‘Roads or borders?’ – this question posed by Chen (2017) succinctly captures the differential impact of urban developments on human and non-human inhabitants of the city. As urban developments encroach upon and intersect nature, the hybrid socio-natural spaces produced encompass variegated encounters between the two realms, with profound consequences (Swyngedouw, 1996). This is clearly illustrated in the case of urban mobility – while transport infrastructures have enabled increasingly rapid movements of people, wildlife movement have been contrastingly impeded.
Reconnecting a divided forest
In 1986, Singapore’s central nature reserve was split into two by the Bukit Timah Expressway (BKE). The six-lane expressway runs through the centre of Singapore, dividing the reserve into the Bukit Timah Nature Reserve and the Central Catchment Nature Reserve.
While enhancing connectivity for motorists, BKE forms a physical barrier to wildlife movement. Wildlife populations were isolated, with knock-on impacts on genetic diversity and biological fitness. For instance, the common Long-tailed Macaque in Singapore’s forests separated into two sub-populations, showing signs of inbreeding depression (Chung et al., 2016).
The throngs of traffic however, did not stop all wildlife from attempting to cross the BKE, with often fatal consequences. The BKE has seen many vehicular-wildlife collisions since its construction. This includes that of critically endangered animals like the Sunda Pangolin – from 1994-2014, an average of 2 pangolins perished from roadkills (Chew and Pazos, 2015). While this number may seem small, there are only roughly 50 pangolins in Singapore (ibid).
With growing environmental consciousness, a wildlife overpass, Eco-link@BKE, was built in 2013. Being the first of its kind in Singapore and South-east Asia, Eco-link@BKE was a major step forward in Singapore’s conservation practise – signifying a shift from merely conserving remaining nature areas to active restoration seeking to undo previous scars.
Laudably, extensive research and nature surveys were conducted to conceive the overpass’s design: including an hour-glass shape to funnel wildlife onto the overpass, and meticulously planned soil and vegetation composition.
Positive results have been seen, with cameras sighting various wildlife crossing the eco-link, such as pangolins and palm civets.
That said, Eco-link@BKE is by no means a panacea. Despite being designed to funnel wildlife, the overpass is ultimately only situated at a particular point along the entire intersection. With the lack of concrete barriers to prevent wildlife from getting on the road, roadkillings still occur (Wang, 2019). For instance, in 2018, a rare Sambar deer was euthanised after a collision on BKE and a pregnant wild boar tragically died along with its unborn litter of piglets.
These large mammals in particular are prohibited from using the Eco-link@BKE as they are thought to damage the Bukit Timah Nature Reserve, with the smaller forest being unable to support the foraging of large mammals. Though this decision was made for the interest of wider conservation aims, it is evident how infrastructural designs continue to control species’ (im)mobility.
The risk of tokenism
Wildlife overpasses risk being portrayed as a magic bullet for habitat fragmentation. In the case of Eco-link@BKE, the overpass is ironically more visible to humans than wildlife, with its beautifully designed façade standing out for passing motorists (Wang, 2019).
With its heavy publicity – from widespread news coverage, grand tree-planting opening event to guided walks for the public – Eco-link@BKE is arguably more than a restoration effort but instead, a branding project promoting Singapore’s dedication to biodiversity conservation. Such an image is key to Singapore’s quest of becoming a ‘leading sustainable city’ (Wang, 2019:19).
In this sense, there lies a danger of wildlife overpasses being used to legitimise developments affecting nature areas. For instance, just opened in December 2019, Singapore’s second wildlife overpass, Mandai Wildlife Bridge, was built as a mitigation measure against wildlife displaced by the upcoming Mandai eco-tourism hub which encroaches on secondary forests. Environmentalists have criticised the move, highlighting the overpass’s inadequacies – narrow width of 30m (compared to the 50m wide Eco-link@BKE), proximity to visitor look-outs of wildlife parks and poor timing (construction of wildlife parks began in 2017, way before completion of the overpass) (NSS, 2016).
Imagining convivial urban mobilities
Evidently, the proximity of nature areas to roads have created treacherous journeys for wildlife in Singapore, exacerbated by developments encroaching upon nature areas. While wildlife overpasses have been constructed to facilitate wildlife movements across roads, perilous and often fatal animal crossings have yet to cease. Regrettably, wildlife overpasses risk becoming an ‘ethical bypass’, justifying continual appropriation of nature for urban growth (Wang, 2019:19). In line with the push for conviviality (Hinchliffe and Whatmore, 2006), it is crucial to rethink our modes of development, in order to enable the mobilities of non-human inhabitants.
Chen, M. (2017) ‘How effective are wildlife corridors like Singapore’s Eco-Link?’ (WWW) Menlo Park, California, United States: Mongabay (https://news.mongabay.com/2017/07/how-effective-are-wildlife-corridors-like-singapores-eco-link/ ; 20 Nov 2020).
Chew, H.M. and R. Pazos (2015) ‘Animals Crossing Eco-Link@BKE: Safe passage for creatures over busy highway’ (WWW) Singapore: The Straits Times (http://graphics.straitstimes.com/STI/STIMEDIA/Interactives/2015/11/feature-ecolink-BKE-national-parks/index.html ; 20 Nov 2020).
Chung, Y.F., T.W. Wong and S. Chan (2016) ‘Eco-Link@BKE: A Safe Corridor for our Biodiversity’, CITY GREEN, 12, 92-95.
Hinchliffe, S. and S. Whatmore (2006) ‘Living cities: Towards a politics of conviviality’, Science as Culture, 15, 2, 123-138.
NSS (2016) Nature Society’s Position Paper on the Mandai Safari Park Holdings (MSPH)’s Mandai Development Plan, Singapore: Nature Society Singapore (NSS).
Swyngedouw, E. (1996) ‘The city as a hybrid: On nature, society and cyborg urbanization’, Capitalism Nature Socialism, 7, 2, 65-80.
Wang, J. (2019) ‘ReImagining Urban Movement in Singapore: At the Intersection Between a Nature Reserve, an Underground Railway and an Eco-Bridge’, Cultural Studies Review, 25, 2, 8-30.