Still marvelous but significantly
reduced
In their Elephants of Savuti, one of the excellent
wildlife videos that Derek and Beverley Joubert have filmed
for National Geographic, a half-grown elephant wanders away
from its herd, and gets surrounded by lions. The Jouberts
record the realities of Africa’s wilderness ecologies
in an unsentimental way, and I expected to see the elephant
being killed and eaten in short order. The lions were literally
all over the young animal, but were, it turned out, unable
to penetrate its skin. It was as though a bunch of kids was
trying to bite into a watermelon that hadn’t been sliced
open – their teeth simply couldn’t get a purchase.
Even though the cats tried vulnerable places like the elephant’s
anus, they just couldn’t get through that fortress-like
animal’s outer “wall.” In the end, they
gave up and the elephant was eventually able to rejoin its
herd.
Lions can and do kill elephants, but it would obviously be
much easier for them to do so, if they had teeth which were
specially evolved to penetrate the skins of animals of that
size. As we’ve seen in several other contexts, early-Pleistocene
Africa had no less than three big cats whose teeth were specially
enlarged and lengthened to penetrate thick skins. These cats
– members of the so-called “machiarodont”
subfamily – were the sabertooth Megantereon,
a “scimitar-tooth” called Homotherium,
and a “dirk-tooth” known as Dinofelis.
Megantereon was about the size of a present-day
jaguar, but very powerfully built. Its front legs, shoulders
and chest were, in particular, massively developed. That,
and the fact that it could open its jaws much wider than any
modern cat can, suggests that it may have used its front limbs,
together with its powerful neck muscles, to push or pull its
teeth into vulnerable parts of its prey like large blood vessels
or the trachea. Megantereon’s stocky build
tell us that it was probably an ambush hunter which only pursued
its prey for short distances. It had a short, bobcat-like
tail. Its six-inch upper canines were laterally flattened
so that they could slice through muscle and skin.
Bigger than Meganterion, the “scimitar-toothed”
Homotherium was about the size of a lion, but more
slenderly built, and possessed of a long, powerful neck like
that of a spotted hyena. Also like the hyenas, it had long
forelimbs, relatively short back ones, and a short tail. Homotherium
seems to have specialized in running pursuit. Like the cheetah,
it had sacrificed the ability to retract its claws in favor
of getting better traction. Like the cheetah, too, it had
large nasal openings – presumably to allow quicker oxygen
intake – and a large and complex visual cortex thought
to be associated with day-time hunting.
Homotherium’s slender upper canines were shorter
than those of the sabertooth Megantereon and more curved.
The rear edges of those canines were crenulated like the cutting
edge of a steak knife. Lack of wear on the upper canines on
both Homotherium and Megantereon suggests
that those teeth were used primarily for the business of killing.
The tearing and cutting involved in feeding was done, in both
species, by very robust incisors, situated much further forward
than those of pantherine cats like lions and tigers, along
with the forward-shifted lower canines, and well-developed
meat-cutting or carnassial teeth in the back of the jaw.
In a 1970 article in the Zeitschrift fur Säugertierkunde,
Vratislav Mazak, a Czech zoologist, drew attention to the
fact that a 30,000-35,000 year-old, ten-inch-long stone carving
found at Isturitz in the French Pyrenees which had been thought,
up to that time, to represent a lion, could be a representation
of Homotherium.
As this drawing shows, the carving depicts a lightly-spotted
cat with a short tail and a “swollen” lower jaw
(Homotherium’s upper canines didn’t protrude
from its mouth; they were housed, instead, in tough, protective
tissue associated with the bone flanges that deepened its
bottom jaw.) Mazak’s suggestion was largely ignored
until the carbon-dating, in 2002, of a Homotherium latidens
lower jaw dredged from the North Sea to about 28,000 years
ago. That confirmed the fact that this species was still living
in Europe after the first members of Homo sapiens
entered that continent.
Homotherium was a long-lived, successful genus.
After it disappeared from Africa in the 1.4 million-year-ago
extinction-spasm we’ll talk about presently, it survived
in the northern parts of Eurasia, and in North America until
near to the end of the Pleistocene. The Friesenhahn Cave in
Texas, in which the remains of 20 adults and 13 juvenile members
of Homotherium serum were found, also contained the
remains of between 300 and 400 juvenile mammoths. The majority
of the individuals represented by these remains were around
two years old – an age at which modern elephants begin
to assert a degree of independence from their mothers. This
may give us an idea about the feeding strategy that Homotherium
could have pursued in Africa.
