric mouse lemur species (Microcebus) in the Ankarafantsika National Park, northwestern Madagascar?Malagasy Nature 6:83–102.
Cowlishaw, G, Hacker, JE. 1997. Distribution, diversity, and latitude in African primates. American Naturalist 150:505–512.
Cox, CB, Moore, PD. 2010. Biogeography: An Ecological and Evolutionary Approach, 8th edition. John Wiley & Sons, Chichester.
Craul, M, Radespiel, U, Rasolofoson, DW, et al. 2008. Large rivers do not always act as species barriers for Lepilemur sp. Primates 49:211–218.
Crottini, A, Madsen, O, Poux, C, et al. 2012. Vertebrate time-tree elucidates the biogeographic pattern of a major biotic change around the K-T boundary in Madagascar. Proceedings of the National Academy of Sciences of the United States of America 109:5358–5363.
Dammhahn, M, Kappeler, PM. 2005. Social system of Microcebus berthae, the world's smallest primate. International Journal of Primatology 26:407–435.
Dammhahn, M, Kappeler, PM. 2008a. Small-scale coexistence of two mouse lemur species (Microcebus berthae and M. murinus) within a homogeneous competitive environment. Oecologia 157:473–483.
Dammhahn, M, Kappeler, PM. 2008b. Comparative feeding ecology of sympatric Microcebus berthae and M. murinus. International Journal of Primatology 29:1567–1589.
Dammhahn, M, Kappeler, PM. 2010. Scramble or contest competition over food in solitarily foraging mouse lemurs (Microcebus spp.): new insights from stable isotopes. American Journal of Physical Anthropology 141:181–189.
Darwin, C. 1859. On the Origin of Species by means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life, 1st edition. John Murray, London.
Dewar, RE, Richard, AF. 2007. Evolution in the hypervariable environment of Madagascar. Proceedings of the National Academy of Sciences of the United States of America 104:13723–12727.
Doyle, GA, Izard, MK (eds.) 1995. Creatures of the Dark: the Nocturnal Prosimians. Plenum Press, New York.
Eberle, M, Kappeler, PM. 2004. Selected polyandry: female choice and inter-sexual conflict in a small nocturnal solitary primate (Microcebus murinus). Behavioral Ecology and Sociobiology 57:91–100.
Eberle, M, Kappeler, PM. 2006. Family insurance: kin selection and cooperative breeding in a solitary primate (Microcebus murinus). Behavioral Ecology and Sociobiology 60:582–588.
Eeley, HAC, Foley, RA. 1999. Species richness, species range size and ecological specialisation among African primates: geographical patterns and conservation implications. Biodiversity and Conservation 8:1033–1056.
Fredsted, T, Pertoldi, C, Olesen, JM, Eberle, M, Kappeler, PM. 2004. Microgeographic heterogeneity in spatial distribution and mtDNA variability of gray mouse lemurs (Microcebus murinus, Primates: Cheirogaleidae). Behavioral Ecology and Sociobiology 56:393–403.
Fredsted, T, Pertoldi, C, Schierup, MH, Kappeler, PM. 2005. Microsatellite analyses reveal fine-scale genetic structure in grey mouse lemurs (Microcebus murinus). Molecular Ecology 14:2363–2372.
Ganzhorn, JU. 1994. Lemurs as indicators for habitat change. In Thierry, B, Anderson, JR, Roeder, JJ, Herrenschmidt, N (eds.), Current Primatology. Vol.1. Ecology and Evolution (pp. 51–56). Universite Louis Pasteur, Strasbourg.
Ganzhorn, JU. 1995. Low-level forest disturbance effects on primary production, leaf chemistry, and lemur populations. Ecology 76:2084–2096.
Ganzhorn, JU, Schmid, J. 1998. Different population dynamics of Microcebus murinus in primary and secondary deciduous dry forest of Madagascar. International Journal of Primatology 19:785–796.
Garbutt, N. 2007. Mammals of Madagascar: A Complete Guide. Yale University Press, New Haven.
Gaston, KJ. 1994. Measuring geographic range sizes. Ecography 17:198–205.
Génin, F. 2008. Life in unpredictable environments: first investigation of the natural history of Microcebus griseorufus. International Journal of Primatology 29:303–321.
