Dr. Jedediah Brodie couldn't see the animals from space, but the satellite images told only half the story. Logging trails disappeared inside national parks, yet the forest canopy kept its secrets — until now. Fresh research from the University of Montana and an international team of scientists from ten countries has revealed something conservation biologists have long hoped to prove: national parks don't just protect wildlife within their boundaries, they create flourishing spillover zones in the surrounding landscape.
The study, published in Nature in August, analyzed bird and mammal diversity across Southeast Asia, one of Earth's most biodiverse regions. Using a massive database of wildlife observations combined with NASA satellite imagery from the International Space Station, researchers discovered that large parks significantly enhance bird diversity inside their borders and—surprisingly—support higher diversity of both birds and mammals in nearby unprotected areas. The finding challenges a lingering concern among conservationists: the fear that parks might simply displace hunting, fishing, and logging to neighboring communities, trading one habitat's loss for another's.
"We knew that protected areas can reduce logging—you can see that from satellite imagery—but you can't see the animals in the forest from space," Brodie, who holds the UM Craighead Chair of Conservation and is a research fellow at Universiti Malaysia Sarawak, explained in the study. "Our new analysis shows that parks benefit forest wildlife, too."
The discovery comes at a pivotal moment. The United Nations recently announced the "30 by 30 goal"—to conserve 30 percent of Earth's lands and waters by 2030. Brodie's findings provide clear justification for the ambitious expansion of global protected areas, but with a critical twist: bigger is better. Larger parks showed significantly stronger influence on mammal diversity in surrounding landscapes, suggesting that creating fewer large protected areas yields greater conservation returns than fragmenting protection across many small reserves.
Dr. Mairin Deith of the University of British Columbia, a co-author, underscores this point: "Larger parks routinely had higher bird diversity. Considering the UN's goal of increasing protected area to 30 percent of the world's surface, these findings support the creation of fewer larger parks compared to many smaller ones, where it is possible to do so."
The research also provides insight into one of Southeast Asia's most persistent conservation challenges: hunting. Dr. Matthew Luskin of the University of Queensland admitted surprise at his own findings. "It's common to see hunters inside and outside of parks in many countries. I expected that hunters' selectively removing game animals would reduce diversity. However, it appears parks limit hunting so it does not drive complete extirpations in most cases." Rather than simply displacing hunters beyond park borders, protected areas appear to sufficiently restrict hunting pressure to allow wildlife populations to recover and spill over into adjacent regions.
The analysis benefited from cutting-edge NASA technology: GEDI, a near-infrared laser instrument aboard the International Space Station that measures forest structure and habitat heterogeneity—data that traditional satellite imagery cannot capture. This combination of field observations, NASA data, and international collaboration created an unprecedented view of how parks shape landscapes.
As Professor Mohd-Azlan Jayasilan of Universiti Malaysia Sarawak warned, the window for large-scale park expansion is narrowing. "If governments responsible for gazetting protected areas think that it is difficult to protect large areas now, it's simply going to get more difficult with exasperating socio-political setbacks in the future." The science is clear: the time to act is now.