MAASAI MARA WILDLIFE CONSERVANCIES
ASSOCIATION
Recommendations for Wildlife Crossings along the
Narok – Sekenani Road in the Mara Ecosystem
_______________________________________________________________
A working paper prepared for the Narok County Government
Dr. Irene Amoke
August 2016
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EXECUTIVE SUMMARY
Kenya’s Vision 2030 outlines the government’s infrastructure plans with aspirations of
linking the country through a network of roads, railways, ports, airports, water and
sanitation facilities as well as telecommunications. In 2014, as part of the development blue
print, the national government announced plans to work with Narok County to tarmac the
85km road linking Narok town to the Maasai Mara National Reserve through the Sekenani
gate. Despite the Maasai Mara being Kenya’s most iconic wildlife destination, it has long
suffered from poor road access and it is widely accepted by all stakeholders that there is an
urgent need to upgrade this road. It has further been recognised that the road, if
constructed to internationally acceptable standards, stands to boost the image of the Mara
which is globally known for its epic wildebeest migration.
However, research has shown that roads and other infrastructure have the potential to
cause mortality in wildlife, severely disrupt their movement and increase the risk of local
extinctions, making it essential to recommend and implement appropriate mitigation
efforts. The Narok –Sekenani road traverses sections of the county’s former group ranches
which have during the past 10 years been subdivided into individually owned plots with
some forming part of the newly established conservancies. The land subdivision in these
former group ranches and the subsequent rise in land sales, mechanised agriculture, fencing
and the indiscriminate and unplanned mushrooming of market centres, in addition to
permanent human settlements, have already been shown as causing adverse impacts on the
ecosystem’s wildlife. Further adverse impacts are expected from the development of a
tarmacked road in this already fragile ecosystem, if mitigation measures are not
incorporated.
While infrastructural development is highly important to the county’s economy, it is
imperative that the impacts of these developments on the county’s flora and fauna are
taken into consideration, not least owing to Narok County being the home of approx. 25% of
Kenya’s wildlife. With the planned tarmacking of the Narok-Sekenani Road, it is important,
now more than ever, to understand the impact of infrastructure, specifically roads, on
wildlife.
This paper highlights the impacts of road construction on wildlife and describes how
innovative wildlife passes have been successfully utilized in different parts of the world to
mitigate the negative impacts of roads on wildlife. By locally adapting these designs
during the upgrade of the Narok-Sekenani Road, Narok County Government will be able to
meet its objective of creating access to the Mara whilst protecting the very resource
millions of tourists visit annually - its wildlife. Through this working paper, the Maasai
Mara Wildlife Conservancies Association (MMWCA) further recommends the engagement
of a consultant to undertake a comprehensive Environmental Impact Assessment (EIA) in
compliance with national regulations, and the identification of focal wildlife species or
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groups that utilise the road in order to identify the most suitable locations for wildlife
crossing mitigation.
Undertake a comprehensive Environmental Impact Assessment (EIA) in compliance with
national regulations
The National Environment Management Authority (NEMA) was established under the
Environmental Management and Coordination Act (EMCA) No. 8 of 1999, as the
government’s principal instrument in the implementation of all policies relating to the
environment. Section 3 of the Act states that “Every person in Kenya is entitled to a clean
and healthy environment and has the duty to safeguard and enhance the environment” and
is intended to ensure that our activities do not compromise the capacity of the resource
base to meet the needs of the present generation as well as those of future generations
(Government of the Republic of Kenya 2000).
Under the 2nd Schedule of the Act (s.58 (1), (4)), it is a requirement that all proposed major
roads undertake an EIA in which all significant effects or impacts on the environment
(including ecological impacts) are considered and measured, and if likely effects are
unacceptable, design measures or other relevant mitigation measures taken to reduce or
avoid these impacts. During the EIA process, the principle of public participation is applied,
where the public are given early and effective opportunities to participate in the decision
making procedures. The Act further tasks NEMA to “propose guidelines for the integration
of standards of environmental protection into development planning and management” and
to “identify and recommend policy and legislative approaches for preventing, controlling or
mitigating specific as well as general adverse impacts on the environment.”
