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."
This is the story of how a problem became a solution, and how a solution changed the way a country thought about its roads. koala windows
It started in the early 2010s on the eastern slopes of the Great Dividing Range, where the Brisbane-Sydney rail line cuts through a remnant patch of eucalyptus forest. Koalas in this region—already stressed by habitat fragmentation and chlamydia—faced a new, silent predator: the 8:15 AM express train. Collisions were rising. A koala, when startled on the ground, doesn't run. It climbs. And the nearest vertical structure was often a steel rail signal post.
They installed five prototypes. Within a week, a female koala named "Bumpy" (for the scar on her nose) was photographed climbing one, pausing at a ledge, and using it to cross over the tracks without ever touching the ground. The panel had a small, circular opening near the top—a "window" through which a koala could observe the other side before committing. Reyes, an amateur photographer, captured Bumpy peering through that hole, her furry face framed like a portrait. The image went viral locally. "Koala Window" stuck. A young wildlife ecologist named Dr
But the heart of the story remains a single email. After the bushfire, Dr. Lin wrote to Reyes: "Bumpy made it. She used the window three times in one night. Her joey was with her. She showed him how."
Enter the engineers. Traditional wildlife crossings—overpasses planted with native shrubs—were too expensive for this narrow rail corridor. Tunnels failed because koalas rarely enter dark, enclosed spaces on the ground. But a chance conversation between Lin and a structural engineer, Tomás Reyes, led to a radical idea. Reyes was designing a noise barrier for a new housing estate. "What if," he asked, "we make the barrier rough, planted, and vertical? A fake tree that's actually a real habitat?" Over three months, she recorded 147 koala approaches
Then came the twist. In 2018, a bushfire tore through the same forest. The main koala habitat was reduced to ash. But the Koala Windows—their polymer surfaces scorched but intact—stood. And weeks later, motion cameras showed surviving koalas using the windows not just to cross the tracks, but to reach a small unburned gully on the other side. The artificial trees had become a lifeline.