Human Activity Affects Wildlife, Even in Nature Reserves

During last year’s United Nations Convention on Biological Diversity, the Kunming-Montreal Global Biodiversity Framework was adopted. The framework includes 23 goals to reverse species and habitat loss by 2030, including setting aside, protecting and managing 30 percent of Earth’s marine, coastal and terrestrial areas for nature, known as “30 x 30,” according to The Nature Conservancy.

The 30 x 30 initiative has the support of more than 100 countries, evidence of the worldwide push for conservation. However, a new study by scientists from the Norwegian University of Life Sciences (NMBU), Wageningen University & Research and Rice University indicates for the first time that protected areas do not keep the tropical mammals living within them from being affected by human activity that occurs outside their borders, a press release from Rice University said.

“Living inside protected areas may not automatically protect tropical mammals from the effects of human activities,” said Asunción Semper-Pascual, a postdoctoral researcher at NMBU and lead author of the study, as The Guardian reported. “We have evidence that animals are affected by both what is happening inside and outside of the protected areas.”

Tropical mammals like the mountain gorilla, jaguar and Sunda pangolin were found to not be fully protected from harmful human activities, even deep inside nature reserves.

The study, “Occurrence dynamics of mammals in protected tropical forests respond to human presence and activities,” was published in the journal Nature Ecology and Evolution.

The research was based on the most extensive long-term wildlife survey using camera traps ever conducted. It showed how human-generated stressors like habitat fragmentation and population density affect 159 species of mammals in 16 protected areas in three biogeographic regions, according to the press release.

Collected over a number of years, the data is made up of millions of images from more than 1,000 sites that are part of a large network of research stations.

“This data set is just phenomenal — it was a herculean effort unlike anything attempted before,” said Lydia Beaudrot, an assistant professor of biosciences at Rice and one of the authors of the study, in the press release.

The researchers found that species occupying only specific habitats, called specialists, thrive in areas with little habitat fragmentation. The animals are highly susceptible to humans’ negative impacts, such as land use and hunting. Generalist species, on the other hand, can survive in a wider array of habitats.

A white-bellied pangolin, for instance, who lives in Uganda’s Bwindi Impenetrable National Park, is a specialist and would do better by making its way to the more insulated areas of the park, rather than existing along its edges.

“What we found is that when the human population density is high in these areas, then these species no longer benefit from being near the border, probably because of pressure from hunting or some other type of human interference,” said Semper-Pascual, as reported by The Guardian.

The tayra, a generalist species in the weasel family, is an omnivore who can thrive in grasslands, cropland or forest on the edge of a protected area, but only if the human population density isn’t too dense, the press release said.

“Habitats are more varied at the edge of the protected area,” said Semper-Pascual in the press release. “There is usually this difference between forest cover and open landscape, such as an area used for agriculture, etc. Some generalist species thrive in this kind of diverse setting because it provides access to different resources.”

Having an understanding of how certain species respond to varied human-generated stressors can serve as a guide for the management of protected areas and in setting priorities for conservation. It can do so on a local level by targeting a region’s most vulnerable species and on a global level by calling attention to factors of a landscape that have an impact on biodiversity beyond the perimeter of a protected area.

“We have to think about the situation holistically,” Beaudrot said in the press release. “Conservation is going to work best when it’s tackled in specific contexts and in concert with the people who live there so as to create win-win situations for both the people and the wildlife.”

Semper-Pascual added that, “As more protected areas are created, we need to think carefully about the factors both within and outside protected areas that influence biodiversity.”