Dominance rank differences in the energy intake and expenditure of female Bwindi mountain gorillas

Wright, Edward; Robbins, Andrew M.; Robbins, Martha M.

doi:10.1007/s00265-014-1708-9

Cited by 22 publications

(28 citation statements)

References 74 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The relationship between dominance rank versus energy intake was not significant for female western gorillas . In contrast, dominance rank was positively correlated with energy intake within one group of Bwindi mountain gorillas . Further evidence of contest competition has been observed among Virunga mountain gorillas, as high dominance rank gives females better access to food resources, higher energy intake rates, and higher reproductive success suggesting that feeding competition has more of an impact than previously thought …”

Section: Hypotheses For Variation In Social Organizationmentioning

confidence: 78%

Variation in the social organization of gorillas: Life history and socioecological perspectives

Robbins

2018

Evolutionary Anthropology

Self Cite

View full text Add to dashboard Cite

A focus of socioecological research is to understand how ecological, social, and life history factors influence the variability of social organization within and between species. The genus Gorilla exhibits variability in social organization with western gorilla groups being almost exclusively one‐male, yet approximately 40% of mountain gorilla groups are multimale. We review five ultimate causes for the variability in social organization within and among gorilla populations: human disturbance, ecological constraints on group size, risk of infanticide, life history patterns, and population density. We find the most evidence for the ecological constraints and life history hypotheses, but an over‐riding explanation remains elusive. The variability may hinge on variation in female dispersal patterns, as females seek a group of optimal size and with a good protector male. Our review illustrates the challenges of understanding why the social organization of closely related species may deviate from predictions based on socioecological and life history theory.

show abstract

Section: Hypotheses For Variation In Social Organizationmentioning

confidence: 78%

Variation in the social organization of gorillas: Life history and socioecological perspectives

Robbins

2018

Evolutionary Anthropology

Self Cite

View full text Add to dashboard Cite

show abstract

“…Their positive correlation could indicate an influence of group size on intragroup feeding competition, whereas our negative correlation is more consistent with theoretical predictions for intergroup contest competition 7,8 . The feeding time of mountain gorillas seems to be more sensitive to differences in energy intake rates than differences in the energy requirements from travel 36,41,72 . If so, then our negative correlation could be interpreted to suggest that larger groups had greater access to areas that facilitate higher energy intake rates.…”

Section: Discussionmentioning

confidence: 99%

“…The energy intake rate for each food site equaled the total energy intake, divided by the food site residence time (FSRT). The FSRT was defined as the elapsed time from when a female settled at a food site and commenced eating, until she stopped eating and/or moved more than one meter 72,79 . The energy intake for each food site equaled the number of food “units” consumed during the FSRT (e.g., one leaf or stem of a specific plant species), multiplied by the average energy content for each type of unit 80,81 .…”

Section: Methodsmentioning

confidence: 99%

Quadratic relationships between group size and foraging efficiency in a herbivorous primate

Grueter

Robbins

Abavandimwe

et al. 2018

Sci Rep

Self Cite

View full text Add to dashboard Cite

The effect of feeding competition on foraging efficiency is an important link between ecological factors and the social organization of gregarious species. We examined the effects of group size on daily travel distances, activity budgets, and energy intake of mountain gorillas in Rwanda. We measured daily travel distances of five groups, activity budgets of 79 gorillas in nine groups, and energy intake data for 23 adult females in three groups over a 16-month period. Travel distances and the proportion of time spent traveling increased with size for most groups, which would be expected if their foraging efficiency is limited by intragroup feeding competition. However, travel distances and times decreased for the largest group, which also had higher energy intake rates than intermediate sized groups. The improved foraging efficiency of the largest group may be explained by advantages in intergroup contest competition. The largest group had much lower home range overlap than the other study groups which may be due to groups avoiding one another as a result of male mating competition. Collectively, our results indicate that intermediate sized groups had the lowest foraging efficiency and provide a new twist on the growing evidence of non-linear relationships between group size and foraging efficiency in primates.