Gligor, M, Ganzhorn, JU, Rakotondravony, D, et al. 2009. Hybridization between mouse lemurs in an ecological transition zone in southern Madagascar. Molecular Ecology 18:520–533.
Goodman, SM. 2003. Predation on lemurs. In Goodman, SM, Benstead, JP (eds.), The Natural History of Madagascar (pp. 1221–1228). University of Chicago Press, Chicago.
Goodman, SM, Ganzhorn, JU. 2004. Biogeography of lemurs in the humid forests of Madagascar: the role of elevational distribution and rivers. Journal of Biogeography 31:47–55.
Goodman, SM, O'Connor, S, Langrand, O. 1993. A review of predation on lemurs: Implications for the evolution of social behavior in small, nocturnal primates. In Kappeler, PM, Ganzhorn, JU (eds.), Lemur Social Systems and Their Ecological Basis (pp. 51–66). Plenum Press, New York.
Green, GM, Sussman, RW. 1990. Deforestation history of the eastern rain forests of Madagascar from satellite images. Science 248:212–215.
Guschanski, K, Olivieri, G, Funk, SM, Radespiel, U. 2007. MtDNA reveals strong genetic differentiation among geographically isolated populations of the golden brown mouse lemur, Microcebus ravelobensis. Conservation Genetics 8:809–821.
Hannah, L, Dave, R, Lowry, PP II, et al. 2008. Climate change adaptation for conservation in Madagascar. Biology Letters 4:590–594.
Hanski, I. 1982. Dynamics of regional distribution: the core and satellite species hypothesis. Oikos 38:210–221.
Hanski, I, Gyllenberg, M. 1997. Uniting two general patterns in the distribution of species. Science 275:397–400.
Hapke, A, Gligor, M, Rakotondranary, SJ. 2011. Hybridization of mouse lemurs: different patterns under different ecological conditions. BMC Evolutionary Biology 11:297.
Harcourt, AH, Coppeto, SA, Parks, SA. 2002. Rarity, specialization and extinction in primates. Journal of Biogeography 29:445–456.
Irwin, MT, Wright, PC, Birkinshaw, C, et al. 2010. Patterns of species change in anthropogenically disturbed forests of Madagascar. Biological Conservation 143:2351–2362.
Kappeler, PM, Rasoloarison, RM, Razafimanantsoa, L, Walter, L, Roos, C. 2005. Morphology, behaviour and molecular evolution of giant mouse lemurs (Mirza spp.) Gray, 1870, with description of a new species. Primate Report 71:3–26.
Kobbe, S, Ganzhorn, JU, Dausmann, KH. 2011. Extreme individual flexibility of heterothermy in free-ranging Malagasy mouse lemurs (Microcebus griseorufus). Journal of Comparative Physiology B – Biochemical Systemic and Environmental Physiology 181:165–173.
Kraus, C, Eberle, M, Kappeler, PM. 2008. The costs of risky male behaviour: sex differences in seasonal survival in a small sexually monomorphic primate. Proceedings of the Royal Society B, Biological Sciences 275:1635–1644.
Krebs, CJ. 1998. Ecological Methodology. Addison-Wesley Educational Publishers, Menlo Park, CA.
Lahann, P, Schmid, J, Ganzhorn, JU. 2006. Geographic variation in populations of Microcebus murinus in Madagascar: resource seasonality or Bergmann's rule?International Journal of Primatology 27:983–999.
Lomolino, MV, Riddle, BR, Whittaker, RJ, Brown, JH. 2010. Biogeography, 4th edition. Sinauer Associates, Inc., Sunderland, MA.
Lutermann, H, Verburgt, L, Rendigs, A. 2010. Resting and nesting in a small mammal: sleeping sites as a limiting resource for female grey mouse lemurs. Animal Behaviour 79:1211–1219.
Mittermeier, RA, Louis, EE Jr, Richardson, M, et al. 2010. Lemurs of Madagascar, 3rd edition. Conservation International, Arlington.
Muldoon, KM, Goodman, SM. 2010. Ecological biogeography of Malagasy non-volant mammals: community structure is correlated with habitat. Journal of Biogeography 37:1144–1159.
