CADIC   02618
CENTRO AUSTRAL DE INVESTIGACIONES CIENTIFICAS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
ECOLOGY OF AN INVASIVE PREDATOR ON AN ISLAND: THE CASE OF AMERICAN MINK (NEOVISON
Autor/es:
A VALENZUELA; RAYA REY A; SCHIAVINI A
Lugar:
Mendoza, Argentina
Reunión:
Congreso; 10th International Mammalogical Congress; 2009
Resumen:
The American mink (Neovison vison) escaped from fur farms on Tierra del Fuego Island in the 1940’s, subsequently spreading to adjacent islands of the entire Fuegian Archipelago. Its introduction to other insular systems around the world has caused the reduction, and even local extirpation, of prey populations and the displacement of native mustelids, becoming one of the main threats to biodiversity in those areas. Knowledge of the ecology of this invasive predator is essential for the planning of control strategies. We, therefore, evaluated abundance, distribution, habitat characteristics and seasonal diet (summer and winter) of American mink in different habitats (marine and freshwater shorelines within forested, shrubland, peatbog, grassland, and pebble/mud beach ecosystems) of Tierra del Fuego Island. We constructed a habitat suitability model based on the location of mink signs (scats and dens) and environmental characteristics of habitats, using generalized linear model (GLM). American mink distribution was heterogeneous and the GLM that best fit the data included habitat type, distance to coastline and coastline slope (for marine coasts). Most dens were found in forest and shrubland habitats in both marine and freshwater ecosystems. Human presence showed no relationship to mink presence. Diet analysis, based on scats, showed differences between marine and freshwater environments, but not between seasons. Mammals were the most consumed item in all sites. Although statistically insignificant, in summer, the consumption of fish and birds increased in all habitats, while crustaceans and insect increased only along marine and freshwater shorelines respectively. From these data, we have also developed a spatially explicit habitat suitability map for entire archipelago that will allow planners to develop management policies aimed at controlling the American mink population in the Fuegian Archipelago.The American mink (Neovison vison) escaped from fur farms on Tierra del Fuego Island in the 1940’s, subsequently spreading to adjacent islands of the entire Fuegian Archipelago. Its introduction to other insular systems around the world has caused the reduction, and even local extirpation, of prey populations and the displacement of native mustelids, becoming one of the main threats to biodiversity in those areas. Knowledge of the ecology of this invasive predator is essential for the planning of control strategies. We, therefore, evaluated abundance, distribution, habitat characteristics and seasonal diet (summer and winter) of American mink in different habitats (marine and freshwater shorelines within forested, shrubland, peatbog, grassland, and pebble/mud beach ecosystems) of Tierra del Fuego Island. We constructed a habitat suitability model based on the location of mink signs (scats and dens) and environmental characteristics of habitats, using generalized linear model (GLM). American mink distribution was heterogeneous and the GLM that best fit the data included habitat type, distance to coastline and coastline slope (for marine coasts). Most dens were found in forest and shrubland habitats in both marine and freshwater ecosystems. Human presence showed no relationship to mink presence. Diet analysis, based on scats, showed differences between marine and freshwater environments, but not between seasons. Mammals were the most consumed item in all sites. Although statistically insignificant, in summer, the consumption of fish and birds increased in all habitats, while crustaceans and insect increased only along marine and freshwater shorelines respectively. From these data, we have also developed a spatially explicit habitat suitability map for entire archipelago that will allow planners to develop management policies aimed at controlling the American mink population in the Fuegian Archipelago.