Influence of food availability on the diet and activity budget of two western lowland gorilla (Gorilla gorilla gorilla) groups of differing size in the Dzanga-Ndoki National Park, Central African Republic

Variation in food availability, body size and group size are known to influence primate diet and activity budgets. Here we report how seasonal food availability shapes the diet and activity patterns of two habituated western lowland gorilla (WLG) groups of differing size. WLGs are ripe fruit opportu...

Full description

Saved in:
Bibliographic Details
Main Authors: Terence Fuh Neba, Giuseppe Donati, Angelique Todd, Shelly Masi
Format: Article
Language:English
Published: Société Francophone de Primatologie 2014-01-01
Series:Revue de Primatologie
Subjects:
Online Access:https://journals.openedition.org/primatologie/1370
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1832581641942335488
author Terence Fuh Neba
Giuseppe Donati
Angelique Todd
Shelly Masi
author_facet Terence Fuh Neba
Giuseppe Donati
Angelique Todd
Shelly Masi
author_sort Terence Fuh Neba
collection DOAJ
description Variation in food availability, body size and group size are known to influence primate diet and activity budgets. Here we report how seasonal food availability shapes the diet and activity patterns of two habituated western lowland gorilla (WLG) groups of differing size. WLGs are ripe fruit opportunists, showing dietary flexibility when preferred foods are scarce. However, as fruit can be rare/ patchily distributed, as intra-group feeding competition increases with group size, access to individual patches may be limited. We thus predicted that frugivory decreases with increased group size and influences diet and activity budgets accordingly (increased diet breadth and time feeding since relying on alternative/lower quality food). First, we compared food availability between home-ranges by monitoring leafing/fruiting patterns of major gorilla food trees. Second, we compared the groups’ activity budgets and diet composition/diversity, testing for differences between high (HF) and low fruit seasons (LF). We measured gorilla activity over six months by continuous focal sampling of 16 target animals rotated daily from both groups (N=9 and N=15). Our results confirm that WLG diet consisted mainly of fruits (36%, then: stems 24%; leaves 21%; insects 14%; other food types 3%, and bark 2%) and spend most of their time feeding (39%, then: resting 33%; traveling 19%; social 5%, and other activities 4%). However, contrary to our predictions, we found no group differences within or between seasons: irrespective of group size both spent significantly less time feeding, but more time traveling and socializing, and consumed significantly more fruits, less leaves and bark during the HF compared to the LF. Our results show that WLG activity budgets and diet appear to vary more in response to ripe fruit availability than group size. We suggest that WLGs may cope with increased group size costs through other mechanisms such as group spread, rather than lowering diet quality or further changing activity patterns. Such flexibility may better allow WLG groups to track ripe fruits when available but, unlike sympatric chimpanzees, switch to more herbivorous diets when necessary, adjusting activity budgets accordingly ; WLGs thus may be considered more resilient faced with environmental change such as forest degradation.
format Article
id doaj-art-f4dbc1d221304ef39a5f3accd7cf1a1a
institution Kabale University
issn 2077-3757
language English
publishDate 2014-01-01
publisher Société Francophone de Primatologie
record_format Article
series Revue de Primatologie
spelling doaj-art-f4dbc1d221304ef39a5f3accd7cf1a1a2025-01-30T10:01:52ZengSociété Francophone de PrimatologieRevue de Primatologie2077-37572014-01-01510.4000/primatologie.1370Influence of food availability on the diet and activity budget of two western lowland gorilla (Gorilla gorilla gorilla) groups of differing size in the Dzanga-Ndoki National Park, Central African RepublicTerence Fuh NebaGiuseppe DonatiAngelique ToddShelly MasiVariation in food availability, body size and group size are known to influence primate diet and activity budgets. Here we report how seasonal food availability shapes the diet and activity patterns of two habituated western lowland gorilla (WLG) groups of differing size. WLGs are ripe fruit opportunists, showing dietary flexibility when preferred foods are scarce. However, as fruit can be rare/ patchily distributed, as intra-group feeding competition increases with group