design of new roads and the upgrading and rehabilitation of existing roads, where appropriate. We are ...... Website: ht
THE ROAD AHEAD:
Guidelines to mitigation methods to address wildlife road conflict in South Africa The Endangered Wildlife Trust: Wildlife and Roads Project By: Wendy Collinson and Claire Patterson-Abrolat
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ACKNOWLEDGEMENTS We would like to thank N3 Toll Concession for their ongoing support of our strategic operations. Our thanks too to Bridgestone SA, Bakwena N1N4 Toll, Rand Merchant Bank, SANRAL, Miss Earth South Africa, and the Development Bank of Southern Africa for their support of our project based work. Thank you to Dr Harriet Davies-Mostert, Dr Marie Parramon-Gurney and Shelley Lizzio for their invaluable input into this document.
SUGGESTED CITATION
Collinson, W. & Patterson-Abrolat, C. 2016. The Road Ahead: Guidelines to mitigation methods to address wildlife road conflict in South Africa. The Endangered Wildlife Trust, Johannesburg, South Africa.
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Contents
FOREWORD
1
1.
INTRODUCTION
2
2.
LIMITATIONS OF THIS HANDBOOK
3
3. RELEVANT ENVIRONMENTAL LEGISLATION 3.1 THE EIA PROCESS 3.1.1 A brief overview of the EIA process 3.1.2 An outline of the impacts road infrastructure can have on wildlife 3.1.3 Examples of how to minimise the impacts 3.1.4 Incorporating mitigation measures following the EIA phase
4 4 5 7 8
4. MITIGATION STRATEGIES FOR RESOLVING WILDLIFE ROAD CONFLICT 4.1 AVOID 4.1.1 Preventing animal access to the road 4.1.2 Road infrastructure adaptation 4.1.3 Habitat adaptation 4.1.4 Risk minimisation 4.1.5 Public awareness campaigns 4.2 FACILITATE 4.2.1 Facilitating habitat connectivity through a wildlife crossing structures 4.2.2 Modification of existing structures and road infrastructure to facilitate wildlife movement 4.2.3 Facilitating movement through risk minimisation
13 13 15 17
5.
MIGATION STRATEGY EXAMPLES
18
6.
FURTHER INFORMATION
19
7.
SUGGESTED LITERATURE
20
8.
PHOTO CREDITS AND SOURCES
21
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9 9 9 10 10 11 13
FOREWORD The N3 Toll Concession (RF) Proprietary Limited (N3TC), as the custodian of the N3 Toll Route between Cedara in KwaZuluNatal and Heidelberg in Gauteng, is privileged to be involved with the development of the Guidelines to mitigation methods to address wildlife road conflict in South Africa, a wonderful initiative, spearheaded by the Endangered Wildlife Trust (EWT). It is very important to ensure that there is a balance between the development of road infrastructure, the economic impact on communities along the route and the impact on the environment. We have an ongoing commitment towards supporting environmental and social issues and in this regard, we have partnered with the EWT on various initiatives along the N3 Toll Route. We trust that the guidelines in this booklet will influence the design of new roads and the upgrading and rehabilitation of existing roads, where appropriate. We are confident that it will initiate further studies and debate from both local and international role-players as well as interested and affected parties, which will result in the development of best practice policies, procedures and solutions to ensure that wildlife and roads co-exist in harmony. The environment cannot be neglected by any segment of society; the world is in need of global leaders pioneering new development processes and techniques that will ensure a balance between development and environmental preservation and conservation. We are, every one of us, responsible for the world we live in. Neil Tolmie Chief Executive Officer N3 TOLL CONCESSION (RF) PROPRIETARY LIMITED
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1.
INTRODUCTION
Road infrastructure is a common feature wherever humans have settled. It is becoming widely recognised that roads and road users affect many aspects of the functionality of the ecosystems in which they occur. Direct collision with wildlife is the most obvious impact due to its visual nature, but the indirect disruption of ecological processes is equally important. Degradation and loss of habitat, habitat and population fragmentation, and disruption of the processes that maintain regional populations are just some of the ways in which roads can affect biodiversity. Although roads are integral to the financial development and prosperity of the national economy in South Africa, there is a potential conflict between the country’s development and conservation goals. To improve the ecological sustainability of roads, best management practices need to be incorporated into the planning and design stages of roads as early on as possible. The Endangered Wildlife Trust developed The Road Ahead: Guidelines to mitigation methods to address wildlife road conflict in South Africa as a user-friendly guide to the practices that should be followed when designing or upgrading roads. It is intended for use by a range of stakeholders including road development agencies, environmental assessment practitioners, decision makers such as the Department of Environmental Affairs and the Department of Transport, and research institutions. It is intended that this handbook informs decision-making, helps raise awareness of the impacts of roads and road users on wildlife, and assists in the identification of appropriate mitigation measures to reduce the impact of roads on wildlife. Ultimately it is hoped that use of the handbook will lead to a reduction in the loss of wildlife.
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2.
LIMITATIONS OF THIS HANDBOOK
As the first of its kind, this handbook seeks to fill knowledge gaps regarding road ecology in South Africa. Although based on an extensive collection and synthesis of current literature, knowledge, and science-based data with regard to the practices already in use in countries around the world, it is recognised that few of these have been field-tested in South Africa, or adapted to local conditions. Some of the recommended techniques may themselves have negative consequences which must be carefully considered. For example, although fences may effectively prevent animals from accessing roads and reduce the possibility of them being killed by vehicles, they also restrict natural movement patterns thereby affecting ecological processes. There are no silver bullets for addressing the impact of roads on wildlife. Each road project needs to be assessed individually and the unique circumstances taken into account when designing a mitigation programme. Ongoing research is needed to appropriately adapt international mitigation measures to the local environment, and to fill gaps in our knowledge. For further reading, key literature is cited at the end of this handbook.
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3.
