A global map of species at risk of extinction due to natural hazards

An often-overlooked question of the biodiversity crisis is how natural hazards contribute to species extinction risk. To address this issue, we explored how four natural hazards: earthquakes, hurricanes, tsunamis, and volcanoes, overlapped with the distribution ranges of amphibians, birds, mammals, and reptiles that have either narrow distributions or populations with few mature individuals. To assess which species are at risk from these natural hazards, we combined the frequency and magnitude of each natural hazard to estimate a probability of impact. We considered species at risk if they overlapped with regions where any of the four natural hazards historically occurred (n = 3,722). Those species with at least a quarter of their range subjected to a high probability of impact were considered at high risk (n = 2,001) of extinction due to natural hazards. In total, 834 reptiles, 617 amphibians, 302 birds, and 248 mammals were at high risk and they were mainly distributed on islands and in the tropics. Hurricanes (n = 983) and earthquakes (n = 868) affected the most species, while tsunamis (n = 272), and volcanoes (n = 171) affected considerably fewer. The region with the highest number of species at high risk was the Pacific Ring of Fire, especially due to volcanoes, earthquakes and tsunamis, while hurricane-related high-risk species were concentrated in the Caribbean Sea, Gulf of Mexico, and northwestern Pacific Ocean. Our study provides important information regarding the species at risk due to natural hazards and can help guide conservation attention and efforts to safeguard their survival.

Methods
To address this knowledge gap, we provide an evaluation of the risk posed by natural hazards to terrestrial vertebrate species worldwide, focusing especially on those species that have limited distributions and/or occur at low numbers. First, we selected all amphibian, bird, mammal, and reptile species with a maximum population size of 1,100 mature individuals and/or those with a range size less than or equal to 2,500 km² based on the IUCN Red List of Threatened Species. Second, we constructed an estimate for the likelihood of impact from four natural hazards (earthquakes, hurricanes, tsunamis, and volcanoes) by analysing approximately 50 years of historical data concerning the frequency and magnitude of events. We then identified all species whose ranges overlap with known occurrences of hurricanes, earthquakes, tsunamis, and volcanoes. Finally, we classified the species at ‘high-risk’ as those for which at least a quarter of their range overlapped with areas of high probability of impact from at least one natural hazard.