Nutrient composition and food availability determine food choices and foraging strategies of animals, while altitude and geographical location affect species distribution and food availability. Tibetan macaques ( Macaca thibetana ) have sophisticated foraging strategies as the largest species in Macaca . They are important in understanding the ecological evolution of the entire genus. However, the mechanism of food selection in Tibetan macaques at low altitudes remains unclear. In this study, we researched a wild Tibetan macaques group (Tianhu Mountain Group, 29 individuals) living in a low‐altitude area around Mt. Huangshan, Anhui Province, China. We used instantaneous scan sampling to observe these macaques' foraging behavior from September 2020 to August 2021. We recorded the dietary composition and food availability, compared the nutrient content of staple food and non‐food items, and analyzed the role of key nutrients in food selection. We found that Tibetan macaques forage on 111 plants belonging to 93 genera and 55 families. The food types included fruits (52.5%), mature leaves (17.0%), bamboo shoots (14.4%), young leaves (6.3%), flowers (4.5%), others (2.1%), stems (1.9%), and tender shoots (1.3%). Tibetan macaques forage for a maximum of 76 plant species during spring. However, dietary diversity was highest during summer ( H′ = 3.052). Monthly fruit consumption was positively correlated with food availability. Staple foods are lower in fiber, tannin, and water than non‐foods. In addition, the time spent foraging for specific foods was negatively correlated with the fiber and tannin content of the food. The results showed that Tibetan macaques' foraging plant species and food types were diverse, and their foraging strategies varied seasonally. Our findings confirmed the effect of nutrients on food choice in Tibetan macaques. We highlighted the important role of fiber and tannin in their food choices and suggested that the foraging behavior of Tibetan macaques is highly flexible and adaptive.

Nutrient composition and food availability determine food choices and foraging strategies of animals. Altitude affects species distribution and food availability, whereas primate food needs increase with body size. However, the mechanism of food selection in large primates at low altitudes requires further investigation. As the largest species in the genus Macaca, the Tibetan macaque (Macaca thibetana) has sophisticated foraging strategies. In this study, we researched a group of 29 wild Tibetan macaques (Tianhu Mountain Group) that live in a low-altitude area around Mt. Huangshan, Anhui Province, China. We used instantaneous and scan sampling for observing the foraging behavior of these macaques from September 2020 to August 2021. We recorded the dietary composition and food availability, compared the nutrient content of staple food and non-food items, and analyzed the role of key nutrients in food selection. We found that Tibetan macaques forage on 111 plants belonging to 93 genera and 55 families. The food types included 52.5% fruits, 17.0% mature leaves, 6.3% young leaves, 1.9% stems, 4.5% flowers, 14.4% bamboo shoots, 1.3% tender shoots, and 2.1% other. Tibetan macaques forage for a maximum total of 76 plant species during spring. However, dietary diversity was highest during summer (H’=3.052). Monthly fruit consumption was positively correlated with food availability. Staple foods are lower in fiber and tannins than non-foods. In addition, there was a positive correlation between the time spent foraging for specific foods and sugar content of the food. The results showed that the plant species and food types fed by Tibetan macaques were diverse, and their foraging strategies varied seasonally. Our findings confirm the effect of nutrients on food choice in Tibetan macaques, highlighting the importance of sugar in their food choices and suggesting that the foraging behavior of Tibetan macaques is highly flexible and adaptive.