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Abstract

At the start of 2018, the United Nations estimated that world population had reached 7.6 billion. Today, there are few untouched natural habitats left, where wildlife can live without crossing paths with humans and our activities. Linear infrastructures, such as roads, are rapidly proliferating all over the world.
FEATURE
JURUTERA SEPTEMBER 2018
26
THE INSTITUTION OF ENGINEERS, MALAYSIA
Elephants, Roads and Drivers:
Case Study of Gerik-Jeli Highway
At the start of 2018, the United Nations estimated that world population had reached 7.6 billion.
Today, there are few untouched natural habitats left, where wildlife can live without crossing
paths with humans and our activities. Linear infrastructures, such as roads, are rapidly
proliferating all over the world.
Vivienne Loke Alicia Solana-
Mena
Dr Pazil bin
Abdul Patah
Salman Saaban Dr Ahimsa
Campos-Arceiz
Dr Wong Ee
Phin
Jamie Wadey Dr Vivek
Thuppil
Nasharuddin
Othman
Southeast Asia, in particular, is
undergoing rapid economic growth
and experiencing a massive,
unprecedented expansion of road
coverage. This is also the region
with a large number of threatened
megafauna, such as elephants, tigers,
and tapirs. The largest terrestrial
animal in Asia, the Asian Elephant
(Elephas maximus), is already
endangered due to the rapid decline
in its population, due mostly to habitat
loss and the resulting human-
elephant conflict in the form of crop
raidi ng (Fernando & Pastorini, 2011). The
expected infrastructure development
over the coming decades will most
likely further threaten elephants and
other megafauna in the region.
Roads affect animal behaviour,
movement and distribution. Roads
also affect wild habitat by modifying
the environmental conditions in their
vicinity, for example, by allowing
more sunlight to penetrate to the
ground and altering humidity and
temperature. This is known as the
“edge effect” and the result is changes
to plant and wildlife populations as
well as community structures in areas
bordering roads and in other habitat
fragments.
Roads impede wildlife movement
and ability to use resources in the
habitat. On a larger scale, roads
can reduce landscape permeability
and connectivity b y a c t i n g a s
barriers that cause fragmentation
and isolation of wildlife populations.
Small populations are usually more
vulnerable to local extinction due to
inbreeding and stochastic events.
Elephants are particularly
susceptible to landscape changes
and the effect of roads as barriers.
They are intelligent and sentient
beings with a high attachment to
traditional and very large home
ranges. Adult females, especially
the matriarchs, store in their memory
intricate details of the lan dscap es,
including movement routes that
have paid rich dividends in the
past (e.g. they remember where
to find resources such as salt-licks,
fruiting trees, grasslands and water).
This perhaps explains why general
patterns of elephant movements and
habitat use have remained relatively
unchanged for more than a century
when one compares Sanderson’s
(1878) description of elephant
movements with a study conducted
by Sukumar (1989) in the same region
of southern India.
Peninsular Malaysia is an important
stronghold for wildlife, including Asian
Elephants (Salman et al., 2011) .
Development has led to many land
use changes in the country. The
peninsula has lost its forest cover from
nearly 80% in the 1940s to less than
Figure 1: Map showing the frequency of road
crossings by GPS collared elephants along the
Gerik-Jeli Highway
Legend
Crossing
Frequency Elephants 608
611
750
609
614
612
846
1017
1402
121
122
247
249
259
260
606
607
0
1-5
6-11
12-22
23-34
35-55
Lake
37% in 2010 (Miettinen, Shi, & Liew
2011).
Recognising the importance of the
country’s biodiversity and the dangers
of a “business as usual” approach,
the Malaysian Government has
developed legislation and policies
to protect its wildlife. The Central
Forest Spine (CFS) is a very important
national land-use master plan to
maintain habitat connectivity for
wildlife across major habitat patches
in Peninsular Malaysia (DTCP, 2009).
THE INSTITUTION OF ENGINEERS, MALAYSIA
FEATURE
JURUTERA SEPTEMBER 2018
27
Figure 2: Juvenile elephant killed in a car
accident on 16 June, 2017, along the Gerik-Jeli
Highway
Figure 3: A translocated elephant killed by
poachers for the tusks
The implementation of the CFS plan
involved the construction of several
viaducts under existing highways
to facilitate wildlife crossing. The
conservation of Asian Elephants
in the peninsula is guided by the
National Elephant Conservation
Action Plan (DWNP, 2013). Scientific
evidence from research will greatly
help the implementation of these
national plans. Here we present
some of our on-going work on
understanding how a major road
affects the movements of elephants
in Belum-Temengor, a priority
landscape for elephant and tiger
conservation.
