Trophic ecology of a new top predator: Comparison of feeding habits of invasive American mink (Neovison vison) between seasons and environments on Tierra del Fuego Island

VALENZUELA, A.; RAYA REY, A; FASOLA ,L; SÁENZ SAMANIEGO, R.; SCHIAVINI, A

MAMMALIAN BIOLOGY

ELSEVIER GMBH

Lugar: Heidelberg; Año: 2013 vol. 78 p. 104 - 110

1616-5047

The American mink (Neovison vison) is a semi-aquatic, generalist carnivore released onto Tierra del Fuego (TDF) Island in the 1940?s, subsequently spreading to adjacent islands in the archipelago with potential effect on native prey populations. Therefore, knowledge of the trophic ecology of this invasive predator is essential for planning strategies to control them and to conserve native fauna. We studied seasonal mink diet in TDF, comparing between different habitats to establish predator-prey relationships. We identified undigested remains from 493 scats collected between May 2005 and March 2009 from marine coasts and freshwater shores (river and lake). The main preys found on TDF were small mammals and fish, which together represented over 65% of diet items. Also, mink diet varied significantly between marine and freshwater habitats, but not between seasons; more terrestrial prey were consumed in lakes and rivers shorelines, compared to the marine coast. Among mammals, mink consumed more native small rodents than exotic species. Native fish consumption was also important with greater representation of species from the families Nototheniidae and Galaxiidae in marine and freshwater habitats respectively. Birds were the third item in importance. Overall, differences found in mink diets between habitats and types of consumed preys reflected their generalist/opportunistic feeding behavior, dependant on prey supply at each site. In the context of an integrated ecosystem conservation program and management strategy in the TDF Archipelago, our results establish the interactions between this exotic predator and its preys.