Nutritional composition of the diet of the western gorilla (Gorilla gorilla): Interspecific variation in diet quality. Issue 9 (28th August 2019)

• Record Type: Journal Article
• Authors: Lodwick, Jessica L.; Salmi, Roberta
• Is Part Of: American journal of primatology. Volume 81:Issue 9(2019)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-08-28
• Subjects: ape -- ecology -- feeding -- nutrition -- primate; Primates -- Periodicals; Primates -- Périodiques; 599.8
• DOI: 10.1002/ajp.23044
• Languages: English
• ISSNs: 0275-2565

Abstract

Abstract: To meet nutritional needs, primates adjust their diets in response to local habitat differences, though whether these dietary modifications translate to changes in dietary nutrient intake is unknown. A previous study of two populations of the mountain gorilla (MG: Gorilla beringei ) found no evidence for intraspecific variation in the nutrient composition of their diets, despite ecological and dietary differences between sites. One potential explanation is that nutritional variability in primate diets requires greater ecological divergence than what was captured between MG sites, underpinning environmental differences in the nutrient quality of plant foods. To test whether Gorilla exhibits interspecific variation in dietary composition and nutrient intake, we studied the composition and macronutrients of the western gorilla (WG: Gorilla gorilla ) staple diets and compared them with published data from the two MG populations. We recorded feeding time and food intake of four adult female WGs from one habituated group over a period of 11 months (December 2004–October 2005) at the Mondika Research Center, Republic of Congo, allowing for assessment of seasonal patterns of nutrient intake. Staple diets of WGs and MGs diverged in their dietary and macronutrient composition. Compared to MGs, the staple diet of WGs (by intake) contained higher proportions of fruit (43%) and leaf (12%) and a lower proportion of herb (39%), resulting in a higher intake of total nonstructural carbohydrate and fiber and a lower intake of crude protein. Staple gorilla fruits and herbs differed in nutrient quality between sites. Gorillas exhibit nutritional flexibility that reflects ecological variation in the nutrient quality of plant foods. Since dietary quality typically affects rates of growth and reproduction in primates, our results suggest that interspecific differences in nutrient intake and food quality may shape differences in gorilla nutrient balancing and female life history strategies. Abstract : Western gorillas consume a diet richer in simple carbohydrates and fiber and lower in protein, compared to mountain gorillas. Research Highlights: Fruit (40%) and herb (35%) accounted for 75% of mean monthly food intake in western gorillas ( G. gorilla ), with leaf (20%) and termite (5%) composing only a quarter of the annual diet. Western gorillas (WGs; G. gorilla ) differed from mountain gorillas (MGs; G. beringei ) in the nutrient composition of their staple diets, with WGs consuming less protein, more fiber, and nearly twice as much total nonstructural carbohydrate as MGs. Nutritional flexibility in Gorilla reflects ecological variability, not only in food availability but in the nutrient quality of plant foods between Central and East Africa.