RELEVANT ENVIRONMENTAL LEGISLATION
3.1.1 A brief overview of the EIA process
South Africa has a legal and moral responsibility to conserve its biodiversity. The Constitution of South Africa (Act 108 of 1996) states that everyone has the right: a. to an environment that is not harmful to their health or well-being; and b. to have the environment protected, for the benefit of present and future generations, through reasonable legislative and other measures that i. prevent pollution and ecological degradation; ii. promote conservation; and iii. secure ecologically sustainable development and use of natural resources while promoting justifiable economic and social development. These principles of environmental sustainability are also encapsulated in the National Environmental Management Act, 109 of 1998 (NEMA) which provides guidelines for conducting Environmental Impact Assessments (EIAs). Updated in 2010, South Africa’s EIA regulations outline the process of assessing, investigating and reporting potential environmental impacts of developments and activities. EIAs are governed by the following regulations: • • • •
•
Environmental Impact Assessment EIA Regulations (Government Notice R.543 in Government Gazette 33306 of 18 June 2010); Listing Notice 1 (Government Notice R.544 in Government Gazette 33306 of 18 June 2010) – activities requiring a Basic Assessment Report (BAR); Listing Notice 2 (Government Notice R.545 in Government Gazette 33306 of 18 June 2010) – activities requiring both scoping and Environmental Impact Reports (EIRs); Listing Notice 3 (Government Notice R.546 in Government Gazette 33306 of 18 June 2010) – activities which require only an environmental authorization through a BAR if the activities are undertaken in a specified geographical area; and Environmental Management Framework Regulations (Government Notice R.547 Government Gazette 33306 of 18 June 2010).
Prior to a road project being undertaken, it is necessary to first conduct an EIA. 3.1 The EIA process An EIA is a support tool to enable sound decision-making which leads to sustainable development. It also provides alternative development scenarios and management measures to minimise negative, and optimise positive consequences. This handbook provides: 1. A brief overview of the EIA process; 2. An outline of the impacts that road infrastructure can have on wildlife; 3. Examples of how to minimise the impacts; and 4. Mitigation measures that can be incorporated into projects following the EIA phase.
The three stages of an EIA surrounding a development such as a road are presented in Figure 1, namely the Screening, Scoping Report and EIA Phase. 1. Screening
2. Scoping Report
3. EIA Phase
Figure 1: The three stages of an EIA. Phase 1: Screening or pre-feasibility Prior to performing an EIA, a screening phase, or pre-feasibility study, is conducted. It is at this stage that the long-term impact of the road on all species (threatened and non-threatened) should be carefully considered, as well as any possible impacts on the biological functioning of the ecosystem in which the development will take place. These impacts may include: • • • • •
Loss, fragmentation or alteration of habitats; Introduction of alien/invasive species; Prevention of access for wildlife to valuable resources (for example, food, water and/or shelter); A barrier effect, displacement and/or disturbance of animal migratory and movement patterns; and Death due to collision with vehicles.
The more specifics generated during the screening phase, the lower the long-term financial and environmental costs and the associated business risks. These risks may include: • • • • • • •
The EIA not being granted, delayed or appealed; Opposition from conservation NGOs and local communities; Compensation and/or biodiversity offset fees; The need to source an alternative location; Costs of mitigation measures as set out in an environmental management programme and conditions of environmental authorisation; The impact on the project footprint; and Potential constraints on investment and financing.
To minimise costs and risks, the following questions outlined in Figure 2 should be considered during a pre-feasibility study:
Is the proposed road/road upgrade likely to have a significant impact on wildlife/habitat ? No
Yes (go to next question) Can the alignment of the road be changed ? No (go to next question) Yes (See Fig. 5 Page 7) What design adaptations can be used to minimise the impact ?
Figure 2: The key questions to be considered during a pre-feasibility study.
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Phase 2: Scoping report A scoping report describes the main environmental challenges or issues to be addressed, identifies available resources and assets, and outlines what intervention options might lead to desired outcomes. Therefore, if it is feasible to continue with the road development and/or upgrade, and having determined that there is no possibility of realigning a road to avoid a negative impact on the environment/wildlife, the following steps should be taken into consideration when producing the Scoping Report (Figure 3):
also be considered. Where possible, an evaluation of project alternatives that demonstrate responses to the concerns should be noted. The EIA Report must also provide suggested mitigation measures, with impacts rated on the basis of their significance before and after the recommended mitigation is applied. Assessment of the impacts that roads and roads-users have on wildlife and habitat can be difficult due to their non-selective impact on species, and the long life-span of the infrastructure. As such, it is strongly urged that the steps as outlined in Figure 4 be considered as levels of priority in terms of a hierarchy of mitigation when working on a road EIA.
Identify the impact to be addressed, through assessing the following: • What species are present and of potential concern (including non-threatened species)? • What habitat types are present? • What is the average daily traffic volume, speed and vehicle type for existing roads or the anticipated for a new road? • What is the road type (e.g. paved or unpaved / provincial, regional and national)?
Where possible, habitat disturbance should be avoided when building or designing a road.
If avoidance of habitat disturbance is not possible, then consider what is available to minimise the impact?
Consider existing infrastructure and surrounding land-use: • Will this infrastructure (e.g. fences) have a negative/positive impact on wildlife? • What natural or man-made features can be adapted to allow connectivity? (e.g. a drainage culvert). • Is it a new road being built, an upgrade or a maintenance operation?
Options: • Develop a risk profile for the impact which assesses the short- and long-term and cumulative impacts of the road over its lifespan in terms of probability and severity. • Recommend a mitigation strategy based on the techniques laid out in this handbook and in line with the mitigation hierarchy (Figure 4). This should be a multi-tool approach detailing what mitigation measures are to be used and where they are to be located.
Figure 3: The process to be followed when producing the scoping report. Phase 3: EIA phase The outcomes of the EIA phase are the EIA Report or Statement, and an Environmental Management Plan (EMP). These documents should address the concerns raised throughout the EIA process by providing a detailed project description along with the specialist study reports. In addition, an integrated synthesis of the specialist reports with a clear and concise summary of the impacts of the project on the receiving environment should
For new and existing roads, what measures are available to rehabilitate habitat?
If rehabilitation is not an option, then what offset can be implemented?
Figure 4: Hierarchy of decision making when considering an Environmental Impact Assessment. 3.1.2 An outline of the impacts road infrastructure can have on wildlife It is important to consider the various impacts that roads and road users have on wildlife species and ecosystems, since these impacts are non-specific and a multitude of species are at threat. A road ecologist can provide valuable input to the scoping report through the following means: • • • •
Identifying species of concern; Describing the behavioural responses of the species of concern; Describing the likely impacts of these species and their habitats; and Recommending mitigation measures through working with road engineers on road design.
