Supplementary electronic material

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13. Dröscher, I. and Kappeler, P.M. (2013) Defining the low end of primate social complexity: The social organization of the nocturnal white-footed sportive lemur (Lepilemur leucopus). Int. J. Primatol. 34, 1225-1243.

14. Hilgartner, R. et al. (2012) Determinants of pair-living in red-tailed sportive lemurs (Lepilemur ruficaudatus). Ethology 118, 1-114.

15. Schülke, O. and Kappeler, P.M. (2003) So near and yet so far: territorial pairs but low cohesion between pair-partners in a nocturnal lemur, Phaner furcifer. Anim. Behav. 65, 331-343.

16. Méndez-Cárdenas, M.G. and Zimmermann, E. (2009) Duetting - a mechanism to strengthen pair bonds in a dispersed pair-living primate (Lepilemur edwardsi)? Amer. J. Phys. Anthropol. 139, 523-532.

17. Norscia, Y. and Borgononi-Tarli, S.M. (2008) Ranging behavior and possible correlates of pair-living in southeastern Avahis (Madagascar). Int. J. Primatol. 29, 153-171.

18. Ramanankirahina, R. et al. (2012) Seasonal effects on sleeping site ecology in a nocturnal pair-living lemur (Avahi occidentalis). Int. J. Primatol. 33, 428-439.

19. Fietz, J. (1999) Monogamy as a rule rather than exception in nocturnal lemurs: the case of the fat-tailed dwarf lemur, Cheirogaleus medius. Ethology 105, 259-272.

20. Overdorff, D., and Tecot, S. (2007). Social pair-bonding and resource defense in wild red-bellied lemurs (Eulemur rubriventer). In Lemurs: Ecology and Adaptation, L. Gould and M. Sauther, eds. (Springer US), pp. 235-254.

21. Dammhahn, M. (2003) MSc thesis, University of Tübingen.

22. Nievergelt, C. et al. (2002). Social system of the Alaotran gentle lemur (Hapalemur griseus alaotrensis): genetic characterization of group composition and mating system. Amer. J. Primatol. 57, 157-176.

23. Radespiel, U. et al. (1998) Sex-specific usage patterns of sleeping sites in grey mouse lemurs (Microcebus murinus) in Northwestern Madagascar. Amer. J. Primatol. 46, 77-84.

24. Dammhahn, M. and Kappeler, P.M. (2009) Females go where the food is: does the socio-ecological model explain variation in social organisation of solitary foragers? Behav. Ecol. Sociobiol. 63, 939-952.

25. Zinner, D. et al. (2003) Social organization of Lepilemur ruficaudatus. Int. J. Primatol. 24, 869-888.

26. Rasoloharijaona, S. et al. (2003) Pair-specific usage of sleeping sites and their implications for social organization in a nocturnal Malagasy primate, the Milne Edwards' sportive lemur (Lepilemur edwardsi). Amer. J. Phys. Anthropol. 122, 251-258.

27. Fichtel, C. et al. (2011) Out of sight but not out of mind? Behavioral coordination in red-tailed sportive lemurs (Lepilemur ruficaudatus). Int. J. Primatol. 32, 1383-1396.

28. Albignac, R. (1981) Variabilité dans l'organisation térritorialé et l'écologie de Avahi laniger (Lemurien nocturne de Madagascar). Compt. Rend. Acad. Sci. Paris 292, 331-334.

29. Fichtel, C. and Hilgartner, R. (2013) Noises in the dark: Vocal communication in Lepilemur ruficaudatus and other nocturnal pair-living primates. In Leaping Ahead, J. Masters, M. Gamba and F. Génin, eds. (New York: Springer), pp. 297-304.

30. Giacoma, C. et al. (2010). Sex differences in the song of Indri indri. Int. J. Primatol. 31, 539-551.

31. Eberle, M. and Kappeler, P.M. (2006) Family insurance: kin selection and cooperative breeding in a solitary primate (Microcebus murinus). Behav. Ecol. Sociobiol. 60, 582-588.

32. Hilgartner, R. et al. (2008). Life history traits and parental care in Lepilemur ruficaudatus. Amer. J. Primatol. 70, 2-11.

33. Schülke, O. (2005) Evolution of pair-living in Phaner furcifer. Int. J. Primatol. 26, 903-919.

34. Fietz, J. and Dausmann, K.H. (2003) Costs and potential benefits of parental care in the nocturnal fat-tailed dwarf lemur (Cheirogaleus medius). Fol. Primatol. 74, 246-258.