Invasion of North American beaver (Castor canadensis) in the province of Magallanes, southern Chile: comparison between dating sites through interviews with the local community and dendrochronology

• Giorgia Graells ^[1] ; Derek Corcoran ^[2] ; Juan Carlos Aravena ^[1]
  1. [1] Universidad de Magallanes

     Universidad de Magallanes

     Punta Arenas, Chile

     
  2. [2] Pontificia Universidad Católica de Chile

     Pontificia Universidad Católica de Chile

     Santiago, Chile

     
• Localización: Revista chilena de historia natural, ISSN-e 0717-6317, ISSN 0716-078X, Vol. 88, Nº. 0, 2015
• Idioma: inglés
• Enlaces
  • Texto completo
• Resumen

  • 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, according to property size, in their ability to detect changes in the environment made by beavers. The dates of arrival estimated through dendrochronology are 23 years prior to those determined through surveys, and they generate a potential route of arrival from the Fuegian Archipelago and migration in the mainland. This route is more parsimonious than the route of dispersal generated through interviews. CONCLUSIONS: Since it was determined that there is no relationship between the dates estimated through surveys and dendrochronology, it is not possible to determine how much lag there is from the time when changes in the environment are produced by beavers and the time when people notice this change. Our results indicate that this lag may not be constant among different groups of people.