Homeostatic responses of animals to environmentally induced changes in nutrient requirements provide a powerful basis for predictive ecological models, and yet, such responses are virtually unstudied in the wild. We tested for macronutrient‐specific compensatory feeding responses by free‐ranging golden snub‐nosed monkeys (Rhinopithecus roxellana) inhabiting high altitude temperate forests, where they experience a substantial difference in ambient temperature in cold winters vs. warmer springs. The monkeys had free access to natural foods throughout the year, and to ensure that any seasonal differences in nutrient intake were due to homeostatic compensation and not constraints on food availability, we studied the monkeys during periods in which they were provisioned with the same amount of supplementary foods in winter and spring. Thermoregulatory energy costs in winter and spring were calculated using partitional calorimetric estimations of convective and radiative heat loss obtained from thermal imaging of free‐ranging monkeys in situ. Daily nutrient intakes were measured using continuous focal follows (average 6.9 hr/day) of free‐ranging individuals (27 days in spring and 28 days in winter). We used a nutritional geometry framework to integrate these data and test three predictions: (a) In order to remain thermoneutral (balance heat loss with heat expenditure), golden snub‐nosed monkeys increase daily energy consumption during the winter compared to spring; (b) this increase is achieved specifically by increasing intake of the primary energetic nutrients, carbohydrate and lipid, relative to protein; and (c) the seasonal increase in ingested fat and carbohydrate calories will quantitatively match the additional thermoregulatory costs in winter compared with spring. Our results showed that daily metabolisable energy intake in winter (721.5 kJ/mbm) was 1.8 times that in spring (399 kJ/mbm). As predicted, this difference was specific to fat and carbohydrate, whereas seasonal protein intake did not differ significantly. Winter consumption of fat and carbohydrate was 326 kJ/mbm per day greater than in spring, a value that closely matched the seasonal difference in the daily energetic costs of thermoregulation (329 kJ/mbm). This is the first study to test for a match between nutrient‐specific homeostatic compensation and environmentally induced perturbations in nutrient requirements in free‐ranging animals and underpins the potential for the homeostasis framework to provide predictive power to ecological models.
There is a great deal of spatial and temporal variation in the availability and nutritional quality of foods eaten by animals, particularly in temperate regions where winter brings lengthy periods of leaf and fruit scarcity. We analyzed the availability, dietary composition, and macronutrients of the foods eaten by the northern-most golden snub-nosed monkey (Rhinopithecus roxellana) population in the Qinling Mountains, China to understand food choice in a highly seasonal environment dominated by deciduous trees. During the warm months between April and November, leaves are consumed in proportion to their availability, while during the leaf-scarce months between December and March, bark and leaf/flower buds comprise most of their diet. When leaves dominated their diet, golden snub-nosed monkeys preferentially selected leaves with higher ratios of crude protein to acid detergent fiber. While when leaves were less available, bark and leaf/flower buds that were high in nonstructural carbohydrates and energy, and low in acid detergent fiber were selected. Southern populations of golden snub-nosed monkey can turn to eating lichen, however, the population studied here in this lichen-absent area have adapted to their cool deciduous habitat by instead consuming buds and bark. Carbohydrate and energy rich foods appear to be the critical resources required for the persistence of this species in temperate habitat. The dietary flexibility of these monkeys, both among seasons and populations, likely contributes to their wide distribution over a range of habitats and environments.
Shift of ingestive behavior is an important strategy for animals to adapt to change of the environment. We knew that shifts in animal dietary habits lead to changes in the structure of the gut microbiota, but we are not sure about if changes in the composition and function of the gut microbiota respond to changes in the nutrient intake or food items. To investigate how animal feeding strategies affect nutrient intakes and thus alter the composition and digestion function of gut microbiota, we selected a group of wild primate group for the study. We quantified their diet and macronutrients intake in four seasons of a year, and instant fecal samples were analyzed by high-throughput sequencing of 16S rRNA and metagenomics. These results demonstrated that the main reason that causes seasonal shifts of gut microbiota is the macronutrient variation induced by seasonal dietary differences. Gut microbes can help to compensate for insufficient macronutrients intake of the host through microbial metabolic functions. This study contributes to a deeper understanding of the causes of seasonal variation in host-microbial variation in wild primates.
A: Rupture of amniotic fluid; B, C: Birthing process; D, E: Mother licked mucus from male infant and tried to help him stand up. F: Infant remained on ground and failed to stand up; G, H: Mother attacked infant, leading to its death.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.