Africa’s third machairodont, the “dirk-tooth”
or “false saber-tooth” Dinofelis, was,
like Megantereon, a jaguar-sized animal. The combination
of powerful forequarters and relatively gracile rear limbs,
suggest that it was, like Megantereon is presumed
to have been, an ambush killer. Dinofelis’ upper
canines weren’t laterally flattened like those of Megantereon
and Homotherium. They were conical, like those of
lions and leopards, and midway between those of the lion and
Homotherium in length. Analysis of its tooth enamel
tells us that this cat lived on animals who ate C4 grasses.
Dinofelis was, therefore, probably a savanna-dweller.
As we'll see in the appendix to this book, savannas became
permanent features of the African landscape between five and
ten million years ago. Africa’s main antelope families
arose in response to this development. Around 2.5 million
years ago, when the earth plunged to a new low of cold and
aridity, those savannas spread, and antelopes reached new
heights of abundance and diversity in Africa. This development
represented a big increase in species which relied on swiftness
rather than large size and thick skins to avoid being eaten
by a predator. “Pantherine” cats like lions and
leopards, and felids like cheetahs, all of which had already
been in existence for some time, rose to prominence in response
to it. Those predators were fast and/or agile enough to catch
the swift new grass-eaters, and their teeth didn’t have
to be particularly big to penetrate the relatively thin skins
of this new kind of prey.
Machairodonts must, of course, have competed with pantherines
to a degree, but neither group was able to push the other
out of existence. “What is now abundantly clear,”
the fossil-cat expert Alan Turner tells us
is that the machairodont cats co-existed
in Africa with the modern feline cats for a very long period
of time, considerably reducing the force of the argument that
their demise may have resulted from competition with the modern
species.
The machairodonts would, as a group, have lived off larger,
thicker-skinned animals than the pantherines did, and each
of the three machairodont species must have occupied more-or-less
separate “sub-niches” within that “larger
prey” category. But how many large-prey sub-niches,
you might ask, could Africa’s biggest herbivores offer?
That continent only has one elephant species, after all, along
with two rhino and two hippo species. The answer is that early-Pleistocene
Africa was much richer in megaherbivore species than the Africa
of today is – so much richer, in fact, that a person
familiar with Africa’s present-day fauna would be astounded
if she could take a time-trip to the Africa of 1.5 million
years ago. Her Collins Guide to African Wildlife would
have be quite a bit thicker than it is now. It would, in particular,
have to have an entire chapter devoted to the different kinds
of elephants she’d be encountering. That chapter would
tell her that the diverse collection of elephant species which
inhabited Africa at that time, were divided into two suborders:
The Deinotherioidae and the Elephantoidae.
The Deinotherioidae contained only one family, and that family
was, as far as we can tell, represented only by the genus
Deinotherium which contained, in turn, only one species
that we know about: D. giganteus, an animal somewhat
larger than a present-day African elephant, equipped with
downward-curving tusks growing out of its bottom jaw. The
other proboscidean suborder, the Elephantoidae, consisted
of three families: the Gompotheriidae, the Mastodontidae and
the Elephantidae. We’re not sure if the first two of
those families contained more than one genus, but we know
that the third – the Elephantidae – contained
three: Loxodonta, the genus of the surviving African
species; Elephas, that of the surviving Asian species;
and Mammuthus, that of the (probably hairless) African
mammoths.
Early-Pleistocene Africa was, therefore, inhabited by at
least six genera of elephant-like animals. How many species
did those six genera contain? Nancy Todd of the Department
of Biology of Manhattanville College argues convincingly that
the genus Elephas might have been represented, at
that time, by as many as five co-existing species. Loxodonta
may also have been represented by more than one species
at a time during the Pleistocene. It is, indeed, still variable
enough to create doubt about whether it should be viewed as
a single species.
On the conservative assumption that early-Pleistocene Africa
contained six proboscidean genera, and that each of those
genera was represented, on average, by 1.5 species, we can
conclude that the continent may, at that time, have been inhabited
by nine species of elephant.
