Macronutrient balancing affects patch departure by guerezas (Colobus guereza)

Abstract

Foraging strategies are central in shaping social structure and grouping patterns in primates. We address Colobus guereza foraging strategies by investigating their patch departure decisions in relation to diet composition and nutrition. We examine whether guerezas are constrained in their intake of food in patches and thereby forage according to a fixed amount strategy that dictates patch departure. Additionally, we assess whether guereza employ a fixed time strategy or attempt to balance nutrients when foraging. We measured food patch occupancy time, intake rates, and analyzed foods for macronutrients, fiber, and condensed tannins. We determined that guerezas do not employ a fixed time foraging strategy; patch residence time varied widely between 1 and 290 min. They also did not depart patches or stop eating when they reached a specific intake of dry mass, macronutrients, or condensed tannins. However, guerezas maintained a macronutrient balance when feeding across patches, and the balance of protein to non-protein energy (fats and carbohydrates) in patches is the best indicator of time adult guerezas spent feeding in patches. Previous studies have shown that the protein-to-fiber ratio is important in predicting food selection for folivores and their biomass; however, we found that guerezas did not maximize protein and minimize fiber intake while foraging in patches, nor did they stay longer in patches with the highest ratio of protein to fiber concentrations. This study raises questions about the nutritional and social implications of patch depletion as a foraging strategy in folivorous monkeys where food limitation predicts competitive and social regimes. Am. J. Primatol. 79:e22495, 2017. © 2015 Wiley Periodicals, Inc.

The seasonal feeding ecology of the javan slow loris (nycticebus javanicus)

“…NPE was prioritized during the dry season probably due to their higher gum intake, similar to the energy and protein maximization rule described in Altmann (2006). The slow lorises were able to control their NPE:PE as thoroughly as some generalist species (Johnson et al, 2013(Johnson et al, , 2015, which is consistent with slow lorises following an energy and nutrient maximization strategy. The only significant source of protein for our slow lorises was insects, with their availability decreasing in the lean season.…”

“…It also provides the possibility to model single individual or entire population nutrient intakes'. With primates, this methodology has been successfully applied to Peruvian spider monkeys (Ateles chamek- Felton et al, 2009) Johnson et al, 2015) and two strepsirhines, diademed sifakas (Propithecus diadema- Irwin et al, 2014;Irwin, Raharison, Raubenheimer, Chapman, & Rothman, 2015) and white-footed sportive lemurs (Lepilemur leucopus-Droscher, Rothman, Ganzhorn, & Kappeler, 2016).…”

Diet complementation as a frequency‐dependent mechanism conferring advantages to rare plants via dispersal

“…Although studies evaluating the regulatory effects of nutrients on frugivore movements are lacking, abundance of certain frugivorous species has been found to be more strongly associated with fruit nutrient qualities than by overall fruit availability (Blendinger et al., ). Moreover, animal movement patterns driven by their nutritional demands are commonplace in nature (e.g., Johnson et al., ; Nie et al., ). In our simulations, fruit‐tracking behaviour emerged from the necessity of frugivores to search alternative food resources to meet their nutritional demands.…”

The nutritional nexus: Linking niche, habitat variability and prey composition in a generalist marine predator

“…Over the three seasons studied, the nutriscapes were patchily distributed, fluctuated from shallow to deeper areas and had different nutritional composition; clearly, the temporal extent of this dataset and the proposed approach brings a novel opportunity to better understand whether the prey consumed by wild predators could be supplementary (similar P:L ratios across prey) or complementary (different P:L ratios) with respect to the diet. Thus, this approach could become the stepping stone for research of foraging strategies in marine predators by investigating habitat use and food patch selection and depletion in relation to prey and diet composition and nutrition as previously seen in Guerezas Colobus guereza (Johnson et al., ).…”