The use of fruiting synchrony by foraging mangabey monkeys: a ‘simple tool’ to find fruit

Abstract

Previous research has shown that a considerable number of primates can remember the location and fruiting state of individual trees in their home range. This enables them to relocate fruit or predict whether previously encountered fruit has ripened. Recent studies, however, suggest that the ability of primates to cognitively map fruit-bearing trees is limited. In this study, we investigated an alternative and arguably simpler, more efficient strategy, the use of synchrony, a botanical characteristic of a large number of fruit species. Synchronous fruiting would allow the prediction of the fruiting state of a large number of trees without having to first check the trees. We studied whether rainforest primates, grey-cheeked mangabeys in the Kibale National Park, Uganda, used synchrony in fruit emergence to find fruit. We analysed the movements of adult males towards Uvariopsis congensis food trees, a strongly synchronous fruiting species with different local patterns of synchrony. Monkeys approached within crown distance, entered and inspected significantly more Uvariopsis trees when the percentage of trees with ripe fruit was high compared to when it was low. Since the effect was also found for empty trees, the monkeys likely followed a synchrony-based inspection strategy. We found no indication that the monkeys generalised this strategy to all Uvariopsis trees within their home range. Instead, they attended to fruiting peaks in local areas within the home range and adjusted their inspective behaviour accordingly revealing that non-human primates use botanical knowledge in a flexible way.

What, where and when: spatial foraging decisions in primates

“…Thus, some primates know where the resources are (Garber, 1989;Garber & Paciulli, 1997;Janson, 2007), when to look for them (Janmaat et al, 2006a,b) and what or how much is likely to be available (Cunningham & Janson, 2007a,b). For example, studies on grey-cheeked mangabeys (Lophocebus albigena) suggested that they (i) may use the calls of hornbills to locate fruit (Olupot et al, 1997), (ii) seem to take into account past weather conditions when searching for food, and are more likely to approach trees with fruit at various stages of development than empty trees of the same species (Janmaat et al, 2006b), and (iii) seem to use cues related to synchronous fruiting during foraging (Janmaat et al, 2012). The latter strategy allows prediction of the fruiting state of a large number of trees of the same species without having to check specific trees (Janmaat et al, 2012).…”

Contrasting responses to novelty by wild and captive orangutans

“…Second, novelty may cause stronger reactions in a familiar environment [Harris & Knowlton, 2001], and the zoo animals live in far smaller enclosures than their wild counterparts. However, the latter are obviously also very familiar with their habitat, [e.g., Janmaat et al, 2012], and continued to show no response toward the novel objects after dozens of passes. Thus, while the comparison cannot be made totally unbiased, the dramatic difference we observed is real and requires explanation.…”

Sooty mangabeys scavenge on nuts cracked by chimpanzees and red river hogs—An investigation of inter‐specific interactions around tropical nut trees

“…Sooty mangabeys are West African cercopithecid monkeys that live in the rainforests to the west of the Sassandra River (Mittermeier et al, ). They live in groups numbering from 30 to 120 individuals that occupy home ranges estimated at 5 km 2 (Janmaat, ; Shultz & Noë, ). White breasted Guinea fowl are indigenous to West Africa.…”