This is the story of how a problem became a solution, and how a solution changed the way a country thought about its roads.
A young wildlife ecologist named Dr. Maya Lin was tasked with monitoring the corridor. She placed heat-motion cameras on five signal posts. Over three months, she recorded 147 koala approaches. 119 ended with the koala climbing the post. 12 of those koalas were later struck by trains after descending onto the tracks.
Her report was clear: "Koalas perceive vertical structures as trees. To a koala, a steel post is a eucalyptus. The solution is not to stop koalas from climbing—it is to give them a tree worth climbing." koala windows
Today, Koala Windows are standard infrastructure on new road and rail projects in Queensland and New South Wales. They have been adapted for squirrel gliders (smaller ledges), spotted-tailed quolls (wider platforms), and even tree frogs (grooves that hold water). The design was open-sourced by the Australian government in 2021. Versions now exist in Japan (for raccoon dogs), Brazil (for golden lion tamarins), and Canada (for martens).
The results were astonishing. In a two-year trial along a 3-kilometer stretch of rail, koala mortality dropped by 91%. Gliders, possums, and even a goanna were recorded using the windows. The structures required no lighting, no moving parts, no electricity. They worked in drought and flood. This is the story of how a problem
Reyes replied: "So we didn't build a crossing. We built a lesson."
But the real innovation came when Lin asked a simple question: "What do they see through the window?" She realized that if the view from the climbing panel showed only more fragmented habitat, the koala would simply climb back down. So the team began orienting the windows toward intact vegetation corridors. They even experimented with scent—smearing eucalyptus oil on the inside rim of the window to suggest that the destination was worthwhile. She placed heat-motion cameras on five signal posts
The first "Koala Window" was not a window at all. It was a 6-meter-high panel of recycled polymer, molded to mimic ironbark bark, with hidden ledges and woven vines of durable coir fiber. It was attached to the side of an existing overpass. It cost $4,000 AUD—less than one rail signal post replacement.