Site identification and construction of wildlife crossings
According to (Ostlind 2010), long-distance animal migrations around the world are
disappearing due to habitat loss, developments blocking off corridors and people killing
wildlife due to conflict. He highlights the Greater Yellowstone Ecosystem, which is
connected to Trappers’ Point (Figure 3) through the movement of the pronghorn. In this
ecosystem, six of eight historic big-game migration corridors were blocked and are no longer
available to the animals that once relied on them, resulting in the deer, elk, bison, and
The Maasai Mara Wildlife Conservancies Association (MMWCA) therefore requests that
the following recommendations be adequately and fully implemented in order to ensure
that both wildlife and people are not adversely affected by the proposed upgrade of the
Narok –Sekenani Road and Narok County meets international standards of road
construction, befitting to its prominent role within Kenya.
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antelope restricted to isolated ranges where they are susceptible to harsh weather,
inbreeding, or disease.
As studies on the effects of roads on wildlife in Africa are limited, science-based evidence is
therefore imperative to mitigating the effects of roads on wildlife. Deciding where to locate
wildlife crossing structures requires adequate tools and resources to identify the most
suitable sites for these crossing structures (Clevenger and Huijser 2011). An important first
step is the identification of a focal species or group that utilise the road and recommending
the most suitable locations for wildlife crossing mitigation. Once a species is identified,
many of the resources listed in Table 1 below can be used to identify the best locations for
wildlife crossing mitigation. Bennett (2003) states that information concerning the spatial
scale of a species’ movements, its habitat requirements, diet, and other necessary resources
are important and will assist in managing habitats within any proposed linkages. Other
behavioural and ecological attributes, such as the ability to cross gaps, the level of tolerance
of disturbed habitats, the role of dispersal in the life-history, the age and sex of dispersing
individuals, and dispersal behaviour also determine the most effective type of linkage and
the ability of species to effectively use such links. He further notes that species that live in
groups or colonies generally require greater habitat area than do similar solitary-living
species and, therefore, may require broader habitat links to meet these demands for living
space. Linkages that encompass the requirements of the most ‘extinction prone’ species
will, in most cases, also be effective for the majority of more common species. For linkages
to be effective in maintaining continuity of ecological processes, the requirements of the
key species involved in such processes must be met.
Key words: Development, Impacts, Infrastructure, Maasai Mara National Reserve,
Migration, Mitigation, Narok County Government, Overpasses, Policy, Roads, Underpasses,
Vision 2030, Wildlife passes
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Table of Contents
EXECUTIVE SUMMARY ...................................................................................................... 2
Introduction ..................................................................................................................... 6
Impacts of Roads on Wildlife ............................................................................................ 6
The Greater Mara Ecosystem: A Background ..................................................................... 7
The Proposed Upgrade of the Narok – Sekenani Road ....................................................... 9
Potential Cumulative Impacts of Tarmacking the Narok-Sekenani Road .......................... 10
Positive Impacts .............................................................................................................. 10
Negative Impacts ............................................................................................................. 11
Mitigation Recommendations to Manage Adverse Impacts of Roads on Wildlife ............. 11
Wildlife Crossings ............................................................................................................ 12
Case Studies ................................................................................................................... 14
Case Study 1: Banff National Park – Alberta, Canada ....................................................... 14
Case Study 2: Mount Kenya Elephant corridor (underpass) - Kenya ................................. 14
Case Study 3: Trapper's Point Wildlife Overpass – Wyoming, USA ................................... 15
Case Study 4: Natuurbrug Zanderij Crailo - The Netherlands ............................................ 16
Case Study 5: Eco-Link@BKE, Singapore .......................................................................... 17
References ..................................................................................................................... 20
List of figures & tables
Figures
Figure 1: Map of the Mara – Serengeti Ecosystem showing location of the Mara Ecosystem .............. 8
Figure 2: Map showing Mara conservancies in relation to the location of the Narok-Sekenani Road 10
Figure 3: Wildlife overpass in Banff National Park. Joel Sartore (Amusing Planet 2015) .................... 14
Figure 4: Elephants using the Mt. Kenya underpass. Associated Press (Amusing Planet 2011) .......... 15
Figure 5: Development of Trapper's Point Wildlife Overpass (Contech Engineered Solutions 2013) .. 16
Figure 6: The extent of Natuurbrug Zanderij Crailo in Netherlands. Atlas Obscura (Josh 2015) ......... 16
Figure 7: Aerial view of Eco-Link@BKE (National Parks Board, 2014) .................................................. 17
Tables
Table 1: Recommended resources to successfully identify potential wildlife crossings. Adapted from
(Clevenger and Huijser 2011) ................................................................................................................ 19
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Introduction
Kenya’s development agenda is based on Vision 2030, the country’s long-term national
planning strategy which states the main goals of the Economic, Social and Political pillars
that underpin it (Government of the Republic of Kenya 2007). Through this document, the
government has outlined its infrastructure plans with aspirations of being firmly
interconnected through a network of roads, railways, ports, airports, water and sanitation
facilities, and telecommunications. With regards to infrastructure, the agenda notes that “by
2030, it will become impossible to refer to any region of the country as “remote”. Investment
in the nation’s infrastructure has been given the highest priority according to the plan.