Africa was also, at this time, inhabited by at least four
kinds of Hippo. The genus Hippopotamus had two species,
the still-living H. amphibius, and a variant with
more extreme aquatic adaptations, such as periscope-like eyes
and snorkel-like nostrils, called H. gorgops. The
pig-like genus Hexaprotodon had at least two: the
still-living H. liberiensis, the pygmy hippopotamus,
and one or more larger species which are thought to have preferred,
like the pygmy member of this genus still does, to spend most
of their time on land, in forest cover.
Africa had two rhino species in the early Pleistocene, as
it does today, but it was also inhabited by a large relative
of the rhino-tapir-horse family known as Ancylotherium.
This perissodactyl had a ground-sloth-like body, with short,
powerful hindquarters and long, muscular “arms”
which it seems to have used in conjunction with claw-like
hoofs to pull branches within reach of its mouth.
The elephants, hippos and big perissodactyls we’ve
just talked about would have been the most visible part of
the continent’s fauna, making up perhaps ninety percent
of its mammalian biomass. Pleistocene Africa’s medium-sized
animals would have been overshadowed by these giants, but
the members of that group were also bigger and more diverse
than their present-day counterparts. Metridochoerus
was a giant version of the present-day warthog, while Colpocheorus
was a giant bush-pig. Africa was, during the Pleistocene,
also inhabited by the giant member of the wildebeest-hartebeest
family, Megalotragus; a giant relative of the still-living
roan and sable antelopes named Hippotragus gigas;
a large zebra known to science as Equus capensis;
a large, big-antlered member of the giraffe-okapi family,
Sivatherium; and the two huge baboon species I mentioned
in Chapter 9 – one as big as a gorilla, and the other
about the size of a modern human.
The vast majority of African mammals which disappeared during
the Pleistocene were distinguished by their large size. The
ground-dwelling Paracolobus which vanished near the beginning
of that epoch was Africa’s largest monkey. Only a few
of the vanishing mammals were the same size as their present-day
relatives: Makapania, which was allied with the still-existing
musk ox and takin was one, as was Africa’s three-toed
horse Stylohipparion. Both the “gracile”
and “robust” australopithecine members of the
human family which disappeared during that time were smaller
than Homo erectus. Only one small antelope that we
know of disappeared from Africa during the Pleistocene: a
steenbok-like animal assigned, possibly in error, to the springbok
genus as Antidorcas bondi.
* * *
When did the various species of this extinct African fauna
make their last appearances? Giant tortoises were, as we saw
in the previous chapter, already dwarfed and/or exterminated
in the late Pliocene. The last of the gracile australopithecine
fossils date from about 1.7 million years ago, i.e. at roughly
the same time as Homo erectus made its first appearance.
About 1.4 million years ago – i.e. about a quarter
of the way through the Pleistocene – a much larger wave
of extinctions hit Africa. All of the continent’s elephant
genera except Elephas and Loxodonta were
swept away by it. (Loxodonta survives, of course,
in present-day Africa; Elephas only disappeared from
that continent about 125,000 years ago and survives in South
Asia.) One or more of Africa’s Hexaprotodon
or “forest hippo” species, as well as its big
ground-sloth analog Ancylotherium, were also annihilated
in this early-Pleistocene extinction-spasm. This huge drop
in the diversity of Africa’s megaherbivores
was accompanied by the disappearance of the lion-sized hyena
Pachycrocuta, the cheetah-like “running hyena”
Chasmaporthetes, all three of that continent’s
machairodont or “sabertooth” cats, as
well as that of a large, poorly-identified dog which could
have been related to the present-day Africa wild dog.
This 1.4 million-year-ago hemorrhage was the most destructive
extinction episode which Africa was to suffer during the Pleistocene,
but the diversity of that continent’s big-animal species
would, during the rest of that epoch, continue to bleed away
at a reduced level. Africa’s giant pigs, its “super-aquatic”
hippo H. gorgops, and its hipparions would disappear
in the middle of the Pleistocene around 900,000 years ago.
Near this point, the last of the australopithecines, the so-called
“robusts,” also disappeared from Africa –
and from the planet – leaving H. erectus as
the only representative of a formerly diverse family.
