Search

Start Over Creator Fischer, David

2. Predation of the alien American mink, Mustela vison on native crayfish in middle-sized streams in central and western Bohemia

Creator:
Fischer, David, Paluvčík, Petr, Sedláček, František, and Šálek, Martin
Type:
article and TEXT
Subject:
mink diet, stone crayfish, prey selectivity, density-dependent predation, and Czech Republic
Language:
English
Description:
The impact of predation by alien American mink (Mustela vison) on endangered stone crayfish (Austropotamobius torrentium) was examined in middle-sized streams in central and western Bohemia for the duration of two years. The most frequent food source of the American mink were crustaceans, followed by mammals, amphibians and fish. Crustaceans consisted entirely of one species, the stone crayfish, which was represented in 82% of all collected mink droppings. Analysis of the relative composition of summer and winter diet showed no significant differences between these periods. The identification of predation of the American mink on stone crayfish was based on the collection of prey remains during the period monitored. Predation rates at particular localities were highly variable (0.85–21.5%, average = 7.4%), and decreased significantly in winter periods. The use of crayfish seems to reflect their spatial availability, suggested by the good correspondence between the population density and the number of prey remains. Minks preyed selectively on sexually mature individuals, which increases the seriousness of their predation impact. This study suggests that alien mink could be an important mortality factor for stone crayfish populations on a local scale.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/