Similar to Vision 2030, Hopcraft, Bigurube et al. (2015) explain that national progress in
developing countries is dependent on the development of infrastructure such as effective
transportation networks. He further points out that the development trajectory in
developing countries is contingent on maintaining healthy ecosystems that are capable of
providing ecological services such as clean water, stable fertile agricultural soils and sources
of revenue (for instance, through tourism) to the citizens.
Following the proposed tarmacking of the Narok-Sekenani, this paper seeks to highlight the
impacts of infrastructural developments, especially roads, on wildlife. It further proposes
ways in which the Narok County Government can mitigate these impacts by illustrating how
wildlife overpasses and underpasses have been successfully employed in different parts of
the world to mitigate the adverse impacts of roads on wildlife
Impacts of Roads on Wildlife
Across the world, roads, railways and other linear infrastructure are pervasive components
of most landscapes. Combined with the effect of vehicles, they have the potential to cause
mortality in wildlife, severely disrupt animal movement and increase the risk of local
extinction. (Rodney van der Ree, Grift et al. 2007). Clevenger and Huijser (2011) reiterate
this by describing the impact of roads on wildlife populations as a significant and growing
problem worldwide, noting that many roads and highways cut across landscapes,
intersecting ecosystems and impacting on local habitats. The result is that terrestrial and
aquatic flows such as wildlife movements and distributions, subsurface and surface
hydrology and wind erosion may be blocked or altered.
The increasing development of roads across wild ecosystems and their perceived impacts on
wildlife has seen the emergence road ecology, a discipline that studies the interactions
between roads and the environment. Over the last ten years since its emergence, it has
strived to understand surface transportation infrastructure and its impacts on wildlife and
motorist safety, aquatic resources, habitat connectivity, and many other environmental
values (Clevenger and Huijser 2011). Road ecologists assert that roads can be ecologically
catastrophic, indirectly impacting wildlife through; habitat destruction and degradation,
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spread of exotic species like weeds, genetic isolation and the creation of unstable meta-
populations by fragmenting habitat patches which may result in the restriction of animal
movements leading to the functional isolation of populations. More directly, roads can
cause pollution, noise, animal avoidance, act as barriers to animal movement and cause the
direct mortality of millions of animals as a result of collisions with the vehicles that travel on
them (Rodney van der Ree, Grift et al. 2007, Clevenger and Huijser 2011, Ogden 2012,
Hopcraft, Bigurube et al. 2015, Kioko, Kiffner et al. 2015).
A case study of the Serengeti highway in Tanzania (Hopcraft, Bigurube et al. 2015) highlights
the need for careful planning in the development of new roads and infrastructure so as not
to jeopardize the country’s sources of foreign revenue from tourism. The Serengeti is one of
the best studied ecosystems in the world and is known for the annual migration of 1.38
million wildebeest and 250,000 zebra which move in a seasonal pattern between Tanzania
and Kenya. This mass migration drives virtually every other ecological component in the
ecosystem, from the diversity of plants and insects, forests and predator-prey interactions.
It also provides water, soil nutrients as well as a vibrant tourism industry for the nation. The
formerly proposed highway has been described as bisecting the migration and cutting the
ecosystem in half. According to Thirgood, Mosser et al. (2004), a loss of part of the
wildebeest’s migration route, even if only used for short periods, could leave the population
at risk. In their paper, Hopcraft, Bigurube et al. (2015) describe a preliminary assessment of
a road through Serengeti aimed at a capacity of 3,000 vehicles and transport trucks per day
(equivalent to 125 vehicles per hour) which would seriously place at risk the exclusive
product Tanzania as a country currently markets in the Serengeti. Additionally, the
competitive international trade that a highway of this magnitude would bring poses a
distinct risk for the traditional lifestyle of Maasai people, especially if adequate land use
planning and laws are not already in place to protect them.