Olivieri, G, Craul, M, Radespiel, U. 2005. Inventaire des lémuriens dans 15 fragments de forêt de la province de Mahajanga. Lemur News 10:11–16.
Olivieri, G, Zimmermann, E, Randrianambinina, B, et al. 2007. The ever-increasing diversity in mouse lemurs: three new species in north and northwestern Madagascar. Molecular Phylogenetics and Evolution 43:309–327.
Olson, LE, Goodman, SM, Yoder, AD. 2004. Illumination of cryptic species boundaries in long-tailed shrew tenrecs (Mammalia: Tenrecidae; Microgale), with new insights into geographic variation and distributional constraints. Biological Journal of the Linnean Society 83:1–22.
Pearson, RG, Raxworthy, CJ. 2009. The evolution of local endemism in Madagascar: watershed versus climatic gradient hypotheses evaluated by null biogeographic models. Evolution 63:959–967.
Poux, C, Madsen, O, Marquard, E, et al. 2005. Asynchronous colonization of Madagascar by the four endemic clades of primates, tenrecs, carnivores, and rodents as inferred from nuclear genes. Systematic Biology 54:719–730.
Radespiel, U. 2006. Ecological diversity and seasonal adaptations of mouse lemurs (Microcebus spp.). In Gould, L, Sauther, ML (eds.), Lemurs: Ecology and Adaptation (pp. 211–233). Springer, New York.
Radespiel, U, Ehresmann, P, Zimmermann, E. 2003a. Species-specific usage of sleeping sites in two sympatric mouse lemur species (Microcebus murinus and M. ravelobensis) in northwestern Madagascar. American Journal of Primatology 59:139–151.
Radespiel, U, Lutermann, H, Schmelting, B, Bruford, MW, Zimmermann, E. 2003b. Patterns and dynamics of sex-biased dispersal in a nocturnal primate, the grey mouse lemur, Microcebus murinus. Animal Behaviour 65:709–719.
Radespiel, U, Olivieri, G, Rasolofoson, DW, et al. 2008a. Exceptional diversity of mouse lemurs (Microcebus spp.) in the Makira region with the description of one new species. American Journal of Primatology 70:1033–1046.
Radespiel, U, Rakotondravony, R, Chikhi, L. 2008b. Natural and anthropogenic determinants of genetic structure in the largest remaining population of the endangered golden-brown mouse lemur, Microcebus ravelobensis. American Journal of Primatology 70:860–870.
Radespiel, U, Jurić, M, Zimmermann, E. 2009. Sociogenetic structures, dispersal and the risk of inbreeding in a small nocturnal lemur, the golden-brown mouse lemur (Microcebus ravelobensis). Behaviour 146:607–628.
Radespiel, U, Ratsimbazafy, JH, Rasoloharijaona, S, et al. 2012. First indications of a highland specialist among mouse lemurs (Microcebus spp.) and evidence for a new mouse lemur species from eastern Madagascar. Primates 53:157–170.
Rakotondranary, SJ, Ganzhorn, JU. 2011. Habitat separation of sympatric Microcebus spp. in the dry spiny forest of south-eastern Madagascar. Folia Primatologica 82:212–223.
Rakotondravony, R, Radespiel, U. 2007. Variation de la distribution de deux espèces de microcèbes dans le Parc National Ankarafantsika. Lemur News 12:31–34.
Rakotondravony, R, Radespiel, U. 2009. Varying patterns of coexistence of two mouse lemur species (Microcebus ravelobensis and M. murinus) in a heterogeneous landscape. American Journal of Primatology 71:928–938.
Rakotondranary, J, Ratovonamana, RY, Ganzhorn, JU. 2010. Distributions et caractéristiques des microhabitats de Microcebus griseorufus (Cheirogaleidae) dans le Parc National de Tsimanampetsotsa (Sud-ouest de Madagascar). Malagasy Nature 4:55–64.
Rakotondranary, SJ, Hapke, A, Ganzhorn, JU. 2011a. Distribution and morphological variation of Microcebus spp. along an environmental gradient in southeastern Madagascar. International Journal of Primatology 32:1037–1057.
