Tracking the expansion of the American mink Emph

Authors: Diana C Rodrigues Luciana Simões Jacinta Mullins Simone Lampa Raquel C Mendes Carlos Fernandes Rui Rebelo Margarida SantosReis

Publish Date: 2014/05/04

Volume: 17, Issue: 1, Pages: 13-22

PDF Link

Abstract

Invasive in many European countries the American mink Neovison vison was introduced in Portugal in the late 1980’s presumably escaping from Spanish fur farms close to the border In spite of the biological richness of the invaded area no study ever addressed the evolution of the invasion process We aimed to investigate the current distribution and status of the mink in NW Portugal and discuss some contributing factors to explain the rate of invasion We detected mink presence using floating rafts as footprint tracking devices and scats as a molecular tool aiding in species identification Results demonstrate a clear range expansion southwards with mink already occupying most of the region’s hydrographic basins After a first phase of slow expansion 55 km in 20 years mink seems to have expanded its range quite rapidly in only 2 years 45 km The initial delay could be due to local thriving otter populations whereas the recent establishment of red swamp crayfish Procambarus clarkii in the area could be a plausible explanation for the acceleration in the mink’s expansion Being a key food resource crayfish may be playing an important role as an expansion facilitator Mink eradication is probably no longer feasible since well established populations near the border continue to function as sources for the Portuguese population Therefore a control program should start immediately in the NW region preferably in conjunction with Spanish authoritiesWe would like to thank the Portuguese “Fundação para a Ciência e Tecnologia” for funding Project DILEMA—“Alien species and conservation dilemmas the effects of native competitors and alien prey species on the spread of the American mink in Portugal” PTDC/BIABEC/102433/2008 Furthermore we thank the German Academic Exchange Service DAAD D/07/49405 and the Helmholtz Interdisciplinary Graduate School for Environmental Research HIGRADE for funding Simone Lampa We are very grateful to Francisco Moreira Julien Goebel Rita Duarte Sofia Gonçalves Carlo Rusponi Laura Kuipers Mafalda Basto Teresa SalesLuís Ana Catarina Silva and Céline Madeira for assisting in the field and laboratory work We also thank Nuno Pedroso Helena Rio Maior Renato Fernandes João Branco Associação GuardaRios do Lima Carlos Rio Ana Carvalho Patrícia and José Luís Sequeira for providing data on American mink sightings We are grateful to the staff of the Gaia Biological Park for allowing us to test the tracking device with captive mink and polecats and that of the Lagoons of Bertiandos and S Pedro d’Arcos Protected Area for logistic support during fieldwork Finally we are most grateful to Lauren Harrington and another anonymous reviewer for providing valuable inputs that have greatly contributed to improve this paper

Keywords: