A biological marvel that behaved more like a mouse than a traditional flying mammal. While most bats around the world are masters of the air, the New Zealand short-tailed bats evolved to be masters of the forest floor. The Peka-peka-tou-nui was the larger, more robust cousin of the surviving lesser short-tailed bat, and it possessed a suite of physical adaptations that allowed it to scramble, run, and burrow through the leaf litter with astonishing agility. Its wings were uniquely designed to fold away into leathery sheaths along its sides, protecting the delicate flight membranes while the bat used its sturdy elbows and clawed feet to hike across the ground. It did not just fly to its food. It hunted on foot, lunging after large flightless insects, scavenging fallen fruit, and even drinking nectar from the flowers of the ground-dwelling Dactylanthus plant. This grounded lifestyle, perfected over millions of years in a land without mammalian predators, became a fatal liability when rats arrived. The extinction of the greater short-tailed bat is a direct and heartbreaking consequence of a single biosecurity failure. In the early 1960s, ship rats accidentally reached Big South Cape Island, the species' final sanctuary. Within just a few years, the rats had decimated the bird and bat populations of the island. The last confirmed sighting occurred in 1967. Despite several expeditions into the remote, rugged corners of the southern islands, no one has heard the high-pitched chatter or seen the scurrying shadow of this bat since. It vanished before we had the technology to properly map its genome or understand the full complexity of its social life in the deep forest. Physically, the greater short-tailed bat was a heavyweight compared to its surviving relative, with a larger wingspan and a more powerful build. It lived in large communal roosts, sometimes numbering in the hundreds, tucked away in the warm, dry hollows of ancient trees. These roosts were social hubs, filled with the scent of musky oils and the constant sound of social grooming. The bats played a vital role in the forest ecosystem as pollinators and seed dispersers, moving silently through the night to ensure the next generation of trees could take root. Because they spent so much time on the ground, they were also highly susceptible to changes in the forest floor, making them the canary in the coal mine for the health of the New Zealand bush. Today, the greater short-tailed bat exists only as preserved specimens in museum drawers and as a cautionary tale in the annals of conservation. It serves as a stark reminder that in New Zealand, the difference between survival and extinction can be as small as a single rat on a single boat. While some hold out hope that a small, undetected population might still linger in the inaccessible caves of the subantarctic islands, the silence of the last sixty years is heavy. To remember the Peka-peka-tou-nui is to acknowledge the fragility of our unique evolutionary treasures. It was a bat that chose the earth over the sky, and in doing so, it became one of the most distinctive and missed inhabitants of the New Zealand night.