Tropical mammals living inside protected reserves still feel the effects of deforestation, largely driven by farming and logging activities. This is the finding from a collaborative effort by researchers at the Norwegian University of Life Sciences (NMBU), Rice University, and Wageningen University and Research. The study highlights species such as gorillas and jaguars as among those impacted.
“Living in protected areas does not automatically shield tropical mammals from human pressures”, noted a lead researcher from NMBU. The researchers emphasized that wildlife is affected by activities both inside and outside the borders of protected zones.
The conclusions draw from one of the most extensive long-term camera-trap studies conducted to date. Millions of footage clips from thousands of camera locations were analyzed to understand how human activity has shaped the lives of 159 mammal species across 16 protected tropical sites spanning three continents. Over a decade, monitoring devices in rainforest habitats provided a rich dataset for analysis.
Protected landscapes include Africa’s Bwindi National Park, South America’s Yasuni National Park, and Southeast Asia’s Pasoh Forest Reserve. Across these sites, researchers observed patterns that point to the uneven ways different species respond to habitat changes.
Some species show heightened vulnerability to habitat fragmentation and loss, particularly specialists that depend on specific habitat types. These animals tend to occupy core areas deep within reserves where conditions remain stable. In contrast, generalist species that exploit a broader range of habitats and food sources fare better in edges and transitional zones where ecological opportunities diversify.
Edge habitats, where dense rainforest blends into farmland or open agricultural patches, can create a mosaic that appears more varied than the interior. Yet this diversity comes with trade-offs. Species living near the boundary are more exposed to threats, including predation and human-wildlife conflict, which can increase their vulnerability.
Evidence from the study shows that when population densities near reserve borders grow, some edge-dwelling species lose the benefits of proximity to protected zones. The reason appears to be increased hunting pressure and other human-induced risks that accompany denser edge populations.
On the policy front, global leadership has signaled strong intent to safeguard large swaths of the Earth’s ecosystems for wildlife. In December 2022, negotiators at the UN Conference on Biodiversity set a bold target: to protect 30 percent of the planet’s land and oceans by 2030. By mid-2021, about 16.64 percent of land and 7.74 percent of oceans were under protection, illustrating substantial progress yet signaling continued work ahead. These numbers underscore the importance of integrating inside-out management—recognizing how actions beyond reserve borders ripple into protected zones.
The broader context remains clear: tropical forests continue to face significant pressure from development and exploitation. The study adds to a growing body of evidence that protecting biodiversity requires more than establishing boundaries. It calls for strategies that reduce outside pressures, improve habitat connectivity, and address edge effects in reserve design.
In summary, protected areas do conserve many species, but the benefits are not automatically guaranteed. The health of tropical mammals depends on a combination of effective protection, responsible land-use practices around reserves, and ongoing monitoring to adapt management as threats evolve. The research illustrates that biodiversity protection must be dynamic, informed by robust data, and supported by global and local action alike to ensure lasting outcomes for wildlife across tropical regions.