Expansión del visón europeo Mustela lutreola (Linnaeus, 1761) hacia el este de su área de distribución en España: primeros datos en Aragón

Abstract

The European mink was first reported in Spain in the 1950s. Since then it has expanded its range in centralnorthern Spain. In 2007 the first European mink was captured in Aragón, in the province of Zaragoza. Since 1999, the rivers rising in eastern Zaragoza and Huesca have been trapped and surveyed to detect the presence of European mink in Aragón and confirm its slow expansion towards the east and south-east of the Iberian Peninsula. Trapping was carried out during seven years (1999, 2002, 2003, 2005, 2007, 2008 and 2009), with a total of 128 trapping stations and 9,680 trap nights. The rivers Ebro, Queiles, Huecha, Arba, Alera, Castiliscar, Onsella, Veral, Esca, Regal and Aragón were trapped. 16 different European minks were captured between 2007 and 2009, with 27 captures (11 recaptures): nine males and seven females. Mean weight of males was 894,4 g (SD= 150,4) and 514,7 g (SD= 18,7) for females. European mink was detected in the Huecha and Queiles rivers in the south of Aragón, where capture densities were higher; 1,19 and 1,28 different minks per 100 trap nights respectively. It was also detected in the Onsella, Castiliscar and Alera rivers in the north of Aragón, where capture densities were lower; 0,19, 0,55 and 0,66 different minks per 100 trap nights respectively. Its presence was detected in 7 UTM 10x10 km squares. By contrast, its presence was not detected in the upper basin of the River Aragón, probably as a consequence of the barrier constituted by the dam and water reservoir of Yesa, and in the River Ebro.