Agricultural expansion is driving a steep decline in wildlife across the world’s most biologically rich regions, with more than a quarter of species lost in areas converted to farmland, according to a new global study. The findings highlight an urgent need to rethink food production and conservation strategies in biodiversity hotspots, where unique ecosystems are already under severe pressure.

The study, published on December 26, 2025, in the journal Communications Earth & Environment, found that farming within biodiversity hotspots has caused a 26 per cent decline in species richness compared to natural habitats. These losses are most pronounced among small-ranged vertebrates such as amphibians, birds and small mammals, which are particularly vulnerable because they occupy limited geographical areas.

Biodiversity hotspots are regions that contain exceptionally high numbers of species found nowhere else on Earth. Although they cover a relatively small portion of the planet’s land surface, they support a disproportionate share of global biodiversity. However, these areas have already lost more than 70 per cent of their original natural vegetation due to human activities, leaving remaining wildlife confined to shrinking and fragmented habitats.

The study shows that agriculture is compounding this crisis. As global food demand rises with population growth, wild landscapes are increasingly being converted into cropland. Inside biodiversity hotspots, this conversion has resulted not only in fewer species, but also in fewer individual plants and animals overall. Researchers documented a 12 per cent decline in total abundance and nearly a 9 per cent reduction in community diversity when accounting for population size.

The impacts are especially severe for species with small ranges. Even minor habitat losses can eliminate entire populations of these animals, many of which perform critical ecological functions such as pollination, seed dispersal and pest control. Their disappearance can set off cascading effects that destabilise entire ecosystems.

To assess the scale of the problem, the researchers analysed wildlife survey data from across the globe stored in the PREDICTS database, comparing natural forests and grasslands with areas converted to agriculture. They also used high-resolution satellite imagery to track cropland expansion between 2000 and 2019.

The results revealed that cropland within biodiversity hotspots expanded by 12 per cent during this period, outpacing the global average expansion rate of 9 per cent. The fastest growth occurred in tropical regions near the equator, including parts of South America, Southeast Asia and Africa—areas that are already among the most species-rich on the planet.

A key concern raised by the study is that much of the remaining wildlife in biodiversity hotspots exists outside formally protected areas. By overlaying maps of cropland expansion with the distribution of small-ranged vertebrates, researchers identified 3,483 high-risk zones covering approximately 1,741 million hectares. Alarmingly, around 1,031 million hectares of these zones lie outside protected parks and reserves, leaving them highly vulnerable to further agricultural conversion.

Some of the regions facing the greatest risks include the Atlantic Forest, Indo-Burma, the Western Ghats and Sri Lanka, Sundaland and the Eastern Himalaya. In these areas, ongoing land-use change threatens to push already stressed ecosystems past a tipping point.

The global patterns identified in the study are clearly visible in India’s Western Ghats, one of the world’s most important biodiversity hotspots. Agricultural expansion in this region often takes the form of plantations, orchards and mixed-use farming rather than large monoculture fields. While less visually dramatic, this type of development fragments habitats into smaller, disconnected patches, making it harder for wildlife to move, breed and survive.

The Western Ghats are home to more than 5,000 flowering plant species, hundreds of mammals and birds, and hundreds of globally threatened species, many of which—particularly amphibians and plants—are found nowhere else. Studies from the region have shown that converting unique ecosystems such as rocky plateaus into rice fields and orchards leads to steep declines in frog and other amphibian diversity.

International assessments have flagged the Western Ghats as an area of significant concern, citing land-use change and development pressures as major threats. Protecting biodiversity in such landscapes is especially challenging because much of the land is privately owned and used for agriculture or plantations, making regulation and enforcement more complex than in national parks.

Although the global study did not analyse plantation landscapes separately, its findings underscore the broader risks of continued land conversion in biodiversity-rich regions, regardless of the form agriculture takes.

The authors argue that simply expanding farmland to meet rising food demand is not a sustainable solution in biodiversity hotspots. Instead, they call for a combination of targeted measures. These include strategically expanding protected areas in regions where rare and range-restricted species are concentrated, strengthening management and enforcement in existing reserves, and improving productivity on land that is already under cultivation to reduce pressure on remaining natural habitats.

They also stress the importance of international cooperation on food trade, to ensure that economically vulnerable countries rich in biodiversity are not forced to sacrifice ecosystems to supply global markets. Finally, the study emphasises the need to involve local communities in conservation and monitoring efforts, recognising that people living in these landscapes must play a central role in safeguarding biodiversity.

Without such interventions, the study warns, the world’s richest ecosystems may continue to lose species at an alarming rate, with consequences that extend far beyond the regions where the losses occur.