The faunal assessment of the EIA process must evaluate all possible impacts of roads on animals. Not all animals react the same way to approaching vehicles. Many animals such as rabbits
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‘freeze’ when caught in headlights and, even if they are not killed by the first vehicle, a stationary animal will then be at risk from other vehicles. African Civets characteristically move slowly and when disturbed lie still or stand motionless. They also frequent roads, preferring to use established pathways. Their nocturnal habits and cryptic colouring could explain why road mortality is so high for this species. Similarly, snakes cross roads slowly and individuals that stop moving in response to traffic noise can remain immobile for up to a minute or more. Other factors that make animals vulnerable to being hit by vehicles (direct mortality) are: • • •
Snakes and other ectotherms habitually bask on asphalt; Birds consume spilt grain along roadsides and some birds use roadside gravel to aid digestion; and Antelope and other browsing herbivores are attracted to the dense vegetation or so called ‘green curtain’ of roadside edges. New growth on burnt firebreaks alongside roads also attracts antelope.
responders, pausers, speeders and avoiders. Knowing how an animal will react will often help a driver avoid collisions (Table 1). Table 1: Risk profile and type of impact: four wildlife behavioural responses to roads and traffic, outlining the impacts (positive and/or negative), with some species examples. WILDLIFE BEHAVIOURAL RESPONSE
SPECIES EXAMPLES
Nonresponders
These animals fail to detect or take avoidance behaviour to oncoming vehicles and will continue to try cross the road. The likelihood of a successful crossing decreases with an increase in traffic. These species are vulnerable to populations reductions and fragmentation effects.
Invertebrates Frogs Some snakes Livestock
Pausers
These species detect the danger oncoming traffic poses to them but respond by stopping. The longer they stop or pause, the greater the risk of them being hit by the oncoming vehicle. High traffic volume presents a complete barrier to these species.
Snakes Turtles Western Leopard Toad
Speeders
These species flee from danger but may flee directly into an oncoming vehicle. Shy species may be at risk from a barrier effect and population fragmentation.
Antelope Guineafowl
Avoiders
These species will only cross when traffic volumes are fairly low. Generally these species experience the lowest mortality rates but may suffer from population fragmentation depending on how often traffic volumes are low.
Carnivores
In addition, cascade effects are seen along the trophic hierarchy where scavenging animals seek out roadkill and often become roadkill themselves. Some species avoid roads altogether and may shift home ranges, feeding sites and nesting areas away from the roads. Additionally, it has been noted that certain animals avoid crossing roads due to noise avoidance which in turn can impact their migratory routes. Scientists have determined that animals have four general responses to approaching vehicles: the non-
IMPACT
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3.1.3 Examples of how to minimise the impacts Usually, most species exhibit a combination of the aforementioned four behavioural responses and once the behaviour is understood, the impact, and mitigation measures will be better informed and can be determined by the following strategies: i)
AVOID: Reduce collisions though preventing animal-access to the road or reducing collision only: ii) FACILITATE: Prevent collisions but keep animal connectivity.
STRATEGY
No single method of preventing wildlife-road conflict has proven totally effective in all circumstances and a number of methods should be considered for implementation relative to the behaviour and location of the particular species/problem in the area of concern. From an ecological perspective, mitigation which allows habitat connectivity is always preferred to an option which prevents natural movement. Examples are given below that provide two mitigation strategies for resolving wildlife road conflict; avoid and facilitate (Figure 5).
HOW Preventing animal access
WHAT Fencing Curbs
Road infrastructure adaption
Using noise as a deterrent Managing roadside habitat
AVOID - reduce the probability of a collision through:
Habitat adaption
Risk minimisation
Intercept feeding
Speed reduction / traffic calming / weight limits
MITIGATION STRATEGIES FOR RESOLVING WILDLIFE ROAD CONFLICT
Signage Reflectors
Public awareness campaigns
Facilitate habitat connectivity through a wildlife crossing structure
Social media / posters / etc.
Overpass (landscape bridge / green bridges / canopy crossing) Underpass (Via ducts / herpetile tunnel)
Bridges Drainage culverts FACILITATE
Modification of existing structures and road infrastructure to facilitate wildlife movement
Drainage gates Jersey barriers Noise reduction
Facilitating movement through risk minimisation
Lighting Raised embankments / bird poles
Figure 5: Mitigation techniques suitable for addressing wildlife road conflict. ROAD AHEAD | 7
3.1.4 Incorporating mitigation measures following the EIA phase Road ecology is a relatively new concept in South Africa and ongoing monitoring and evaluation of the proposed mitigation measures will assist in ensuring continuous learning and skills transfer. It is unrealistic to aim for the complete elimination of the
problem and the goal should be to reduce impacts to socially and environmentally acceptable levels. Procedures for the monitoring and maintenance of a mitigation measure, once implemented, should be included in the EMP. We recommend that the steps described in Figure 6 be kept in mind.
Mitigate
• •
Have you identified target species? Have you identified appropriate managemnet of the biodiversity adjacent to the road?
Monitor
• •
Does the province have data pertaining to wildlife road conflict. Are you working with strategic partners that include a team that includes biologists, engineers, non-profits, and local planners? Is there a monitoring plan in place?
• Maintain
• •
Have you consulted with an expert on the most effective mitigation measures for your target species? Is there a maintenance plan in place?
Figure 6: The three steps in the follow up stages of an EIA.
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4. MITIGATION STRATEGIES WILDLIFE ROAD CONFLICT
FOR
RESOLVING
Reducing roadkill and developing wildlife habitat linkages is critical for the conservation of wildlife. Success is greatest where communities and agencies come together to share ideas and information for developing effective road mitigation programs. Engineers, biologists, and conservationists must work handin-hand to implement effective solutions. In this chapter we outline the current state of global knowledge on the subject of wildlife-road-prevention and wildlifeconnective-passageways and provide possible solutions to preventing roadkill and providing connectivity for wildlife populations. The chapter is divided into two sections proposing possible mitigation strategies for resolving wildlife road conflict; the first being to avoid a collision with an animal through preventing it from crossing the road, and the second being to allow the animal an opportunity to cross the road through facilitating a wildlife-crossing-structure. 4.1 AVOID Reducing the probability of a collision with an animal on the road can be done through the following: • • • • •
Preventing animal access to the road; Adapting road infrastructure; Adapting roadside habitat; Implementing risk minimisation schemes; and Public awareness campaigns.
4.1.1 Preventing animal access to the road Fragmentation of natural habitats is an important cause of biodiversity loss with roads acting as barriers to movement. In response to this, numerous studies have reported on the technical aspects of mitigation fencing and its value in reducing wildlife-road mortalities, through preventing animal access to the road.