show abstract

“…However, there are also theoretical reasons to expect faunivory to vary with female social status. Wright et al (2014) found that higher-ranking female gorillas had higher foraging efficiency compared to lower-ranking females. In wild bonobos, where females are dominant over males, prey carcasses are controlled more often by females- particularly high-ranking females (Fruth and Hohmann, 2002).…”

Section: Introductionmentioning

confidence: 92%

“…Despite relatively low levels of overt female aggression (reviewed in Murray et al, 2007; Miller et al, 2014), high female dominance rank affords myriad benefits to female chimpanzees, including higher-quality core ranging areas (Murray et al, 2006; Emery Thompson et al, 2008), shorter inter-birth intervals (Jones et al, 2010), reduced offspring mortality, and more rapidly maturing daughters (Pusey et al, 1997). These disparities may stem, at least in part, from a high-ranking female’s ability to maintain greater access to high quality foods or greater feeding efficiency even in the presence of conspecific competitors (Wittig and Boesch, 2003; Wright et al, 2014). As they are discrete, high-energy, nutrient-dense packages, we hypothesize that vertebrate and invertebrate prey are useful dietary components with which to examine female contest competition (in this case, meaning competition for spatially or temporally clumped and therefore monopolizable resources; Nicholson, 1954; van Schaik and van Noordwijk, 1986, 1988).…”

Section: Introductionmentioning

confidence: 99%

Reproductive state and rank influence patterns of meat consumption in wild female chimpanzees (Pan troglodytes schweinfurthii)

O’Malley

Stanton

Gilby

et al. 2016

Journal of Human Evolution

View full text Add to dashboard Cite

An increase in faunivory is a consistent component of human evolutionary models. Animal matter is energy- and nutrient-dense and can provide macronutrients, minerals, and vitamins that are limited or absent in plant foods. For female humans and other omnivorous primates, faunivory may be of particular importance during the costly periods of pregnancy and early lactation. Yet, because animal prey is often monopolizable, access to fauna among group-living primates may be mediated by social factors such as rank. Wild chimpanzees (Pan troglodytes) across Africa habitually consume insects and/or vertebrates. However, no published studies have examined patterns of female chimpanzee faunivory during pregnancy and early lactation relative to non-reproductive periods, or by females of different rank. In this study, we assessed the influence of reproductive state and dominance rank on the consumption of fauna (meat and insects) by female chimpanzees of Gombe National Park, Tanzania. Using observational data collected over 38 years, we tested (a) whether faunivory varied by reproductive state, and (b) if high-ranking females spent more time consuming fauna than lower-ranking females. In single-factor models, pregnant females consumed more meat than lactating and baseline (meaning not pregnant and not in early lactation) females, and high-ranking females consumed more meat than lower-ranking females. A two-factor analysis of a subset of well-sampled females identified an interaction between rank and reproductive state: lower-ranking females consumed more meat during pregnancy than lower-ranking lactating and baseline females did. High-ranking females did not significantly differ in meat consumption between reproductive states. We found no relationships between rank or reproductive state with insectivory. We conclude that, unlike insectivory, meat consumption by female chimpanzees is mediated by both reproductive state and social rank. We outline several possible mechanisms for these patterns, relate our findings to meat-eating patterns in women from well-studied hunter-gatherer societies, and discuss potential avenues for future research.

show abstract

Dominance rank differences in the energy intake and expenditure of female Bwindi mountain gorillas

Cited by 22 publications

References 74 publications

Variation in the social organization of gorillas: Life history and socioecological perspectives

Variation in the social organization of gorillas: Life history and socioecological perspectives

Quadratic relationships between group size and foraging efficiency in a herbivorous primate

Reproductive state and rank influence patterns of meat consumption in wild female chimpanzees (Pan troglodytes schweinfurthii)

Contact Info

Product

Resources

About