Ten-thousand miles from home, soaked in the relentless downpour of the Mauritian rainy season, and splattered with the mud of mountain trails, Kayla Flamm, Jean Claude Sevathian, Becky Sucher, and Andrew Wyatt found themselves peering over the edge of a 500-foot waterfall in search of any hint of the delicate blue flowers of the Nesocodon. 

The Pieds 500 waterfall in Mauritius is the location of the largest known population of Nesocodon on Earth. This photo was taken by drone, and the red circle marked on the photograph indicates the location of the Garden’s conservation horticulturists. Photo taken by Kayla Flamm using the  Mavic 2 Zoom drone.

Sucher and Wyatt were no strangers to this cliffside; they’d been here before on the Missouri Botanical Garden’s previous conservation missions to Mauritius, and Sevanthian is a longtime partner and local. But this time, they were joined by a new weapon in their arsenal: GIS specialist Kayla Flamm and her flying drone.

Their mission took place in the nick of time—it was early March, just before the COVID-19 pandemic took hold in the States. They had come to study Nesocodon mauritianus, an extremely rare plant that’s only been confirmed to have a large population in one place on earth: clinging to the face of the cliff that they stood atop. It was discovered there in the 1970s, on the brink of extinction. Efforts to conserve Nesocodon have prevented its extinction thus far, but there is still much more to learn about the plant in order to ensure its survival. One of the most important steps in the conservation process is to learn as much as we can about precisely where Nesocodon occurs and how it grows there. That’s where the drone comes in. Since it only grows on a few treacherous cliffsides in Mauritius, it is difficult for scientists to climb to the Nesocodon to study it up close. But this time, they hoped they could “fly” there. By inching up to the edge of the cliff and looking through virtual reality goggles paired with the flying drone, they could see the cliffside through the eyes of the drone and take photographs to document the plant’s location. 

Footage taken by Kayla Flamm using the  Mavic 2 Zoom drone.

But even with the help of technology, it was no easy task. The constant storms of the rainy season made for cancelled drone flights and slow-going on slippery mountain trails. It had been years since Sevanthian, who lives in Mauritius, had scouted some of the areas the crew was hiking through. And the high winds and complex topography made for exceptionally challenging drone flights. 

Dense foliage, muddy trails, steep terrain, frequent downpours, and thick fog made for a challenging mission in Mauritius.

GIS Specialist Kayla Flamm of the Missouri Botanical Garden and Mauritian conservationist Jean Claude Sevanthian search for Nesocodon as Flamm flies the drone. The drone controls feature a screen that allows the user to see what the drone is seeing as they fly. Photo by Becky Sucher.

 “Looking over the edge of a cliff like that…it’s scary,” said Flamm. “When we got there and I first saw it in person, I really started shaking. It’s terrifying to fly that close to the cliff with a waterfall right there and the pressure of everyone wanting the drone to fly closer to the plants to help ID them.”

“You can fly the drone using a programmed flight where you basically draw a path, press go, and it will take that path,” Senior Manager Living Collections Becky Sucher explained. “But it is challenging to do that with the complicated topography. It was a huge learning experience from that perspective and probably in the most difficult learning environment possible.” One mistake, and the drone could go down.

The drone soars over the Black River Gorges National Park. Windy conditions and elevation changes made for challenging flights. Photo by Becky Sucher.

To complicate matters further, the team had packed just one SD card with them. “We did such a good job remembering all the equipment, all the batteries, everything,” Sucher says. “The one thing we didn’t think about was a backup SD card. We only had one, so if the drone had gone down at any point, we would have lost all that work.”

“There were instances for sure where we doubted that we’d get what we needed,” said Flamm, “and there were three different times when I really thought I was going to lose the drone,” but she didn’t. And despite rain, wind, the challenging landscape, and a trip complicated by COVID-related travel restrictions, the resulting images are promising.

Click to expand each image and learn more about drone photography.

“It was definitely a success that proved proof of concept,” Flamm said. “I’m really excited for what we were able to get done, and even more for what we will be able to do in the future.” The Garden plans to continue its conservation work in Mauritius once travel restrictions allow and is working with Mauritians to hire permanent staff for the project. 

In challengingly windy conditions, Kayla Flamm and Jean Claude Sevanthian demonstrate a drone flight for Mauritian reporters. Photo by Becky Sucher.

Why Nesocodon?