Rakotondranary, SJ, Struck, U, Knoblauch, C, Ganzhorn, JU. 2011b. Regional, seasonal and interspecific variation in 15N and 13C in sympatric mouse lemurs. Naturwissenschaften 98:909–917.
Randrianambinina, B, Rakotondravony, D, Radespiel, U, Zimmermann, E. 2003. Seasonal changes in general activity, body mass and reproduction of two small nocturnal primates: a comparison of the golden brown mouse lemur (Microcebus ravelobensis) in northwestern Madagascar and the brown mouse lemur (Microcebus rufus) in eastern Madagascar. Primates 44:321–331.
Rapoport, EH. 1982. Areography: Geographical Strategies of Species. Pergamon Press, New York.
Rasoloarison, RM, Weisrock, DW, Yoder, AD, et al. 2013. Two new species of mouse lemurs (Cheirogaleidae: Microcebus) from eastern Madagascar. International Journal of Primatology 34:455–469.
Rendigs, A, Radespiel, U, Wrogemann, D, Zimmermann, E. 2003. Relationship between microhabitat structure and distribution of mouse lemurs (Microcebus spp.) in northwestern Madagascar. International Journal of Primatology 24:47–64.
Samonds, KE, Godfrey, LR, Ali, JR, et al. 2012. Spatial and temporal arrival patterns of Madagascar's vertebrate fauna explained by distance, ocean currents, and ancestor type. Proceedings of the National Academy of Sciences, USA 109:5352–5357.
Scheumann, M, Rabesandratana, A, Zimmermann, E. 2007. Predation, communication, and cognition in lemurs. In Gursky, SL, Nekaris, KAI (eds.), Primate Anti-Predator Strategies (pp. 100–126). Springer, Oxford.
Schliehe-Diecks, S, Eberle, M, Kappeler, PM. 2012. Walk the line – dispersal movements of gray mouse lemurs (Microcebus murinus). Behavioral Ecology and Sociobiology 66:1175–1185.
Schmelting, B, Ehresmann, P, Lutermann, H, Randrianambinina, B, Zimmermann, E. 2000. Reproduction of two sympatric mouse lemur species (Microcebus murinus and M. ravelobensis) in north-west Madagascar: first results of a long term study. In Lourenço, WR, Goodman, SM (eds.), Diversité et Endémisme à Madagascar (pp. 165–175). Société de Biogéographie, Paris.
Schmelting, B, Zimmermann, E, Berke, O, Bruford, MW, Radespiel, U. 2007. Experience-dependent recapture rates and reproductive success in male grey mouse lemurs (Microcebus murinus). American Journal of Physical Anthropology 133:743–752.
Schmid, J. 1998. Tree holes used for resting by gray mouse lemurs (Microcebus murinus) in Madagascar: insulation capacities and energetic consequences. International Journal of Primatology 19:797–809.
Schmid, J, Kappeler, PM. 1994. Sympatric mouse lemurs (Microcebus spp.) in western Madagascar. Folia Primatologica 63:162–170.
Schmid, J, Kappeler, PM. 1998. Fluctuating sexual dimorphism and differential hibernation by sex in a primate, the gray mouse lemur (Microcebus murinus). Behavioral Ecology and Sociobiology 43:125–132.
Schneider, N, Chikhi, L, Currat, M, Radespiel, U. 2010. Signals of recent spatial expansions in the grey mouse lemur (Microcebus murinus). BMC Evolutionary Biology 10:105.
Schwab, D. 2000. A preliminary study of spatial distribution and mating system of pygmy mouse lemurs (Microcebus cf myoxinus). American Journal of Primatology 51:41–60.
Schwab, D, Ganzhorn, JU. 2004. Distribution, population structure and habitat use of Microcebus berthae compared to those of other sympatric cheirogalids. International Journal of Primatology 25:307–330.
Stevens, GC. 1989. The latitudinal gradient in geographical range: how so many species coexist in the tropics. American Naturalist 133:240–256.
Thiele, D, Razafimahatratra, E, Hapke, A. 2013. Discrepant partitioning of genetic diversity in mouse lemurs and dwarf lemurs – biological reality or taxonomic bias?Molecular Phylogenetics & Evolution 69:593–609.