In the vicinity of 500,000 years ago, Africa’s giant
Hippotragus antelope, its giant baboon species, and
the Sivatherium giraffe/okapi slipped into extinction.
As we’ve already seen, Elephas, the animal
now known as the Asian elephant, became extinct in Africa
around the time of the second-last Interglacial, the Eemian,
which occurred around 125 thousand years ago.
At or near the end the Pleistocene, around 12,000 years ago,
Africa’s megafauna experienced a final extinction episode
which coincided, for reasons we’ll discuss in Part 4,
with the catastrophic disappearance of the bulk of the megafauna
of both Eurasia and the New World. This final spasm swept
away the giant wildebeest Megalotragus, the large
zebra Equus capensis, the African musk-ox Makapania,
and the small steenbok-like antelope which I referred to as
“Antidorcas” bondi. The long-horned buffalo
Pelorovis antiquus also disappeared from Southern
Africa at this time, but it seems have survived on the savannas
of the interglacial Sahara until about five thousand years
ago.
All these losses have left present-day Africa with “the
still-marvelous but significantly reduced collection of big-animal
species” that I talked about in Chapter 1.
* * *
The only region other than Africa to experience significant
losses of big-animal species in the earlier part of the Pleistocene
was South Asia. As we saw in Chapter 11, giant tortoise species,
including the supergiant Megalochelys, became extinct
there early on in that epoch.
The diversity of South Asia’s biggest animals also
experienced a crash around 1.4 million years ago. South Asia
lost proboscidean species in that crash, as well as one or
more Hexaprotodon forest-hippos. At about the same
time, South Asia’s Megantereon sabertooths
followed these big herbivores into extinction. South Asian
megafaunal losses would, like those suffered by Africa, continue
at a reduced level throughout the Pleistocene. Later in that
epoch, South Asia would loose Gigantopithecus, the
largest ape that has ever existed, and the giraffe/okapi
Sivatherium. Pachycrocuta survived longer than
Megantereon in this region, but it would also slip
into extinction long before the end of the Pleistocene.
The final spasm of megafaunal extinctions to hit Southern
Asia, took place after Homo sapiens evolved in Africa
and moved into that region some 60,000 years ago. That spasm
was approximately contemporaneous with the large-scale extinction
of the megafauna of the New World, North Asia and Europe,
and with Africa’s final, and relatively small, extinction-spasm
which we discussed a few paragraphs back. South Asia would,
in this “final” or end-Pleistocene spasm, lose
the last of its mastodons, and the last of it machairodonts,
the scimitar-tooth Homotherium ultimum. Like Europe,
it would also lose a hominid species: Homo erectus,
which appeared in South Asia nearly two million years ago,
makes one of its last appearances in that region between 38,000
and 32,000 years ago at Ngadong, Java. H. florisiensis,
thought by many observers to be dwarf variant of erectus,
appears to hang on until about 15,000 years ago.
* * *
Paul Martin, was, as I mentioned in the introduction to this
Part, the first person to present a logical argument for the
proposition that hominids caused the spate of big-animal extinctions
which took place in Africa before the end of the Pleistocene.
In an article published in Nature in 1966, entitled
“Africa and Pleistocene Overkill,” he contrasted
that early diminution of Africa’s megafauna, with the
sudden disappearance of the American “Serengeti”
at the end of the Pleistocene, and the extinction-event which
destroyed Madagascar’s megafauna some 1,500 to 500 years
ago. The fact that those three extinction-episodes were widely
separated in time, excluded, Martin pointed out, the possibility
that they could have been caused by a single, world-wide episode
of climate change. Even the seemingly significant fact that
the American extinctions had taken place at the same time
as the abrupt termination of the last glaciation, did not
support a causal link between those two occurrences: climatic
events as severe as the latest glacial termination had, Martin
argued, been taking place throughout the Pleistocene, and
none of them had diminished the big-animal diversity of North
America to any noticeable degree.
But if climatic turbulence associated with glacial cycles
had visited North America on numerous occasions during the
Pleistocene, humans had not. Members of our family arrived
in North America for the first time near the end of the Pleistocene,
and the collapse of the American megafauna took place relatively
soon after that arrival. Martin pointed out that the same
sequence of events had taken place in Madagascar: very soon
after the humans reached that island for the first time in
the vicinity of 2,000 to 1,500 years ago, Madagascar lost,
among other species, at least six kinds of “elephant
bird,” the largest of which was about three times heavier
than an ostrich, seven genera of lemurs of which the largest
species weighed more than a male gorilla, two species of giant
tortoise, and two kinds of hippo.
