The conservation of tigers and other wildlife in oil palm plantations

Figure 22 - Ranges for two wild pig (light and dark blue), tapir (black), tiger (orange) and sun
bear (purple) from radio tracking fixes. Circles denote capture points for each species.
Species focus: Sumatran tigers and oil palm
As the most endangered and high profile species found to occur on the plantation,
effort was concentrated on monitoring the local Sumatran tiger population and
attempting to determine how tigers were surviving so far from any protected areas.
Results are presented on various aspects of population dynamics, ranging ecology
and explanations of population change. They show tiger densities around the
plantation set-aside areas comparable to those in protected areas at the beginning of
the study, with tigers apparently using the plantation as part of their ranges which also
extended into the forest concession. However, tiger sign declined sharply in 2004,
coinciding with conflict over the conservation areas and the start of clearing by local
settlers. A large scale survey of the entire landscape conducted in 2005 found no
evidence of tigers in the plantation, no evidence of the original plantation tigers in the
forest concession and overall occupancy of the landscape was estimated at under 10%
with only three individuals recorded on camera.
Tigers on the plantation 2001-2002
Population size
At the beginning of the study, tiger evidence was abundant. Within the first two years
of the study, 113 photographs of 11 different tigers were taken in two areas of about
50km 2
each, with evidence of a further 5 cubs from direct sightings (cubs rarely
appeared on camera due to the delay built in to all camera-traps that means only the
first tiger in a group is usually photographed). Four tigers represented nearly 80% of
the photographs and these were considered resident. Converting trapping rates to
densities according to the methods of Carbone (Carbone et.al. 2001) estimated similar
densities of 10-17 tigers / 100km 2 over the two years. Results are summarised in Table
11 and Table 12.
34 Wildlife conservation in oil palm plantations