Walia Special Edition on the Bale Mountains (2011) - Zoologische ...

Transmission risk
Clearly, disease transmission between wild and domestic stock will be minimised if domestic stock
do not encroach the park and this is the primary management measure that must be adopted from
a disease control perspective. Indeed, since this study took place, law enforcement efforts and
cooperation between local communities in the Gaysay area and park authorities have increased and
thus by 2010, domestic stock were only rarely found grazing inside the park in this area, although
large numbers still transit, particularly on market days. The decrease is grazing on the Gaysay
grasslands will have reduced the probability of disease transmission in the high wildlife density of
Gaysay.
Nevertheless, a number of factors mean that contact and transmission risk can now never
be completely removed in the Bale Mountains. First, as this study has shown livestock still traffic
through the park in the Gaysay area and this has increased since the 1980s. Second, despite a
decrease in wildlife grazing inside the Gaysay area, the last decade has seen a significant increase
in livestock numbers in other areas of the BMNP, such as the Web Valley (Vial 2011) or Harenna
forest (BMNP unpublished data), where mountain nyala, warthog or other wild ungulates are also
recorded, at varying densities. Third, there is a high density of humans and their livestock in the
area immediately around the park and both wildlife and livestock co-exist in many of the woodland
or forest areas around the northern park extension either in common land, hunting concessions or
in new participatory forest management areas. Fourth, even where laws are respected and enforced,
livestock graze right up to the park boundary, resulting in a hard edge and close wildlife-livestock
proximity. Some pathogens, particularly viruses, such as foot and mouth disease, are transmitted by
fomites or aerosol and thus can spread without direct contact and over long distances. Finally, wild
ungulates also often leave the park area where there is a hard edge at night, as we frequently saw
mountain nyala and warthog in particular leaving the park at Dinsho after nightfall. Mountain nyala
are also known to eat farmers’ crops in this area. Thus overall, even if all laws are respected and
there is no grazing of domestic animals inside BMNP, the co-existence of wildlife and livestock in
the Bale Mountains will persist.
Management recommendations
Overall, although we have demonstrated the potential for ungulate disease transmission in the Bale
Mountains, we consider the current probability of a major outbreak, with significant wildlife mortality,
to be relatively low. The current major diseases of livestock, which have high pathogenicity, are
generally controlled in livestock in this area of Ethiopia. Nevertheless all efforts should be made to
minimise the chance of a major outbreak occurring and we recommend the following.
Effort should be focused on improving disease control and surveillance in domestic animals,
through national or international schemes. Thus the diseases posing the highest risk to wildlife should
be controlled in their domestic hosts and if outbreaks did occur in livestock, these can be quickly
detected and control measures put in place. This will require long term human and institutional
capacity building and fostering links with national and international organisations.
<strong>Walia</strong>-<strong>Special</strong> <strong>Edition</strong> on the Bale Mountains 279