The Greater Mara Ecosystem: A Background
The Mara Ecosystem lies between 0°45’ and 2°00’ S and 34°45’ and 36°00’ E at an altitude of
1,617 meters above sea level in South Western Kenya (Ogutu, Piepho et al. 2010). It covers
an area of 6,650 km², comprising of the 1,510 km² Maasai Mara National Reserve (MMNR),
the Loita, Siana and Mara plains (Khaemba and Stein 2000, Walpole, Nabaala et al. 2004),
which make up the former group ranches that have recently been converted to community
conservancies. These conservancies and plains covering an estimated 3,000km2 act as
wildlife dispersal areas for the MMNR (Khaemba and Stein 2000, Walpole, Nabaala et al.
2004), supporting higher wildlife densities than the MMNR at certain times of the year
(Ottichilo, De Leeuw et al. 2000).The Mara Ecosystem is bordered to the west by the Mara
River and the Siria escarpment, which separates the reserve from the Trans Mara Plateau,
on the east by the Loita Plateau and by the Kenya-Tanzania border on the southwest
(Thompson, Serneels et al. 2009) (Figure 1).
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The Mara is home to a wide range of wildlife species, supporting the greatest densities of
both wild and domestic herbivores in Kenya (Ogutu, Owen-Smith et al. 2011), with an
estimated herbivore density of nearly 240/km² and a biomass of just under 30 tonnes /km²
(BirdLife International 2010). It is famous for its concentration of migratory herbivores,
providing dry season range for approximately 1.5 million migratory wildebeest
(Connochaetes taurinus), one hundred thousand zebra (Equus burchelli) and large numbers
of other grazers, browsers and their predators (Ojwang', Said et al. 2006, Ogutu, Owen-
Smith et al. 2011). The Mara also hosts the ‘big five’ which are a major tourist attraction;
Cape buffalo (Syncerus caffer), elephant (Loxodonta africana), leopard (Panthera pardus),
lion (Panthera leo) and black rhinoceros (Diceros bicornis (Walpole, Karanja et al. 2003). The
Mara has been named as the only region in Kenya that supports an ecologically viable lion
population and one of the only remaining indigenous black rhino populations. BirdLife
International (2010) classifies it as an Important Bird Area (IBA) hosting over 500 bird
species, including 53 birds of prey.
Source: (Homewood, Lambin et al. 2001)
Figure 1: Map of the Mara – Serengeti Ecosystem showing location of the Mara Ecosystem
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The most commonly used access road to the Maasai Mara National Reserve from Narok
town is the 85 Km Narok-Sekenani Road, currently classified as ‘earthen’. To get to the
reserve, this road traverses sections of the former group ranches which have recently been
subdivided into individually owned plots with some forming newly formed conservancies
(Figures 1 & 2). The land subdivision in these former group ranches and subsequent rise in
land sales, mechanised agriculture, fencing and the indiscriminate and unplanned
mushrooming of market centres and permanent human settlements have already been
shown to have adverse impacts on the ecosystem’s wildlife.
The Proposed Upgrade of the Narok – Sekenani Road
Narok County has a recorded road network of approximately 2,798.4 Km, with 260 Km
classified as bitumen, 840 Km gravel surface and 1,698.4 Km earthen. However due to the
county’s bad terrain, most of these roads, including access roads to Maasai Mara National
Reserve, are unreliable especially during rainy seasons when most of them are rendered
impassable. The county’s poor road network has hindered access to social amenities,
resulted in high cost of transport thereby affecting the performance of the various economic
activities and hampered full realization of the county‘s potential in agriculture,
manufacturing as well as both foreign and domestic tourism. It has been noted that the
main contributing factor to the poor state of roads in the County is inadequate funding for
construction, rehabilitation and maintenance of both classified and unclassified roads. In
order to improve the road network, there is need to open-up new roads, rehabilitate and
carry out frequent maintenance of roads to all weather condition (County Government of
Narok 2013).
In 2014, the national government announced that it would work with Narok County to
tarmac the 85 Km road linking Narok town to the Maasai Mara National Reserve through
the Sekenani gate (Figure 2). This is in a bid to improve roads to the Mara, which brings an
estimated income of KES 3 billion per year, and is the leading revenue resource for Narok
and an economic pillar to achieving the country’s Vision 2030 (Government of the Republic
of Kenya 2007, Sayagie 2014). According to the principal secretary for infrastructure, the
road will be constructed to internationally acceptable standards and stands to boost the
image of the Mara which is globally recognised for its epic wildebeest migration from
Serengeti to Kenya (Sayagie 2014).
