This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: Research published in the journal Ecology analyzed 12 years of records from a population of degus in central Chile, revealing that these endemic rodents managed to withstand nearly a decade of megadrought but disappeared locally following the extreme drought of 2019. The study, which involved Annemarie van der Marel, a postdoctoral researcher at the Institute of Ecology and Biodiversity (IEB), highlights the vulnerability of species to climatic events that exceed the resilience limits of ecosystems.
For nearly a decade, a population of common degus (Octodon degus) inhabiting Rinconada de Maipú, in Chile's Metropolitan Region, managed to survive the prolonged megadrought that affected central Chile. Despite declining rainfall and vegetation productivity, these small rodents maintained positive population growth throughout much of the study period. However, in 2019, something happened that abruptly changed their fate.
That year, rainfall was exceptionally scarce, and vegetation production fell to critical levels. The lack of food affected both the animals' survival and the recruitment of new individuals into the population. In 2020, researchers stopped recording degus at the study site despite continued trapping efforts, and no individuals were detected during additional surveys conducted in 2021.
These findings are documented in the study "The Effects of an Extreme Drought Led to the Local Extinction of a Social Rodent," which analyzed data collected between 2009 and 2020 using capture-mark-recapture techniques. The research revealed that the population did not experience a gradual decline throughout the megadrought. Instead, it persisted for years under adverse environmental conditions until the extreme drought of 2019 caused a critical reduction in available resources.
"What happened in 2019 was that there was virtually no rain throughout the entire year. Normally, even during the drought, there was some winter rainfall that allowed plants to grow and provided food for the degus. But that year, the plants didn't grow, and there was practically no food," explains van der Marel, a biologist and postdoctoral researcher at the IEB.
The findings reveal that a population's ability to withstand unfavorable environmental conditions for years does not necessarily guarantee its survival when faced with an exceptionally intense climatic event. The study was made possible by 15 years of records collected at the Germán Greve Silva Experimental Station in Rinconada de Maipú. Originally, these data were gathered as part of research into the social organization of degus—a species that also engages in communal care of its young—conducted by a team led by Dr.
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