Figure 7: Wildlife fencing and one-way escape gate along Trans-Canada Highway, New Brunswick. Consideration needs to be given to the trade-off between the risk of a species being killed on a road and whether fragmentation by fencing will increase population isolation. The combination of fencing and a wildlife crossing structure could then be an effective solution to barriers and roadkill. Further modifications to improve existing fencing include combining fencing with finer mesh to stop smaller animals getting through, or a lip bent at right angles at the top of the fence, away from the direction of the road (with a one metre extension) to prevent animals from climbing over. For smaller vertebrates, low-level mesh fences can be added to guide the individuals towards passages (Figure 8). Fine-meshed fencing buried at the bottom has been successfully used in association with pipe culverts for small animal connectivity under roads.
Fencing South Africa is a country with a ‘fence culture’ with hundreds of thousands of kilometres of game fencing dividing farms, national parks and other properties. Whilst an effective and common method used throughout the world to keep animals off the road and therefore, reduce roadkill, widespread use of game fencing has been shown to increase habitat fragmentation, isolate wildlife populations and constrain the movement of animals, usually by preventing access to adjacent habitats. In addition to causing increased population isolation, many South African fences are electrified and animals can be killed trying to move through or under the fences. Fencing does not stop all animals from accessing a road. Many South African antelope (e.g. Greater Kudu) can easily jump over 2.4 m fences, and other species dig under or push through fences, providing an opening for other animals to breach the fence. However, when used in combination with measures such as reduced speed limits (particularly at fence ends), fencing can be effective in reducing roadkill numbers. To prevent wildlife being trapped between the fence and the road, the use of one-way gates and earthen ramps provide an escape route for those animals that manage to bypass a fence and then find themselves trapped next to the road (Figure 7).
Figure 8: Two photographs showing how mesh fencing can be used to guide animals towards wildlife passages in South Africa.
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CASE STUDY: WESTERN LEOPARD TOAD The Endangered Wildlife Trust’s Wildlife and Roads Project (EWTWRP) collaborated with Toad NUTS (Noordhoek Unpaid Toad Savers) in Cape Town, to mitigate the impacts of roads on the Western Leopard Toad (Amietophrynus pantherinus WLT). The WLT is a coastal species and is listed on the Red List as Endangered. There are several reasons for this, but the most critical one is roadkill. Many amphibian species are only active for a short and specific period of the year. Every year, the WLT migrates to the nearest suitable pond during the months of July–September to breed. Most of these ponds are found in low-lying areas and are surrounded by roads. Toads can be extremely difficult to see on rainy nights and high levels of roadkill have been recorded. A shade-cloth and latte pole barrier was erected along the length of the road reserve for approximately 500 m on both sides of the road (Figure 9a). To prevent the toads from climbing the fence and reaching the road, the fence was placed at a 45° angle to the ground. Open buckets (Figure 9b) were buried at regular intervals along the fence to catch the toads. The toads were then transported to the other side of the road by volunteers. This short-term solution provided a trial for the use of temporary fences to direct movement of the WLT as well as improving the safety of volunteers and increase their availability to patrol other areas where needed. Plans are underway to erect more permanent barriers, as the temporary barriers are prone to damage and theft.
Figure 9: a) shade cloth and latte pole barriers by the road edge, and, b) open bucket with Western Leopard Toad, ready to be released. Curbs An alternate option to assist wildlife road crossings, is to incorporate a more permanent type of ‘fencing’, in the form of a concrete roadside curb. The curb acts as a funnel that can direct smaller species towards culverts underneath the road, whilst the design of the curb incorporates a lip at the top to prevent certain species from climbing or jumping over the barrier (Figure 10). This is effective for small mammals, reptiles and amphibians, and has a low labour cost. However, it is not easily deployed at locations with little or no shoulder, or where the shoulder is inundated with water.
Figure 10: A wall with a lip and culvert to prevent amphibians and small reptiles from crossing the road. The wall also directs them towards the culvert. 4.1.2 Road infrastructure adaptation Using noise as a deterrent Road noise causes certain species to avoid habitat around roads and may be an effective mitigation measure to drive animals away from roads. Applying rumble strips to the road surface may be a useful deterrent, since the tyre noise of the vehicles driving over the rumble strips will likely alert and scare animals away. This mitigation measure may reduce habitat connectivity as animals will be unlikely to cross the road, and should be considered alongside other mitigation measures.
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4.1.3 Habitat adaptation
4.1.4 Risk minimisation
Managing roadside habitat The cutting/removal or seasonal burning of dense vegetation on road verges will enable motorists to spot animals that are about to cross the road. However, care should be taken to minimise creating ‘open areas’ that effectively generate natural crossing areas which encourage animals to cross. Signage alerting drivers to animals crossing should also be used. The removal of roadside vegetation is controversial since it alters the habitat available for small rodents, and results in the destruction of plants along roadsides and contributes to fragmentation. Alternatively, rather than the complete removal of roadside vegetation, planting thorny, unpalatable cover plants for grass verges, and refraining from planting fruit-bearing vegetation along the roadside would discourage browsing/grazing roadside species. Intercept feeding The United States have tried interception feeding, placing food plots in areas away from the road thus drawing animals away from the road. This is a cost-effective measure and may be effective in South Africa where many grazers and browsers are often observed feeding on grass verges.
Whilst roadside fencing, and the road itself, may act as a barrier to wildlife populations, research suggests using these measures alongside other methods such as implementing slow speed zones, installing traffic-calming devices (e.g., speed-bumps) or placing cattle guards across the road, all of which may increase the effectiveness of the mitigation measure. Speed reduction / traffic calming / weight limits Existing studies from other countries have shown that animals often avoid roads when traffic volumes are high (~2000 vehicles/ day, Sweden) because high traffic volumes effectively act as a barrier to wildlife crossing roads. To prevent the ‘barrier-effect’, areas with high traffic volumes in South Africa should consider facilitating habitat connectivity through a wildlife crossing structure (Section 4.2.1). Speed restrictions and signage should be considered in areas where there are low traffic volumes to allow successful crossing by the animal. Slower speeds allow wildlife more time to cross the road as well as providing the driver with more time to see and react to the presence of an animal.
CASE STUDY: REDUCING OWL ROAD MORTALITIES IN SOUTH AFRICA A 9 km section of the N17 highway in Gauteng, South Africa, has seen numerous owl species killed on this road, including Marsh Owls, Grass Owls and Barn Owls. The Springbok Branch of the South African Hunter’s Association embarked on a conservation project to curb owl mortality on roads through erecting self-feeders away from the road so that the owls could feed in safer areas and avoid being killed on the roads.
Recent roadkill research studies in South Africa have shown more roadkill occurring when there were heavy trucks (5-6 axles) using the road. This would suggest that in some areas it may be appropriate to implement traffic control measures which limit the axle load of vehicles using the road. Signage specifying the vehicle types that are allowed access to the road will need to be erected in conjunction with enforcement measures by the appropriate enforcement agencies.