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Figure 2: Map showing Mara conservancies in relation to the location of the Narok-Sekenani Road
Potential Cumulative Impacts of Tarmacking the Narok-Sekenani Road
Positive Impacts
It is perceived that with the tarmacking of the Narok- Sekenani, the communities around the
Mara will see significant benefit through the following means:
1) Improved accessibility to the domestic tourism market: By tarmacking the Narok-
Sekenani road, which is the most used road to the Mara, transport links between the
Mara and other towns in the country will be greatly improved. This is expected to
lead to a marked increase in the number of local (domestic) tourists visiting the
Mara. This in turn could lead to increased employment opportunities in the tourism
and associated sectors across the Mara, ultimately improving local livelihoods.
2) Improved service delivery: By tarmacking the Narok-Sekenani road, it is anticipated
that access to much needed services like healthcare, education and finance could
improve due to developed transport links.
Narok- Sekenani Road
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Negative Impacts
The construction of a tarmacked road, earmarked to be a highway, in this highly fragile
ecosystem poses a great threat to the county’s wildlife and consequently, its tourism
industry through:
1) Reduction in the number of migrating ungulates: The Narok-Sekenani Road traverses
several wildlife hotspots including the migratory path of the local Mara-Loita migration,
an east-west movement of 35,000 wildebeest, zebra and gazelles between the Loita
plains and the Mara conservancies. It is widely believed that any negative impact on the
Mara’s ungulate population will result in a knock on impact on the ecosystem’s predator
population.
2) Loss of tourism revenue at local (community), county and national levels: The Maasai
Mara National Reserve, Kenya’s highest earning protected area is estimated to collect
collecting between KES 3.3 billion annually (Narok County Council and Trans Mara
County Council, 2012). Any adverse impacts from the road to the Mara’s wildlife
population has the potential to significantly reduce this income, leading to a loss of
livelihood to the communities that directly benefit from tourism, the County
Government that relies on this income and the highly significant numbers of jobs
created through the Mara’s tourism sector.
Mitigation Recommendations to Manage Adverse Impacts of Roads on
Wildlife
With the growing realisation of the impacts of infrastructure developments on migrating
wildlife species, there has been an upsurge in new techniques to identify remaining wildlife
movement paths with the hope of informing conservation and management decisions
(Seidler, Long et al. 2015). Numerous studies of the oil and gas industries have made it clear
that migratory wildlife are detrimentally affected by the habitat loss and disturbance
associated with these developments (Seidler, Long et al. 2015). Understanding migration
patterns before developments are planned or approved would aid in protecting these
migrations. It is therefore important that the extents of these impacts are critically analyzed
and necessary information is provided to relevant authorities for mitigation and improved
planning.
While the economic benefits of roads are widely known and appreciated, their negative
impacts especially to wildlife are rarely considered and few attempts are made to find
workable solutions for these opposing objectives (Clevenger and Huijser 2011). According to
Ogden (2012), avoiding road construction to begin with or restoring disused roads to natural
habitats in order to save wildlife corridors is the top priority from an ecological perspective.
However, “One size and strategy does not fit all” and researchers have identified important
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factors that can inform the design of effective mitigation structures such as wildlife
crossings (discussed below). These include location, size, shape and openness of proposed
structures in addition to habitat cover, fencing, and surrounding environmental conditions
such as moisture, temperature, light, and substrate.
Wildlife Crossings
Research carried out in North America show that roads are a serious obstacle to maintaining
population connectivity (the degree to which a landscape facilitates or hinders free wildlife
movement) and a threat to the long-term survival of some regionally important wildlife
populations such as Pronghorn antelope. As a result of human-safety issues, the highly
visible nature of road-kill carcasses and the potential conservation implications, agencies
responsible for road construction and management have attempted to reduce the number
of road kills by preventing animals from accessing roads and facilitating crossing by
constructing tunnels, culverts and overpasses. There has been considerable effort to
document the use of these crossing structures by wildlife, and studies have been conducted
in Europe, North America and Australia (Rodney van der Ree, Grift et al. 2007, Clevenger
and Huijser 2011).
Wildlife crossing are permanent structures embedded within a dynamic landscape and are
intended to increase permeability of roads or other linear infrastructure by facilitating the
safe passage of animals over or under it. They increase habitat connectivity across roads and
reduce wildlife–vehicle collisions. In addition, they play an integral role in protecting and
maintaining the health of animal populations, allowing them to roam great distances and
prevent in-breeding that can lead to disease and possible extinction. Like landscape
corridors, the conservation value of wildlife crossing structures are gaining attention as
applied measures to help adapt changes in species ranges and animal distributions to
climate change. Wildlife crossing structures may be purpose built for wildlife or may
primarily serve other functions such as water drainage or access by humans (Rodney van der
Ree, Grift et al. 2007, Clevenger and Huijser 2011, Christy 2014).
