A research project looks at whether wildlife crossings work.
Where roads cut into wild areas, special animal crossings are built to prevent roadkill. But do these measures work?
THE forest reserves around Tasik Kenyir in Terengganu teem with wildlife. Aside from the 230 bird species which the area is known to harbour, research group Rimba in recent surveys has recorded at least 19 mammal species in the area.
Their camera traps have captured stunning images of various rare and endangered species. In one picture, a female Asian elephant and her calf, their eyes shining in the flash of the camera, are seen making their way through leaf litter. In other images, tigers, sun bears, clouded leopards, tapirs and serows make up more of the jungle milieu.
For most of these animals, a large expanse of habitat is crucial for populations to remain viable in the long term. But their habitats are being cut up by advancing development. In addition to being a barrier for animals to reach resources such as food, shelter and mates, isolated and fragmented habitats pose a threat to the healthy mixing of populations. A genetically diverse pool of individuals is needed to avoid the negative effects of inbreeding and reduced genetic diversity.
Unfortunately habitat fragmentation is a problem in Malaysia, albeit one that has, to an extent, been addressed by the Central Forest Spine (CFS). Part of the National Physical Plan, the CFS is a masterplan which delineates a network of forest complexes connected by ecological linkages (corridors of forested land) to create a contiguous forest running the length of Peninsular Malaysia.
The forests around Tasik Kenyir, including the Hulu Temelong, Petuang and Tembat forest reserves (in which Rimba researchers are surveying a 140sqkm stretch), make up one such linkage. Known as Primary Linkage 7, this green corridor links Taman Negara to forests in the north. The area is one of three priority areas in the National Tiger Action Plan, a blueprint document on the conservation of the big cat.
The reserves are bisected by the Kuala Berang highway, which forms a dangerous barrier for migrating wildlife. Intrusions such as this into the sanctity of our wilderness are by no means unique and are a regular occurrence worldwide.
The trend of building wildlife crossing structures began in the 1950s and is today a common strategy deployed in many countries. Some of the most recognisable structures were built in the 1970s in Banff National Park in Alberta, Canada, where 24 vegetated overpasses provide safe passage over the Trans-Canada Highway for bears, moose, wolves and many other species.
Crossings don’t have to pass over obstacles, however. In the Netherlands, over 600 tunnels have been installed under major and minor roads to aid in movements of the endangered European badger.
In Malaysia, the Kuala Berang highway features 10 viaducts which offer traffic-free crossing points for wildlife. Viaducts are elevated road structures, typically passing over a valley or lower ground, and supported by arches or columns. Three of these viaducts were built specifically as wildlife crossing points, and have been termed “eco-viaducts”. Unlike the vegetated overpasses in Alberta, safe passage for wildlife in our viaducts lies with passing under the structure.
The construction of eco-viaducts in Malaysia has been championed by environmentalists as a promising measure but there have as yet been no studies to confirm their effectiveness in the tropical context. The task of verifying their usefulness is a huge undertaking and requires many months of survey and data collection through thick forest, followed by months of data analysis.
Nonetheless, having science to verify the effectiveness of well-intentioned policy is important to ensure the best solutions for protecting Malaysia’s valuable stocks of biodiversity. That is precisely the thinking behind Rimba, a coalition of local and foreign scientists, which has embarked on a project to monitor the use of wildlife crossings along the Kuala Berang highway.
The combination of wildlife crossings and roadside fencing has been found to be helpful for some species. Rimba’s Kenyir Wildlife Corridor Project lead researcher Gopalasamy Reuben Clements, 32, says that in Malaysia, the Wildlife and National Parks Department (Perhilitan) had previously tried to funnel animals underneath viaducts through the construction of electric fences.
But what works for wildlife crossings in other countries might not be appropriate for Malaysia. One consideration is a difference in local fauna. Elephants, for example, are known to have fixed migration routes; they broke through the fencing.
Another important factor is rampant illegal trade in wildlife. The country’s excellent infrastructure and road networks, many of which bypass forest reserves, not only open up access to wildlife poachers but offer convenient routes for a speedy onward journey.
“So far, NGOs have been recommending the building of viaducts but the poaching element hasn’t been looked at,” Clements points out. The conservation biologist hopes his study will determine whether animals at such wildlife crossings might in fact, be more vulnerable to poachers.
The Kenyir Wildlife Corridor Project is part of his PhD research with James Cook University in Queensland, Australia. A Singaporean and Master’s graduate from the National University of Singapore, Clements is also a research associate with Universiti Malaya and previously worked at World Wide Fund For Nature Malaysia on tiger and rhinoceros conservation projects.
