AT THE END of a road deep within Khao Yai National Park in Thailand’s Nakhon Nayok province, near a low-slung rangers’ cottage, Professor Vijak Chimchome of the Thailand Hornbill Project delivers a stern warning to the six of us gathered around, all graduate students in Miami University’s Global Field Program. “We’re going to be approaching a nesting pair of great hornbills. Their eyesight is extremely sharp — better than ours. We will take cover in a blind, where you can sit or stand. But once there, you have to be very still. The male hornbill will notice every move, and if he doesn’t trust the situation, he will not approach.”

He pauses to let that sink in. He’s already taught us about the extraordinary dependence of female great hornbills and their chicks during reproductive season. Having found a suitable cavity hundreds of feet in the air in one of the tropical forest’s soaring trees, the female will seal herself inside with a brick-hard mix of soil and dung, proof against predatory red martens, climbing pythons, and binturong (bearcats). She will stay inside for more than three months, during which time she’ll lay her eggs and raise a single chick to the point it is nearly ready to fly. Her only source of food is the male, who forages incessantly for figs, other fruit, and the occasional lizard or insect. He brings them back to the nest and feeds the family — long, curved beaktip to long, curved beaktip — through the narrowest of openings.

If something happens to the male, or if he gets spooked off, that will be that: The nest will fail. Great hornbill pairs at best raise one chick a year — and only when conditions are right.

It is the narrowness of those conditions that represent the great hornbill’s biggest vulnerability, one it shares with most of the other 31 species of Asian hornbills, roughly two thirds of which are at risk of extinction. These birds nest only in the tallest trees of Asia’s primary rainforest, dipterocarps and other emergent trees that are also the target of both legal and illicit logging. And not many of these increasingly rare trees will develop a rotted-out cavity of the perfect type: dry, firmly floored, with a narrow opening and enough living space for birds that grow 3 to 4 feet tall. The resilience of the species in the face of its other threats — from hunting to the capture and sale of their chicks as pets — depends on the availability of such cavities for raising the next generations.

Pilai Poonswad’s name has become synonymous with hornbill conservation.

The rainforest, in turn, might depend on those generations. As Chimchome has explained, hornbills are synonymous with primary rainforest for many reasons, as keystone, indicator, umbrella, and flagship species. Keystone because they are top-level foragers and agents of seed dispersal, earning the nickname “farmers of the forest” for their role in spreading the seeds of figs and other fruit trees across a range that can extend 300 square miles. Umbrella because any effort that saves the great hornbill, with its needs for nest and range, will necessarily protect large stands of rainforest and thousands of other species. Indicator because their well-being suggests the well-being of the greater ecosystem. And flagship for sheer charisma. With their white-tipped, black wingspans that stretch up to eight feet wide and distinctive bicornial orange and red casques perched above their intelligent eyes like jaunty berets, great hornbills are a ready symbol for the wild — and an inspiration to act to preserve it.

Perhaps more than anyone else, that inspiration has been a guiding force in the life of one woman: Dr. Pilai Poonswad. The Thai ornithologist and conservation biologist has dedicated the past half-century to protecting the stunning birds. Her name has become synonymous with hornbill conservation, and with the Thailand Hornbill Project, which she founded nearly 50 years ago. At 78, Poonswad is starting to step back from the work and make space for others like Chimchome to carry it forward. That transition poses a number of challenges. And it raises a tricky question for environmental organizations whose efforts at conservation must succeed over many human generations: What happens to a conservation project when a charismatic — some would say, flagship — leader steps away from the work?

IT IS HARD to know where to begin in characterizing Poonswad’s impact on hornbill conservation, the decades-long accumulation of scientific insights, practical innovations, and institution building that earned her a Rolex Award for Enterprise and Thailand’s Dushdi Mala medal, the kingdom’s highest award for service to the state. Her work also earned her the nickname “Great Mother of the Hornbills,” and if she isn’t literally that — midwife might be a better term, given the untold numbers who have nested safely because of her — she is certainly the mother of hornbill conservation.

