Re-introduction of the Mount Lofty Ranges southern emu-wren to Cox Scrub Conservation Park, South Australia

Summary

The Mount Lofty Ranges southern emu-wren (Stipiturus malachurus intermedius), an Endangered 7-gram passerine reduced to roughly 20 fragmented South Australian populations totaling 250-500 birds, was reintroduced to Cox Scrub Conservation Park, from which fire had eliminated it in 1983, in the species' first translocation attempt, run by the Conservation Council of South Australia in 2001-2002. Following a feasibility study and a translocation proposal meeting IUCN and state guidelines, 46 birds were transferred from the larger Deep Creek Conservation Park population, 30 in mid-2001 and 16 more in mid-2002 (short of the original target due to trapping shortfalls), captured as intact pairs where possible, color-banded, and released across 13 sites in 2001 to spread pairs across suitable habitat. Nearly all released birds dispersed from their release points, most putative pairs did not stay intact, and only 33% of settled pairs matched their original pairing, prompting 2002 releases to instead target areas already occupied by 2001 dispersers. By December 2003, founders and progeny had bred, though only about half of pairs bred each season and annual founder survival averaged just 32%; at least 15 individuals including four breeding pairs were confirmed present by late 2003, with a small population still detectable as late as 2009-2010 despite drought-driven habitat dieback from 2002-2004. Major difficulties included failure to reach the target founder number, the species' cryptic nature, widespread dispersal, and declining habitat quality from poor seasons. The project rates itself Partially Successful, having only partly met its predefined benchmarks despite establishing a persisting, breeding population.