Scientists from the National Tropical Botanical Garden have discovered a new, native plant related to the carnation growing on the cliffs of Kauai.
The discovery might not have been made if not for the use of drones, which detected it growing about one-half mile down on a remote cliff face at Waimea Canyon.
The plant, according to scientists, is a member of the Schiedea species native to Hawaii. With its discovery, there are now 36 known Schiedea species, with 12 of them found only on Kauai.
NTBG drone operator Ben Nyberg first photographed the shrub during a survey in December 2021, and based on the images and location, experts presumed it to be an extinct species.
For surveys he uses a DJI Phantom 4 pro quadcopter, which is what many consumers use to take aerial photos.
“Initially, we thought it was an extinct species in the same genus, so we were really excited,” said Nyberg, NTBG’s geographic information systems and drone program coordinator.
It wasn’t until March 2022 that scientists were able to return to the site, and used the Mamba, a specialized robotic arm, to collect a sample of the plant.
Seeds from the plant were sent to Schiedea-specialized botanists Ann Sakai and Steve Weller at the University of California, Irvine.
The botanists were able to grow plants from seed in a greenhouse, and upon examination confirmed that this indeed was a species new to science.
The plants had enlarged, somewhat whitish sepals and flowers similar to the endangered Schiedea attenuata, another cliff-dwelling plant that occurs in Kalalau Valley, but also had many differences.
NTBG research botanist Warren Wagner of the Smithsonian Institution and senior research biologist Ken Wood named the new species Schiedea waiahuluensis after the region in which it was discovered — on the dry cliff faces of Waiahulu Valley at Waimea Canyon.
An article on the discovery of this “enigmatic new species from Kauai,” dubbing it the first species discovered by a drone collection system, was recently published in the journal PhytoKeys.
Scientists estimate there are about 345 individuals of the new species growing on the cliff, most of them on vertical, bare rock, in “minute cracks” and “small pockets of soil.”
Much of the native vegetation in Waimea Canyon has been degraded by goats, but patches of endemic plant species still can be found at these inaccessible, vertical cliffs.
Were it not for the introduction of feral goats, the distribution of Schiedea waiahuluensis may have been more extensive, authors said.
The use of drone technology in tandem with the Mamba has been a game-changer in the quest for plant discovery, according to Nyberg, especially for extreme cliff habitats.
Previously, botanists dropped off by helicopters in remote locations would spend hours searching for rare plant populations, plus risk the danger of rappelling down sheer cliff faces to get a glimpse of what grew along them — sometimes finding nothing.
“There’s a lot of guesswork that went into these cliff surveys,” said Nyberg. “It was a lot of hard work and time-consuming to go on rope, and sometimes you’re down 300 feet off the edge of a 1,000-foot cliff.”
The drones speed up the survey process and open a window to a whole new world of possibilities.
NTBG first began experimenting with drones in 2016 to map its gardens on Kauai. One of its earliest discoveries was in 2017, when a team found new populations of laukahi on the cliff face of Mauna Pulou on Kauai’s north shore.
The Mamba, developed in collaboration with Outreach Robotics of Canada, is suspended by a drone and has propellers that move a robotic arm back and forth to collect cuttings.
Nyberg works regularly with Adam Williams, a botanist at the state Division of Forestry and Wildlife, to detect and collect samples of rare plants along these sheer cliff faces.
“We are learning so much about these often overlooked environments with drones and the Mamba robotic arm assisting plant conservation in ways we never thought possible,” said Nyberg.
Warren, lead author of the article, called it a “new era of exploration and documentation of cliff ecosystems.”
The NTBG had used drones previously to find rare plants.
In 2019 a team from NTBG, along with Outreach Robotics, rediscovered Hibiscadelphus woodii, a hibiscus relative previously thought to have gone extinct.
NTBG and its partners, including the Plant Extinction Prevention Program, have used drones over the past two years to find and collect samples from at least 15 rare and endangered native Hawaiian plant species from cliffs.
Concurrently, scientists believe they discovered a potentially new species of insect — a tiny, native mirid bug that happened to be collected along with the new Schiedea, which is now being examined by entomologist Dan Polhemus.
If proved to be a new species, it also may be the first new species of insect to have been collected by drone.
