The Octodon pacificus is one of the close relatives of the Octodon degus commonly found in households. In total, there are five members of the Octodon genus. The Octodon pacificus is classified as critically endangered01, and the last known individuals were found deceased in 201602. The previous living observation of this species dated back to 1959, when it was first described by zoologist Rainer Hutterer03 04.
On March 19, 2024, Julian Reyes García, head of the Biological Diversity Conservation Section at CONAF05, along with student researchers from the University of Chile, captured living Octodon pacificus specimens. This breakthrough was made possible through years of collaboration between the two entities. After analyzing the captured specimens, it was confirmed that they were indeed Octodon pacificus, a species exclusively found on Mocha Island.
A fragile and threatened ecosystem
Rodents play an essential role in the food chain and in protecting the ecosystems where they live. Julian Reyes García explained that the Octodon pacificus contributes to seed dispersal and parasite population control. According to him, finding this rare species indicates that Mocha Island’s ecosystem is healthy. Thus, the Mocha Island National Reserve ensures the protection of this fragile ecological balance.
The reappearance of the Octodon pacificus opens up new possibilities for research and conservation. Paula Aravena, director of the Wildlife Rehabilitation Center, highlighted that education is a major challenge in protecting this species. Many people mistake local species for exotic or pest rodents. She emphasized the importance of establishing effective conservation programs for endangered species, including the Octodon pacificus.
Meanwhile, Flavio Espinoza, a Universidad Católica de la Santísima Concepción professor, suggested creating specific management plans for the Octodon pacificus. These would include captive breeding and controlled reintroduction into its natural habitat to ensure the species’ survival.
Unique evolutionary traits of the Octodon pacificus
The Octodon pacificus displays unique characteristics compared to its continental relatives, notably a significantly larger size and weight. According to the island gigantism theory, some species develop larger traits when isolated on islands. The specimens captured on Mocha Island weighed an average of 200 grams, nearly double the weight of their mainland counterparts.
This unexpected return of the Octodon pacificus provides new opportunities to study the species’ social behavior and evolution in an insular environment. Researchers are particularly curious to determine whether, like their mainland relatives, these rodents exhibit a complex and cooperative social structure.
This discovery opens up extensive research opportunities on the Octodon pacificus, particularly to understand its behavior, its role in the ecosystem, and how best to protect it. The Mocha Island National Reserve is becoming a key site for studying and preserving the island’s unique biodiversity.
The return of the Octodon pacificus is an exciting event for the scientific community and marks a new chapter in conserving Chile’s endemic species.
Sources
Translated and adapted from: https://www.diarioconcepcion.cl/ciudad/2024/04/09/revelan-inedita-historia-detras-del-hallazgo-del-roedor-extinto-de-la-isla-mocha.html
- IUCN Redlist[↩]
- EXTINCT BRUSH TAILED RAT aka DEGU REDISCOVERED IN MOCHA ISLAND, IN CHILE[↩]
- Past and present small mammals of Isla Mocha (Chile)[↩]
- Island rodents: a new species of Octodon from Isla Mocha, Chile (Mammalia: Octodontidae)[↩]
- Después de 65 años encuentran al degú en la Reserva Nacional Isla Mocha[↩]