Study Shows Native Chilean Rodents Disappear Following Unprecedented 2019 Drought

After examining over ten years of field observations, researchers have recorded the abrupt loss of a previously plentiful degu population—the indigenous rodent of central Chile—triggered by the nation’s most extreme drought on record.

Published in the peer‑reviewed journal Ecology, the results rely on twelve years of systematic population tracking. The team noted that the degu assemblage survived a near‑decade‑long megadrought, keeping its numbers steady even as water supplies dwindled and plant cover thinned.

Degus are modest, burrowing rodents that contribute significantly to seed dispersal and soil aeration, and they have traditionally been viewed as tolerant of the fluctuating climate in central Chile’s Mediterranean‑like zone. Their persistence during the prior megadrought was linked to behavioral adaptability, including altered foraging habits and use of moisture stored deeper in the soil.

Yet the severe 2019 drought proved too much to endure. Post‑2019 field surveys documented a steep drop, with the species vanishing from multiple monitoring locations altogether. This swift disappearance indicates that the drought surpassed the physiological and ecological limits the rodents could bear, resulting in local extirpation.

The research highlights that climate extremes can outstrip wildlife’s adaptive capacity, even for species once thought robust. Chile has endured a succession of dry years tied to wider Pacific Ocean warming, with the 2019 episode reaching an unprecedented intensity. These circumstances jeopardize not only single species but also the wider ecosystem services that rodents provide.

Scientists emphasize that ongoing long‑term monitoring remains crucial for spotting early warning signals in other at‑risk groups. Conservation approaches might have to include habitat restoration, artificial water provisioning, or assisted migration to cushion future megadrought effects. The degu example starkly demonstrates how rising climate variability can manifest as concrete biodiversity losses, urging a reevaluation of resilience expectations for fauna in dry and semi‑dry regions.