Trophic ecology of a top predator colonizing the southern extreme of South America: Feeding habits of invasive American mink (Neovison vison) in Tierra del Fuego

A VALENZUELA; A RAYA REY; L FASOLA; SAENZ SAMANIEGO R; A SCHIAVINI

MAMMALIAN BIOLOGY

ELSEVIER GMBH

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 1940s, subsequently spreading to adjacent islands in the archipelago with potentialeffects on native prey populations. Knowledge of this new predator?s trophic ecology is essential toidentify threats, plan control strategies and conserve native fauna. We studied seasonal mink diet inTDF in different habitats. We identified undigested remains from 493 scats collected between May 2005and March 2009 along marine coasts and freshwater shores (rivers and lakes). Small mammals and fishwere the main mink prey in TDF (over 65% of diet items). Seasonal variations were not detected, butdiet did vary significantly between marine and freshwater habitats, where more terrestrial items wereconsumed. Among mammals, mink consumed more small native rodents than exotic species. Native fishconsumption was also important with greater representation of species from the families Nototheniidaeand Galaxiidae in marine and freshwater habitats respectively. Birds were the third item in importance,but did not constitute a particularly large part of the mink?s diet on TDF. Overall, differences found in minkdiet between habitats reflected their generalist/opportunistic feeding behaviour and did not differ greatlyfrom observations in its native range or in other areas where it has been introduced. Our results establishthe interactions between this novel predator and its prey and also illustrate the need to continue researchon native prey populations to quantify mink impact on them and understand the ecological context ofthis biotic assemblage.