Patch depletion behavior differs between sympatric folivorous primates

Abstract

Food competition in group-living animals is commonly accepted as a critical determinant of foraging strategies and social organization. Here we examine food patch depletion behavior in a leaf-eating (folivorous) primate, the guereza (Colobus guereza). Snaith and Chapman (2005) studied the sympatric folivorous red colobus (Procolobus rufomitratus), which shares many food resources with the guereza. They determined that red colobus deplete the patches (feeding trees) they use, while we found contrary evidence for guerezas using the same methods. We found that the time guerezas spent feeding in a patch was affected by neither tree size, an indicator of food abundance, nor the size of the feeding group, an indicator of feeding competition. For their principal food item (young leaves), intake rate remained constant and coincided with a decrease in the distance moved to find food within a patch, implying that guerezas do not deplete patches. This points to a fundamental difference in the use of food by guerezas and red colobus, which may be linked to the large difference in their group sizes and/or to a disparity in their digestive physiologies. However, further analyses revealed that the number of feeders within a patch did not affect patch depletion patterns in either species, leaving the potential for a physiological basis as the most plausible explanation. Our research highlights the need for a more critical examination of folivorous primate feeding ecology and social behavior, as all folivorous primates are typically lumped into a single category in socioecological models, which may account for conflicting evidence in the literature.

The effects of plant nutritional chemistry on food selection of Mexican black howler monkeys (Alouatta pigra): The role of lipids

“…However our data also revealed that assumptions regarding the nutrient content of individual foods consumed by primates are sometimes incorrect. For example, although it is often assumed that immature and mature leaves ingested by primates differ in fiber, available protein, and secondary metabolites [Chapman & Chapman, 2002;Milton, 1979;Mowry et al, 1996;Tombak et al, 2012], mature and young leaves consumed by howler monkeys in the present study did not differ in their nutritional components. Given …”

Contagious Deposition of Seeds in Spider Monkeys' Sleeping Trees Limits Effective Seed Dispersal in Fragmented Landscapes

“…Thus, the abundance and species diversity of seeds within latrines is expected to be lower in fragments where spider monkeys usually spend more time consuming leaves [18], [30], and the number of feces without seeds is usually higher than in continuous forests [19]. However, we also predict that fruit scarcity in fragments will ‘force’ spider monkeys to spend more time consuming the available fruit patches; i.e., they will deplete the available patches more intensively than in continuous forest sites [34], [35]. As consequence, the seed rain in fragments will be dominated by a few plant species, reducing the number of common ( 1 D) and dominant species ( 2 D), as well as the seed community evenness in forest fragments.…”

Linking feeding ecology and population abundance: a review of food resource limitation on primates

“…To determine if leaves can be a superabundant fallback food, we need to know if the leaf quality that is required for the animal's digestive ability to extract sufficient nutrients is suitable, and that leaf production of this required quality is sufficiently high to maintain the primate population. This information is generally unavailable, but there is a growing body of evidence that even folivorous primates experience food competition (Snaith and Chapman 2007;Tombak et al 2012).…”