Sometime ago, I posted that mountain gorillas are NOT vegans. (The claim that mountain gorillas are vegans, is typically the "last stand" of fruitarian zealots trying to claim that we are natural vegans/fruitarians.) So that you have the data needed to prove that mountain gorillas are not vegans, the following material is provided. In the material below, note: * the deliberate consumption of ants by some mountain gorillas * the consumption of considerable amounts of insects on the leaves that are the basis of the diet of mountain gorillas (i.e., the mountain gorilla regularly consumes insects, even if not deliberate). Why do fruitarians cite the mountain gorilla to support their position? Mountain gorillas eat mostly leaves, very little fruit, and some insects. The mountain gorilla really does not support the position they advocate! Also, see the interesting references on lowland gorilla diet and chimp diets, and how chimps are more flexible in food choices. Let's see: chimps more advanced than gorillas, chimps more flexible in food utilization than gorillas. Humans more advanced than chimps, so humans are more flexible in food utilization than chimps? That inference, of course, contradicts the narrow fruitarian view. I hope you find the material below of interest! Regards, Tom Billings [log in to unmask] -------------------------------------------------------------------------------------------------------------- Watts, D P. Ant eating behavior of mountain gorillas. Primates, v.30, n.1, (1989): 121-126. Abstract: Eleven cases of feeding on driver ants (Dorylus sp.) by mountain gorillas (Gorilla gorilla beringei) are described. Ant eating provides the gorillas with more animal protein and other nutrients per unit feeding time than do other forms of insectivory that contribute to their diet, but it is so rare that it is unlikely to be of real nutritional significance. Gorillas obtain ants with their hands and do not use tools. Immature individuals (except infants) ate more ants than did adult females, and silverbacks were not seen to eat ants. These differences are more likely to reflect differences in individual taste and interest in novelty than differences in nutritional strategy. Not all gorillas in the Virungas population eat ants. Intra-population variability may be ecologically contingent, but ant eating appears to be a socially acquired and transmitted taste. Williamson, E A; Tutin, C E G; Rogers, M E; Fernandez, M. Composition of the diet of lowland gorillas at Lope in Gabon. American Journal of Primatology, v.21, n.4, (1990): 265-278. Abstract: This report described the composition of the diet of lowland gorillas, Gorilla gorilla gorilla, at Lope in central Gabon. This population inhabits mature evergreen tropical forest and is not habituated to human observers. Data were collected during 6 years of an ongoing long-term study, from feeding-trails and by direct observation, but mostly by fecal analysis. Gorillas ate 182 plant foods from 134 species and 36 families. The fruit diet was diverse: 95 species were consumed, most with succulent pulp, and some immature seeds were eaten. Fruit remains were recorded in 98% of dung. Vegetative parts of Aframomum and Marantaceae formed staple foods, as they were abundant, accessible, and available year-round. Soil and social insects were also ingested; remains of weaver ants were recorded in one third of feces. More foods have been recorded for gorillas at Lope than elsewhere and this is the most frugivorous population studied so far. Yamagiwa, J; Mwanza, N; Yumoto, T; Maruhashi, T. Seasonal change in the composition of the diet of eastern lowland gorillas. Primates, v.35, n.1, (1994): 1-14. Abstract: Details are presented of the composition of the diet of eastern lowland gorillas, derived mainly from a study of their fresh trails and fecal analysis, during the course of an entire year in the tropical lowland forests of the Itebero region, Zaire. Gorillas ate 194 plant foods from 121 species and 45 families. They consumed 48 species of fruits; and 89% of fecal samples contained fruit seeds, but fruits were a relatively small part (25%) of the total number of food items. The composition of their diet changed seasonally. When consumption of fruit decreased in the long rainy and the long dry seasons, the gorillas ate, in addition to Zingiberaceae and Marantaceae, many kinds of leaf and bark, which may be an important buffer