Elephantine dilemmas

Full text

14 Quest 1(4)2005
High elephant densities in
protected areas are changing
environments significantly, in
ways that may reduce biodiversity.
The dilemma for conservation
authorities and the public is whether
or not to contain, or even reduce,
elephant numbers in national parks.
Evolving populations
Hominids and elephants share a long
evolutionary history in the African
savannas, with anatomically modern
humans appearing about 200 000
years ago.
In the sense that humans and
elephants can have enormous impact
on their habitats, both species are
‘environmental engineers’.
Understanding those impacts in an
evolutionary way helps today’s debate
on managing elephants in protected
areas, because present-day
human–elephant–plant interactions
almost certainly bear little resemblance
to those that existed in the millennia
before about AD 1500, when human
populations were a fraction of their
current levels and elephants could
range freely.
What do we know about early
human–elephant–habitat interactions?
How true is the ‘myth of wild Africa’,
where the land was supposedly
untouched by humans? Two things are
clear – when humans learned to use
fire they had the means to manage
landscapes in a way that no other
animal could do and hominids were
superb predators. Once they developed
stone tools and poison-tipped spears
and arrows, elephants would have
featured as prey. But the key question
“Did human predation contribute to
limiting elephant numbers in African
savannas?” remains unanswered.
It is clear from cave paintings that the
San were hunting elephants a few
thousand years ago. Archaeological and
historical research reveals that ivory
was traded for centuries from the east
African coast. Between 1546 and 1881,
annual exports from Isle de
Moçambique amounted to about 135
tonnes, suggesting a sustainable harvest
Elephants in southern Africa, south of the Zambezi river, have recovered from
a population low of a few thousand in 1900 to more than 200 000 today.
What problems do they cause? What's the solution? The debate rages
and David Cumming presents some of the concerns.

from southeastern Africa. Worked ivory
from archaeological sites in the
Limpopo basin, particularly from
Mapungubwe, reveal that ivory was
traded in this region a thousand years
ago. We have no good information on
the size or density of elephant
populations in southern Africa a
thousand or even five hundred years
back. But we do know that elephant
numbers and the centuries-old ivory
trade in southern Africa collapsed about
120 years ago through over-hunting.
100 years of successful
elephant conservation
By 1900, few elephants were left south
of the Zambezi river and it was feared
that they would become extinct in
southern Africa. There are now more
than 200 000 in the subcontinent – by
any reckoning, an outstanding
conservation success.
Contributing to the extraordinary
recovery of elephant populations in the
region was the high level of protection
given them by colonial
governments. In Zimbabwe
during the 1920s, for
example, killing a crop-
raiding elephant needed the
governor’s permission.
Further protection came from
an agreed Africa-wide ban in
1908 on the export of tusks
of cows and calves. The high
reproductive rate of elephant
and low calf mortality
resulted in population
growth rates of about 5% per
annum, with a doubling time
of approximately 15 years.
Elsewhere in Africa
elephants fared less well. By
the mid-1980s, the weight of
ivory leaving the continent
had risen to some 850 tonnes
a year – the same level it had
reached in 1880 before the
ivory trade collapsed. The
dramatic decline of elephants
in East and Central Africa during the
1970s and early 1980s through illegal
hunting and uncontrolled export of
ivory resulted in elephants being listed
on Appendix I of the Convention on
International Trade in Endangered
Species (CITES) in 1989. The listing
effectively banned all international
trade in elephants and elephant
products until a partial downlisting to
Appendix II in 1997, and it had major
implications for the management of
southern Africa’s still well-protected
and burgeoning elephant populations.