Figure 11: The Springbok Branch Owl Project with photos showing an African Grass-owl road mortality and details of the project. ROAD AHEAD | 11
Signage Signage is a common approach to informing motorists when road characteristics vary (such as bends in roads or bridges) as well as alerting drivers to the presence of animals near to the road. When used in isolation, signage is largely ineffective as the signs are usually fixed in one spot, South African animal signage is limited and drivers often ignore them. Figure 12: Species-specific signage as used in South Africa; (a) small species in Pilanesberg National Park, (b) African Wild Dogs in Pilanesberg National Park, (c) penguin signage in Table Mountain National Park, and (d) Western Leopard Toad signage in Noordhoek, Western Cape.
Species-specific signage has also proven successful in alerting drivers to animal presence, such as the African Wild Dog and Western Leopard Toad in South Africa (Figure 12), alongside better fencing and roadside verge maintenance. In addition, solar powered signage (as used in in Switzerland and Finland) (Figure 13) utilise motion sensors that flash when an animal breaks the infrared beam between signs, therefore alerting drivers to animal presence. This may also be effective for South African wildlife.
Figure 13: Road signs employed in Switzerland and Finland that respond to animal presence and alert drivers with flashing signage.
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Reflectors Many existing measures in the world have involved mitigating the impacts of deer-vehicle-collisions, most likely because they are the number one cause of insurance claims in a number of countries, causing the most damage to vehicles and/ or injury and even death to vehicle occupants. A cost-effective mitigation method adopted in the USA sees reflectors being used to deter deer from roadsides. These reflectors have shown a 79-90% reduction in deer-vehicle collisions and are mounted on posts along roadsides. They deter deer from attempting road-crossings by redirecting light from oncoming vehicle headlights across the road (Figure 13), creating an optical warning fence to deer. These tools may be effective for antelope in South Africa.
4.1.5 Public awareness campaigns Across the world, systems have been created to record wildlife-road-mortality observations by researchers, road maintenance workers, law officers, wildlife agency staff, insurers, and volunteers. These wildlife/roadkill observation systems (WROS) can include mobile recording devices for data collection, a web-site for data management and visualisation, and social media to reinforce reporting activity. One perception of volunteer science gathered data is that it may suffer from observer bias and identification error. However, this has not often been the case, and inaccuracies may be outweighed by the size of datasets available from volunteers. The Endangered Wildlife Trust has developed a Smartphone application, Road Watch, which integrates the roadkill photograph (taken by the data collector) with a global positioning system (GPS) that aids collection of roadkill data (Figure 15). This information is being used to identify roadkill hotspots and mitigation measures are being proposed for these danger zones.
Figure 15: Example of the Smartphone application, Road Watch, to allow the public to assist with roadkill data collection. 4.2 FACILITATE Facilitating a crossing whilst reducing the likelihood of a collision with an animal on the road can be done through the following: Figure 13: A photograph of a deer reflector.
•
CASE STUDY: ANIMAL-VEHICLE DETECTION SYSTEMS
•
Vehicle manufacturers are working towards improving driver safety and reducing wildlife collisions through animal-vehicle detection systems.
•
Bonnet-mounted ultrasonic whistles are devices intended to warn animals of approaching vehicles, but their effectiveness is still unproven as antelope appear to habituate to them very quickly. As a result, car manufacturing companies have piloted a system specifically designed to sense animals that are on the road ahead, warn the driver and hopefully reduce the chance of a collision taking place. The technology is based on existing pedestrian detection systems and uses both radar and infrared sensors to scan the road ahead. If a collision is thought likely, the system emits an audible warning and if no action is taken, the brakes of the vehicle are automatically applied. This would be of particular value in areas where large species occur (e.g. Greater Kudu).
Facilitating habitat connectivity through a wildlife crossing structure (over or underpass); Modifying existing structures and road infrastructure to facilitate wildlife movement; and Implementing risk minimisation schemes.
4.2.1 Facilitating habitat connectivity through a wildlife crossing structures Roads tend to restrict the movement of animals within their home ranges with many species completely avoiding crossing roads. It has been demonstrated that a variety of species will utilise man-made crossing structures specifically designed to facilitate animal movement. Movement patterns of many wildlife species are often associated with drainage lines, topography, and habitat, and through understanding the characteristics of species most at risk from roads, appropriate habitat-crossing-corridors can be designed. Wildlife under- and overpasses are used extensively in Europe and America. When there is suitable habitat at, and leading to, these passes, they are effective for a wide variety of animal
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species including invertebrates. Knowledge of the exact location of the migration route, correct tunnel design and installation, as well as the presence of guiding fences are all factors to be considered when designing wildlife passages. Overpasses Landscape bridge Also known as an “ecoduct” or “green bridge,” these crossing structures consist essentially of a bridge which extends over the road. The bridge has soil on it, and is planted with vegetation and enhanced with other habitat features (e.g. logs, rocks, waterbodies, etc.). These are suitable for animals of all sizes (Figure 16a/b), and are usually located in areas with high roadkill incidences, such as highways. A constraint is that they are often expensive to construct, although this cost should be weighed against the benefits to human-life through reducing a collision with large species that may result in either vehicle damage or vehicle occupant injury or death, as well as the loss of biodiversity.
Figure 17: Two photographs of rope bridges being used by (a) Lemuroid Ringtail Possum, (b) Angolan Colubus Monkey.
