Authorities have extended the seasonal surveillance of European starlings, following the capture of 11 of the pest birds between Hopetoun and Condingup.
The Department of Primary Industries and Regional Development have urged the community to be especially vigilant and to report any unusual findings to authorities.
The seasonal surveillance period was due to finish at the end of October but was extended to ensure a breeding population was not present along the state’s south coast.
Department invasive species manager Richard Watkins said an incident team had been established to extend trapping, with additional staff on the ground.
“We are also calling on residents and travellers to work closely with us to look out for and report any unusual black birds,” he said.
“The earlier a pest is detected, the more successful control will be.”
The surveillance program has been running for several years in a bid to prevent breeding populations from being established in Western Australia.
A watch alert was issued to residents in the Esperance region only last month, after four starlings were detected along the coast.
The birds were found 30 kilometres north-east of Esperance during the surveillance program run by the department.
The common starling is considered one of the world’s worst bird pests, feeding on cultivated grain, horticultural crops and foul wool, dispersing weeds and displacing many native bird species.
The aggressive birds, which were introduced to Australia, can form large flocks and tend to move, feed and roost in tight groups.
The birds are small to medium in size and of glossy appearance and, despite their iridescent green and purple sheen, starlings can appear plain black from a distance.
Seen during the spring and summer months, young starlings are mouse-brown in colour, becoming a patchy brown and black colour after moulting in the autumn months.
Adult starlings are patchy brown and black in appearance and are known to stand on the backs of livestock.
Suspected sightings can be reported using the MyPestGuide Reporter app, by calling the Pest and Disease Information Service on 93683080 or via email on firstname.lastname@example.org
The app can be downloaded for free via the Google Play store or the App store.