COMPLEX EFFECT OF ROADS
ON ELEPHANTS
Our study (Wadey et al., 2018)
used GPS telemetry data and a
mechanistic movement modelling
framework to understand when
and where wild elephants crossed
the Gerik-Jeli Highway, a 120km
long road that bisected the Belum-
Temengor Landscape (BTL, Fig. 1).
The highway is fully asphalted,
with a width of 2-3 lanes (~25 m), and
often has additional structures such
as steel and concrete barriers as well
as concrete drains along its sides.
Between 1970 and 1995, the forest
reserves that run parallel to the road
were heavily logged.
Wadey et al., (2018) monitored
17 wild elephants (10 local and 7
translocated from conflict areas) and
found that local elephants crossed
the road 14 times more frequently
than translocated ones, indicating
that familiarity with the landscape
was important for elephants (Fig.
1). Elephants also crossed the road
predominantly at night (81% of
crossings were between 7.00 p.m.
and 7.00 a.m.), when traffic density
was lower. A study done in India found
that Asian Elephants crossed roads in
a wildlife sanctuary in order to get to
a water source during the dry season,
but they also showed higher levels of
agitation in response to disturbance
from vehicles (Vidya & Thuppil,
2010).
The Malaysian study also found
that the Gerik-Jeli Highway acted
as a strong barrier to elephant
movements, with an 80% reduction in
permeability.
However, the relationship
between elephants and the road
is very nuanced and although the
road seriously disrupts elephants’
availability to move from one
side to the other, it also acts as an
attractor as elephants spend a lot of
time feeding on the abundant fodder
on the roadside.
In another study in the same
landscape, we found that elephants
staying near the Gerik-Jeli Highway
were able to consume more of their
preferred food, such as grass and
other early succession plants, while
elephants far (> 5km) away from the
road had to consume more woody
plants (Yamamoto-Ebina et al.,
2016) .
Asian Elephants are known to be
edge specialists (Campos-Arceiz,
2013) and so they are attracted
to the roadsides. They are often
labelled as mega-gardeners of
the forest due to their important
ecological role as agents of seed
dispersal (i.e. they consume large-
seeded fruits like mango and
durian and disperse the seeds in
new places for the next generation
of trees to grow; Campos-Arceiz &
Blake, 2011). Given that the road
affects their diet and movements,
elephants that stay near the
road end up consuming a much
simpler diet, with less wild fruit and
they disperse seeds over shorter
distances than elephants living in
the primary rainforest.
The steady increase in traffic
volume (~4% annually between 2005
and 2014; MoWM, 2014) along the
Gerik-Jeli Highway can eventually
deter elephants from crossing the
road altogether, majorly impacting
habitat connectivity between
Belum and Temengor. In 2017,
two elephants, a juvenile and a
sub-adult, were killed in a collision
with a vehicle on this highway
(Fig. 2).
In addition, two of the nine (22%)
males we tracked in the Belum-
Temengor landscape were poached
for their ivory (Fig. 3) within 3 km
from the road. The BTL is considered
one of the hotspots for poachers.
According to WWF-Malaysia (2011),
there are at least 80 access points
which facilitate poaching along
the 120km highway in BTL. The road
has become what is called an
ecological sink (or ecological trap)
because elephants are attracted by
the abundant food but also suffer
negative effects on their movements
and safety due to collisions and
poaching.
VIADUCTS, DRIVER BEHAVIOUR
AND MITIGATING THE IMPACT
OF ROADS
Towards the end of our study, the
Malaysian Government had
constructed a wildlife viaduct along
the Gerik-Jeli Highway. Our elephant
movement data was collected prior
to the establishment of the viaduct
and we cannot, therefore, judge its
effectiveness, although before the
viaduct construction we detected
FEATURE
JURUTERA SEPTEMBER 2018
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THE INSTITUTION OF ENGINEERS, MALAYSIA
A MEME’s satellite-collared elephant walking near the barrier along the Gerik-Jeli Highway
only one road-crossing event in that
area.
Follow-up studies are now
necessary to monitor the movement
of elephants near the viaduct to
assess its effectiveness in facilitating
landscape connectivity for elephants
and other wildlife. In any case, a
single viaduct across such a long
stretch of road is not sufficient to
provide landscape connectivity
for elephants. The viaduct should
therefore, be considered as part of
a suite of mitigation tools, rather
than as a silver bullet to maintain
permeability in the BTL.
Although much has been
discussed about green infrastructure
(e.g. viaducts), the role of infrastructure
user behaviour has been largely
neglected so far, in spite of its high
potential to mitigate the impact of
roads on wildlife.