Underpasses Viaducts and underpasses for large species Wildlife underpasses are bridges and/or large culverts over dry land and sometimes land and water, constructed expressly to facilitate wildlife movement in important corridor areas. The length and height of these large culverts or bridges varies with the wildlife expected to use them and are a potential solution for the entire spectrum of species moving through an area (Figure 18a, b and c), although they may be expensive to install. Smaller mammals are likely to use some existing road structures, but larger underpasses are needed for larger species, such as antelope. These have been effective in other parts of the world, and may be of benefit in South Africa in protected areas and wildlife conservancies that are divided by roads. Figure 16: Two overpass wildlife passageways (a) Wolverine Overpass across the Trans-Canada Highway, Banff National Park, and (b) Hilversum Green Bridge, the longest wildlife overpass in the world, Holland. Canopy crossing Rope bridges across roads have proven successful for a number of arboreal species across the world. Rope bridge overpasses in Australia were effective in restoring rainforest habitat connectivity for the Lemuroid Ringtail Possum (Figure 17a) that was found to suffer high levels of road mortality, whilst rope bridges (called Colobridges) were adapted for the Angolan Colubus Monkey in Kenya (Figure 17b). These bridges may be particularly effective for the Samango Monkey in South Africa and are cost-effective to install. ROAD AHEAD | 14
Figure 19: Two photographs showing the Mount Elephant Corridor in Kenya with, (a) an overview of the underpass beneath the Nanyuki-Meru Highway, (b) elephants utilising the underpass. Herpetile tunnel Herpetile tunnels have proven effective for amphibians in many countries for reducing roadkill numbers as well as providing habitat connectivity. They are cost-effective as underground culverts can be easily converted into herpetile tunnels. These tunnels are installed at intervals along the road, between the amphibian’s pond and migrating habitat. In addition, a fence system can be jointly installed to direct the amphibians to the tunnel entrance. Vents in the top of the tunnels allow airflow, light and moisture which aids in the animals feeling ‘safe’ as climatic conditions remain constant within the tunnel (Figure 20). Figure 18: three examples of wildlife underpasses used in the world. (a) viaduct on the Ljubljana–Trieste Highway in Slovenia [593m in length] used in Slovenia on the Ljubljana–Trieste highway, (b) Idaho underpass with Elk passing through, and (c) underpass cutting beneath a major highway in America.
CASE STUDY: THE MOUNT KENYA ELEPHANT CORRIDOR The Mount Kenya Elephant Corridor comprises a 14 km fenced corridor that directs African Elephant beneath a busy underpass from one game reserve to another (Figure 19). Benefits of the connective corridor include a reduction in wildlife-vehicle collisions and loss to human-life.
Figure 20: Herpetile Tunnel - amphibian underpass design, with surface holes to allow water to keep tunnel wet, Australia. 4.2.2 Modification of existing structures and road infrastructure to facilitate wildlife movement Bridges Bridges over roads can be modified to aid wildlife crossings with the addition of a shelf pathway going under the bridge (Figure 21a/b). More permanent verge shelving can assist in directing wildlife towards crossings. Small mammals, such as rodents, are likely to benefit from these crossings.
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To prevent access to the road, the drainage culverts beneath roads can be modified with mesh fencing (attached using lowlevel fencing poles) to encourage small vertebrate species and amphibians to cross (see Section 4.1.1). Drainage grates Many smaller species have been found to use existing features of roads such as drainage grates (Figure 23a). These are only effective for small species, and drownings of smaller species may occur if additional mitigation such as ledges are not implemented. To prevent drownings, climb-out aids, for example synthetic fabric and perforated aluminium boards can be added to the drains (Figure 23b).
Figure 21: Photographs showing (a) a modified shelf pathway under a bridge for small mammals, and (b) a pedestrian underpass with modified crossing structure for arboreal species. Drainage culverts Drainage culverts beneath roads can be modified to allow small vertebrate species and amphibians to safely cross roads. Animals are able to move through the culverts on shelves and floating docks or through wildlife tunnels built parallel to the wet culvert (Figure 22). The additional cost for these modifications is minimal in comparison to the overall cost of the structure, although theft is a potential challenge.
Figure 23: Photographs showing a) rabbit using a storm drain in the UK, and b) a frog using an aluminium climb-out board to exit a drain.
Figure 22: Small mammal wooden plank crossing in a drainage culvert.
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Modified Jersey barriers Highway traffic barriers or ‘Jersey barriers’ are the central reservation between two streams of traffic. They usually act as safety barriers (to prevent head-on-collisions) and light reduction against oncoming traffic. Unfortunately, they also impede wildlife crossings, as wildlife may reach the centre of the road and then be unable to reach the other side. Jersey barriers can be modified to enable wildlife crossings by placing breaks at intermittent sections of the barrier, or placing ‘scuppers’ in the barrier for small species (such as small mammals, reptiles and amphibians) to crawl through (Figure 24 a/b). These are relatively cost-effective to install but will not assist larger species to cross the road.
Lighting A very important characteristic of functional crossings and wildlife corridors in urbanised areas is the absence of artificial lighting in the remaining fragmented natural areas. Some species of birds are attracted by street lights. To counteract this, varying the angle of the street light may deter wildlife attracted to roads, and reduce the chance of a collision. Alternatively, the colour of the street light can be changed from white to orange or yellow. Altering the street lighting is fairly effective in urban areas, particularly for minimising secondary roadkill (animals that scavenge roadkill carcasses). However, there is a high level of complexity with setup and there are little data available to support the installation of this method. Raised embankments / bird poles Global mitigation efforts for birds are limited due to the very nature of bird behaviour. Birds react to traffic by flying away, and this very act is often what results in their mortality as the down-draught from traffic ‘sucks’ them in and results in being killed on the road. Unlike terrestrial species, flying birds are unlikely to use wildlife passageways. The construction of high embankments on either side of the road to force birds to fly higher and avoid being pulled into the down-draught of vehicles may be an effective deterrent, particularly in certain areas of South Africa where large flocks of birds are likely to occur (Figure 25).
Figure 24: Central road barriers on American highways showing a) a break in the barrier for wildlife to cross, and b) concrete barriers with scuppers that allow small and mid-sized species to cross under the median barriers. 4.2.3 Facilitating movement through risk minimisation Controlling human activities is a significant factor in the success or failure of wildlife crossings and passageways. Adapting the roadside vegetation can reduce noise levels, block light spillage, and block the visibility of human activities. Below are some further examples of how to avoid a collision with an animal and still facilitate wildlife movement. Noise reduction Highway noise has become a factor in causing species to avoid habitat around the roads, which not only increases species fragmentation, but has been known to alter certain species’ mating calls. Suggestions to eliminate this include making quieter road surfaces, motors, tyres, and vehicle aerodynamics, and reducing pollution dispersal and using cleaner fuels.
Figure 25: A photograph showing a dual-carriageway in Australia with raised roadside embankment either side of the road. A further practise to mitigate for bird roadkill was implemented in Florida, America. PVC pipe poles were installed perpendicular to the railing on a bridge to keep bird flight patterns above the elevation of traffic (Figure 26). The rationale was to keep those birds that hover over the bridge from dropping down into traffic crossing the bridge and this saw a 64% reduction in bird road mortalities.
Figure 26: Bird poles erected on the Sebastian Inlet Bridge in Florida, America, have been found to reduce bird road mortalities by forcing the birds to fly higher above the traffic.
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5.