Nesocodon is far from being the only Mauritian plant in need of conservation––the island of Mauritius is a biodiversity hotspot. Qualification as a biodiversity hotspot requires two criteria: first, that a high percentage of its plant life is found nowhere else on Earth; second, that that plant life is under threat. Mauritius has the third-most endangered flora in the world (after Hawaii and the Canary Islands); around 95% of its endemic flora is of conservation concern. On the Garden’s last trip to Mauritius, conservationists worked with Mauritians to identify a list of 70 species in need of immediate attention. “Each time we go, we target species from this list,” explained Senior Vice President of Horticulture & Living Collections Andrew Wyatt. “For this trip, the overriding priority was to confirm, photograph, and map all the recorded locations of Nesocodon, but we also looked for seed from Elaeocarpus bojeri and Tambourissa.”

A Nesocodon in bloom. It is one of just a handful of plants on Earth to produce red nectar and was the first of its kind ever discovered. Photo by Cassidy Moody.

Nesocodon was chosen for a number of reasons. The striking beauty of its soft purple petals and incredibly rare red nectar make it relatively easy to spot in the wild. The horticulturists also knew the hike well from previous trips and were optimistic about the usefulness of the drone in that location. Additionally, all Nesocodon in cultivation comes from seed collected from a very few individuals, which means that there is a need to identify the location of all individuals and collect propagules in order to conserve the entire remaining genetic diversity for the species. Beyond those practicalities, though, is a deeper connection between the Nesocodon and Missouri Botanical Garden President Dr. Peter Wyse Jackson. In the 1980s, when Nesocodon was a newly discovered plant on the brink of extinction, Jackson leaned over the edge of this same cliff and, using a camera strap, was able to hook precious seeds to propagate the plant for conservation in botanic gardens. It’s a story that’s well-known by botanists worldwide, including those who work at the Garden.

Dr. Peter Wyse Jackson looks over the edge of Cascade Pieds 500 in the 1980s.

“The Nesocodon is very near and dear to Peter Wyse Jackson’s heart,” said Flamm. “It’s rumored to occur in other very remote locations on Mauritius. We are just hoping to get plant material and drone data to confirm where it grows.”

The Race Back Home

Even the journey home from Mauritius proved to be nerve-racking. The conservation team left St. Louis for Mauritius on February 29, at which time there were no cases of COVID-19 in Mauritius, and the outbreak was still very small in most countries. But it was during their time there that the virus began to take hold in Europe and the United States. 

“Becky left Mauritius a week earlier than Kayla and I, who left on March 15th,” Wyatt explained. “During that week, travel bans were put in place for several European countries, including France, which Kayla and I were traveling back through. I hurriedly changed the tickets to go back through the UK and Ireland, which were still open for travel. It was touch and go for a while because we were a little worried about a cyclone that could have moved in; then the flights would be cancelled and we would be stuck in Mauritius. Thank goodness this did not happen.” Wyatt and Flamm landed in Chicago just four hours before travel restrictions also went into place in the U.K. and Ireland. The plant material that they had collected had been shipped back by mail a few days before they flew out of Mauritius, and had actually beaten them back to the United States.

What Now?

In the months since the trip, the mission has not stopped just because the team is no longer overseas; they have continued to study the things they were able to collect during their time there. Flamm has continued to work her way through interpreting the massive amounts of photographs and data from the drone flights, and several plant specimens (Barleria observatrix, Psiadia pollicinia, and Carissa spinarum) that were collected in Mauritius are now growing alongside Nesocodon in the Missouri Botanical Garden greenhouses.

Click to expand each image and learn more about some of the Mauritian plant specimens now growing in our greenhouses.

In the case of especially rare plants, cuttings are usually the preferred way to preserve plants because scientists want to conserve individual genets. However, collecting seed makes for easier transport and reduces the chance of the plant material dying. “It can be difficult to grow the plants to a size where they are sustainable to potentially move back into the wild; we have to get them to a certain stage where they are hardy enough to put back without them just dying,” Sucher explains.

Sometimes, visitors can see these plants growing in the Climatron® as well. “The plants in the Climatron®, in my view, are important because the public can see it and appreciate it and know about the work that we do and understand why it’s important,” Sucher says. “Also, our horticulturists can learn how to grow it and what it likes. We plant it in different locations, different soils, different moistures. We try lots of different things and document it. And we share that information and try to fit it back into Mauritius: How does what we are doing here translate back to there? How can we help inform Mauritians about how to reestablish it there? It helps to have people to record these cultivation protocols.”

