Environmental Correlates of Body Mass in True Lemurs (Eulemur spp.)
An organism’s body size is intrinsically related to its metabolic requirements, life history profile, and ecological niche. Previous work in primates generally, and lemurs specifically, has shown that body size often correlates with ecological parameters related to temperature and energy availability in the environment, although other studies indicate the absence of any such patterns in lemurs. Here we test hypotheses that predict that body mass in Eulemur should covary with 1) overall food availability or resource seasonality and/or 2) temperature, i.e., Bergmann’s rule. We use data from 722 wild true lemurs to identify population-specific body mass for 27 populations representing 11 of the 12 described Eulemur species, and derive climatic data for each population from the WorldClim database. We use phylogenetic generalized least squares models to evaluate these hypotheses and find that body mass significantly negatively correlates with annual mean temperature and positively correlates with standard deviation of temperature, but does not significantly correlate with annual rainfall or number of dry months. These results indicate that body mass distribution across populations in Eulemur is consistent with Bergmann’s rule, but does not track resource seasonality as seen in other lemurs, e.g., Propithecus. We suggest that the fact that body mass in various lemur radiations correlates with different environmental variables may result in these patterns being obscured when such taxa are combined in a single analysis. This may help explain why some previous work has found little evidence of ecogeographical correlates with body mass across all Lemuriformes.
KeywordsBergmann’s rule Heat conservation hypothesis Madagascar Phylogenetic methods
We are grateful to Giuseppe Donati for inviting us to contribute to this issue, and we thank him, Joanna Setchell, and three anonymous reviewers for their valuable comments on earlier versions of this manuscript. We also thank the government of Madagascar for permission to conduct the original research that was used for this analysis. We thank Omaha’s Henry Doorly Zoo and Aquarium Center for Conservation and Research, the Madagascar Biodiversity Partnership, and Madagascar Institut pour la Conservation des Écosystèmes Tropicaux (MICET) for assistance in original data collection, along with many individuals involved in original research (including Kira Delmore, Sheila Holmes, Christina Ingraldi, Annemarie Rued, and Hobinjatovo Tokiniaina). Grant sponsors for original research included the National Geographic Society (6613.99); Margot Marsh Biodiversity Fund; Conservation International; Primate Conservation, Inc.; the Natural Science and Engineering Research Council of Canada; the University of Calgary; the American Society of Primatologists; and the Ahmanson Family Foundation. A. D. Gordon also thanks the participants of the 2014 AnthroTree Workshop (supported by the National Science Foundation and the National Evolutionary Synthesis Center, NSF grants BCS-0923791 and EF-0905606) for discussions on phylogenetic comparative methods.
- Bergmann, C. (1847). Uber die verhaltnisse der warmeokonomie der thiere zu ihrer grosse. Göttinger Studien, 595–708.Google Scholar
- Brenneman, R. A., Johnson, S. E., Bailey, C. A., Ingraldi, C., Delmore, K. E., Wyman, T. M., Andriamaharoa, H. E., Ralainasolo, F. B., Ratsimbazafy, J. H., & Louis, E. E. (2012). Population genetics and abundance of the endangered grey-headed lemur Eulemur cinereiceps in south-east Madagascar: assessing risks for fragmented and continuous populations. Oryx, 46, 298–307.CrossRefGoogle Scholar
- Burnham, K. P., & Anderson, D. R. (2002). Model selection and multimodel inference (2nd ed.). New York: Springer Science+Business Media.Google Scholar
- Delmore, K. E., Brenneman, R. A., Lei, R., Bailey, C. A., Brelsford, A., Louis, E. E., & Johnson, S. E. (2013). Clinal variation in a brown lemur (Eulemur spp.) hybrid zone: combining morphological, genetic and climatic data to examine stability. Journal of Evolutionary Biology, 26, 1677–1690.CrossRefPubMedGoogle Scholar
- Gerson, J. S. (1999). Size in Eulemur fulvus rufus from western Madagascar: sexual dimorphism and ecogeographic variation. American Journal of Physical Anthropology (Supplement), 28, 134.Google Scholar
- Gerson, J. S. (2000). Social relationships in wild red-fronted brown lemurs (Eulemur fulvus rufus). Ph.D. dissertation, Duke University.Google Scholar
- IUCN (2014). IUCN Red List of Threatened Species. Version 2014.3.Google Scholar
- Mittermeier, R. A., Ganzhorn, J. U., Konstant, W. R., Glander, K., Tattersall, I., Groves, C. P., Rylands, A. B., Hapke, A., Ratsimbazafy, J., Mayor, M. I., Louis, E. E., Jr., Rumpler, Y., Schwitzer, C., & Rasoloarison, R. M. (2008). Lemur diversity in Madagascar. International Journal of Primatology, 29, 1607–1656.CrossRefGoogle Scholar
- Orme, D., Freckleton, R., Thomas, G., Petzoldt, T., Fritz, S., Isaac, N., & Pearse, W. (2012). Caper: Comparative analyses of phylogenetics and evolution in R. R package version 0.5.Google Scholar
- Overdorff, D. J., & Johnson, S. E. (2004). Eulemur, true lemur. In S. M. Goodman & J. Benstead (Eds.), The natural history of Madagascar (pp. 1320–1324). Chicago: University of Chicago Press.Google Scholar
- R Development Core Team. (2014). R: A language and environment for statistical computing. Vienna: R Foundation for Statistical Computing.Google Scholar
- Terborgh, J., & van Schaik, C. P. (1987). Convergence vs. non-convergence in primate communities. In J. H. R. Gee & P. S. Giller (Eds.), Organization of communities, past and present (pp. 205–226). Oxford: Blackwell.Google Scholar