The elephant ‘problem’
The recovery of elephant numbers
generated problems and conflicts. As
elephant populations grew rapidly
during the early 20th century, so too
did rural human populations, so, by the
1930s and 1940s, crop-raiding by
elephants had become a problem for
peasant farmers. In Zimbabwe, for
example, the human population grew
from about 500 000 in 1900 to more
than 12 million in 2000 and, during the
1950s, there was a 15% per annum
increase in the number of elephants
destroyed in areas surrounding Hwange
National Park. Wildlife departments
were tasked with what was
Quest 1(4)2005 15
Examples of elephant impact on Zimbabwe's woodlands
Sengwa Wildlife Research Area in the early 1970s (1 elephant per km2)
■The proportion of dead trees in miombo, acacia, and mopane woodlands in 1972 averaged 32% (the range
was 22–48%)
■The proportion of trees converted to shrubs averaged 30% (range: 12–45%)
■The decline in woody biomass in miombo woodland between 1974 and 1978 was estimated at 46.4%
(23 023 kg to 12 585 kg per ha).
Mana Pools National Park
■Of 124 baobab trees monitored at monthly intervals over 4 years, 29% died as a result of elephant damage.
Changes in elephant numbers in
countries south of the Kunene–Zambezi
rivers (1900–2000)
Country 1900 2000
Botswana < 800 c. 120 000
Mozambique < 500 c. 3 500
Namibia < 500 c. 14 000
South Africa 150–200 c. 15 000
Zimbabwe < 4 000 > 100 000
Total < 6 500 c. 250 000
Left: Elephants in a mature
Faidherbia albida
woodland,
Mana Pools National Park, Zimbabwe.
Photograph: Tim Wellington
Above: San painting of an elephant, in Chikupu cave about
50 km north of Harare.
Photograph: David Cumming
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euphemistically referred to as ‘problem
animal control’ and errant crop-raiding
elephants were increasingly hunted
down and shot. The meat from animals
killed in control operations provided
some compensation to villagers for
their loss while governments retained
the ivory.
Within protected areas, elephant
populations grew at about 5% per year
with a doubling time of 12 to 15 years.
Outside protected areas, elephant range
shrank as rural populations and
agriculture expanded, with elephants
being displaced into protected areas.
The result was rapidly escalating
densities of elephants within protected
areas and increasing human–elephant
conflict on park boundaries.
By the early 1960s, the impact of
elephants on woodlands in several
national parks in the region became a
concern. Studies revealed high
mortalities of mature trees combined
with minimal replacement of canopy
trees. By then, elephant densities had
reached or exceeded 1 elephant per 2.5
km2. In some habitats, opening the
canopy encouraged grass growth,
which in turn resulted in higher fuel
loads and hotter fires causing further
woodland damage. In the early 1970s,
in Zimbabwe’s Chizarira National Park,
for example, Brachystegia boehmii trees
were ring-barked or felled by elephants
at the rate of 21% per year. The
outcome was that, in six years,
elephants had removed the woodland
over large areas of the park. Similar
effects occurred elsewhere in the
Zambezi Valley escarpment in
Zimbabwe and, by 1994, 88% of
miombo woodland within protected
areas had been severely affected.
Culling started in Hwange National
Park in 1965 and in Kruger National
Park during 1967, followed by regular
annual culls in several national parks in
Zimbabwe where elephant numbers
were considered to be too high. The
tusks and hides were recovered while
the meat was dried and sold to nearby
communities. Tusks and hides
supported local ivory carving and
leather manufacturing enterprises.
Substantial revenue also came from the
safari hunting of elephants and more
than 90% of the revenue earned in
Zimbabwe’s CAMPFIRE programme*
came from elephant trophy hunting.
Safari hunting of elephants also
developed in Botswana.
Countries in southern Africa
responded in different ways to the
‘elephant problem’. Zimbabwe
continued culling until the late 1980s.
The Kruger National Park culled
annually until 1994. Namibia conducted
a single pre-emptive cull during a
drought year in Etosha National Park,
where the population has grown slowly
and appears to be regulated by anthrax.
Botswana did not cull at all.
In Mozambique, populations were
greatly reduced during the 20 years of
civil war (1974–1994).
In retrospect, the region’s countries
provided what were in effect large-
scale experiments in managing
elephants, from which we can draw
useful conclusions.
• Elephants are remarkably robust and
in several parts of the region they
recovered rapidly. The only
protected sub-population to become
extinct was the very small herd in
the Tsitsikamma forest, near Knysna.
Southern Africa now has at least six
separate populations larger than
5 000 animals (one population
exceeds 150 000). Elephants are
clearly no longer an endangered
species in the region.
