Wildlife Research Wildlife Research Society
Ecology, management and conservation in natural and modified habitats

Can the Judas technique be applied to pest birds?

Andrew P. Woolnough A B , Tim J. Lowe A and Ken Rose A

A Vertebrate Pest Research Section, Department of Agriculture and Food, Western Australia, 100 Bougainvillea Avenue, Forrestfield, WA 6058, Australia.

B Corresponding author. Email: awoolnough@agric.wa.gov.au

Wildlife Research 33(6) 449-455 http://dx.doi.org/10.1071/WR06009
Submitted: 19 January 2006  Accepted: 11 August 2006   Published: 4 October 2006


The Judas technique was evaluated for its use as a technique to assist with the control of the common starling (Sturnus vulgaris). This technique uses the natural behaviour of a gregarious animal to betray the location of itself and its companions through radio-telemetry. Two trials were conducted to assess and develop the technique for starlings. The first trial was conducted near the western edge of the starling’s current established range in Australia, at Penong in South Australia. Nine out of ten radio-tagged birds were successfully tracked from the ground and air. Estimates of the areas utilised varied from 1.1 km2 to 96.5 km2 (100% convex polygons). Night-time roosts were found for three of the nine radio-tagged birds and control (shooting) recovered just one bird directly associated with a Judas starling, as well as the radio-tagged bird. The second trial was conducted at Munglinup near Esperance in Western Australia. Munglinup is the site of a recent infestation of starlings and is the most western-known outlier of this pest in Australia. At this site, five radio-tagged starlings tracked from the ground and air, utilised areas ranging from 0.7 km2 to 51.6 km2. Reduced fidelity to roosting trees impaired our ability to destroy starlings here. However, the real value of the Munglinup trial was to expand the geographical area known to be occupied by this population from 103 km2 to more than 225 km2 and to identify habitats and roost sites used by the starlings. We conclude that the Judas technique could be applied to starlings and other pest birds with similar social structures as a means of strategic surveillance rather than as an adjunct to control per se.


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