In total, Clements and his team have installed 80 camera traps – 40 within forest reserves on either side of the highway, and the rest, in and around the viaducts. They
have covered 140sqkm of jungle, trekking some 8km a day and roughing it out in the jungle, to look for signs of wildlife and rotate cameras around the study grid to get a more representative data.
Covering the entire area took them three months, and they still have two more rounds of sampling to go before it’s time to analyse the data. Nevertheless, the team has already been able to glean some insights.
For example, they noticed one particular tiger, recognisable by its stripes, was captured by cameras located both north and south of the highway, but not at ones placed near or under any of the viaducts.
“That shows it didn’t use the viaduct. So for large mammals, these viaducts may not be so useful. But as you can see, you have tapirs and other animals to consider, too. And we don’t know whether the tiger will use the viaduct in the period between now and the end of the study, so it’s just preliminary.”
Part of the project’s mission is to identify potential access routes for encroachment. This they found – near, under and along the viaduct access road. They also found old camps in sheltered areas underneath the viaducts, and cameras have captured images of people carrying fishing rods. Such evidence of human presence is not seen at three of the newer viaducts. Clements hypothesises that these are probably too remote.
The study should reveal if wildlife are actually utilising the structures and if so, which ones. But what do we do if the ecoviaducts prove to be less effective than hoped? That, according to Clements, does not mean the structures lose their usefulness. It might call for a tweak in strategies – such as more wildlife patrols – to increase their effectiveness.
By seeing how other factors determine the effectiveness of eco-viaducts, future crossings can be planned accordingly. Potential factors, says Clements, could be the distance between the viaducts and human settlements, the quality of forests on the other side of the road barrier, and physical features such as reduced vegetation under the viaduct or reduced food resources due to the presence of large adjacent water bodies.
The Rimba project is a mammoth undertaking requiring expensive technology (the cameras, password-protected and possessing inbuilt lens, cost RM1,500 each) and manpower (to conduct surveys and handle the cameras). Clements has 80 camera traps in action right now but needs 150. With more cameras, his team can do more accurate population estimates.
So far, funds have come from grant disbursing organisations, including the two universities Clements is attached with, and private donors. These are enough to pay for the 80 cameras and five field assistants.
Rimba also needs funds for 10 satellite collars for a project on the management and ecology of Malaysian elephants, to be led by Ahimsa Campos-Arceiz, an assistant professor with the University of Nottingham (Malaysia campus). At RM13,000 each, the collars will show the movement patterns of each animal, thus providing insight into how they cross roads and use viaducts.
Companies, organisations, societies, schools and individuals can support the work of Rimba by adopting a camera, satellite collar or ranger.
Camera trap (RM1,500) – You will get a certificate, the opportunity to personally place your camera trap in the forest, and get e-mail updates of captured images every three months.
Satellite collar (RM13,000) – You will get updates of the collared animal every three months, a half-yearly progress report and a three day-two night stay at Rimba Field House.
Ranger (RM18,000) – You will get a certificate, an opportunity to place three camera traps in the forest, receive e-mail updates on these traps every three months as well as a half-yearly progress report, and a three daytwo night stay at Rimba Field House plus an opportunity to accompany the ranger on field surveys.
Clements believes that creating a bridge between researchers and the public as well as providing people with opportunities to get involved in conservation projects can make a difference. Research is important – it helps indirectly by knowledge creation, and deters illegal poachers by the mere presence of researchers in the forest. On that note, it is a cause worth supporting.
For more on Rimba: myrimba.org or facebook.com/pages/Rimba/154235447971255 or e-mail firstname.lastname@example.org.
Look before you cross: This leopard, about to cross the Kuala Berang highway in Terengganu, could easily end up as roadkill. — Pic courtesy of Rimba
Come this way: An ‘eco-bridge’ at Sungai Kembur along the Simpang PulaiKuala berang road enables animals to cross between forests fragmented by the highway. (Pic right) When roads cut through wild areas, animals can end up as roadkill.
Gopalasamy reuben clements, co-founder of rimba and lead researcher of the Kenyir Wildlife corridor Project, fixing a camera trap to a tree in a forest reserve near Tasik Kenyir. He and his team have fixed some 80 camera traps in the forests around the Kuala berang highway in Terengganu to monitor wildlife there.
Caught on camera:
(From left) Serow, sun bears, clouded leopard, tapirs and dholes (wild dogs). — Pics by rimba