MIGATION STRATEGY EXAMPLES
No single method of mitigation for wildlife-vehicle collision has proven totally effective and we suggest that a number of methods be applied depending on the behaviour and location of the particular species in the hotspot area (e.g. fencing and signage). However, it is not always practical to design mitigation
projects that account for the specific requirements of all species affected by a road, and more generalised strategies may be more appropriate for making roads more permeable to wildlife passage for a large number of species (Table 2). The proposed mitigation measures recommended thus far are generic and do not take into account differences amongst individual species.
Table 2: Species identified as roadkill in South Africa with recommended mitigation measure to be applied.
Underpass
Overpass
Reflectors
Rumble strips
Intercept feeding
Canopy crossing
Managed roadside habitat
Bird poles
Raised embankments
Signage
Modified culveryt
Recommended mitigation measure
Fencing
Vertebrate species identified as at threat from roads
Herpetile tunnels
Taxon Group
Amphibians Amphibians Reptiles Snakes / agamas / geckos / chameleons Tortoise / terrapins / turtles Birds Birds of Prey Owls Ground-dwelling birds (e.g. francolins / quail) Seed eaters (e.g. weavers / canaries) Insect eaters (e.g. rollers / swallows) Mammals Pangolin Aardwolf / African Civet / Honey Badger Rodents Scrub Hare Vervet Monkey / Samango Monkey Genets / Bat-eared Fox / Black-backed Jackal / mongooses Small – medium sized antelope (e.g. duikers / Steenbok) Large antelope (e.g. Greater Kudu) Note: The list is not complete for all roadkill species, and is a recommendation for the species most commonly reported to date. Furthermore, traffic monitoring (for speed and volume) should also be included to determine if traffic calming measures should be included as a measure. ROAD AHEAD | 18
6.
FURTHER INFORMATION
For further reading and information, please consult the following: Website:
http://www.ewt.org.za/programmes/WTP/wtp.html
Blog:
http://endangeredwildlifetrust.wordpress.com
Facebook:
https://www.facebook.com/EndangeredWildlifeTrust
LinkedIn:
http://www.linkedin.com/groups/Roadkill-Research
Twitter:
@EwtRoads
We’ve also created a global Road Ecology Facebook page, so we can share more ideas with our global neighbours and partners: Facebook:
https://www.facebook.com/groups/roadecology/
Alternatively, you are welcome to contact us at: Telephone: E-mail:
+27 (0)11-372-3600
[email protected]
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7.
SUGGESTED LITERATURE
Bellis, M. A., Jackson, S. D., Griffin, C. R., Warren, P. S. & Thompson, A. O. (2007). Utilizing a multi-technique, multi-taxa approach to monitoring wildlife passageways on the Bennington bypass in southern Vermont. Road Ecology Center. Bertwistle, J. (1999). The effects of reduced speed zones on reducing bighorn sheep and elk collisions with vehicles on the Yellowhead Highway in Jasper National Park. In Proceedings of the International Conference on Wildlife Ecology and Transportation, Missoula, MT, September 13: 727. Bissonette, J. & Hammer, M. (2000). Effectiveness of earthen return ramps in reducing big game highway mortality in Utah. Road Ecology Center. Caltrans (2003). Literature review paper. Ventura 118; wildlife corridor assessment project, Caltrans District 7. Prepared by LSA Associates, Inc. California (Caron, P. & Pettler, A.). Caro, T. M., Shargel, J. A. & Stoner, C. J. (2000). Frequency of medium-sized mammal road kills in an agricultural landscape in California. The American Midland Naturalist, 144 (2), 362-369. Clevenger, A.P., Chruszez, B. & Gunson, K.E. (2001). Highway mitigation fencing reduces wildlife-vehicle collisions. Wildlife Society Bulletin, 29: 646-653. Clevenger, A. P. & Waltho, N. (2001). Factors influencing the effectiveness of wildlife underpasses in Banff National Park, Alberta, Canada. Conservation Biology, 14 (1): 47-56. Coffin, A.W. (2007). From roadkill to road ecology: A review of the ecological effects of roads. Journal of Transport Geography, 15: 396-406. Collinson, W.J. (2013). A standardised protocol for roadkill detection and the determinants of roadkill in the Greater Mapungubwe Transfrontier Conservation Area, Limpopo province, South Africa. (M.Sc. thesis). Grahamstown, South Africa: Rhodes University. Collinson, W.J., Parker, D. M., Bernard, R. T., Reilly, B. K. & Davies‐Mostert, H. T. (2014). Wildlife road traffic accidents: a standardized protocol for counting flattened fauna. Ecology and Evolution, 4 (15): 3060-3071. Craighead, L.F., Craighead, A.C. & Roberts, E.A. (2001). Bozeman Pass wildlife linkage and highway safety study. Proceedings for the International Conference on Ecology and Transportation (ICOET), North Carolina State University, Raleigh, NC: 405-422. D’Angelo. G.J., D’Angelo, J. G., Gallagher, G. R., Osborn, D. A., Miller, K. V. & Warren, R. J. (2006). Evaluation of wildlife warning reflectors for altering white‐tailed deer behavior along roadways. Wildlife Society Bulletin, 34 (4): 1175-1183. Evink, G.L. (2002). Interaction between roadways and wildlife ecology: a synthesis of highway practice. NCHRP Synthesis 305. Transportation Research Board of the National Academies. Goosem, M., Weston, N. & Bushnell, S. (2005). Effectiveness of rope bridge arboreal overpasses and faunal underpasses in providing connectivity for rainforest fauna. Road Ecology Center. Hedlund, J., Curtis, P. D., Curtis, G. & Williams, A.F. (2004). Methods to reduce traffic crashes involving deer: what works and what does not. Traffic Injury Prevention, 5 (2): 122-131. Hobday, A.J. & Minstrell, M.L. (2008). Distribution and abundance of roadkill on Tasmanian highways: human management options. Wildlife Research, 35 (7): 712–726. Jackson, S.D. & C.R. Griffin. (2000). A strategy for mitigating highway impacts on wildlife. In Messmer, T.A. and B. West, (eds.). Wildlife and highways: seeking solutions to an ecological and socio-economic Dilemma. The Wildlife Society: 143-159. Jaeger, J.A.G., Bowman, J., Brennan, J., Fahrig, L., Bert, D., Bouchard, J., Charbonneau, N., Frank, K., Gruber, B. & Tluk von Toschanowitz, K. (2005). Predicting when animal populations are at risk from roads: an interactive model of road avoidance behavior. Ecological Modelling, 185: 329-348. Kobler, A. & Adamic, M. (1999, September). Brown bears in Slovenia: identifying locations for construction of wildlife bridges across highways. In: Proceedings of the third international conference on wildlife ecology and transportation. FL–ER–73–99. Florida Department of Transportation, Tallahassee : 29-38. Lesbarrieres, D. & Fahrig, L. (2012). Measures to reduce population fragmentation by roads: what has worked and how do we know? Trends in Ecology and Evolution, 3: 1-7.