• Controlled harvesting of elephants
and the legal ivory trade did not
prejudice elephant conservation in
southern Africa.
• No elephant populations or
ecosystems have collapsed, either as
a result of culling or from non-
intervention strategies.
• Elephant populations at densities
greater than 1 per 2 km2where
rainfall is low reduced some types of
woodland to shrubland over large
areas. Where elephant ranges were
16 Quest 1(4)2005
Feeding and foraging
■The elephant is a large, generalist herbivore.
■Adult bulls may weigh as much 7 500 kg. The average weight of an elephant in a typical population is taken
to be 1 725 kg.
■Adults eat 50–150 kg of plant material a day.
■During the wet season, elephants feed mainly on grass and, during the dry season, increasingly on woody
plants – taking leaves, twigs, and even branches.
■An adult bull may knock over as many as 1 500 trees in a year.
■Elephants walk, on average, about 12 km a day
■The pressure of their feet on the ground (in kg per cm2) is similar to that of a 5-kg dik-dik but, because
elephants take relatively shorter steps, they trample a greater area per unit distance walked than
smaller animals do.
How elephants affect species diversity
■There are remarkably few studies on this important topic.
■In the succulent thicket of the Eastern Cape, a 1994 study found that elephants and goats greatly
reduced the diversity of
Mesembryanthemum
species.
■In miombo woodland in the Zambezi escarpment, a 1994 study found reduced diversity in trees, birds
(particularly arboreal birds), and ants in woodlands affected by elephants compared with adjacent intact
woodlands.
■In the Chobe river front, a 1995 study found no marked effects on bird species diversity where
woodlands had been heavily affected by elephants.
■A longer-term study (in 2004) of elephants and ecology of the Chobe river front also found little evidence
of species loss resulting from marked changes in the structure and composition of the riparian zone.
* The CAMPFIRE programme was set up to benefit local communities who bear the costs of living with wildlife.
An aerial photograph of the southern boundary of
Mana Pools National Park taken in May 1996. The miombo
woodland in the park, to the right of the fence that was
erected in 1968, was removed by elephants and fire.
The neighbouring unoccupied communal land with intact
woodland (to the left of the fence) was largely free of
elephants and subjected to early burns.
Photograph: David Cumming
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not confined by fences, however,
impacts on vegetation seem to have
been less marked.
• Trophy quality has been
maintained, if not improved, in
safari hunting areas.
What now?
The Kruger National Park suspended
culling in 1994, since when the
elephant population has nearly
doubled. If southern Africa does not
contain elephant population growth,
we can expect to have 400 000
elephants in southern Africa by 2020.
This scenario would amount to carrying
out a single large-scale experiment
across the entire elephant range of the
subcontinent.
The current debate centres on three
main areas of concern: the ecological
impacts of elephants in ecosystems, the
socio-economic effects of alternative
choices about elephant management,
and the moral and ethical issues related
to killing elephants.
Ecological impacts of high and
increasing elephant densities. A central
question is “What impacts will the
continued growth of elephant
populations have on plant and animal
communities and the conservation of
biodiversity in areas that have a legal
mandate to conserve biodiversity?” A
corollary is “What are the long-term
impacts on ecosystem processes,
resilience, and ultimately on
biodiversity, of curtailing or reducing
elephant population numbers?”
The paradigms guiding ecological
research and the management of parks
have evolved over the last 40 years.
Early on it was believed that nature
naturally preserved a state of balance or
equilibrium. Now we hold the more
dynamic view that ecosystems are in a
continual state of flux both spatially and
temporally. They are complex, adaptive
systems that may shift between
alternative stable states – as, for
example, between grassland and
woodland, depending on fire,
herbivory, and the influence of external
drivers such as rainfall. In keeping with
this paradigm shift, the Kruger National
Park has taken the lead in embracing a
paradigm of managing for
heterogeneity.
