"Leif Erikson" > wrote in message k.net...
>
pearl wrote
<..>
> > "It is highly probable that plant foods were indeed the major part
> > of the early hominid economy, and unequivocal evidence for hunting
> > as against scavenging carrion does not appear until relatively late in
> > the fossil record, probably not earlier than half-a-million years ago."
>
> Humans hunted from the beginning.

'... while early humans ate some meat, we do not know how
much meat they ate, nor whether they got the meat by hunting
or scavenging. It is not until much later, around 100,000 years
ago, that we have good evidence about human hunting skills,
and it is clear that humans then were still very ineffective
big-game hunters. Human hunters of 500,000 years ago and
earlier must have been more ineffective.
...
http://tinyurl.com/dahps

> Chimpanzees have *always* hunted as well.

'According to Tuttle, the first substantive information on chimp diets
was provided by Nissen in 1931 (p.75). In 1930 Nissen spent 75
days of a 3-month period tracking and observing chimps. He made
direct unquantified observations and examined fecal deposits and
leftovers at feeding sites. He also found "no evidence that they ate
honey, eggs or animal prey" - this observation may have been too
limited due to seasonal variations in the chimp diet.

In Reynolds and Reynolds (1965), Tuttle says that a 300 hour
study of Budongo Forest chimps over an 8-month period revealed
"no evidence for avian eggs, termites or vertebrates", although
they thought that insects formed 1% of their diet (p.81).

In another study of Budongo Forest chimps from 1966 to 1967,
Sugiyama did not observe "meat-eating or deliberate captures
of arthropods", although he reported that "the chimpanzees
did ingest small insects that infested figs" (p.82).

Tuttle says that later observations at Budongo by Suzuki revealed
meat eating. Where the earlier observations wrong, or incomplete,
or maybe an accurate reflection of their diet at the time? Did the
chimps change their diet later? We do not know. Chimps sometimes
change their diets on a monthly basis. A study of chimps at the
Kabogo Point region from 1961 to 1962 by Azuma and Toyoshima,
revealed that they witnessed "only one instance of chimpanzees
ingesting animal food, vis. termites or beetles from rotten wood."
(p.87).

From 1963 to 1964, similar observations were found in Kasakati
Basin by a Kyoto University team, and when Izawa and Itani published
in 1966 they reported "no chimpanzees eating insects, vertebrates,
avian eggs, soil or tree leaves and found no trace in the 14 stools
that they inspected " (p.86). In contrast Kawabe and Suzuki found
the Kasakati chimps hunting in the same year (p.88), although only
14 of 174 fecal samples contained traces of insects and other animal
foods. So perhaps these differing observations are due to seasonal
variation, or even local differences (cultural variation) in feeding
preferences - Tuttle does not reveal which. Maybe some of the chimps
groups are 'vegetarian', while other are not. But see the Kortlandt
observations below before believing that all chimps are meat-eaters.

Far less is known about bonobo feeding habits than about the
common chimpanzee. Like chimps, the bonobo is also known
to eat insects and carrion, although unlike chimps it has not been
observed to hunt. Kano and Mulavwa provided the most detailed
account of the feeding behaviour of Wamba bonobos based on
a 4-month study. Tuttle reports that their diet was 80% fruit pulp,
15% fibrous foods and 5% seeds, and that "Animal foods
constituted a minute part of their fare" (p.95).

The best evidence, if there is any, of a "vegetarian" ape is the
gorilla. As with the other apes, there is great variation in what
gorillas eat based on their locality, and season. A 15-month
study of gorillas at Campo by Calvert, is reported by Tuttle
(p.100), in which he says that out of 280 stools, 1 example of
stomach contents and 1400 feeding sites, plus direct
observations, there was "no evidence" that "Campo gorillas
ingested animal matter." Similarly, Casimir and Butenandt
followed a group about 20 gorillas at Kahuzi during 15 months
in 1971 to 1972 (Tuttle, ibid., p.102). They collected 43 fecal
samples at fairly regular intervals but none "contained remains
of vertebrates or invertebrates". In addition, the gorillas did
not disturb active birds and honeybee nests that were clearly
visible near their own nests. Nor did they unearth bee nests.
Goodall also noted that Kahuzi gorillas ignored eggs and
fledglings and did not invade bees nests (Tuttle, ibid., p.105),
and that none of the many fecal samples he found contained
animal remnants. Tuttle also reports that the "most detailed"
study of 10 groups of Zairean Virunga mountain gorillas by
Schaller in 13 months from 1956 to 1960, including fecal
samples and 466 direct hours of observation, found "no
evidence that they raided apian nests, which were common
at Kabara, ingested animal foods, or drank water." (p.107)
In 1959, a 64-day study by Kawai and Mizuhara of gorillas
at Mts. Muhavura and Gahinga also found "no evidence for
animal foods in the gorillas' fare." (p.108)

The story for gorillas is by no means a clear one, as findings
seem to vary from one study to another. You can pick them
to suit your agenda. For example, Adriaan Kortlandt says in
'Food Acquisition And Processing In Primates', page 133-135,
that "Gorillas have never been observed to eat honey, eggs,
insects or meat, not even when they were sitting or nesting
almost on top of honeycomb or a bird's nest, except for
one single case of honey-eating reported by Sabater-Pi (1960)"
He adds however, that Fossey (1974) reports that slugs, larvae
and worms were found to constitute 1% of the food item
observations recorded. Kortlandt adds that "No animal remains
have been found in gorilla dung, except for one case presumably
indicating cannibalism (Fossey, 1981)."
...
Kortlandt states that predation by chimpanzees on vertebrates is
undoubtedly a rather rare phenomenon among rainforest-dwelling
populations of chimpanzees. Kortlandt lists the reasons given below
in his evidence.

# the absence (or virtual absence) of animal matter in the digestive
systems of hundreds of hunted, dissected or otherwise investigated cases
# the rarity of parasites indicating carnivorous habits
# rarity of pertinent field observations
# the responses when he placed live as well as dead potential prey
animals along the chimpanzee paths at Beni (in the poorer environments
of the savanna landscape however, predation on vertebrates appears to
be much more common)

Kortlandt concludes this section on primate diets by saying that
the wealth of flora and insect fauna in the rain-forest provides
both chimpanzees and orang-utans with a dietary spectrum that seems
wide enough to meet their nutritional requirements, without hunting
and killing of vertebrates being necessary. It is in the poorer
nutritional environments, where plant sources may be scarce or of
low quality where carnivorous behaviour arises. Even then he says
that the meat obtained are minimal and perhaps insufficient to meet
basic needs. Finally he adds "The same conclusion applies, of course,
to hominids . . . it is strange that most palaeoanthropologists have
never been willing to accept the elementary facts on this matter
that have emerged from both nutritional science and primate research."
...'
http://tinyurl.com/d8aqw