As drought intensifies worldwide, wildlife are suffering and the science isn’t keeping up

Droughts are becoming more frequent and severe, but for most of the world’s wildlife, we don’t have a clear picture of what that means. Are birds, mammals, reptiles, and amphibians all affected the same way? Are we studying the right places? A new review by Rocky Mountain Research Station and Colorado State University scientists set out to answer these questions by synthesizing over four decades of research on how drought affects land-dwelling vertebrates around the globe.

Photo Credit

USDA

The team reviewed more than 500 studies published between 1982 and 2024 and compiled 3,324 documented wildlife responses to drought. The pattern was strikingly consistent: when the focus of a study was a single species 66% of documented responses to drought were negative, such as lower survival, poorer body condition, or reduced reproduction, while only 2% were positive. Studies of entire communities of species told a more complicated story — a quarter of responses were negative, but 71% were too ambiguous to categorize as clearly good or bad, largely because many studies report effects for a whole community with potentially mixed responses.Th at gap points to a real challenge for scientists and managers alike: it’s hard to protect what you can’t clearly measure.

The review also revealed major blind spots in what’s being studied. Birds account for half of all documented responses, while amphibians make up 16% and reptiles just 5%, even though amphibians and reptiles may be especially vulnerable to long-term drying trends. Geographically, research has clustered in places like the United States, South Africa, and southeastern Australia. But some areas projected to face the steepest increases in future drought, including northern Africa, coastal South America, and parts of the Amazon, remain largely unstudied, despite supporting high levels of biodiversity. The team also found scientists rarely agree on how to define or measure drought itself, which makes it difficult to compare results across studies or build a reliable early-warning picture of risk.

For land managers, these findings highlight the need for robust monitoring and adaptive management in the drought-vulnerable regions, especially focused on taxonomic groups that have received the least research attention such as reptiles and amphibians. For the public and media, the review is a reminder that drought’s toll extends well beyond dry reservoirs and stressed crops; it is reshaping the survival odds of animals across every continent. And for those shaping science priorities, it highlights concrete, addressable gaps, standardizing how drought is measured and directing research effort toward understudied species and geographies. This research and future work addressing the identified gaps in understanding will help address this increasing conservation threat.
 

Publications

McTigue et al. 2026. Global trends in drought impacts on wildlife -- a review.

van den Bosch et al. 2026. Projected increases in climate extremes across global vertebrate diversity hotspots.