The evidence regarding effects of
increasing elephant densities on
ecological processes and biodiversity is
interpreted in different ways. One
argument claims that the present rise
in elephant populations is simply a
return to earlier conditions and part of
longer-term spatial and temporal
dynamics, but it takes no account of
the extent to which humans and
livestock now dominate the region and
where wildlife forms only about 10%
of the total large herbivore biomass.
Furthermore, the ecological impacts of
containing elephant population
eruptions have also not been
examined critically. We urgently need
experimental research in the study of
elephant–habitat interactions.
Economic and social consequences of
unrestricted elephant population growth.
The social and economic consequences
of alternative elephant management
strategies have been almost entirely
neglected. Key questions include “What
social and economic benefits are being
lost by communities, land owners,
countries, and the region by not
harvesting elephants on a sustainable
basis?” “What are the opportunity costs
of allowing unrestricted growth of
elephant populations?” Or, alternatively,
“What are the benefits and costs of
differing management strategies for
elephant?” These are not trivial
questions. A harvest of 5 000 elephants
from a population of 200 000 elephants
could generate US$40 million a year –
enough to protect and manage 200 000
km2of protected area at a rate of $200
per km2. National parks in Mozambique
and Zimbabwe are currently operating
on budgets as low as about $5 and $10
per km2, respectively.
Moral, ethical, and humanitarian
values regarding animal rights and
the rights of elephants. Is the killing of
sentient mammals such as elephants
morally right and defensible in the
21st century? Alternatively, is it morally
right to deny rural communities and
land owners in Africa the right to kill
and use elephants and their products
to better their lives and, in so doing,
maintain wild land in the face of
pressures from expanding agriculture
or other land uses? Or, is it wrong for
national parks and protected areas to
maximize economic returns from
elephants so as to conserve better a
full range of biodiversity within the
protected areas for which they are
responsible?
The ecological and economic
questions can be examined and
analysed scientifically. But, ultimately,
management decisions have to do with
public choice, governed by the world-
views and the values of those who
influence and take decisions. Science
can, nevertheless, contribute to the
moral and ethical debate through
research on such matters as sentience
in non-human animals, or the effects of
alternative management regimes and
actions (or lack of them) on stress and
suffering in the animals or animal
populations concerned.
In considering what’s involved in
conserving and managing elephant
populations, we’re no longer dealing
simply with managing the numbers of a
single species. We are instead dealing
with a complex social-ecological system
at scales that range from the local
habitat patch and rural household to
the international platform. The science
involved spans many disciplines and
cultures – from normal hypothetico-
deductive ‘hard’ science, to inductive
and more inclusive science, and the
multidisciplinary integration of science
into the political arena. ■■
Dr Cumming has been involved in elephant
conservation and management since the
mid-1960s. Formerly Deputy Director in
Zimbabwe’s Department of National Parks
and Wild Life Management and Programme
Director for WWF’s Southern African
Regional Office, he now works as an
independent scientist and is a research
associate at the Tropical Resource Ecology
Programme at the University of Zimbabwe.
Quest 1(4)2005 17
Ground photographs, taken in November 1994, show the
contrast between the vegetation on either side of the fence
line on the southern boundary of Mana Pools National Park.
The miombo woodland (above) was in an area largely free of
elephants and the picture below was within the park.
(See aerial photograph opposite.)
Photographs: David Cumming
For more, read J.C. du Toit, K.H. Rogers, and H.C. Biggs (eds.),
The Kruger
Experience: Ecology and management of savanna heterogeneity
(Washington: Island Press, 2004); P.A. Jewell, S. Holt, and D. Hart (eds.),
Problems in Management of Locally Abundant Wild Mammals
(New York:
Academic Press, 1981); D.H.M. Cumming, M.B. Fenton,
et al
., “Elephants,
woodlands and biodiversity in southern Africa”, in
South African Journal of
Science
, vol. 93 (1997), pp.231–236; C.Skarpe, P.A. Aarestad,
et al
., “The
return of the giants: ecological effects for an increasing elephant
population”, in
Ambio
, vol. 33 (2004), pp.276–282; and D. Western and
D. Maitumo, “Woodland loss and restoration in a savanna park: a 20-year
experiment”, in
African Journal of Ecology
, vol. 42 (2004), pp.111–121.