The Harpy Eagle as a Keystone Species
From its nests high in the canopy of the Amazon, the harpy eagle (Harpia harpyja) depends on and is critical to the health of the forest around it. This species controls the numbers of animals such as sloths and monkeys that, unchecked, could consume too many leaves and turn the canopy into lace. However, massive tree loss in the world’s largest rainforest has hampered the survival of the harpy eagle. Too few tall trees near their nests means fledgling chicks lack safe landing areas as they learn to fly. Habitat loss, along with hunting, has led to population declines. Removing this keystone species entirely could accelerate ecosystem collapse, with knock-on effects such as diminished rainfall on farmland in the region, according to conservationist Harvey Locke, co-founder of the Yellowstone to Yukon Conservation Initiative based in Canada.
“The harpy eagle is not just an amazingly cool bird,” Locke told Mongabay. “It’s not a luxury in that biome. It’s vital to it.” Just as other keystone species like elephants, beavers, and bison play similar roles, harpy eagles help hold together even heavily impacted ecosystems. “If we pull these pieces out, it unravels,” he added.
Tracking Ecosystem Health Beyond Species Counts
In a study published April 8, 2026, in the journal Frontiers in Science, Locke and his colleagues use the harpy eagle as one example of the importance of tracking broad natural processes and ecosystem health alongside species number counts. They advocate for nature-positive approaches to address biodiversity loss. With the looming 2030 deadline of the Kunming-Montreal Global Biodiversity Framework (GBF) to halt and reverse nature loss, the concept of a “nature-positive” future has gained prominence. The Nature Positive Initiative, representing conservation groups, institutions, and businesses, has used that goal. On July 14, 2026, the initiative opened a summit ahead of U.N. meetings on biodiversity and climate later in 2026.
The Three Global Conditions Framework (3Cs)
Locke and his colleagues advocate for using the Three Global Conditions Framework (3Cs), first introduced in 2019, to tackle GBF goals. The 3Cs categorizes different parts of the Earth by the extent of human impact on ecosystems. This information guides solutions to stem global biodiversity loss. The framework categorizes regions by human-impact level to guide targeted conservation efforts ahead of the 2030 deadline.
- Areas with minimal human impact: focus on preserving intact ecosystems.
- Shared areas: balance human use with conservation.
- Cities and farms: implement nature-friendly practices.
The authors argue that rather than searching for a sweet spot where society, economy, and environment overlap, these elements should be seen as fully embedded in nature. “The Earth is the context for everything humans do,” Locke said. He noted that resources are finite and human actions—burning fossil fuels, destroying forests, eliminating species—have real consequences. He referenced traditions like Taoism, Hinduism, and Indigenous thought that understand this embeddedness.
Challenges and Implementation
Experts say implementation remains a challenge, partly because the GBF is not legally binding. “Ultimately it is a lot about what countries decide to do and how they operationalize alignment,” said Nathalie Pettorelli, a conservation biologist at the Zoological Society of London’s Institute of Zoology, who was not involved in the research. She highlighted the need to agree on what a desired environment looks like and to address social impacts: “who defines priorities, whose perspective counts, and who bears the costs of the ‘identified’ solutions.” Without addressing people and social aspects, progress is unlikely.
Planetary Boundaries and Progress
Johan Rockström, a co-author and professor at Stockholm University, led the team that introduced the concept of planetary boundaries in 2009, setting safe limits for nine key metrics. As of 2025, seven of those boundaries have been crossed. Marco Lambertini, convener of the Nature Positive Initiative, said 2030 “is fast approaching” and “the message is once again that we are behind.” However, he expressed optimism: “by bringing innovative examples from around the world, the Summit will demonstrate that we can and we know how to embrace nature-positive practices.”
Toward a Nature-Positive Future
The study calls for a shift from merely counting species to tracking ecosystem health and natural processes. The 3Cs framework provides a roadmap for targeted actions. Real progress depends on countries adopting specific, tailored solutions and addressing the economic and social costs. As Pettorelli noted, implementable solutions must be seen working for individual countries. The future of keystone species like the harpy eagle—and the ecosystems they sustain—hangs in the balance.