To catch a starling: testing the effectiveness of different trap and lure types

Abstract

Context Worldwide, invasive fauna species present one of the most intractable problems for agriculture and natural systems. Our ability to improve control techniques to combat the global invasive species predicament is constrained within the bounds of both economic and ethical considerations. In south-eastern Australia, the common starling (Sturnus vulgaris) is an established invasive avian pest that is now making incursions into areas of Western Australia (WA) that are currently free of this species. The most cost-effective and widely implemented starling control tool is trapping with live-lure birds. In recent years, the use of live-lure birds has been questioned on both economic and ethical grounds, and consequently alternative lure methods need investigating. Aims To evaluate the effectiveness of different trap and lure combinations for the capture of starlings in western South Australia (SA). Methods Modified Australian Crow (MAC) traps, used traditionally in WA to trap starlings, and Myna traps, originally designed for trapping common mynas (Sturnus tristis), were set during the peaks in starling flocking activity (Austral summer, 2007) using three different lure types: (1) live lure (live starlings); (2) moving water; and (3) acoustic lures. A trapping grid consisting of a single Myna trap with live lure and three MAC traps, each with one type of lure (live, water or acoustic) was established at five sites on the Eyre Peninsula in SA and monitored twice daily for 28 days. Key results Live lures were significantly more effective at attracting starlings into traps compared with both water and sound lures. We also trapped at an additional three sites and showed that Myna traps caught ~1.5 times more starlings than MAC traps when both traps were fitted with live-lure birds. Conclusions Neither moving water nor acoustic play-back lures proved suitable replacements for the use of live-lure birds to capture starlings. The efficacy of alternative lure types may depend on several factors and may include neophobic response(s) to novel signals and also the length of time that an invasive population has been established. Implications We recommend that use of live lures is continued in ongoing starling control programs, and that MAC traps currently in use be modified to capitalise on known starling behaviour. Further research and development of traps that do not contain live lures will improve the welfare of invasive species control programs.