against the shortage of fruits. Gorillas also fed regularly on ants (Ponerinae), and the frequency of consumption showed small seasonal variations. From a comparison of diet composition, eastern lowland gorillas appeared to be intermediate between the other two subspecies. The choice of food showed differences in preference of fruits and insects between subspecies and may reflect high similarities within subspecies in lowland and montane forests. Tutin, C E G; Fernandez, M. Insect-eating by sympatric lowland gorillas (Gorilla gorilla gorilla) and chimpanzees (Pan troglodytes troglodytes) in the Lope Reserve, Gabon. American Journal of Primatology, v.28, n.1, (1992): 29-40. Abstract: Sympatric populations of lowland gorillas (Gorilla gorilla gorilla) and chimpanzees (Pan troglodytes troglodytes) in the Lope Reserve in central Gabon consumed insects at similar average frequencies over a 7-year period (30% versus 31% feces contained insect remains). Data came mostly from fecal analysis supplemented by observation and trail evidence. The weaver ant (Oecophylla longinoda) was the species eaten most frequently by both gorillas and chimpanzees. Other species of insects were eaten but there was virtually no overlap: Chimpanzees uses tools to eat Apis bees (and their honey) and two large species of ants; gorillas ate three species of small ants. Thus, despite their shared habitat, the resources utilized were not identical as gorillas do not show the tool-use "technology" of chimpanzees. The frequency of insect-eating by both species of ape varied seasonally and between years but in different ways. This variation did not seem to be related to the ration of fruit of foliage in their diets. Gorillas of all age-classes ate insects at similar rates. Comparisons with insectivory by other populations of gorillas indicate differences exist. Mountain gorillas (Gorilla g. beringei) in the Virunga Volcanoes, Rwanda, consume thousands of invertebrates daily, eating them inadvertently with handfuls of herbaceous foods but they deliberately ingest insect-foods only rarely. Lowland gorillas at Lope habitually ate social insects, and their selective processing of herbaceous foods probably minimizes inadvertent consumption of other invertebrates. Gorillas at Belinga in northeastern Gabon, 250 km from Lope, ate social insects at similar rates but ignored weaver ants in favor of Cubitermes sulcifrons, a small speices of termite that occurs at Lope but was not eaten by gorillas. This indicates that local traditions similar to those reported for chimpanzees also exist amongst populations of gorillas. Tutin, C E G; Fernandez, M. Composition of the Diet of Chimpanzees and Comparison with That of Sympatric Lowland Gorillas in the Lope Reserve Gabon. American Journal of Primatology, v.30, n.3, (1993): 195-211. Abstract: Over an eight-year period, a total of 174 food items were recorded for chimpanzees (Pan t. troglodytes) in the Lope Reserve in central Gabon. Plant foods, principally fruit, dominated the diet but insects were eaten regularly, and predation on at least three species of mammal occurred infrequently. The diversity of the vegetative component of the diet (leaves, stems, and bark) was probably underestimated by fecal analysis. Comparison of chimpanzee diet at Lope with that of sympatric lowland gorillas showed the majority of foods were eaten by both species (73% of chimpanzee food items and 57% of gorilla food items). The overlap of fruit species was greater (82% and 79%, respectively) than that of other food classes. Both chimpanzees and gorillas harvested the majority of their plant foods arboreally (76% and 69%, respectively). The high degree of dietary overlap suggested that ecological competition between these two closely related species might exist. Few overt signs of competition for food either between or within species were observed but when fruit was scarce, the diets of the two species showed greatest divergence. The major differences between chimpanzee and gorilla diet at Lope were the larger quantities of vegetative foods regularly eaten by gorillas and their ability to resort to a diet dominated by vegetative foods when fruit was scarce. In these respects, chimpanzees at Lope resembled populations of Pan troglodytes studied elsewhere while Lope gorillas resembled mountain gorillas (Gorilla g. beringei) and bonobos (Pan paniscus) in their greater dependence on vegetative foods.