size, access to individual patches may be limited. We thus predicted that frugivory decreases with increased group size and influences diet and activity budgets accordingly (increased diet breadth and time feeding since relying on alternative/lower quality food). First, we compared food availability between home-ranges by monitoring leafing/fruiting patterns of major gorilla food trees. Second, we compared the groups’ activity budgets and diet composition/diversity, testing for differences between high (HF) and low fruit seasons (LF). We measured gorilla activity over six months by continuous focal sampling of 16 target animals rotated daily from both groups (N=9 and N=15). Our results confirm that WLG diet consisted mainly of fruits (36%, then: stems 24%; leaves 21%; insects 14%; other food types 3%, and bark 2%) and spend most of their time feeding (39%, then: resting 33%; traveling 19%; social 5%, and other activities 4%). However, contrary to our predictions, we found no group differences within or between seasons: irrespective of group size both spent significantly less time feeding, but more time traveling and socializing, and consumed significantly more fruits, less leaves and bark during the HF compared to the LF. Our results show that WLG activity budgets and diet appear to vary more in response to ripe fruit availability than group size. We suggest that WLGs may cope with increased group size costs through other mechanisms such as group spread, rather than lowering diet quality or further changing activity patterns. Such flexibility may better allow WLG groups to track ripe fruits when available but, unlike sympatric chimpanzees, switch to more herbivorous diets when necessary, adjusting activity budgets accordingly ; WLGs thus may be considered more resilient faced with environmental change such as forest degradation.https://journals.openedition.org/primatologie/1370western lowland gorilladietactivity budgetfood availabilitygroup size group spread
spellingShingle Terence Fuh Neba
Giuseppe Donati
Angelique Todd
Shelly Masi
Influence of food availability on the diet and activity budget of two western lowland gorilla (Gorilla gorilla gorilla) groups of differing size in the Dzanga-Ndoki National Park, Central African Republic
Revue de Primatologie
western lowland gorilla
diet
activity budget
food availability
group size group spread
title Influence of food availability on the diet and activity budget of two western lowland gorilla (Gorilla gorilla gorilla) groups of differing size in the Dzanga-Ndoki National Park, Central African Republic
title_full Influence of food availability on the diet and activity budget of two western lowland gorilla (Gorilla gorilla gorilla) groups of differing size in the Dzanga-Ndoki National Park, Central African Republic
title_fullStr Influence of food availability on the diet and activity budget of two western lowland gorilla (Gorilla gorilla gorilla) groups of differing size in the Dzanga-Ndoki National Park, Central African Republic
title_full_unstemmed Influence of food availability on the diet and activity budget of two western lowland gorilla (Gorilla gorilla gorilla) groups of differing size in the Dzanga-Ndoki National Park, Central African Republic
title_short Influence of food availability on the diet and activity budget of two western lowland gorilla (Gorilla gorilla gorilla) groups of differing size in the Dzanga-Ndoki National Park, Central African Republic
title_sort influence of food availability on the diet and activity budget of two western lowland gorilla gorilla gorilla gorilla groups of differing size in the dzanga ndoki national park central african republic
topic western lowland gorilla
diet
activity budget
food availability
group size group spread
url https://journals.openedition.org/primatologie/1370
work_keys_str_mv AT terencefuhneba influenceoffoodavailabilityonthedietandactivitybudgetoftwowesternlowlandgorillagorillagorillagorillagroupsofdifferingsizeinthedzangandokinationalparkcentralafricanrepublic
AT giuseppedonati influenceoffoodavailabilityonthedietandactivitybudgetoftwowesternlowlandgorillagorillagorillagorillagroupsofdifferingsizeinthedzangandokinationalparkcentralafricanrepublic
AT angeliquetodd influenceoffoodavailabilityonthedietandactivitybudgetoftwowesternlowlandgorillagorillagorillagorillagroupsofdifferingsizeinthedzangandokinationalparkcentralafricanrepublic
AT shellymasi influenceoffoodavailabilityonthedietandactivitybudgetoftwowesternlowlandgorillagorillagorillagorillagroupsofdifferingsizeinthedzangandokinationalparkcentralafricanrepublic