The Thailand Hornbill Project is the longest-running hornbill research effort in the world; it has monitored nests in Khao Yai since shortly after Poonswad founded it in 1978. Her observations and insights brought to world attention the limiting factor of nesting sites for hornbill populations and how that multiplied the threat of deforestation. In addition to her scientific publications, she organized the first-ever international conference on the hornbill in 1992, and repeated the feat every four years, bringing together scientists and conservationists from across Asia and the world to share discoveries and conservation initiatives.

These include systematic efforts to repair abandoned hornbill nests. Beginning in the 1990s, she and her team scaled immensely tall trees and studied interventions they could accomplish with carpentry. They widened openings where tree cambium (the growing part of the trunk) threatened to close them, narrowed them where rot had gone too far. They hauled up hundreds of pounds of soil to fill in and level cavity floors for the females, who need to be able not just to get food through the narrow nest opening, but angle themselves to defecate out through it as well.

Results published in 2005 showed that hornbills would return to repaired cavities, and that more usable nests translated into more nesting success. This applied to not only great hornbills, but also the other hornbills — wreathed, oriental pied, rufous necked, and others — that had grown scarcer at Khao Yai, Thailand’s oldest national park.

Poonswad’s energy, inventiveness, and dedication essentially called into being an entire ecosystem of institutional partnerships.

Poonswad expanded her efforts to the south of Thailand too, to the Budo-Sungai Padi National Park region, where there was greater diversity of hornbill species — and greater intensity of threats, with extensive illegal logging, poaching of chicks, and hunting of helmeted hornbills, the only hornbill with a solid casque. Because of the market for this casque (called “red ivory”), it’s one of the most endangered hornbill species in the world. Despite an active insurgency among the ethnic minority peoples of the region at the time, Poonswad worked across cultural and language barriers to talk directly to hunters, educating them, and hatching plans to turn their extensive knowledge of hornbill habits into an asset and coax them away from poaching to protecting. To replace hunting income, she initiated a program for people across Thailand and the world to “adopt” nests, paying a small monthly amount to support a particular hornbill family. It’s still a thriving program. She also established an ecotourism operation, the Budo Hornbill Conservation & Education Centre, to boost local training and employment. To support fundraising for these activities, in 1993 Poonswad established the Thailand Hornbill Research Foundation.

None of this even begins to capture her full impact. The Rolex Award, which supports innovative projects to preserve our natural heritage, cites her consultancies to the governments of Myanmar, China, and Bhutan, and her fostering of a sister organization in India that’s among the most active in the world in hornbill conservation. She changed national culture in Thailand, establishing a “Love Hornbill Day” on February 13, the day before Valentine’s Day, through which the birds’ strict monogamy became symbolic and aspirational.

I spoke to her over the phone when I got back to the US, and she confirmed something I’d heard but not believed: hornbills had never been her job. Her career was as a lecturer on parasitology at Mahidol University. At times she’d rushed back to the classroom having already spent the dawn at Khao Yai, hours, away, to observe the birds.

She laughed about the name “great mother of the hornbills,” saying she thought the Rolex people had just made that up. A moment later, she added: “But it fits. I never had children of my own. The hornbills are my children.”

Over the years, her charisma has drawn tremendous funding and support and followers to the cause of hornbill conservation. Her energy, inventiveness, and dedication essentially called into being an entire ecosystem of institutional partnerships, and her campaigns, together with those of South African ornithologist Alan Kemp, the “Father of Hornbills,” have, at times, been nearly synonymous with the thriving of the species. But in the past five years, age and physical issues have forced her to step away from fieldwork and begin transitioning out of a leadership role at the organization she founded. She is suffering from back problems from the decades of hauling heavy packs up and down Thailand’s mountains, and as we spoke, she was awaiting rotator cuff surgery. For the Thai Hornbill Project and the birds it champions, this handoff to the next generation is a moment of vulnerability.

“WHEREAS MANY INDIVIDUALS have ideas about different ways to improve the human condition [and] safeguard the environment, relatively few individuals in the world are sufficiently determined to set up an organizational entity to translate their ideas into reality,” management expert Stephen R. Block writes in Why Nonprofits Fail.

We honor such people, Block writes. Admire them. And sometimes witness negative effects from their continued involvement with the organizations they create. He devotes an entire chapter of Why Nonprofits Fail to “Founder’s Syndrome,” where profound conflict arises between an organization’s needs as it matures, and the tenacious, driven, high-achievement leadership style of a founder who cannot seem to share control.

Less dramatic, perhaps, but just as threatening to an organization’s long-term viability, is the situation where founders seem — to themselves or to others — irreplaceable. Founders like Poonswad are motivated by a passion for their cause that doesn’t blink at hardship or low or no pay. If an organization operates on a shoestring, who but a founder is willing to put on those shoes, and feel their pinch? And if the organization evolved around one key person with the unique skills, knowledge bases, and relationships to keep it running, how can it develop further when such leaders reach their limits?

If an organization operates on a shoestring, who but a founder is willing to put on those shoes, and feel their pinch?

When I asked Poonswad about the transition to new leadership, she showed she was focused, as she always seems to be, on nurturing next generations. She spoke of consciously stepping back so others could lead. “I don’t even go to some conferences anymore,” she said. “If I’m there, people will seek me out as if I’m still in charge.” The Foundation now relies on chemical engineer Woraphat Arthayukti, its chairman since 2020, and Professor Chimchome, its secretary and research director, to lead in representing the project to potential donors and conducting public education and advocacy.

Still, there’s a dusty feel to the Hornbill Research Foundation’s website. Its first category under “About” reads simply “Pilai Poonswad,” and under financials it says “coming soon.” When I ask Chimchome about current challenges he’s clear that sustaining their funding, with Poonswad less active, is a great worry: “For the last few years our largest grant is from a single philanthropist in Thailand.”

Nurturing new leadership to follow not just Poonswad, but him and his colleagues, he says, is also a concern. “The average age of our team is 55,” with many, like Chimchome himself, having been inspired to join Poonswad in the early years when she was building the organization. The work of dawn-to-dusk field observation and the grind of advocacy can be wearying — and is not well-rewarded. Chimchome says he doesn’t see as many fresh faces in the field as he would like.

Poonswad’s intentionality around the transition gives the Hornbill Research Project its best chance of finding a way forward. A cautionary story comes from Iceland, where the North Atlantic Salmon Fund (NASF) was founded by visionary Orri Vigfússon in 1989 to end the practice of ocean fishing for Atlantic salmon. Vigfússon — who was recognized on the cover of Time magazine and awarded the prestigious Goldman Environmental Prize — was described to me by organization chairman Friðleifur Guðmundsson and others in much the same terms as people discuss Poonswad: as a force of nature.

Having grown up in a northern Iceland town decimated by the collapse of the country’s herring fishery, Vigfússon, a passionate fly fisherman, experienced with trepidation the declining numbers of Atlantic salmon returning to Iceland’s rivers throughout the 1970s. Taking no income — in fact, putting all of his personal savings into the effort — Vigfússon raised funds from across the Atlantic, made allies that included then-Prince Charles of England and President George HW Bush, and leveraged buyouts of entire nations’ worth of ocean fishing fleets, paying fishermen not to take salmon. The hope was that he could keep up such payments until the fishing fleets would permanently transition to other quarry, or legislation and regulation could catch up to the dire threat facing the species.

“We can’t just identify heroes and put all the onus on them, or say, ‘Oh, this NGO is going to fix it.’”

It largely worked — and Vigfússon was gearing up to take on the next great threat emerging for wild salmon, open-net pen salmon farming — when he was struck by lung cancer and passed away in 2017. When supporters gathered to grieve his passing, they discovered that NASF, despite brokering agreements in the millions of dollars and having a far-flung international network of supporters, had no other employees than Vigfússon himself. Always suspicious of NGOs with expensive overheads, Vigfússon had clearly taken the idea of a “lean operation” to the extreme.

NASF also had no contingency plans in place for someone to administer the agreements he’d forged with partners such as the entire (former) salmon fishing fleet of the Faroe Islands. Not only that, supporters discovered an idiosyncratic style of recordkeeping: Vigfússon had saved his emails not on a computer, but as printouts. Some 300,000 messages filled dozens of boxes stacked against walls.

Fortunately for the continuity of NASF’s work, Vigfússon’s inspirational qualities extended beyond his untimely death. A coalition of American financiers and Icelandic lawyers rebuilt the organization from the ground up, hiring its first-ever paid employees, younger activists who shared Vigfússon’s passions for fly fishing and conservation — and who promptly took up the cause of limiting or ending Iceland’s open-net pen salmon farming.

But not every organization can be so lucky when it comes to the unexpected loss of a flagship leader. Which is why intentionally evolving campaigns past the type of singular leadership that births them is so important. That can sometimes mean weaving nonprofits into larger organization-ecosystems where they can find support and build capacity, such as fiscal sponsor nonprofits like Earth Island, or the Association and Zoos and Aquariums’ SAFE program (Saving Animals From Extinction), which pools the resources of 235 facilities in the US and abroad to offer robust, coordinated support to partners such as the Thailand Hornbill Research Foundation. It can also mean an emphasis on ongoing conservation education, and employment through ecotourism. This is a strategy Poonswad stresses in her publications, and one that is already supporting the longevity of her hornbill conservation work. The Hornbill Research Foundation’s video on nest adoptions, for example, emphasizes how children of former poaching villages have grown up to prize and study the birds, not hunt them.

Chris Myers, founder of the graduate program that brought us to Khao Yai, echoes this view: “Community-embedded issues need community-embedded educational models. When people see themselves as part of the conservation equation, and take ownership of their own places, things get more hopeful. We can’t just identify heroes and put all the onus on them, or say, ‘Oh, this NGO is going to fix it.’”

BACK IN THE forest, the problems for me begin just outside the blind, a rough-hewn wooden structure camouflaged by a roof of large leaves. On the moist red clay hillside leading into it I slip and Whomp! I go down, the noise loud even through the incessant chirruping of cicadas. “I’m okay, I’m okay,” I whisper, embarrassed, not daring to move further. It looks like I’ll be sitting.

That leads to the next problem: With the other hornbill watchers, my classmates, standing in front, I have only a narrow slit through which I can peer — and no view of the bird’s nest, some 200 feet high in the tree in front of us.

I can hear, though, and when it comes, the sound of the male’s approach is tremendous, a whoosh, whoosh of immense wings that fills the forest. Excitement spreads as the others see something. Suddenly it occurs to me that if I rock back slightly and tug the leaf cover down, I can look over the top.

I have light. Air. A view!

But no bird. Instead that whoosh, whoosh again. The sound stops above us — where the male must have alit on a branch. The back of my neck crawls. And I fear I’ve made a terrible mistake. Small as my movement had been, the hornbill, with eyesight that can hone in on a cherry-sized forest fruit from hundreds of feet in the air, could easily have been spooked by it. I imagine it staring down at me right now. Assessing.

Worst-case scenarios flash through my mind. That I’ve undermined the group’s experience, ruined months of painstaking observation, caused the mother and her fledgling to go hungry, the nest to be abandoned. Each minute, the sense of consequence grows.

And then, with the power of a blessing, I hear those vast unfurled wings. Whoosh. Suddenly the male is at the nest, improbably large, impossibly colored. His talons grip the tree trunk just next to the narrow opening to the nest.

I almost laugh as, out from the slit, comes the tip of the chick’s long curved bill, seeking. The male makes a slight movement of his head, and like a conjurer he is suddenly in possession of a ripe orange fruit that he’s borne in a throat pouch. It passes from his bill to the chick’s. Magic.

In much the same way that the persistence of hornbills depends on this fragile exchange between generations, the success of our human efforts at conservation depends on our ability to nurture the next generation of environmental stewards. To handoff our institutions, and transmute the legacies of founders into something enduring.