Revista Chilena de Historia Natural 81 (1): 123-136, 2008
RESEARCH ARTICLE
Knowing for controlling: ecological effects of invasive vertebrates in Tierra del
Fuego
The Tierra del Fuego (TDF) archipelago is recognized as part of the last places on Earth
that may still be considered wild. However, this condition may be threatened by the large number of invasive species present on the
archipelago. These species can have significant effects on the ecology of the invaded ecosystems, at the genetic as well as at
population, community and ecosystem levels. The aim of this study is to, by a bibliographic review, systematize existing information on
the ecological impacts these species would be having on the TDF archipelago and detect information gaps in order to orient future
research and effective management programs on these species. We restricted our review to vertebrate, non-marine invaders. We
determined which species have invaded TDF, described their impacts on the archipelago and evaluated their potential impacts; this
last issue was determined by reviewing some of the impacts these species have had in other geographic areas. Our findings indicate
that at least nine vertebrate species (Salmo trutta, Salvelinus fontinalis, Oncorhynchus
mykiss, Castor canadensis, Ondatra zibethicus, Oryctolagus cuniculus,
Pseudalopex griseus, Mustela vison and Sus scrofa) have wild populations
established away from human settlements in TDF. There is some scientific evidence on ecological impacts on the area for only five of
these invaders, with the American beaver (Castor canadensis) being the species monopolizing the greatest number of
studies. These results contrast with the recognition, both in TDF and worldwide, of the potential of most of these species to cause
significant ecological impacts, which makes it unlikely that the lack of verified impacts on TDF reflects an absence of significant effects
of these invaders on the archipelago. We suggest that future research should focus on determining population density and distribution
of these and other (i.e., feral species) invasive vertebrates, as well as their impacts mainly on freshwater systems, vegetation, soil and
ground nesting birds. Regarding management, interactions between invaders must be considered. Whether the TDF archipelago is
especially vulnerable to biological invasions remains to be proven, however, future introductions should be carefully weighed.
Key words:
impacts, introduced,
exotic, Chile, Argentina
