In 2008, 25 New Zealand rock wrens were translocated onto Secretary Island, with excellent results. A search by DoC rangers two years later found twelve unbanded rock wrens, confirming that natural breeding started to occur shortly after the translocation. Sixteen more birds were transferred in 2010. With its southern location and many areas over 1000 metres above sea level, Secretary Island is the most suitable offshore island for these alpine birds, as it offers the harsh alpine areas they prefer. On the mainland, rock wren are threatened by introduced predators.