Many people had, up to that time, used the example of Africa
to refute the idea that human hunters could have caused extinctions
such as those that occurred on Madagascar and in the New World.
Martin explained this reasoning as follows:
If Early Man was responsible for
the destruction of the New World fauna, the argument goes,
why did the evolving hominids leave the African fauna intact
during their evolutionary development over more than a million
years?
Martin’s article then went on to inform his readers of
the state of affairs we’ve just been discussing: that
the present-day African fauna is by no means intact. In the
1960s (early days, as far as geochronology is concerned) paleontologists
were still vague about the timing of events like the Pleistocene
extinctions of many of Africa’s biggest animals, and the
advent of Acheulian technology. Martin’s research had,
however, given him an accurate idea of the kinds of animals
that Africa had lost during the Pleistocene, and informed him
of the fact that the vast majority of those losses had taken
place well before the end of that Epoch.
No extraordinary losses of big-animal species were taking
place elsewhere on the planet at that time (except, as would
later become apparent, in South Asia, the only other land-mass
then inhabited by hominids). Madagascar in particular, whose
climate is closely tied to that of Africa, did not experience
any discernable increase in extinctions during the “hemorrhage”
which bled away most of Africa’s elephant species and
many of its other species of megafauna. For Martin, the only
remaining explanation for that hemorrhage was a “cultural”
one – i.e. one which involved hominids, and, presumably,
the unprecedented degree of power which a member of members
of that family was developing. He pointed out that a new technology,
the Acheulian, had emerged in Africa near the time when Africa
was losing many of its big animals. (We’ve learned,
since Martin made this argument, that the “Acheulian
revolution,” as I refer to in Chapter 14, included discovery
of fire-use.)
The timing of the latest two of the three extinction-episodes
Martin was contrasting in his 1966 article supported the notion
that they had been caused by the spread of our family across
the planet: the American extinction-spasm happened soon after
sapiens reached North America via the Bering land
bridge, and the collapse of the Madagascan megafauna took
place soon after that species became capable of reaching the
planet’s last uncontacted islands by undertaking long
sea voyages.
The differing degrees of intensity of those three extinction-spasms
also supported that the idea that they were caused by our
family: the fact that extinctions were relatively moderate
in Africa, heavy in America and extremely heavy in Madagascar,
fit with the likelihood that the African fauna, which had
evolved in company with hominids, would have been more resistant
to the advent of hominid ingenuity than the American fauna
was, while Madagascar’s animals and birds – which
had no exposure at all to large, sophisticated predators before
the arrival of humans – would have been even more vulnerable
to humans than those of the Americas.
* * *
After returning to the topic in a chapter (Prehistoric Overkill:
The Global Model”) in the 1984 Quaternary Extinctions
which he co-edited with Richard Klein, Paul hasn’t written
anything further about the African Pleistocene. The body of
work which has, over the last forty years, established him
as a leader in the field of Pleistocene extinctions, is focussed,
for the most part, on the end-Pleistocene disappearance of
the North American megafauna.
Since Paul first mooted the question in 1966, relatively little
has been written about the possibility that humans caused
the early-Pleistocene African extinctions. That’s not
to say it wasn’t on anyone’s mind: In Richard
Leakey’s 1995 Sixth Extinction, written with Roger Lewin,
a caption under an illustration on page 176 reads “The
deinotherium, one of the giants of the Pleistocene that became
extinct at the hand of man.” Since the last deinotheriums
disappeared some 1.4 million years ago, that caption was clearly
implying that at least one hominid-caused extinction had
taken place in the early Pleistocene. (Leakey’s parents
had, as we’ll see in this Part, unearthed a partly-butchered
deinotherium carcass, associated with stone tools, at Olduvai
Gorge.) The authors did not, however, elaborate on that caption,
or say anything further on the topic in their book.
