Introduction
European mink, Mustela lutreola (Linnaeus 1761) look so similar to American mink, Mustela vison (Schreber, 1777) that the two were formerly distinguished only as subspecies (Ognev, 1931; Heptner et al., 1967; for a review, see Novikov, 1939). This similarity offers not only a striking instance of convergence, but also a plausible explanation of the European mink's precipitous decline to the verge of extinction. In fact, phylogenetically the European mink is probably closest to the Siberian polecat, Mustela sibirica (Pallas, 1773), whilst the American mink is the most aberrant in the genus Mustela (Lushnikova et al., 1989; Graphodatsky et al., 1976; Youngman, 1982).
The European mink was formerly widespread in eastern Europe, but has declined over a long period and by 1990 was clearly endangered (Maran, 1994 b). Here, after reviewing briefly the species’ biology, we will present the results of an up–dated survey of the European mink's status. Against that background we will present a critical review of hypotheses that might explain its decline, dwelling in particular on two that we will subject to a preliminary test by presenting new data. These two implicate the American mink, first through the transmission of disease and second as a direct aggressor.