2025-08-26 ラトガース大学
Orangutans and humans have similar physiological and metabolic processes, dietary needs and behavioral adaptations, according to Erin Vogel, a Rutgers anthropologist who has studied the great apes for more than a decade in the rainforests of Borneo. Ilya Raskin
<関連情報>
- https://www.rutgers.edu/news/be-it-feast-or-famine-orangutans-adapt-flexible-diets
- https://www.science.org/doi/10.1126/sciadv.adv7613
- https://onlinelibrary.wiley.com/doi/full/10.1002/ajpa.70042
生態学的要因による食餌変動に対する野生オランウータンの統合的行動・代謝適応反応 Integrated behavioral and metabolically flexible responses of wild orangutans to ecologically driven dietary variation
Erin R. Vogel, Shauhin E. Alavi, Malcolm Watford, Rebecca S.A. Brittain, […] , and David Raubenheimer
Science Advances Published:27 Aug 2025
DOI:https://doi.org/10.1126/sciadv.adv7613
Abstract
Diet and nutrition are critical factors influencing energetics and health. Laboratory studies show that organisms adjust to changes in nutrient intake through flexible metabolic responses such as fuel switching. While the physiological effects of nutrient balance in humans have been studied, data from closely related species living in nature are lacking. We integrate macronutrient regulation and metabolic flexibility to elucidate how wild orangutans (Pongo pygmaeus wurmbii) are buffered against natural fluctuations in nutritional resources. We found that these orangutans regulate protein and regularly switch between exogenous and endogenous nutritional substrates as preferred food resource availability declines. When total caloric, lipid, and carbohydrate intake declined during episodes of fruit scarcity, orangutans drew on fat and endogenous amino acids for energy. This strategy is beneficial only in the context of alternating periods of fruit scarcity and abundance. We discuss our findings in relation to the current global obesity pandemic, which has arisen with transitions in human diets toward low-cost, energy-dense, protein-dilute foods.
ボルネオオランウータン個体群における藤類種の栄養的重要性 Nutritional Importance of a Liana Species for a Population of Bornean Orangutans
Correction(s) for this article
William D. Aguado, Astri Zulfa, Timothy D. Bransford, Kristana P. Makur, Maria A. van Noordwijk, Sri Suci Utami Atmoko, Erin R. Vogel
American Journal of Biological Anthropology Published: 10 April 2025
DOI:https://doi.org/10.1002/ajpa.70042
ABSTRACT
Objectives
Temporal variation in food availability can pose nutritional challenges to primates. Characterizing the nutritional content of the non-preferred foods that primates switch to, termed fallback foods, is useful for identifying the nutritional challenges of lean periods, the nutritional limits of what primates can subsist on, and physiological adaptations. We explored the temporal patterning and the nutritional contribution of food items for Bornean orangutans (Pongo pygmaeus wurmbii) at Tuanan, Indonesia, with particular attention to the liana, Bowringia callicarpa.
Materials and Methods
We quantified the nutritional contribution of food items to the diet of wild orangutans over 18 years. We modeled the relationship between preferred food availability and the nutritional contribution of Bowringia.
Results
Bowringia played an outsize role in the feeding time and nutritional intake of orangutans. It can be characterized as a fallback food because it is increasingly consumed when preferred tree fruits are less available. Its immature leaves are particularly important as the greatest source of protein and energy. However, the nonprotein energy-to-protein ratio of Bowringia is extremely low, and overreliance on it would bring orangutans away from their estimated nutritional intake target.
Discussion
Despite its high energy and protein content, Bowringia is a nutritionally imbalanced food. Fallback food quality should thus be evaluated based on the ability to bring an animal toward its nutritional goal rather than nutrient density. We propose that orangutans are preadapted to falling back on protein-dense foods and the great abundance of Bowringia has contributed to the high population density of orangutans at Tuanan.
