Advance in the biological invasion process of the large hairy armadillo Chaetophractus villosus (Dasypodidae) in Tierra del Fuego Island: a new binational challenge

Abstract

Biological invasions by mammals on islands have been identified as one of the main causes of global biodiversity loss, but research and management has been biased towards those species that are already in the final stage of the invasion. Therefore, it is necessary for managers and decision makers to keep updated on the biological invasion process of these species to implement conservation measures that also include introduction and expansion stages. In particular, it is important to prevent the initial invasion stages from going unnoticed, either due to the species’ biological characteristics, such as cryptic habits or low densities, but also social factors that could condition this bias, such as species that were introduced in one political jurisdiction and expanded to another whose authorities and scientists were unaware of the newly invaded area. We present new records about the expansion of the large hairy armadillo (Chaetophractus villosus), a native species in the Chilean and Argentine mainland, but an exotic on Tierra del Fuego Island (TDF), that allow us to alert a change to the expansion stage in this biological invasion process. The armadillo was introduced in the Argentine side of TDF in 1982, where it occupied a thin strip of the Atlantic coast between Río Grande city and San Sebastián Bay, and their burrows were highly associated with natural gas and oil pipelines. In 2014, the armadillo was classified, based on its ecological impacts, among the priority species for management; however to date we found no plan, project or legislation focused on controlling this species’ invasion. This work’s new records extend the armadillo’s distribution, on both the Argentine and Chilean sectors of TDF. We detected both natural dispersion and human transportation as possible causes and vectors of their expansion. This case again demonstrates the lack of a binational and socio-ecological perspective on the study and management of biological invasions, which has severe consequences for the conservation of native ecosystems. We highlight that this case has become a binational biological invasion process that should be quickly addressed together between the managers and decision makers of both countries.