Animal crossings: the ecoducts helping wildlife navigate busy roads across the world

India's tiger corridor and Australia's possum tunnel of love' are among the myriad infrastructure projects providing safe passage

• How creating wildlife crossings can help reindeer, bears - and even crabs
• Read more in our series Biodiversity: what happened next?

From a tiny railway bridge for dormice in the UK to elk, deer and bears benefitting from a slew of new animal crossings in Colorado, wildlife bridges are having a moment. As the human footprint on the planet continues to expand, a growing number of roads and railways include provisions for wildlife to pass through fragmented landscapes.

In January, we reported on Sweden's plans to build a series of renoducts" to help reindeer traverse the country's main roads. The Swedish Transport Administration has since completed an ecoduct over the E6 in Skane in southern Sweden, the third in the county. In southern California, work is due to begin on the largest wildlife bridge in the world in 2022, to connect isolated mountain lion populations north of Los Angeles that are becoming dangerously inbred. Joe Biden has earmarked $350m (260m) of his $1.2tn infrastructure package for wildlife bridges to lessen the multibillion annual cost of collisions.