Nutritional ecology of wild Bornean orangutans (Pongo pygmaeus wurmbii) in a peat swamp habitat: Effects of age, sex, and season

Abstract

The spatial and temporal variation in food abundance has strong effects on wildlife feeding and nutrition. Here we present the first long term study of the effects of variation in fruit availability and age/sex class on nutritional ecology of wild Bornean orangutans. We examined variation in nutrient intake of wild orangutans in living in a peat swamp habitat over a 7-year period at the Tuanan Orangutan Research Station in Central Kalimantan. We conducted 2,316 full-day focal follows on 62 habituated orangutans (Pongo pygmaeus wurmbii). We found differences in total energy and macronutrient intake across age-sex classes, controlling for metabolic body mass. Intake of both total energy and macronutrients varied with fruit availability, and preference of dietary items increased with their nutritional quality. Foraging-related variables, such as day journey length, travel time, and feeding time, also varied among age-sex classes and with fruit availability. Our results add to the growing body of literature suggesting that great variation in foraging strategies exists among species, populations, and age-sex classes and in response to periods of resource scarcity.

Cyclical nursing patterns in wild orangutans

“…( 22 , 51 )]. Top: The percentage of fruiting trees derives from 1868 marked trees in monthly monitored phenology plots, 98% of which are species consumed by orangutans.…”

Dietary generalists and nutritional specialists: Feeding strategies of adult female blue monkeys (Cercopithecus mitis) in the Kakamega Forest, Kenya

“…Seasonal changes in food availability also relate to diet selection, driving variation in food item types, and sometimes nutrients consumed. For example, energy intake in orangutans ( Pongo pygmaeus wurmbii ) related positively to seasonal fruit availability (Vogel et al, ). Sifakas ( Propithecus verreauxi ) consumed more total nonstructural carbohydrates (TNC), structural carbohydrates (neutral detergent fiber (NDF)), fat and overall energy during the late wet season compared with early wet and dry seasons (Koch, Ganzhorn, Rothman, Chapman, & Fichtel, ).…”

Nutrient intake and balancing among femaleColobus angolensis palliatusinhabiting structurally distinct forest areas: Effects of group, season, and reproductive state

“…Interestingly, there were virtually no significant differences in the relative contributions of different macronutrients to ME among seasons. Thus, C. a. palliatus at Diani were able to maintain consistent relative macronutrient intakes across seasons, unlike some other primate species who face more drastic seasonal changes in food availability and must alter their macronutrient intakes (Conklin‐Brittain et al, ; Irwin et al, , ; Koch et al, ; Vogel et al, ).…”

“…Some caution should be exercised when comparing the results of this study to other GF nutritional ecology studies due to the differences in methods and statistical approaches. While many previous studies have reported daily nutrient intakes based on full‐day follows of individuals (Felton, Felton, Raubenheimer, et al, 2009; Felton, Felton, Wood, et al, 2009; Irwin et al, ; Johnson et al, ; Rothman et al, ; Vogel et al, ), this study combined behavioral scans used to estimate time spent feeding on various species‐specific plant parts with short focal follows used to quantify ingestion rates of species‐specific plant parts. Rather than reporting true daily nutrient intake estimates, this study estimated an individual's nutrient intake over the course of a monthly observational period and divided these values by the number of days an individual was observed (i.e., to scale data to daily intake values).…”

“…The GF has since been used to study the nutritional ecology of a variety of free‐ranging animals including several primate species (Dröscher, Rothman, Ganzhorn, & Kappeler, ; Felton, Felton, Raubenheimer, et al, ; Felton, Felton, Wood, et al, 2009; Irwin et al, ; Johnson, Raubenheimer, Rothman, Clarke, & Swedell, ; Johnson et al, ; Rothman, Raubenheimer, & Chapman, ; Vogel et al, ). From these studies it is evident that different primate species balance their intake of non‐protein energy (NPE) (i.e., energy from carbohydrates and fats) and available protein (AP) at different ratios likely due to differences in activity, body size, digestive physiology, and food availability.…”