Why We'll Have to Share More and More Space with Wild Animals

Coexistence between humans and wildlife is expected to increase across more than half of the world’s land area by 2070. The primary driver of this trend is human population growth. This is the main conclusion of our new study published in the journal *Science Advances*.   Our research suggests that, as the human population grows, people and animals will share increasingly densely populated spaces. For example, as more and more people settle in forests and agricultural regions, human-wildlife interactions there will increase sharply. But they will also increase in urban areas as people move to cities in search of jobs and opportunities. Animals are also migrating, primarily in response to climate change, which is shifting their ranges. In most regions, species richness—that is, the number of unique species present—will decline as animals follow the climates they tolerate best. But as the human population continues to grow, there will nevertheless be increasing human-wildlife interaction across most regions. We have also identified regions where human-wildlife interaction will decrease as human populations shift, but these areas remain much rarer than those where such interaction is expected to increase.

We thus found that Africa is the continent where interactions between humans and wild animals will increase the most (70.6%), followed by South America (66.5%). Conversely, Europe is where coexistence between humans and wildlife will decline the most (21.4%).  

Why This Matters

Around the world, humans and wild animals are increasingly competing for limited land. This situation can lead to harmful consequences, such as an increase in human-wildlife conflicts and the spread of diseases between humans and wild animals. However, interactions with wildlife can also have benefits. For example, birds help control parasites in certain crops. Furthermore, studies show that observing wild birds and animals can improve people’s mental health. It is therefore important to manage these interactions in a way that minimizes negative impacts and maximizes benefits. This is, in fact, a key objective of the Global Biodiversity Framework, which 196 countries adopted in 2022 as a guideline for conserving life on Earth and slowing the loss of wild species. Our findings also highlight the need for effective management of human-wildlife coexistence, particularly in areas identified by our research as those where interactions will be most frequent in the future.  

How We Conducted Our Research

To this end, we developed a spatial index to measure the future degree of coexistence between humans and wildlife worldwide. To assess this phenomenon region by region, we multiplied human population density by the number of wild species present in a given area. To do this, we included 22,374 terrestrial species of amphibians, birds, mammals, and reptiles. By combining published datasets on the most recent population figures (2015) and future projections (2070), we were able to analyze how human-wildlife interactions will change by 2070 and identify the locations where shared space will increase most dramatically. We then studied changes in species richness for each landscape type (farmland, grasslands, urban areas, and forests) depending on whether interactions between humans and wildlife increase or not.  

Next Steps

Our work provides an overall picture of how human-wildlife interactions will change, but further research will also require local studies to better understand the consequences. Future research on lands shared by humans and wildlife should therefore seek to analyze factors such as species abundance, behavior, and ecology, as well as the types of interactions between humans and wildlife. Policy makers can also use the results of our work to guide conservation planning in a future where the ranges of certain species will be more densely populated by humans. For example, our projections can help identify the locations of habitat corridors —those crucial spaces that allow wild species to move between key areas within a fragmented habitat. They could also help identify areas that are relatively protected from the effects of climate change over time and that could serve as refuges for endangered species. Our research can also help guide future conservation investments, such as the rewilding of areas where human population density is declining, or the preservation and enhancement of wildlife habitats in increasingly urbanized areas. Finally, our study underscores the importance of involving local communities in wildlife conservation. We are convinced that employing a variety of conservation strategies and taking human needs into account is the most effective way to ensure sustainable coexistence. Neil Carter , Associate Professor of Wildlife Conservation, University of Michigan , and Deqiang Ma , Postdoctoral Researcher in Environment and Sustainability, University of Michigan This article is republished from The Conversation under a Creative Commons license. Read the original article.