Drones combing cliffsides discover rare plant life on Kaua‘i

  • Courtesy / Ben Nyberg

    Endangered plant species grow deep in the island’s most remote locations. Drone technology sends botanists to otherwise inaccessible areas.

  • Courtesy / Seana Walsh

    Kamapua‘a (Kadua fluviatilis) shares its name with a figure in Hawaiian mythology. An NTBG drone found 10 individuals in June.

  • Courtesy / Steve Perlman

    The endangered haha (Cyanea asarifolia) produces white flowers with purple stripes. A new population of 95 specimens was discovered this summer.

  • Courtesy / Steve Perlman

    Haha (Cyanea asarifolia) grows on near-vertical cliff faces near Mt. Wai‘ale‘ale.

  • Courtesy / Ken Wood

    NTBG drone operator Ben Nyberg deploys his machine somewhere in the Kaua‘i backcountry.

KALAHEO — Over 100 endangered plant specimens were uncovered on the cliffsides of Kaua‘i this summer during a drone survey conducted by National Tropical Botanical Garden personnel.

The discoveries included 95 haha (Cyanea asarifolia), a flowering shrub thought to grow only near the base of Mt. Wai‘ale‘ale, at the headwaters of the Wailua River.

That changed on June 30, when a drone piloted by Ben Nyberg spied a new population on the windward side of the island.

“It’s a very narrow endemic,” Nyberg said after the Botanical Garden announced the discovery earlier this month. “Endemic just to this one valley — until we found these other plants.”

Nyberg’s fellow surveyors included NTBG botanist Ken Wood and Hawai‘i Division of Forestry and Wildlife botanist Adam Williams. Merely finding a new, distinct population of such a vulnerable species — all but four or five of 21 then-known specimens survived Hurricane ‘Iniki in 1992 — is notable. But Nyberg and his colleagues cannot rest. They must find a way to harvest seeds from the haha growing on wet, near-vertical rock walls before climate change and invasive weeds take their toll.

“We at NTBG try to get seed collections from as many individual plants and especially from each population of plants that we find, so we can store them in our seed bank and hopefully prevent them from ever going extinct,” Nyberg explained. “Once we have them in our seed bank and the wild plants die, at least we can grow them out and preserve the genetic diversity from that specific population.”

That is easier said than done.

The plants’ backcountry home is difficult to approach on foot. Any seed collector who managed to reach the site during fruiting season must hope to find a specimen within arm’s reach. Otherwise, the NTBG may have to get creative with its drone technology.

“That’s definitely something that’s on our radar,” Nyberg said. “I have a project in progress with National Geographic to really develop a drone mechanism that could collect seeds of plants on cliffs.”

Robotics experts will conduct preliminary testing on Kaua‘i in October.

Ten kamapua‘a (Kadua fluviatilis), a climbing shrub in the coffee family, were also discovered on the windward side of Kaua‘i in June. Unlike haha, its range includes another Hawaiian island.

“I think it’s very rare on O‘ahu, and we’re just down to a few populations left on Kaua‘i,” Nyberg said.

The shrub, which boasts four-petaled white flowers, shares its name with an ancient godlike being. Kamapua‘a, or Hog-child, was a half-man, half-pig shapeshifter whose forms included the future state fish of Hawai‘i, the humuhumunukunukuapua‘a, according to ethnologist Martha Beckwith’s “Hawaiian Mythology,” published by University of Hawai‘i Press.

This summer’s discoveries are not the first made by NTGB’s drone program, which began on the North Shore in 2016. Three years ago, it discovered Hibiscadelphus woodii — a species thought to be extinct — on a remote cliff in the Kalalau Valley on the Na Pali Coast.

“We work in dry mesic and wet cliff,” Nyberg said. “We’ve been aimed at a lot of these areas that have just never been able to be looked at, because they’re too steep or dangerous to get to … the drone program has really proven to be extremely effective at finding rare plants.”

The National Tropical Botanical Garden did not provide specimen locations for this story, citing potential plant poaching.


Scott Yunker, general assignment reporter, can be reached at 245-0437 or syunker@thegardenisland.com.

  1. Davis Jeffreis September 28, 2021 6:35 pm Reply

    What a wonderful article !!!!!

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