Invasive American mink Mustela vison in wetlands of the Cape Horn Biosphere Reserve, southern Chile: what are they eating?.

„X IBARRA, J.T., FASOLA, L., MACDONALD, D.W., ROZZI, R., BONACIC, C.

ORYX

Año: 2009 vol. 43 p. 87 - 90

0030-6053

Abstract We investigated seasonal variation in the diet of a recently arrived invasive predator, the American mink (Mustela vison), in the Sub-Antarctic Cape Horn Biosphere Reserve, Chile. Diet was determined identifying undigested remains in 414 scats collected from 27 ponds in Navarino Island. The diet of mink in these wetlands consisted mainly of mammals and birds. Mammals, including both native and exotic rodents, were the predominant prey in all seasons, but birds were of equal importance during the summer (when birds breed and their abundance and diversity increases on the island). Exotic rodents were the only identifiable mammals prey item during winter. Native wetland birds constituted a substantial proportion of mink diet, greater than that reported in other areas of the world. Many birds breeding on Navarino are ground-nesting, a strategy evolved in the absence of native mammalian predators. Considering the international importance of this ecoregion, our results emphasise the need for an assessment of the impact of mink predation on the populations of native prey.