Apart from a very recent publication by Todd Surovell, Nichole
Waguespack and P. Jeffrey Brantingham entitled “Global
evidence for proboscidean overkill,” (PNAS April 26,
2005, 6231-6336) which touches briefly on the subject, only
one person other than Paul, has, as far as I know, produced
reasoned arguments that hominids were responsible for the
early-Pleistocene extinctions. In 1990, Wilhelm Schüle,
the archeologist whose thoughts on the disappearances of Africa’s
giant tortoises we discussed in the previous chapter, published
an article entitled “Human evolution, animal behavior,
and quaternary extinctions: A paleo-ecology of hunting,”
in the journal Homo, and a chapter, “Landscapes
and climate in prehistory: Interaction of wildlife, man and
fire,” in a book entitled Fire in the tropical biota,
edited by J. G. Goldhammer. In these and other articles, and
in a 1997 book entitled Prähistorisher Faunenschwund
– Ursache und Wirkung die Absterbens, (Prehistoric
disappearances of fauna – the cause and mechanism of
the extinctions) Schüle presented a comprehensive set
of climatic, biogeographical, anatomical, physiological and
behavioral arguments in support of Paul’s suggestion
that hominids might have been responsible for the early-Pleistocene
extinctions that took place in Africa.
I found Schüle’s behavioral arguments particularly
persuasive. The actions of non-hominid animals are, he points
out, much more rigidly circumscribed by instinct than that
of our family. Just as the birds and animals of the Galapagos
cannot, he points out, learn to fear large terrestrial carnivores,
whales cannot alter the inappropriately trusting behavior
they display in the presence of our species. Because we have
only begun to hunt them in the last few centuries, whales
simply haven’t had time to evolve appropriate behavioral
reactions to our species. “Melville’s Moby Dick,”
Schüle tells us “is a beast of fiction only. Most
deaths suffered by whalers in bygone days were accidental,
and not due to aggressive actions by the whales.”
Because it occurs close to land, Megaptera novaeangliae,
the humpback whale, has been hunted by our species for several
centuries. The population of this animal has, over that time,
been reduced to about a third of its pre-whaling level. But
the surviving members of this species do not, as one might
expect of such intelligent animals, react to humans with fear
or aggression. Consider this meeting between a humpback and
a human kayaker off the north-west coast of Hawaii’s
Big Island:
Gently the whale rose in the water,
until it loomed like a gleaming gray rock, and I could see
its huge eye, just below the surface, checking me out. Its
gaze seemed cool, but not unfriendly; more curious than anything
else. It seemed to be wondering what something so small was
doing “way out here.” Its enormous pectoral fin
extended under my kayak as I floated like a gnat beside it,
and it was impossible not to consider the fact that it could
easily swat me like that same gnat, had it wished. But the
gentle smoothness of its movements, compared to the wildly
playful breaches and leaps it had been executing a short while
earlier, indicated an understanding of my fragility, and its
unwillingness to do me harm.
In April of 2001 my son Eric paddled a surfboard up to a
southern right whale lying off the middle beach at Plettenberg
Bay, on South Africa’s southern coast, approaching –
illegally – to within fifteen feet of the animal’s
head. The whale didn’t react at all. Intelligent as
many of them are, whales don’t have the cognitive power
to “figure out” that our species is very dangerous
to them, or the linguistic powers to communicate that kind
of realization to other members of their various species.
Like all non-human animals, they must evolve appropriate instinctual
responses rather than “figuring out” how to react,
and a few centuries of persecution by our species simply hasn’t
provided a long enough time-span for that evolution to take
place.
Elephants have, on the other hand, been hunted by hominids
for many hundreds of thousands of years. It’s not surprising,
therefore, that it would be impossible at best, and suicidal
at worst, to approach a wild elephant as closely as the Hawaiian
kayaker, and my son, got to their whales. In areas where they’re
well-protected and frequently visited by humans, elephants
can stay relaxed in the presence of people inside motor vehicles,
but, even in those circumstances, they frequently become nervous
or irritable. Drive the Kruger Park’s 200-mile length
from Malelane up to Pafuri, and, even if you don’t approach
them closely, you’ll almost certainly provoke some degree
of annoyance in the elephants you’ll meet along the
way: head-tossing, trunk-raising, ear-flaring, or assertive
approaches that will make you stop or retreat. You’ll
be fairly safe, though – attacks on vehicles happen
very seldom. When they do take place, however, they can be
terrifying. George Wittemyer, working, as it happened, on
the Save the Elephants project, was lucky to survive the total
destruction of his 4 X4 truck by a bull elephant in Kenya’s
Samburu National Park in May of 2001:
[H]e hit us so hard that the car
was lifted into the air, and flipped once again onto its wheels.
