In urban areas where natural animal habitats are often limited to small areas, ecological corridors are one way to maintain vibrancy and biodiversity. By linking disparate nature reserves, wildlife corridors create a greater composite habitat for plant and animal species, increasing genetic diversity by allowing interbreeding and allowing species that require large land areas to survive to return to urban areas.
One such example exists in Singapore, where large swatches of rainforest have been preserved as nature reserves. Two of the most important reserves were isolated from each other in 1983 by the construction of the Bukit Timah Expressway, a busy six-lane dual carriageway expressway, severing natural connections between the Bukit Timah Nature Reserve
(around 1.64 square kilometres) and the Central Water Catchment (Singapore’s largest nature reserve at around 28.8 square kilometers).
In 2013, the Bukit Timah Eco-Link was completed, a 16 million dollar bridge exclusively for the use of animals, birds, and insects to cross between the two nature reserves. This green connection joins similar structures around the world (ranging from simple tunnels under expressways to other lushly planted bridge structures.
See more on the design of the Eco-link @ BKE and the environmental rationale behind wildlife crossings.
