Brown
Hyena Movement, Behaviour and Abundance, and Implications for their Long-term
Conservation within the Sperrgebiet
This project aims to
intensively investigate the effects of diamond mining activities on the brown
hyena population in the southern coastal
Brown hyenas are one of the
SKB flagship species. Their occurrence within this biome, an internationally
recognised biodiversity hotspot, is of extreme importance, especially as
numerous large mammal species in this area have become extinct.
The Sperrgebiet
supports four mainland seal colonies. These provide a permanent, concentrated
food source and are essential for the maintenance of a healthy and viable brown
hyena population as other food items are scarce. Brown hyenas are the apex
predators along the coast and fill the highest trophic
level in the food chain, as other large predators are absent and as they feed
and prey on marine predatory mammals. This unique predator-prey ecosystem is
influenced by new and existing land development.
In this study we (a) survey
home range size, habitat use and activity patterns through GPS telemetry of
coastal brown hyenas, (b) determine changes in behaviour through the analysis
of GPS data in the area most likely affected by mining disturbance, and (c) gain
spatial information (e.g. about location of core areas). The goal is to provide
information about brown hyena behavioural ecology and the sensitive nature of
their predator-prey ecosystem to reduce long-term threats and impacts posed by
land use.
Human
wildlife conflict with spotted hyenas around the Sperrgebiet
boundary
This
project aims to study the spotted hyena population in Garub
area in the south-eastern corner of the
Spotted
hyenas were first reported in the Garub area at the
beginning of the 1990s. It is assumed that they migrated into this area from
the north, following the game species during a period of extreme drought. Since
then, incidental sightings around the mountain Dikwillem
and at the water trough at Garub have been recorded
and occurrences of spotted hyena roadkills on the tar
road between Aus and Luderitz indicate that it is a
resident population. Farmers also reported sightings of spotted hyena spoor,
although it cannot be excluded that some of these spoor were of brown hyenas.
The BHRP distributed a carnivore and livestock related questionnaire to farmers
in the buffer zone around the Sperrgebiet and
·
Carnivores contributed
considerably to cattle, calve, sheep and goat mortality (up to 70% of the
losses)
·
Brown and spotted hyenas were
considered a low threat, spotted hyenas occasionally a high threat to livestock
·
One brown and one spotted hyena
were killed on farmland in 2003
·
All carnivore related cattle
losses were attributed to spotted hyenas
·
40% of the farmers would not
tolerate spotted or brown hyenas on their farms
These
results highlight the necessity to carry out a first study on the spotted hyena
population in this area and also to look at the interspecific
relationship between both hyena species.
The
objectives of the project are to gain detailed data about spotted hyena
abundance and distribution, and to evaluate true conflict with humans in the
area surrounding the Parks.
The
analysis of scat samples will give insight into the spotted hyena’s diet and
will provide baseline information about whether livestock is consumed. Stable
isotope analysis of hair samples of the captured hyenas, their potential prey
species and the investigation of bone material found at den sites will give
further insight into their feeding ecology.
GPS
and VHF telemetry will provide data to estimate home range sizes and the
analysis of their movements will indicate the frequency of possible conflict
with humans on adjoining communal and farmland.
The
brown hyena clans that have been studied by the BHRP so far, do not interact
with the spotted hyena population around Garub, and
the comparison of those brown hyena clans with the clan around Garub is of basic ecological interest for the conservation
of brown hyenas along the boundary fence of the Sperrgebiet.
Competition with spotted hyenas may either be positive, as their predatory behaviour may provide brown hyenas with additional carrion,
or negative, as they may compete for the same niche.
Spotted
hyena clan structure, foraging and hunting behaviour
depends largely on the habitat, and the Garub spotted
hyenas might show a different structure and behaviour
than the ones in, for example, Etosha National Park.
The data obtained with this study will allow a first comparative study with
other Namibian spotted hyena populations.
Carnivore
conflict with humans often results in financial losses. Nevertheless it is
often difficult to attribute certain livestock losses to specific carnivores
and objective monitoring is therefore of major importance to be able to
mitigate the conflict. At present spotted hyenas are mostly not tolerated
outside protected areas. It is basically unknown, whether the Garub spotted hyenas really pose a threat to livestock on
adjoining farms, and their present persecution may be without reason. The
results of this study will contribute to the general understanding of the Garub spotted hyena ecology and behaviour
and will give background data to be able to discuss conflict issues with the
affected parties.