Human-wildlife overlap is projected to increase across more than half of all land areas worldwide by 2070. The primary driver of these changes is human population growth. That’s the key finding of our newly published study in the journal Science Advances.
Our research suggests that as the human population grows, people and animals will share increasingly crowded landscapes. For example, as more people move into forests and agricultural areas, human-wildlife overlap will increase sharply. It will also increase in urban areas as people move into cities in search of jobs and opportunities.
Animals are moving too, mainly in response to climate change, which is changing their ranges. In most areas, species richness—the number of unique species present—will decline as animals follow their preferred climates. But as human population growth increases, there will be greater human-wildlife overlap on most lands.
We also found that areas of human-wildlife overlap decreased as human populations changed, but these were much rarer than areas of increase.
We found that Africa will have the largest proportion of land with increasing human-wildlife overlap (70.6%), followed by South America (66.5%). In contrast, we found that Europe will have the largest proportion of land with decreasing human-wildlife overlap (21.4%).
Why is it important?
Around the world, people and wildlife are increasingly competing for limited space on land. This can lead to harmful consequences, such as human-wildlife conflicts and the spread of diseases between people and animals.
But interacting with wildlife can also have benefits. For example, birds provide valuable pest control for some crops. And studies show that observing birds and animals in nature can improve people’s mental health.
It’s important to manage these interactions to minimise negative impacts and maximise benefits. This is one of the key goals of the Global Biodiversity Framework, which nations adopted in 2022 as a plan to protect life on Earth and slow the loss of wild species.
Our findings underscore the need to manage the coexistence between people and wildlife. Our research provides a broad understanding of where changes in human-wildlife overlap will occur in the future, including hotspots that will require more effective measures to improve human-wildlife interactions.
How we did our work
We developed a spatial index to measure human-wildlife overlap worldwide. To calculate the degree of overlap by region, we multiplied human population density by the number of species found in a given area. Our study included 22,374 species of terrestrial amphibians, birds, mammals, and reptiles.
By combining recent (2015) and future (2070) published datasets on populations, species distributions and landscape types, we were able to investigate how human-wildlife overlap is likely to change by 2070 and identify locations where this overlap is likely to increase most dramatically. We then investigated changes in species richness in each landscape type (arableland, grassland, urban and forest) with increasing human-wildlife overlap.
What’s next?
Our research provides a broad picture of how human-wildlife overlap is changing, but researchers will need local studies to understand the implications. Future research on shared landscapes should analyze factors such as species abundance, species behavior and ecology, as well as types of interactions between people and wildlife.
Policymakers can use insights from our work to guide conservation planning in a more populous future. For example, our projections can help identify locations for habitat corridors that allow wildlife to move between critical habitats. They can also help identify areas that are relatively protected from the impacts of climate change over time and that can serve as refuges for at-risk species.
Our work could inform future conservation investments, such as wildlife restoration in areas where human populations are declining or protecting and restoring wildlife habitat in increasingly urbanized areas.
Finally, our study demonstrates the importance of involving local communities in wildlife conservation efforts. In our view, using multiple conservation strategies and taking human needs into account will be the most effective way to achieve sustainable coexistence.
A Research Summary is a brief summary of interesting academic work.
This article is republished from The Conversation, a nonprofit, independent news organization that brings you facts and trusted analysis to help you understand our complex world. By Neil Carter University of Michigan and Deqiang Ma, University of Michigan
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The authors do not work for, consult, own shares in, or receive funding from any company or organization that would benefit from this article, and they have disclosed no affiliations beyond their academic appointment.