Elephants are water-dependent, and drink up to 200 litres per
day. An adult elephant may consume up to 170 kg of browse
and grass per day, largely perhaps because its digestive ability is
so low: only 40% of what is ingested. It is this appetite that has
produced the ‘elephant problem’
In 1991 the total area utilized as elephant range comprised of
2.1% of the country and of these 75% where situated in one
Reserve namely Kruger National Park which was habitat to
85% of all the country’s elephants. The remaining 25% were
13% other national or provincial reserves and only 12% was
privately owned. (Guldemond & van Aarde, 2007)
1.2.2 Elephant impacts on biodiversity/ecosystems
“Not only have elephants got huge appetites, but one of their
methods of feeding causes great concern for wildlife managers.
Older elephants, particularly bulls, strip bark from trees, break
branches, and frequently push over the smaller trees. Culling
was seen as the answer to the elephant problem, and in the
1960s such population reduction exercises were started in
Uganda, Zambia, the then Southern Rhodesia, and South
Africa”. (Mundy, 2006:p590-591)
Elephant herbivory has been the objective of many studies, and
as have been shown in some of these studies, elephants at high
densities do negatively affect biodiversity (Cumming et al 1997,
Western & Gichohi 1989). Coetzee et al. (1979) have already
then reported a decline in Sclerocarya birrea (Marula trees) in
the Satara area of KNP. — Up to 13% of Marula trees larger than
5m have been lost due to destructive damage by elephant.
Eckhardt ef a/ (2000) reported significant decline in large trees
in both the granites and basalts of the KNP.
From research done by (Hiscocks, 1999) and (Johnson et al,
1999) it is clear that elephant do have a preference in their
palate and that they prefer certain vegetation species above
others. The following is a consensus of plant species that are
preferred by elephants and also occur in all four the selected
study areas: Sclerocarya birrea (Marula tree), Terminalia
sericea, Dichrostachys cinerea (Sicklebush), Acasia nilotica,
Acasia sieberana, Acasia robusta and Acasia burki. One aspect
that can be deduced from this list is that the Acasia spesies are a
favourite with elephant.
1.3 Elephant Management Plans
To successfully manage elephants, managers of conservation
areas require knowledge about the rates at which their elephant
populations may grow and what number and structure of re-
located elephant population will be best their long-term
conservation needs. (Mackey, Page, Duffy & Slotow, 2005)
Even before the Norms and Standards for elephant management
was made into policy (DEAT, 2008) KNP developed a new
elephant management policy which differed from the old one in
that the elephant population will be managed according to
measured impacts on biodiversity rather than on absolute
numbers of elephants (carrying capacity).
Managers of conservation areas are concerned that high
elephant densities will harm biodiversity by degrading
ecosystems (Owen-Smith, 1996; Whyte et al, 2003;
Guldemond & van Aarde, 2007). Culling, translocation and
birth control are short term solutions and are ethically frowned
upon (van Aarde et al., 1999; Pimm & van Aarde, 2001).
The size and structure of a reserve’s desired elephant population
will depend on the objectives of that reserve; for example, a
reserve being managed for the conservation of biodiversity will
want fewer elephants than a similarly sized reserve that stocks
elephants for tourism or consumptive use. (Mackey et al, 2005)
14 Role of Remote Sensing in Reserve Management
To understand the dimensions of the problem that conservation
managers face, Yough & Van Aarde (2011) did research on the
practises of the conservation managers in developing an
‘elephant management plan’ as prescribed by the DEAT policy
(2008) .Of the 30 managers interviewed, all but one viewed
science as an important basis for making decisions on elephant
management and the maintenance of biodiversity.
Remote sensing, as a relatively new science, is seen as a useful
instrument to assist conservation managers with the
development and implementation of their respective elephant
management plans.
When using satellite imagery the following aspects need to be
considered with the elephant population management as well as
general biodiversity base line studies and ecological assessment.
e Mapping the vegetation types and possible changes in
biodiversity with regards to specie richness.
e Mapping and detecting the changes that have occurred
over time.
e Mapping possible “refugia” sites for endangered species
in the Park as well as the changes in the thicket patch
and woody canopy sizes over time.
e The possibility of identifying biomass (for carrying
capacity and carbon sink potential) using satellite data.
e Cost implications of the data needed as well as image
analysis needed in order to get results.
2 STUDY AREAS
Kruger National Park as flagship reserve in South Africa is (and
has been) the focus of research for many years and by many
different researchers, not only from South Africa but also from
foreign researchers as far afıeld as the USA, Scandinavia, the
UK and even other parts of the world. With all this interest on
the largest conservation area there is unfortunately a severe lack
of attention on the medium and smaller reserves and parks in
South Africa, both private and government owned. This study
focuses on four medium sized reserves (+ 300km”) listed in
Table 1.
Table 1: Four study areas with elephant populations and
densities
Conservation Current Elephant Date of re-
Area Population (density | introduction of
(size in km?) elephant/km?) Elephants
Tembe 156 1991 (enclosed)
Elephant Park (0.52)
(300)
Ithala Game 104 1990
Reserve (298) (0.35)
Marakele 118 1995
National Park (0.31)
(380)
Welgevonden 124 1994
Private Nature (0.38)
Reserve (330)
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