The first wildlife crossings were constructed in France during the 1950s. Since then, a
number of other European countries including the Netherlands, Switzerland and Germany
have constructed various crossing structures to reduce the impact caused by roads on
wildlife (Amusing Planet 2015). With the lifespan of wildlife crossing structures around 70–
80 years, the location and design of these crossings need to accommodate the changing
dynamics of habitat and climatic conditions and their wildlife populations over time
(Clevenger and Huijser 2011). Over the years, the design of wildlife crossings have evolved in
their design structures and according to Animal Road Crossing (2015), the time has come for
new solutions. New solutions to wildlife crossing infrastructure are needed to reduce the
costs and to tailor each type of crossing to the specific species in various landscape contexts
(Marie-Lister 2012). It has been proposed that in general, wildlife crossings should be:
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a) considered as early as possible in the transportation planning process so as to avoid
the more costly problem of retrofitting or rebuilding;
b) cost-effective in terms of materials, construction and maintenance;
c) ecologically responsive to current and anticipated conditions;
d) safe for humans and wildlife alike;
e) flexible or modular for possible use in other locations;
f) adaptive, to facilitate mobility of wildlife under dynamic ecosystem conditions;
g) sustainable in terms of materials and energy use, and responsive to climate change;
h) educational, revelatory and communicative to the public; and
i) beautiful, engaging and remarkable
Adapted from (Animal Road Crossing 2015)
The two common types of wildlife crossings are:
1) Above-grade (wildlife overpasses): These are structures that allow passage above
transportation infrastructure. Wildlife overpasses have been constructed in Europe,
the U.S., and Canada, with the most effective ranging in width from 50 m wide on
each end narrowing to 8-35 m in the centre, to structures up to 200 m wide. Wildlife
overpasses appear to accommodate more species of wildlife than underpasses as
they are less confining, quieter, maintain ambient conditions of rainfall, temperature
and light, and can serve both as passage ways for wildlife and intermediate habitat
for small animals such as reptiles, amphibians and small mammals (Jackson and
Griffin 2000).
2) Below-grade (wildlife underpasses): These are structures that allow passage below
transportation infrastructure or obstacles. According to Bennett (2003), underpasses
have been shown to assist movements of large wide-ranging species such as Cougars
or Panthers in California and Florida, USA. They are also used to facilitate
movements, or to reduce the road toll, for species as diverse as Badgers in Britain
and the Netherlands, Mountain Pygmy-possum in Australia and Common Toads and
other amphibians in numerous European countries.
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Case Studies
Case Study 1: Banff National Park – Alberta, Canada
With a total of 44 wildlife crossing structures (6 overpasses and 38 underpasses), and 82 km
of highway fencing (see figure 3 below), Banff National Park in Canada has the most wildlife
crossing structures and highway enclosure fencing in a single location, making it the host of
the most recognizable wildlife crossings in the world (Parks Canada 2014). To reduce to
effect of the four-lane Trans-Canada Highway, these wildlife crossings were built to ensure
habitat connectivity and protect motorists. They help sustain healthy wildlife populations by
allowing animals to cross under or over the highway and are used regularly by bears, moose,
deer, wolves, elk, and many other species. According to Strother (2013), bear populations
have been found to remain strong in the park, despite the fact that a major highway divides
their habitat. In addition, fences were installed on both sides of the twinned highway to
keep large animals from accessing the highway right-of-way.
After construction, tracking animal movement at the newly constructed wildlife crossings
was made a top priority. Such work has been on-going in the park since 1996; the longest
on-going wildlife crossing research and monitoring program in the world (Parks Canada
2014, Amusing Planet 2015).
Figure 3: Wildlife overpass in Banff National Park. Joel Sartore (Amusing Planet 2015)
Case Study 2: Mount Kenya Elephant corridor (underpass) - Kenya
As a result of the Kenya’s booming human population, incidences of human-wildlife conflict
across the country have increased. In the Mount Kenya-Laikipia landscape, elephant
migration routes are becoming increasingly unsafe. As a result, many elephant herds were
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recorded as staying on in Lewa for longer periods of time, rather than migrating through the
Conservancy, causing an ecological strain on its resources (Lewa Wildlife Conservancy 2015).