A Nesocodon grows in the Missouri Botanical Garden greenhouses. Photo by Cassidy Moody.

“Sometimes these experiments can inform us about possibilities of the species’ past,” Flamm added. “For example, maybe it’s been chased up the cliffside by population and sugar cane farms encroaching; maybe it doesn’t actually prefer that environment but is living there out of necessity.”

“With very, very rare plants, which is what we are dealing with on Mauritius, the first step is to make sure we safeguard the remaining individuals by propagating them either here or there to prevent extinction,” Wyatt continued. “It’s very helpful to have ex situ (off-site) collections as backup not on the island because if a disaster wipes out the plants growing on the island we can always send some back.” 

The Oil Spill

The recent oil spill in Mauritius is a tragically perfect example of disaster in a nation that cares so deeply about its wildlife. “They are doing a lot of conservation work right there, protecting that whole little island of Ile Aux Aigrettes,” Sucher said. “There are tons of animals, a fruit bat nursery, a tortoise nursery, so many birds, a lot of rare species of plants…and it is something like five feet above sea level. The people that we work with there have put their lives into protecting the flora and fauna of that island, and to see that catastrophe breaks my heart.”

This photo of Île aux Aigrettes was taken during the trip in back in March. These clear, blue waters are now the location of a catastrophic oil spill. Photo by Becky Sucher.

Sucher said that there were already concerns that the changing climate and rising sea levels could wipe out everything that is conserved on that tiny island. “If anything good can come of it, it’s making a priority of getting that stuff on the mainland where it will be better protected. ”

It also makes it all too clear how important it is to carry out the kind of conservation, propagation, and studies that the Garden is conducting alongside the Mauritians. If disaster had struck the now-well-known Nesocodon cliff 50 years ago, Nesocodon would have been wiped from the face of the earth; if something happened now, it would be protected and could potentially be reintroduced, straight from the Missouri Botanical Garden’s seed bank or the Climatron®, right here in St. Louis.

Why Protect Plants?

The Garden’s conservation work doesn’t take place in Mauritius alone; it happens all around the world, from Madagascar to right here in the United States. “This story would not be the same if we were working on a subspecies of oaks in the Ozarks, you know? It’s just not as exciting to people,” Sucher said. But that doesn’t make the work any less important. 

“These exciting stories are sort of the gateway to inspire people to care,” said Flamm. She noted that regardless of how interesting or beautiful a plant appears to be, its role in the ecosystem cannot be underestimated. Nesocodon, for example, has blood-red nectar that attracts a unique pollinator––geckos. “In such a unique biodiversity hotspot, you never know the effect of one species. From our perspective it might seem like just one plant or one animal, but when it comes from an ecosystem that is already experiencing such stress, you never know what could cause a domino effect of collapse. Instead, we are hoping to cause a cascade of positive effects by conserving those things.”

The drone zooms through the mist alongside a breathtaking Mauritian mountain. Photo by Andrew Wyatt.

Sucher also emphasized that the conservation work in Mauritius is a far cry from a solo effort on the Garden’s part alone; Mauritians themselves are deeply dedicated to preserving the dazzlingly distinct flora and fauna of their homeland. “We couldn’t do this without Mauritians,” she said. “They are extremely proud of their island and what they do. Jean Claude in particular knows the island like the back of his hand–he knows every plant. They have such an immense amount of knowledge. So they are passionate about their conservation and we couldn’t do the work without them.”

“The effect of one species on an ecosystem is such a delicate, complicated web,” she continues. “I think it’s our duty and our passion to not lose species to extinction. There is so much diversity that we don’t know. We should be stewards and use our skills to save what we can save.” And that’s exactly what the Garden hopes to do––not just for the beautiful, elusive, cliffside Nesocodon, but for endangered plants great and small, pretty and plain, here at home and all around the world. It’s an uphill battle, but our horticulture team is used to climbing mountains. 

Kristina Schall DeYong
Digital Media Specialist 

To donate in support of the Garden’s mission, visit mobot.org/donate.

For updates and information about the oil spill and its ongoing cleanup, follow the Mauritian Wildlife Foundation on Facebook.

Feature photo by Becky Sucher.