The force of that blow was tremendous – beyond anything
I could fathom an animal was capable of. I could see him clearly
at this point, coming for my door. I felt he would not quit
until he had finished us.
Move around in Africa’s wilderness areas on foot, and
the risk of a violent confrontation with an elephant increases
considerably. In the one-year period preceding February of
2005, when I started writing this chapter, five elephant attacks
on humans took place in South Africa, involving two walking
parties protected by armed escorts, an unarmed pedestrian,
and a ranger riding a bicycle. Those attacks resulted in the
deaths of three humans and at least three elephants. In April
of 2005, a tourist walking in the bush was killed by an elephant
in Uganda’s Murchison Falls National Park.
I won’t overstate this argument by denying that elephants
can become completely relaxed around humans in captivity.
I should mention, too, that one particular herd of wild elephants
– a group that spends a lot of time in the unfenced
staff village at Skukuza in the Kruger National Park –
has become accepting of humans walking very close to them.
Situations such as these cannot, however, disprove the existence
of a strong tendency among elephants which are not habituated
to close human contact, to feel fear and/or irritation when
a member of our species approaches them.
In the 1990 Homo article I mentioned earlier, (“Human
evolution, animal behavior, and quaternary extinctions: A
paleo-ecology of hunting,”) Schüle suggests that
defensive evolution added an extraordinary level of intelligence
to the “distrust humans” response which it installed
in the instinctual armamentarium of the surviving elephant
species:
Surviving terrestric [sic.] megaherbivores
live and evolved where man also evolved. Supposing that
early hominids hunted the ancestors of living elephants,
one may postulate a reciprocal influence over the evolution
of behavioural patterns in both. Today’s elephants
are the most cerebralized of the ungulates, and have a complicated
social structure. In their herds not only the mothers but
also any other member of the herd will attack and even kill
anyone they consider dangerous to their young including
humans.
Elephants have not, of course, become smart enough to emulate
the inventiveness that has become a way of life for our species,
but their intelligence has, nonetheless, added a great deal
of flexibility to their behavior. They help each other during
birth, injury or sickness, and females have been seen to adopt
orphaned members of their species – a very unusual phenomenon
in the animal world. Elephants pick up bones that belonged
to members of their species (particularly members they have
known) and handle them obsessively, and they cover their dead
infants with branches – behaviors which speak of an
awareness going well beyond that of any other ungulate.
Earth’s other surviving megaherbivore species
don't share this exceptional level of intelligence, but they
are, like the two still-existing elephant species, equipped
with strong instinctive feelings of fear and aggression toward
humans. Black rhinos are notoriously “ill tempered”
in the presence of our species, and extraordinarily fearful
of humans. Fortunately for both them and us, that fear is
usually stronger than their aggressive impulses toward us.
Hippopotamuses kill more humans than any of Africa's other
wild animals. “Provoked,” Chris and Stuart Tilde
tell us in their Field Guide to the Mammals of Southern
Africa, “the hippopotamus can be extremely dangerous...”
In areas where they see relatively few humans, the mere sight
of a member of our species standing on the banks of one of
their pools is often provocation enough. I've had to beat
several hasty retreats from these animals while fishing in
Botswana and Zimbabwe.
Pliocene and early Pleistocene megaherbivores would not,
Schüle reasoned in his 1990 “Paleo-ecology of hunting”
article, have been equipped with this instinctive aversion
to our species, nor with the exceptional intelligence of the
surviving elephant species:
Upper Tertiary and Quaternary megaherbivores
were in exactly the same positions as today’s whales:
a new predator had appeared and hunted animals never hunted
before. For the whales, time is too short to develop new patterns
of behaviour. Time was too short, too, for most Quaternary
megaherbivores as well. Because of the megaherbivores (sic.)
lack of fear-patterns, the problem for early hominids was
not to get close to them, but to find a means to kill the
megaherbivores.
CHAPTER 13
–
Technological
evolution stimulates – and is stimulated by – the
evolution of bigger brains and bodies