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Ludwig, J. & Bremicker, T. (1983). Evaluation of 2.4 m fences and one-way gates for reducing deer-vehicle collisions in Minnesota. Transportation Research Record, 913: 19-22. Orlowski, G. (2008). Roadside hedgerows and trees as factors increasing road mortality of birds: Implications for management of roadside vegetation in rural landscapes. Landscape and Urban Planning, 86: 153-161. Parris, K.M. & Schneider, K. (2008). Impacts of traffic noise and traffic volume on birds of roadside habitats. Ecology and Society, 14: 29. Putnam, R.J. (1997). Deer and road traffic accidents: options for management. Journal of Environmental Management, 51: 43-57. Seiler, A. (2003). The toll of the automobile: wildlife and roads in Sweden. PhD thesis, Swedish University of Agricultural Sciences, Uppsala. Shilling, F., Collinson, W.J. & Perkins, S. Wildlife Road Observation Reporting Systems van der Ree, R., Smith, D. J., and Grilo, C. (eds) (2015). Handbook of Road Ecology. John Wiley & Sons, Oxford. Spellerberg, I.F. (1998). Ecological effects of roads and traffic: a literature review. Global Ecology and Biogeography, 7: 317–333. Sun, J. W. & Narins, P. M. (2005). Anthropogenic sounds differentially affect amphibian call rate. Biological Conservation, 121 (3), 419427. Taylor, B.D. & Goldingay, R.L. (2010). Roads and wildlife: impacts, mitigation and implications for wildlife management in Australia. Wildlife Research, 37: 320-331. van der Ree, R., Gulle, N., Holland, K., van der Grift, E.A., Mata, C. & Suarez, F. (2007). Overcoming the Barrier Effect of Roads – How effective are mitigation strategies? An international review of the use and effectiveness of underpasses and overpasses designed to increase the permeability of roads for wildlife. In: Proceedings of the 2007 International Conference on Ecology and Transportation (ICOET), edited by C. Leroy Irwin, Debra Nelson, and K.P. McDermott. Raleigh, NC: Center for Transportation and the Environment, North Carolina State University, 2007: pp. 423-431. van der Ree, R., Smith, D.J. & Grilo, C. 2015. Handbook of Road Ecology. Wiley-Blackwell. 552pp. Veenbaas, G. & Brandjes, J. (1999). Use of fauna passages along waterways under highways. In Proceedings of the 1999 International Conference on Wildlife Ecology and Transportation: 269-255. Waring, G. H., Griffis, J.L. & Vaughn, M. E. (1991). White-tailed deer roadside behavior, wildlife warning reflectors, and highway mortality. Applied Animal Behaviour Science, 29 (1): 215-223. Wood, P. & Wolfe, M.L. (1988). Intercept feeding as a means of reducing deer-vehicle collisions. Wildlife Society Bulletin, 16 (4): 376380.
8. PHOTO CREDITS AND SOURCES Figure 7: Canadian Ecosytems Alliance http://www.canadianecosystemsalliance.ca Figure 8 and 9: Collinson (2015) and Faraday (2013). Figure 10: FHWA http://www.fhwa.dot.gov Figure 11: Collinson (2014), Van Vuuren (2014). Figure 12: Collinson (2014). Figure 13: Western Transportation Institute. www.westerntransportationinstitute.org ROAD AHEAD | 21
Figure 14: Strieter-Lite ® 2002. http://www.strieter-lite.com Figure 15: Burger (2014). Figure 16: Gunson http://www.mun.ca/biology/conservation/mitigation2.php http://www.wildlifeandroads.org/decisionguide/2_1_6.cfm Wageningen http://www.atlasobscura.com/places/natuurbrug-zanderij-crailoo Figure 17: Goldingay https://pollinatorlink.wordpress.com/page/6/ Coastweek http://www.coastweek.com/3820-Colobus-monkey-canopy-bridge-is-saving-lives-over-Ukunda-Road.htm Figure 18: Nationalzoo.si.edu http://nationalzoo.si.edu/SCBI/WildTigers/pdfs/Evaluation%20of%20Best%20Mgmt%20Practices.pdf Idaho Department of Fish and Game http://arc-solutions.org/wp-content/uploads/2012/07/ID_20_ARTICLE_PHOTO_cLuEC. AuSt_.36.jpeg Live Science http://i.livescience.com/images/i/000/062/693/original/grizzly-bear-family-using-metal-culvert-underpass[17]. jpg?1392763725 Figure 19: Lewa http://www.lewa.org/wildlife-security/the-elephant-underpass/ Figure 20: FHWA https://www.environment.fhwa.dot.gov/ecosystems/wvc/images/fig115.jpg Figure 21: Ferreira http://digital.csic.es/bitstream/10261/42404/1/CAPITULOS_DE_LIBROS311821[1].pdf smh.com http://www.smh.com.au/ffximage/2004/06/27/430-koala,0.jpg Figure 22: Cramer (2004) http://www.wildlifeandroads.org/media/images/gallery/pc_mt_us93-01.jpg Figure 23: Bunyard http://i2.coventrytelegraph.net/incoming/article2980470.ece/ALTERNATES/s615/paul-bunyard-took-this-picture-of-an-rabbit-in-a-drain-797345138.jpg Amphibians in Drains Project 2012. Figure 24: FHWA http://naturewalkswithmark.org/blog/wp-content/uploads/2011/04/Jersey-Barrier1.jpg http://naturewalkswithmark.org/blog/tag/jersey-barrier/ https://www.environment.fhwa.dot.gov/ecosystems/wvc/images/fig9.jpg Figure 25: https://upload.wikimedia.org/wikipedia/commons/e/e6/Eastern_Freeway_Belford_St.jpg Figure 26: Marcel Huijser https://www.environment.fhwa.dot.gov/ecosystems/wvc/images/fig135.jpg
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Physical Address: Building K2, Ardeer Road, Pinelands Office Park, Modderfontein 1609, Gauteng, South Africa, Postal Address: Private Bag X 11, Modderfontein 1645, Gauteng, South Africa Tel: +27 (0) 11 372 3600 Fax: +27 (0) 11 608 4682
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