Residents in Esperance and along the South Coast are urged to keep a look out for starlings.

Common starlings are a declared pest prohibited in Western Australia, which means any birds found must be removed.

The Department of Agriculture and Food has been undertaking a successful starling eradication program along the South Coast.

Department biosecurity officer Col Parry said it was important that any new sightings were reported immediately.

"Department staff have conducted searches for the bird but are also relying on local residents to keep a look out and report anything unusual as well," he said.

"Starlings are easier to remove during the summer season, while the females are breeding and remain close to the nest while searching for food and the juveniles are flying."

Starlings are considered a major pest of primary production and present a serious threat to WA.

Starlings have the potential to damage cultivated grain and horticulture crops, foul wool and damage buildings through nesting. They also compete with native birds for food and nesting sites and have the potential to cause major impact on biodiversity.

Starlings are about 21 cm long, twice the size of swallows and stockier, with fine, pointed beaks and short tails.

They are usually seen in flocks and move across the ground by waddling, not hopping, and prefer feeding in open grassland, although they are found in many habitats from urban to rural.

They are sometimes seen standing on the backs of sheep or cattle or following the livestock around the paddock, collecting insects.