Fallback Foods of Red Leaf Monkeys (Presbytis rubicunda) in Danum Valley, Borneo
- 391 Downloads
Animals in Southeast Asia must cope with long periods of fruit scarcity of unpredictable duration between irregular mast fruiting events. Long-term data are necessary to examine the effect of mast fruiting on diet, and particularly on the selection of fallback foods during periods of fruit scarcity. No such data is available for colobine monkeys, which may consume substantial amounts of fruits and seeds when available. We studied the diet of red leaf monkeys (Presbytis rubicunda, Colobinae) in Danum Valley, Sabah, northern Borneo, using 25 mo of behavioral observation, phenology and vegetation surveys, and chemical analysis to compare leaves eaten with nonfood leaves. The monkeys spent 46% of their feeding time on young leaves, 38% on seeds, 12% on whole fruits, 2.0% on flowers, 1.0% on bark, and 1.2% on pith. They spent more time feeding on seeds and whole fruit when fruit availability was high and fed on young leaves of Spatholobus macropterus (liana, Leguminosae) as fallback foods. This species was by far the most important food, constituting 27.9% of the total feeding time, and the feeding time on this species negatively correlated with fruit availability. Consumed leaves contained more protein than nonconsumed leaves, and variation in time spent feeding on different leaves was explained by their abundance. These results suggest that red leaf monkeys show essentially the same response to the supra-annual increase in fruit availability as sympatric monogastric primates, increasing their seed and whole-fruit consumption. However, they depended more on young leaves, in particular Spatholobus macropterus, as fallback foods during fruit-scarce periods than did gibbons or orangutans. Their selection of fallback food appeared to be due to both nutrition and abundance.
KeywordsDiet Fallback foods Functional response General flowering Spatholobus macropterus
This study would not have been possible without the hard work of our field assistants, Syamsudin Jail, Sharry bin Mustah, Saharudin Idos, Unding Jami, Sallehudin Jail, and Rayner Jupili. We thank the staff of the Danum Valley Field Centre and our colleagues there for their hospitality and help, in particular Jimmy Omar, Mike Bernadus, Glen Reynolds, Tomoko Kanamori, Noko Kuze, and Siew Te Wong. Constructive comments by Drs. Joanna Setchell, Oliver Shülke, and an anonymous reviewer greatly improved the manuscript. The Economy Planning Unit of Malaysia and the State of Sabah and the Danum Valley Management Committee of Yayasan Sabah permitted our study. This study was financed by the JSPS Core-to-Core Program (HOPE), the MEXT Grant-in-Aid for JSPS Overseas Fellows, Grant-in-Aid for Young Scientists (No. 20770195 and No. 22687002) to G. Hanya, Primate Society of Japan, the 21st Century COE Program (A14), and the Global COE Program “Formation of a Strategic Base for Biodiversity and Evolutionary Research: From Genome to Ecosystem”.
- Burnham, K. P., & Anderson, D. R. (2002). Model selection and multi-model inference (2nd ed.). New York: Springer.Google Scholar
- Clutton-Brock, T. H. (1977). Primate ecology: Studies of feeding and ranging behaviour in lemurs, monkeys and apes. Brighton: Academic.Google Scholar
- Itioka, T., Inoue, T., Kaliang, H., Kato, M., Nagamitsu, T., Momose, K., Sakai, S., Yumoto, T., Mohamad, S. U., Hamid, A. A., & Yamane, S. (2001). Six-year population fluctuation of the giant honey bee Apis dorsata (Hymenoptera: Apidae) in a tropical lowland dipterocarp forest in Sarawak. Annals of the Entomological Society of America, 94, 545–549.CrossRefGoogle Scholar
- Kirkpatrick, R. C. (1999). Colobine diet and social organization. In P. Dolhinow & A. Fuentes (Eds.), The nonhuman primates (pp. 93–105). Mountain View, CA: Mayfield.Google Scholar
- Lambert, J. E. (2007). Seasonality, fallback strategies, and natural selection: A chimpanzee and Cercopithecoid model for interpreting the evolution of the hominin diet. In P. S. Ungar (Ed.), Evolution of the human diet: The known, the unknown, and the unknowable (pp. 324–343). Oxford: Oxford University Press.Google Scholar
- Lingenfelder, M. (2005) Rain forest dynamics and response to drought in a Bornean primary lowland dipterocarp forest. Ph.D. thesis, University of Bern, Bern.Google Scholar
- Newbery, D. M., Kennedy, D. N., Petol, G. H., Madani, L., & Ridsdale, C. E. (1999). Primary forest dynamics in lowland dipterocarp forest at Danum Valley, Sabah, Malaysia, and the role of the understorey. Philosophical Transactions of the Royal Society B: Biological Sciences, 354, 1763–1782.CrossRefGoogle Scholar
- Norhayati, A. (2001) Frugivores and fruit production in primary and logged tropical rainforests. Ph.D. thesis, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi, Malaysia.Google Scholar
- Porter, L. J. (1989). Tannins. In P. M. Dey & J. B. Harborne (Eds.), Methods in plant biochemistry, vol 1. Plant Phenolics (pp. 389–419). London: Academic.Google Scholar
- Soxhlet, F. (1879). Die gewichtsanalytische Bestimmung des Milchfettes. Polytechnisches J, 232, 461–465.Google Scholar
- van Schaik, C. P., & Pfannes, K. (2005). Tropical climates and phenology: A primate perspective. In D. K. Brockman & C. P. van Schaik (Eds.), Seasonality in primates: Studies of living and extinct human and non-human primates (pp. 23–54). Cambridge, UK: Cambridge University Press.CrossRefGoogle Scholar