Ecological context of savanna chimpanzee ( Pan troglodytes verus ) termite fishing at Fongoli, Senegal

I studied insect-foraging strategies of great apes and aimed to define niche differentiation in their insect diet. I investigated seasonality in fruit-, foliage-, insect-, and meat-eating by great apes in southeast Cameroon via indirect methods and measured activity and nest densities of insect prey. I used a multinomial logistic regression to analyze the data. Gorilla and chimpanzee insect-, ant-, and termiteeating does not correlate with rainfall. Ant-and nonwinged termite-eating by chimpanzees increased in periods of succulent fruit scarcity and provided protein and energy, which might have compensated for the protein-low foliage eaten then. The apes ate winged termites when succulent fruit was abundant. Ant and winged termite consumption by gorillas correlates positively with that of chimpanzees. Anteating by gorillas increased when fruit was scarce, but was also associated with temporal ant activity and nest density. Both ape species also encountered more ant nests and trails in that period, as they predominantly foraged for herbs in vegetation types with high ant availability. In contrast, fruit-eating correlates positively with nonwinged termite-eating by gorillas, but again temporal prey availability is also associated. Termites might have provided 1) supplemental iron when tannin-rich fruits were eaten or 2) antidiarrheal properties when gorillas ate too much laxative fruit. Termite-eating by both ape species is not associated with spatial termite availability. In conclusion, there is niche differentiation in their insect diet. Based on the trade-off between foraging effort and nutritional gain, chimpanzees use a highenergy and gorillas a low-energy strategy when feeding on termites, but both use a low-energy strategy when feeding on ants. However, more information on the consumption of ant larvae is necessary to define niche differentiation in their ant diet.

Section: Temporal Variation In Insect-eatingmentioning

confidence: 87%

Temporal Variation in Insect-eating by Chimpanzees and Gorillas in Southeast Cameroon: Extension of Niche Differentiation

Deblauwe

2009

“…Ficus spp., which typically produce fruit throughout the year, have been documented as fallback foods at some sites (Tweheyo and Lye 2003;Wrangham et al 1993) but not at others (Basabose 2002;Gross-Camp et al 2009). Insects, such as honeybees, ants, and termites, have also been suggested to be fallback foods at some sites (Yamagiwa and Basabose 2009) but not others (Bogart and Pruetz 2008).…”

Section: Introductionmentioning

confidence: 99%

The Influence of Seasonal Variation on Chimpanzee (Pan troglodytes schweinfurthii) Fallback Food Consumption, Nest Group Size, and Habitat Use in Gishwati, a Montane Rain Forest Fragment in Rwanda

Chancellor

Rundus

Nyandwi³

2011

The increased number of primates living in fragmented habitats necessitates greater knowledge of how they cope with large-scale changes to their environment. Chimpanzees (Pan troglodytes) are exceptionally vulnerable to forest fragmentation; however, little is known about chimpanzee feeding ecology in fragments. Although chimpanzees have been shown to prefer fruit when it is available and fall back on more abundant lower quality foods during periods of fruit scarcity, our understanding of how chimpanzees use fallback foods in forest fragments is poor. We examined how chimpanzees cope with periods of fruit scarcity in Gishwati Forest Reserve, a disturbed montane rain forest fragment in Rwanda. We assessed seasonal changes in chimpanzee diet and the use of preferred and fallback foods through fecal and food site analysis. We also examined seasonal variation in nest group size and habitat use through marked nest censuses. We found that chimpanzees experienced a seasonal reduction in preferred fruit availability, which led to a seasonal diet shift to more fibrous foods, including several that functioned as fallback foods. Our results suggest that during periods of fruit scarcity the chimpanzees also reduced nest group size. However, we found that the chimpanzees did not alter their habitat use between high-and low-fruit seasons, which suggests that the small size of the forest limits their ability to change their seasonal habitat use. Consequently, fallback foods appear to be particularly important in small food-impoverished habitats with limited ranging options.

“…Unlike other dry sites where the apes were not habituated (Hunt and McGrew 2002), we present data from direct observation of chimpanzees, describe the behavior, determine exactly what was reingested (fiber, seeds, or the entire dung) and when, and calculate the importance of seed reingestion relative to overall feeding. Some of the hypotheses listed in the preceding text are unlikely to apply: Wild chimpanzees are unlikely to be bored; Fongoli chimpanzees frequently eat insects, which provide B complex vitamins yearround (Bogart and Pruetz 2008); and temperatures are generally very high, making the climatic hypothesis unlikely. Of the remaining hypotheses, the food scarcity hypothesis may apply because, like other dry-habitat populations (Duvall 2008;Hunt and McGrew 2002;McGrew et al 1988), Fongoli chimpanzees have a relatively narrow diet, eating ca.…”

Section: Introductionmentioning

confidence: 99%

Seed Reingestion in Savannah Chimpanzees (Pan troglodytes verus) at Fongoli, Senegal

Bertolani

Pruetz

2011

Self Cite

Coprophagy is common in captive primates but has also been reported in the wild. For example, wild apes extract and reingest items from faeces. We term this behavior seed reingestion because the dung matrix is not consumed. We assessed the importance of seed reingestion in a population of savannah chimpanzees at Fongoli, southeastern Senegal, one of the hottest and driest areas of the species' range, where chimpanzees have a relatively narrow dietary repertoire. We observed habituated chimpanzees on 122 d during 8 mo in 2005 and 2006, employing both focal subject and scan sampling of identified individuals for 1278 h of data collection. Chimpanzees reingested seeds of 2 species: Parkia biglobosa and Adansonia digitata. Both seed species have a hard protective shell, and the embryos are rich in proteins and lipids. Chimpanzees initially ate the fruit matrix pulp and swallowed intact seeds before reingesting and chewing/destroying seeds. Seed reingestion accounted for almost 2% of feeding time. We suggest that at Fongoli this behavior may be an adaptive strategy to maximize food intake, by softening the seed's shell and making the seed's content more accessible.