Ben Nyberg stood on a knife-edge ridge along Hawaii’s Na Pali Coast, his eyes scouring the leafy recesses of the neighboring red-rock ridges. It was quiet, if not for a faint buzzing of a drone flying among flocks of curious white-tailed tropicbirds.

Nyberg steered the drone closer towards the opposing ridge, scanning the iPad in his hands, which acted as a viewfinder. Then, he saw it: Wilkesia hobdyi.

Its tufted bright green leaves stood out from other plants clinging to the cliff, appearing like something out of a Dr Seuss book. A member of the sunflower family known by its common name dwarf iliau, W. hobdyi was once abundant on the Hawaiian island of Kauai. But after Europeans introduced goats to the isle in the late 1700s, the plant was grazed into near-extinction.

Isolated from continental landmasses, W. hobdyi had never evolved defenses against hungry livestock, such as bitter leaves or sharp thorns. For decades, searching for such hard-to-reach plants and collecting samples was carried out by intrepid botanists who rappelled by rope down dangerous cliffs to hunt for what was lost.

But this daredevil approach meant it was easy to miss plants. Ropes could only stretch so far, there were few clip-ins on steep cliffs, and sightlines were often obstructed by bushes. New technologies have meant that scientists can now reach places too risky for humans and cast about for the last surviving individuals before its too late.

In 2016, Nyberg, who serves as the GIS and drone program coordinator at the National Tropical Botanical Garden, helped launch an aerial program to look for rare species with drones.

Published in Dawn, December 11th, 2022