A pilot program for the eradication of beavers and environmental restoration in Tierra del Fuego. First results

JUSIM, P; SCHIAVINI, A; ESCOBAR, J; CURTO, ERIO

Dundee

Congreso; Island Invasives 2017; 2017

South Georgia Heritage Trust

A pilot program for eradicating beavers in Tierra del Fuego started as part of a binational agreement signed between Argentina and Chile for restore environments affected by beavers. The program covers eight pilot areas of different landscapes and land tenures in Argentinian Tierra del Fuego. We report results of eradication operations achieved form November 2016 to January 2017 in the first pilot area and discuss challenges of this operation.Ten trappers using bodygrip traps (B), snares (S) and a rifle, operated during 12 weeks in blocks of 4 trapping nights/week. Trappers deployed 1378 and 956 trap/nights for B and S respectively. Rifle effort was not monitored. A total of 175 and 28 individuals were removed with B and S respectively (seven more by rifle), with an efficiency of 13,3% for B and 2,9% for S. At the same time a monitoring program started for assessing the environmental benefits of the beaver removal.After nominal eradication was declared, an independent group revisited the area for detecting remnants and declaring operational eradication. Revision involved an effort of 112 camera-nights and the trapping of remnants.The pilot area was divided in 18 sectors of grouped dams for data analysis. 65% of the beavers were harvested during the first week, with an efficiency of 14% against the 9% for the rest of the trapping nights (p