Abundance and habitat preferences of the southernmost population of mink: implications for managing a recent island invasion

Abstract

Since 2001 invasive American mink has been known to populate Navarino Island, an island located in the pristine wilderness of the Cape Horn Biosphere Reserve, Chile, lacking native carnivorous mammals. As requested by scientists and managers, our study aims at understanding the population ecology of mink in order to respond to conservation concerns. We studied the abundance of mink in different semi-aquatic habitats using live trapping (n = 1,320 trap nights) and sign surveys (n = 68 sites). With generalized linear models we evaluated mink abundance in relation to small-scale habitat features including habitats engineered by invasive beavers (Castor canadensis). Mink have colonized the entire island and signs were found in 79% of the surveys in all types of semiaquatic habitats. Yet, relative population abundance (0.75 mink/km of coastline) was still below densities measured in other invaded or native areas. The habitat model accuracies indicated that mink were generally less specific in habitat use, probably due to the missing limitations normally imposed by predators or competitors. The selected models predicted that mink prefer to use shrubland instead of open habitat, coastal areas with heterogeneous shores instead of flat beaches, and interestingly, that mink avoid habitats strongly modified by beavers. Our results indicate need for immediate mink control on Navarino Island. For this future management we suggest that rocky coastal shores should be considered as priority sites deserving special conservation efforts. Further research is needed with respect to the immigration of mink from adjacent islands and to examine facilitating or hampering relationships between the different invasive species present, especially if integrative management is sought.

The impacts of beaversCastorspp. on biodiversity and the ecological basis for their reintroduction to Scotland,UK

“…Therefore, the apparent avoidance of beaver‐modified habitat by mink reported from Patagonia (Schüttler et al. ) and Russia (Kiseleva ) is interesting and, if this pattern is translated to Scotland, could have important implications for the future strategic management of mink.…”

Primera década de investigación y educación en la Reserva de la Biosfera Cabo de Hornos: El enfoque biocultural del Parque Etnobotánico Omora

“…Fuentes: (1) Arróniz-Crespo et al 2014;Jofre et al 2010, Lewis et al 2014aMéndez, 2013;Méndez et al 2013;Rozzi et al 2008b; (2) Mansilla et al 2012Mansilla et al , 2013aMansilla et al , 2014aOjeda et al 2014Ojeda et al , 2015; (3) Contador et al 2012Contador et al , 2014; (4) Merino et al 2008;Reyes et al 2015;(5) Crego et al 2014(5) Crego et al , 2015Ibarra et al 2009Ibarra et al , 2010Schüttler et al 2008Schüttler et al , 2009Schüttler et al , 2010Schüttler et al , 2011Jiménez et al 2014;(6) Berghöfer et al 2008(6) Berghöfer et al , 2010Jax & Rozzi, 2004;Rozzi & Schüttler, 2013;Rozzi, 2004, Rozzi et al 2006a,b, 2007, 2012a; (7) Aguirre, 2015; Ibarra et al 2012;Massardo et al 2012;Poole et al 2013;Rozzi 2012aRozzi ,b, 2013Rozzi et al 2010bRozzi et al ,c, 2014Rozzi et al , 2015(8) Medina, 2013;Pizarro & Caballero, 2011;Sherriffs et al 2005;Zárraga et a...…”

Experimental Evaluation of Koala Scat Persistence and Detectability with Implications for Pellet-Based Fauna Census

“…These indirect methods include, but are not limited to, sign surveys [6,7]; of which scat (fecal pellet) survey is one of the oldest and most widely used indirect methods [8,9]. More specifically, scat surveys are often used to determine habitat preferences and predict habitat quality (e.g., [10,11]) and are thus commonly used for monitoring endangered wildlife [12] or managing game species [13]. However, variability of both scat detectability and decay rate has led to the expression of concerns regarding the reliability of such surveys [14].…”