On March 28, 2025, the Cornell K. Lisa Yang Center for Wildlife Health launched its inaugural Cornell K. Lisa Yang Distinguished Speaker Series with double-header One Health talks featuring Dr. Craig Stephen and Dr. Marcela Uhart. The event highlighted the center’s commitment to advancing One Health—a collaborative, multidisciplinary approach that recognizes the interconnectedness of human, animal, and environmental health.

The new speaker series brings One Health thought leaders from around the world to Cornell to share their insights, stimulate dialogue, and inspire solutions to emerging One Health and Planetary Health challenges. The inaugural Distinguished Speakers offered powerful insights into systems thinking and real-world applications, moving from big-picture readiness to the urgent challenges posed by issues such as H5N1 avian influenza.

Preparing for the Era of Polycrisis

Dr. Craig Stephen, a veterinary epidemiologist and executive director of the McEachran Institute in Canada, presented "Lessons from the Field for Future Readiness in an Era of Polycrisis." He discussed how to move ideas into action at a time when many One Health professionals may feel discouraged by trends embedded in humanity’s disregard of planetary boundaries. We are witnessing the use of natural resources at unsustainable rates, and can feel overwhelmed by the amount of work that needs to be done to mitigate pollution, extinctions, and more.

Reflecting on his early work treating sick and injured wildlife as a rural mixed-animal veterinarian in British Columbia, Canada, Stephen described how he came to realize that reactive care was not enough. “I kept putting them back into environments that weren’t good for them. And I realized that this endless stream of wildlife diseases is not going to stop by just treating sick individuals.”

"I recognized that I could help more by moving toward root causes," Stephen said.

That insight drove him to embrace systems-based approaches and focus on root causes. “I recognized that I could help more by moving toward root causes,” Stephen said. He emphasized the need for adaptive thinking in a world where systems—whether ecological, agricultural, or public health—do not face just one problem at a time.

Stephen then introduced the concept of an "interproblemary approach," designing solutions to address multiple, interconnected issues simultaneously. He also cautioned against “collective global amnesia,” our tendency to intensely address a threat for a few years before moving on without resolving the underlying issues.

Stephen encouraged a mindset of collaboration and humility, urging One Health practitioners to approach communities asking, "How can I help?" rather than arriving with assumed solutions. By developing resilience and focusing on future readiness, Stephen argued, One Health professionals can better navigate an increasingly interconnected, unpredictable, and crisis-prone world.

A Daring Experiment in Global Health

Dr. Marcela Uhart, a wildlife veterinarian and director of the Latin America Program at the Karen C. Drayer Wildlife Health Center, University of California, Davis, School of Veterinary Medicine, followed with a lecture entitled "Why H5N1 Avian Influenza is a Daring Experiment in Global Health."

Drawing from her extensive fieldwork across Latin America, Uhart highlighted the profound implications of highly pathogenic avian influenza (HPAI) outbreaks for wildlife conservation and public health. She detailed how repeated spillover and spillback events between wild birds and poultry have driven the evolution of HPAI strains that can now infect mammals—a dramatic shift from the virus’ original form as a bird-specific disease.

To date, H5N1 animal influenza has killed over half a million birds and at least 50,000 mammals across 80 species in South America. In 2022, Uhart’s team documented a mass mortality event among southern elephant seals, with the virus killing nearly 20,000 seals, including 97% of pups born in 2023.

Uhart warned that, in addition to impacting wildlife, the ability of the H5N1 virus to infect mammals significantly increases the risk to human health. With documented cases of HPAI in humans, the virus has more opportunities to recombine with seasonal influenza strains, raising the risk of new, more dangerous variants. “We are putting our global health system into a stress test,” Uhart said.

“H5N1 is a global problem that needs global solutions," Uhart added.

Long-distance dispersal by migratory birds has enabled HPAI to reach nearly every continent, except Oceania. “H5N1 is a global problem that needs global solutions,” she added.

Beyond the implications for wildlife and human health, Uhart emphasized that HPAI now poses a serious risk to food security and livelihoods. Agricultural practices that place poultry and dairy farms adjacent to wetlands, critical stopovers for migratory birds, create high-risk interfaces between wildlife and food systems.

“We can continue business as usual… or we can think differently,” Uhart said. “It is not going to be easy or happen overnight, but we have to start thinking about different models of food production.” She called for nature-based strategies, such as habitat restoration, wetland conservation, and thoughtful agriculture land-use planning, to reduce the risk of future pandemics.

Bridging Vision and Action

While Stephen offered a broad vision of how One Health professionals can adapt and lead in an increasingly VUCA (Volatile, Uncertain, Complex, Ambiguous) world, Uhart grounded that vision in a pressing case study that exemplifies how environmental degradation, animal health, and the growing risks to humanity are deeply intertwined.

Together, the two lectures underscored a core message: future readiness requires us to address root causes and collaborate across sectors to build more resilient, integrated systems. The Cornell K. Lisa Yang Center for Wildlife Health’s Distinguished Speaker Series was created specifically to foster this type of dialogue—to bring science, policy, and practice together to define and help address the One Health challenges of our time.

Written by Victoria Priester, DVM ‘26, and Melisa DeGroot, PhD ’22