In order for the natural world to exist alongside fast-moving vehicles and towering skyscrapers, we’ve had to come up with some creative solutions to ensure the conservation of animal species.

In Singapore, If you’ve driven on the Bukit Timah Expressway, you might have noticed an eco-bridge linking the Bukit Timah Nature Reserve and Central Catchment Nature Reserve.

What you might not know is that this bridge, the first of its kind in Southeast Asia, was built with one main purpose: To promote biodiversity conservation. With no safe passage across the two nature reserves, existing plant and animal species (with already shrinking populations) would be cut adrift from their kind on the other side of the expressway.

Singapore isn’t the only country that had to think up a solution to make sure that wildlife would not be harmed by human development.

Here are some inventive animal crossings around the world that have been successful in allowing their wild pedestrians to go about their daily lives safely:

Elephant Tunnel, Kenya

Photo: Africa Geographic

This tunnel is located beneath a main road in Kenya, at the foothills of Mount Kenya. It was built to unite two distinct elephant populations that had been separated for years by the road. The tunnel is lined with elephant dung and hay to encourage the animals to move through it instead of across the busy road.

Besides putting the elephants in danger, the main road also became hazardous to motorists whenever an elephant decided to use it to cross over to the grasslands on the other side. To date, the tunnel has been successful in linking 2,000 elephants on Mount Kenya with 5,000 more below.

Blue Penguin Underpass, Oamaru

Photo: The Country News

New Zealand’s blue-feathered little penguins are the tiniest species of penguin in the world, where their lives on the coast of New Zealand are often threatened by cars, larger animals and the occasional human being. The little birds fish at sea, but nest on land at a particular part of Oamaru Harbour where the underpass was built.

At the end of each day, the penguins would have to cross a busy road to get back to their nests where their chicks lay waiting. In addition to the danger of speeding vehicles, the birds were also subject to blinding by the white headlights of passing cars, making road-crossing even more dangerous for these little guys.

Thankfully, the penguins have been using the tunnel ever since they realised that it was a safer route than crossing the road.

Crab Bridge, Christmas Island

Photo: The Telegraph

Every year, a whopping 50 million crabs make their way out to sea to spawn in Australia. Unfortunately, many of them did not get very far because of a busy road that stood in the way of their homes inland and their destination out at sea.

In response to this annual tragedy, a five-meter high bridge was constructed to assist the crabs in their migration. To add to that, more than 20 kilometers of plastic barriers were put up to direct the crabs away from the road.

During this epic move, large portions of the Australian island are painted bright red from the crustaceans, which has become a tourist attraction over the years.

*This article was updated on 26 Jul 2020. It first appeared in on 28 Feb 2017.