BACKGROUND: Twenty beavers Castor canadensis (Castoridae) were initially introduced in the Argentinean portion of Tierra del Fuego Island, from where they have occupied most of the Fuegian Archipelago and even reached the continent. This invasion is causing great damage to the subantarctic forest ecosystems, and it is not known how fast the species is spreading. While there is an estimation of this advance using interviews, it is not known how reliable these are and they cannot be made in remote areas. On the mainland, where beavers were present, their date of arrival was estimated using interviews and dendrochronology, and the dates obtained by both methods were compared for each site. RESULTS: Differences were found among the groups of respondents,... |