The predominant determinant of
the risk of motorist-wildlife collision is
vehicular speed. Reducing speed,
either through speed limits or physical
barriers such as speed bumps, will
go a long way towards reducing
collisions. The enforcement of low
speed limits in wildlife habitats should
therefore be a priority. But even when
motorists adhere to speed limits,
collisions with wildlife can still happen
when motorists fail to perceive and
react to the presence of wildlife.
When motorists do not anticipate
encountering hazards, such as in
rural and forest areas, they are prone
to “inattentional blindness” (i.e. failure
to perceive something that exists in
their field of vision). This means that
while motorists “see” an animal on the
roadside, their brains fail to “perceive”
it, so the motorists will either not react
or react only when it is too late. The risk
increases if motorists are driving faster
in rural and forest areas than they
usually do in urban areas.
Inattentional blindness can
also occur when the driver is fully
engaged in focusing on stimuli
relevant to driving (e.g. other vehicles
on the road) and does not perceive
an additional stimulus (e.g. wildlife on
the roadside). Cognitive psychology
has identified that it is easier for us
to detect an additional stimulus that
shares features and characteristics
with the task at hand than it is to detect
a vastly different stimulus. For example,
studies have shown that drivers
perceive pedestrians and animals
more readily in an urban context as
opposed to a rural context (Palmer
& Blink, 2013), implying that drivers
may associate non-urban driving
with hazard-free smooth driving. This
is indeed a problem when it comes
to motorists driving through forested
areas with wildlife crossing the road!
To overcome inattentional
blindness, one possible intervention
is to provide artificial stimuli at the
start of the highway (e.g. a life-size
elephant statue and sound) to prime
the motorist’s attention towards
wildlife presence in the area. After
priming, the driver should be more
likely to self-regulate the driving
speed and spot wildlife by the road,
thereby avoiding collisions. This might
help to reduce vehicle accidents,
save human lives and avoid
wildlife roadkills. Additionally, where
appropriate, traffic management
during the night may help mitigate
the loss of permeability of roads to
wildlife.
OUR RECOMMENDATIONS
To mitigate the impact of roads on
elephants and other wildlife, we
recommend the following:
1. Avoid expanding the number of
lanes on the Gerik-Jeli Highway
and the creation of new roads
in the BTL, as road expansion will
further reduce permeability.
2. Encourage responsible driving
behaviour on roads traversing
important wildlife habitats in
Malaysia. Consider the
implementation of psychological
techniques aimed at safer driving
by priming motorists to be more
vigilant about their surroundings
and to self-regulate their driving
speed.
3. Establish low speed limits and
enforce them through awareness
signs, speed bumps, speed
Elephants crossing the Gerik-Jeli Highway
THE INSTITUTION OF ENGINEERS, MALAYSIA
FEATURE
JURUTERA SEPTEMBER 2018
29
traps and fines to reduce road
accidents and wildlife roadkills.
Consider managing traffic volume
at night.
4. Consider habitat management
(e.g. long-term reforestation)
near the road to reduce grass land s
and avoid the concentration of
elephants on roadsides.
5. Monitor the effectiveness of the
viaduct on habitat connectivity
for elephants and other wildlife.
6. Implement extensive enforcement
patrolling and other anti-poaching
efforts along highways and roads
bisecting forested areas, especially
at viaducts and areas frequently
used by wildlife.
7. Recognise the Belum-Temengor
Landscape as an important
elephant habitat that should be
treasured and promoted as part
of the country’s natural heritage.
CONCLUSION
Our research highlights the
importance of considering the
impact of infrastructure development
on megafauna and other wildlife,
especially in South East Asia, a region
with a large number of threatened
megafauna and with large-scale
infrastructure development plans
for the coming decades. Instead
of working in silo, engineers, wildlife
biologists and psychologists should
work together to develop creative
solutions to help conserve the
rich biodiversity for our future
generations.
A family of elephants in the forest within Belum-
Temengor Landscape
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... The viaducts are part of the larger Central Forest Spine (CFS) project (DTCP, 2005) to connect fragmented forests in Peninsular Malaysia. A total of three wildlife viaducts project were established in 2006 to act as safe highway crossing points for wildlife within forest complexes in Hulu Terengganu , three viaducts have been constructed and completed in 2014 along Kuala Lipis -Gua Musang highway to provide corridors for animals between Sungai Yu Forest Reserve and Tanum Forest Reserve which is connecting to Taman Negara (Suhaida et al., 2017), and viaducts built along the Gerik-Jeli Highway (Wong et al., 2018) to help elephants or other wildlife to crossroads. However, the initiatives mentioned have not been assessed thoroughly for their effectiveness. ...
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