To mitigate this conflict, a 15-foot-high tunnel (underpass) was constructed under a busy
motorway that divided the elephants’ traditional migratory routes. This underpass, the first
of its kind in Africa, was designed to give the elephants safe passage from the north-west
side of Mount Kenya to the Ngare Ndare Forest Reserve and Lewa Conservancy in a pattern
similar to historical migration routes- linking up to 7,000 elephants. Since its construction,
elephants have been recorded moving up and down the corridor on a daily basis in numbers
that have surpassed expectations (Amusing Planet 2011, Tusk Trust 2015).
Figure 4: Elephants using the Mt. Kenya underpass. Associated Press (Amusing Planet 2011)
Case Study 3: Trapper's Point Wildlife Overpass – Wyoming, USA
As the centre of one of the world’s largest intact long-distance animal migrations, Trappers’
Point in Wyoming has attracted human visitors for thousands of years. The abundance of
hardy forage and the sparse snowpack make this an important winter range for as many as
100,000 ungulates, including about 59,000 antelope, the largest gathering of pronghorn on
Earth. At 170 miles one way, the journey of the Teton pronghorn antelope is the second
longest recorded land animal migration in the Western Hemisphere, after caribou in the
Arctic (Ostlind 2010). A decade long study of these pronghorn antelope, found that it’s
habitat and 6,000-year-old migration route across Wyoming had been severely affected by
factors including development, natural resource extraction and an increase in traffic along
U.S. Highway 191 in the area of Trapper’s Point (Contech Engineered Solutions 2013).
In order to allow pronghorn antelope as well as mule deer, elk and moose safe passage
across busy U.S. Highway 191, the Wyoming Department of Transportation installed
concrete arch structures spanning the highway (see fig x below) to serve highway traffic
below and wildlife corridors above. In the year following construction in 2012, at least
36,071 mule deer and pronghorn were recorded as having moved through the new
crossings and reducing wildlife-vehicle crashes by 80% (Travsky 2014).
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Figure 5: Development of Trapper's Point Wildlife Overpass (Contech Engineered Solutions 2013)
Case Study 4: Natuurbrug Zanderij Crailo - The Netherlands
The Netherlands contains over 600 man-made wildlife corridors, including overpasses and
underpasses along busy highways. Completed in 2006, Natuurbrug Zanderij Crailo, roughly
translated as “sand quarry natural bridge”, is the world’s longest overpass at 50 m wide and
over 800 m long. The overpass leads animals safely across the N524 roadway and nearby
railways to the surrounding wooded areas, spanning over a railway line, business park, river,
roadway, and sports complex and forms part of a larger protected area within the country,
the Veluwe, which consists of 1,000 square kilometres of forest and other natural habitats.
Species known to use these corridors include roe deer, red deer, wild boar, and the
endangered European badger (Josh 2015). According to NeoSystek (2015), monitoring is
currently underway to examine the effectiveness of this innovative project combining
wildlife protection with urban development.
Figure 6: The extent of Natuurbrug Zanderij Crailo in Netherlands. Atlas Obscura (Josh 2015)
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Case Study 5: Eco-Link@BKE, Singapore
Constructed over a period of two years from 2011, the $16 million 62m ecological bridge
(Eco-Link) spans the six-lane Bukit Timah Expressway (BKE). Built specifically for animals, it is
the first purpose-built bridge for wildlife in South-east Asia and connects the 163ha Bukit
Timah Nature Reserve to the 2,000ha Central Catchment Nature Reserve which is
Singapore’s largest nature reserve. Home to 40% of the country’s flora and fauna, Bukit
Timah Nature Reserve was officially declared an ASEAN Heritage Park on 18 October 2011.
Together with Sungei Buloh Wetland Reserve, it is now part of the prestigious regional
network of 30 protected areas, forming the complete spectrum of representative
ecosystems in ASEAN. It is also protected by the Parks & Trees Act 2005 for the conservation
of Singapore’s native biodiversity (National Parks Board, 2016). The eco-link was
constructed to link the two nature reserves which had been connected until 1986 when the
BKE was built (Min & Pazos, 2015), with its main purpose being to restore the ecological
connection between two nature reserves, allowing wildlife to expand their habitat, genetic
pool and survival chances (National Parks Board, 2016).
In order to monitor the effectiveness of the eco-link which houses over 3,000 native plants,
eight camera traps with motion sensors have been set up in both nature reserves. These
cameras are triggered when animals move past them and together with numerous surveys,
have so far recorded more than 15 species of mammals and birds using the green corridor.