Thorén, S, Quietzsch, F, Radespiel, U. 2010. Leaf nest use and construction in the golden-brown mouse lemur (Microcebus ravelobensis) in the Ankarafantsika National Park. American Journal of Primatology 72:48–55.
Thorén, S, Quietzsch, F, Schwochow, D, et al. 2011a. Seasonal changes in feeding ecology and activity patterns of two sympatric mouse lemur species, the gray mouse lemur (Microcebus murinus) and the golden-brown mouse lemur (M. ravelobensis), in northwestern Madagascar. International Journal of Primatology 32:566–586.
Thorén, S, Linnenbrink, M, Radespiel, U. 2011b. Different competitive potential in two coexisting mouse lemur species in northwestern Madagascar. American Journal of Physical Anthropology 145(1):156–162.
Tosi, AJ. 2008. Forest monkeys and Pleistocene refugia: a phylogeographic window onto the disjunct distribution of the Chlorocebus lhoesti species group. Zoological Journal of the Linnean Society 154:408–418.
Townsend, TM, Vieites, DR, Glaw, F, Vences, M. 2009. Testing species-level diversification hypotheses in Madagascar: the case of microendemic Brookesia leaf chameleons. Systematic Biology 58:641–656.
Vences, M, Wollenberg, KC, Vieites, DR, Lees, DC. 2009. Madagascar as a model region of species diversification. Trends in Ecology and Evolution 24:456–465.
Wall, D. von der 2008. Der Einfluss von Habitatfragmentierung auf die genetischen Strukturen von Microcebus murinus (Grauer Mausmaki). Diploma thesis,Leibniz University Hanover. 74 p.
Vuarin, P, Dammhahn, M, Henry, PY. 2013. Individual flexibility in energy saving: body size and condition constrain torpor use. Functional Ecology 27:793–799.
Walck, JL, Baskin, JM, Baskin, CC. 1999. Relative competitive abilities and growth characteristics of a narrowly endemic and a geographically widespread Solidago species (Asteraceae). American Journal of Botany 86:820–828.
Weisrock, DW, Smith, SD, Chan, LM, et al. 2012. Concatenation and concordance in the reconstruction of mouse lemur phylogeny: an empirical demonstration of the effect of allele sampling in phylogenetics. Molecular Biology and Evolution 29:1615–1630.
Wilmé, L, Goodman, SM. 2003. Biogeography, guild structure, and elevational variation of Madagascar forest birds. In Goodman, SM, Benstead, JP (eds.), The Natural History of Madagascar (pp. 1045–1058). University of Chicago Press, Chicago.
Wilmé, L, Goodman, SM, Ganzhorn, JU. 2006. Biogeographic evolution of Madagascar's microendemic biota. Science 312:1063–1065.
Wilson, SD, Keddy, PA. 1986. Species competitive ability and position along a natural stress/disturbance gradient. Ecology 67:1236–1242.
Wimmer, B, Tautz, D, Kappeler, PM. 2002. The genetic population structure of the gray mouse lemur (Microcebus murinus), a basal primate from Madagascar. Behavioral Ecology and Sociobiology 52:166–175.
Yoder, AD, Nowak, MD. 2006. Has vicariance or dispersal been the predominant biogeographic force in Madagascar? Only time will tell. Annual Review of Ecology, Evolution, and Systematics 37:405–431.
Yoder, AD, Yang, Z. 2004. Divergence dates for Malagasy lemurs estimated from multiple gene loci: geological and evolutionary context. Molecular Ecology 13:757–773.
Yoder, AD, Cartmill, M, Ruvolo, M, Smith, K, Vilgalys, R. 1996. Ancient single origin for Malagasy primates. Proceedings of the National Academy of Sciences, USA 93:5122–5126.
Zimmermann, E, Radespiel, U. 2013. Life histories in Primates. In Henke, W, Tattersall, I (eds.), Handbook of Paleoanthropology. Springer-Verlag, Berlin.
Zimmermann, E, Cepok, S, Rakotoarison, N, Zietemann, V, Radespiel, U. 1998. Sympatric mouse lemurs in North-West Madagascar: a new rufous mouse lemur species (Microcebus ravelobensis). Folia Primatologica 69:106–114.