PROJECT: SAMANGO MONKEY ROAD KILL MITIGATION IN THE SOUTPANSBERG, SOUTH
AFRICA
The samango monkey (Cercopithecus albogularis) is South Africa's only exclusively forest dwelling
primate representing the southernmost extent of the range of arboreal guenons in Africa. In South
Africa the species distribution is closely correlated with distribution of Afromontane, Coastal and Scarp
forests. Forests are South Africa’s smallest, most fragmented and most vulnerable biome and samango
monkeys play an important role dispersing seeds of many forest plants. In the Red Data Book of the
Mammals of South Africa, the samango is listed as Vulnerable and is considered rare. The samango
population in the study area represents the northernmost population of the species in the country
and is considered to be completely isolated from samango populations further south.
A threat assessment has
shown that one major
threat to samangos in
the area are provincial
roads, specifically one
stretch of ~30 km tar
road. Forests in that
particular area extend
down the southern
slopes of the mountain
and are bisected by this
road. Since June 2012
17 road killed samangos
of all age and sex classes
were collected and
more than a dozen road
crossings
were
observed.
A solution to this problem could be the establishment of road crossing structures, more specifically
canopy bridges that allow safe road crossing for
samangos. Canopy bridges for arboreal
animals have been trialed in Australia, Brazil,
Kenya and Madagascar and have shown
promising results for primates, porcupines
and opossum species.
In order to establish a suitable bridge design
for samango monkeys we are conducting
experiments on habituated samangos at the
Lajuma Research Centre. Parameters tested
are 1) solid pole bridge versus flexible rope
bridge and 2) different levels of vegetation
cover over the bridges. The effectiveness of
the bridges is evaluated through direct
behavioural observations. Preliminary results
show that the samangos prefer using a solid
pole canopy bridge design (99.6% of crossings)
over a flexible rope bridge design. Results of
behavioural data collected show that sub-adult individuals and adult females were most likely to use
bridges when crossing the road, juvenile samangos preferred crossing the road in the tree canopy and
adult male samango monkeys mostly crossed roads on the ground. Further, the results showed that
bridges partially covered with vegetation were used more frequently than uncovered bridges and that
the more vegetation cover over the bridges, the more likely the monkeys were to cross the roads using
the forest canopy. Results from the experiments will be used to design the most suitable and costeffective bridge prototype for erection at the actual road kill hot spots.
This is a collaborative project between the University of Venda, Lajuma Research Centre and the
Endangered Wildlife Trust.
For more information, contact Bibi Linden on [email protected]