These include the common palm civet, several rare and geographically restricted mammals
such as the Lesser Mousedeer, the critically endangered Sunda pangolin and new species of
grasshoppers and crickets. Understory forest birds, such as barbets and bulbuls, have also
been observed in the vicinity of the Eco-Link@BKE. These species are vulnerable to local
extinction and would rarely traverse the expressway in the absence of an ecological bridge.
Figure 7: Aerial view of Eco-Link@BKE (National Parks Board, 2014)
18
Policy Harmonisation at County Level
Under the Kenyan Constitution (Laws of Kenya 2010), provision of roads is a function of both
National Government under the Fourth Schedule Part 1(18)(a,b,c) and County Government,
under the Fourth Schedule Part 2(5)(a,b,c). Narok County has a poor and dilapidated
physical infrastructure, mostly as a result of inadequate funding and sufficient technical
staff, poor terrain, encroachment of road reserve as well as lack of knowledge amongst the
community on the importance of roads.
In order to comply with both the country’s constitution and vision 2030 objective of
improving and increasing infrastructure in the country, Narok County Government should
ensure that there are adequate transport links to the Mara, its highest income earner.
According to its five year “Integrated Development Plan” (County Government of Narok
2013), the County intends to:
1. Ensure the provision and maintenance of quality roads, especially the main road
network
2. Mobilize and improve resources for opening up of new roads in order to increase
accessibility to the rural areas
3. Develop and enhance road maintenance management capabilities of both public and
private sector under the new Kenya Roads Board (KRB)
4. Operationalize road agents under the KRB and provide effective supervision.
5. Facilitate efficient and better road policy
6. Instil professionalism in the roads sector by training casual contractors and technical
staff in the district and ensuring that only competent contractors are awarded
contracts in the county.
Additionally, on its website (Narok County Government 2015), the county under its
department of public works, roads and transport is tasked with:
1. Implementation of policies on road works, quality standards, materials, mechanical
and transport services for county roads;
2. Undertaking performance and technical audits on road construction and
maintenance for county roads
19
Table 1: Recommended resources to successfully identify potential wildlife crossings. Adapted from (Clevenger and Huijser 2011)
Resource Purpose Source
Aerial photos Can be used to help identify vegetation types and human developments in potential crossing site Government agencies (KWS,
DRSRS), Narok County,
Remotely sensed imagery
Land cover-
vegetation maps
These maps help identify general vegetation types. Land cover maps are more general and include physical (built
areas) and biological information.
Government agencies (KWS,
DRSRS), satellite imagery
Land use maps Important to understand compatibility of adjacent land use in the present and future. Wildlife crossings will only
be as effective as the management strategies developed around them that incorporate all the key landscape
elements (humans, terrain, natural resources and transportation).
National and County
governments
Topographic maps Wildlife crossings should be placed where movement corridors for the focal species are associated with
dominant topographic features (riparian areas, ridgelines, etc.). Sections of roadway can be ignored where
terrain (steep slopes) and land cover (built areas) are unsuitable for wildlife and their movement
National and County
governments
Landownership
maps
Maps that identify adjacent land use management such as public/crown lands, designated reserves, municipal
and private lands are needed for planning corridors and crossings.
Narok County Government
Wildlife habitat
maps
Identify key habitat types for the species for which they are prepared.
Wildlife researchers
GIS based Wildlife
movement model
data
Landscape-scale GIS-based models can identify key habitat linkages, evaluate habitat fragmentation resulting
from human activities, and discover areas where highways are permeable to wildlife movement. Models that
simulate movements of wildlife tend to use “resource selection functions” that map habitat quality.
Wildlife researchers, NGOs
Wildlife ecology
field data
Supplemental data in form of telemetry points or population surveys can help guide the location selection for
connectivity and crossing structures.
Government agencies (KWS &
DRSRS), Researchers, Wildlife
NGOs
Wildlife road-kill
data
Location-specific data on wildlife species killed on roads, either through carcass collections or collision reports.
Can be used to identify road-kill hotspots, but do not provide information on where wildlife is successfully
crossing the roadway.
Wildlife NGOs, researchers
Road network data Road network showing road types.
National and local
government, Google maps
Local knowledge
(through public
participation)
Long-term area residents can provide valuable information about where and how wildlife moves across
landscapes, especially where crossing locations are limited. Citizen science programs, now formalised, encourage
active participation by the local community in wildlife movement and road mortality data collection.
Community leaders,
community focused NGOs
20
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