In the lush, mist-shrouded montane cloud forests of Mexico, even within the boundaries of protected conservation areas, the delicate balance of life is being disrupted. A recent study from the Yale School of the Environment has uncovered that increasing human activity is altering the behavior of carnivores living in these critical ecosystems, including species like jaguars, ocelots, pumas, and margays. This groundbreaking research, led by Germar González ’24 MESc, doctoral student Siria Gámez, and Nyeema Harris, the Knobloch Family Associate Professor of Wildlife and Land Conservation, calls into question the effectiveness of traditional conservation strategies that rely solely on land-use zoning and static boundaries for preserving wildlife.
The study, published in Scientific Reports, reveals that human presence in buffer zones—areas designed to separate protected core zones from surrounding human-dominated landscapes—may not be the benign transitional spaces they were once thought to be. These buffer zones, where small-scale agricultural activities are permitted, actually emerged as hotspots for human-wildlife interactions. This discovery has significant implications for conservation strategies and calls for more dynamic, integrative approaches that engage local communities directly in conservation planning and enforcement.
Germar González, now a conservation program specialist at the San Diego Zoo Wildlife Alliance, explained, “Our findings highlight the need for adaptive conservation strategies that go beyond zoning and land-use designations, and incorporate integrated approaches that involve local communities in conservation planning and enforcement.” González’s statement reflects the growing recognition that simply establishing protected areas is insufficient to address the complex challenges of modern conservation. Instead, strategies that consider the human-wildlife interface and collaborate with local communities are essential to safeguarding biodiversity.
The research took place in the El Triunfo Biosphere Reserve in Chiapas, Mexico, a region renowned for its rich biodiversity. The team used camera traps to capture thousands of images of seven different carnivore species: jaguars, pumas, ocelots, margays, tayras, gray foxes, and coatis. The cameras were placed in various land-use zones, including core zones (where human activity is restricted), buffer zones, and private lands, to examine how different levels of human presence affected the activity patterns of these elusive carnivores.
What the researchers discovered was striking. Contrary to the assumption that human activity would gradually decrease as one moved from the more disturbed buffer zones into the core areas of the reserve, human presence was highest in the buffer zones. This surprising finding challenges the traditional understanding of buffer zones as passive spaces intended to serve as a buffer between human-dominated lands and wilderness areas. Instead, these zones turned out to be areas of active human use, often experiencing the highest human presence in the entire reserve. As a result, carnivores inhabiting these areas were forced to adjust their behavior in response to the changing landscape of human activity.
For example, gray foxes, which are typically nocturnal creatures, exhibited increased daytime activity in areas where human presence was more prevalent. This shift could be driven by an attempt to avoid nighttime human activity, leading the foxes to alter their hunting and movement patterns in ways that might disrupt their natural behaviors. Similarly, ocelots, which are known for their elusive nature and mostly nocturnal habits, became even more nocturnal in buffer zones, possibly as a strategy to avoid direct human encounters.
Nyeema Harris, the Knobloch Family Associate Professor of Wildlife and Land Conservation, emphasized the implications of these findings: “We found that certain species such as margay and gray foxes significantly shifted their activity patterns across zones. Such shifts in carnivore behavior can have huge ramifications for interactions with other carnivore and prey species but also encounter probabilities with domestic species and humans, thus inciting conflict.”
These shifts in behavior are not merely academic curiosities—they have real consequences for ecosystem dynamics. Changes in the timing and patterns of predator activity can disrupt predator-prey relationships, leading to cascading effects throughout the ecosystem. For example, if a carnivore such as a jaguar adjusts its hunting schedule to avoid human interaction, it might find itself competing with other carnivores for the same prey at times when the prey species are more vulnerable. Such disruptions could reduce the availability of food for some species, while others may thrive in the altered conditions. In some cases, these changes in behavior might also increase the likelihood of conflict between wildlife and humans, particularly in areas where human settlements and wildlife habitats overlap.
The research also challenges traditional conservation practices that use land-use designations as proxies for human activity and wildlife impact. Historically, scientists have assumed that the impact of human activity on wildlife would gradually diminish as one moved from outside a protected area into its core. However, the study’s results demonstrate that land-use designations alone do not capture the complex realities of human-wildlife interactions on the ground. The presence of human activity in the buffer zones had a much greater influence on carnivore behavior than expected, further complicating the task of managing protected areas effectively.
Siria Gámez, a doctoral student involved in the research, pointed out the limitations of using static land-use designations to manage protected areas: “Our study challenges how we as researchers use land-use designations as proxies for human activity or potential impact to wildlife. Often there is an assumption about the human impact gradient moving from outside a protected area into the core zones, but our results demonstrate how those designations don’t necessarily capture the reality on the ground.”
The study’s authors argue that conservation management strategies must evolve in response to these complexities. Simply designating an area as “protected” is no longer sufficient. Effective conservation requires a nuanced understanding of the various human activities occurring within and around protected areas, as well as a commitment to involving local communities in decision-making processes. By considering the social and ecological contexts in which wildlife conservation takes place, policymakers can develop more adaptive strategies that foster both biodiversity preservation and human-wildlife coexistence.
As González emphasized, “Studies like ours that survey wildlife across land management types help to inform protected area management, assess effectiveness, and re-evaluate expansion goals.” Indeed, the findings underscore the importance of rethinking how conservation areas are managed and expanded. As the pressures of climate change, land development, and population growth continue to affect natural habitats, the need for innovative conservation strategies is more urgent than ever.
The study also illustrates the critical importance of collaboration between conservation scientists and local communities. In the case of El Triunfo Biosphere Reserve, the team’s ability to collect valuable data was made possible by the foundational work of local researchers, including Gámez, and the involvement of the community in the research process. Local knowledge and participation are key to ensuring the success of conservation efforts, especially in regions where human populations live in close proximity to protected areas.
González, who is of Mexican-American heritage, expressed his deep connection to the project: “This incredible research opportunity in Mexico would not have been possible without the invaluable guidance and financial support of Dr. Harris, the foundational work laid by Siria, and the collaborative spirit of my AWE Lab colleagues.” His personal connection to the region and his ability to collaborate with local researchers highlights the value of community-driven conservation work, which is increasingly seen as essential for achieving long-term wildlife protection goals.
More information: Germar González et al, Carnivore activity across landuse gradients in a Mexican biosphere reserve, Scientific Reports (2025). DOI: 10.1038/s41598-025-87850-7