Corellas in the City of Bunbury

Large flocks of corellas can be a nuisance due to the large amount of noise when congregated at feed and roost sites and droppings can foul recreational, public, and domestic areas.

They cause damage to local sports fields and parks when digging for bulbs and roots, and damage trees and infrastructure through natural branch trimming and biting behaviours when roosting, including chewing cabling, roofing materials and aerials.

Damage to infrastructure and assets in the City is wide-spread and increasing every year. 

Little Corellas (Cacatua sanguinea sanguinea) and Eastern Long-billed Corellas (Cacatua tenuirostris) are native to Australia (eastern states) but are not naturally occurring within Western Australia.

They are an invasive species and Little Corellas are a Category 3 Declared Pest under the WA Biosecurity and Agriculture Management Act 2007.

Land holders are required to undertake measures to reduce their impact. 

The City’s Little Corella management program has been active since 2010. In 2018, the City prepared an Introduced Corella Management Strategy to guide and unify management efforts within the Greater Bunbury region.

The City remains focused on management efforts to minimise the adverse impacts caused by Little Corellas and has revised the strategy and updates its Little Corella Management Plan annually. 

The Little Corella Management Plan is a combination of existing and new techniques that have not yet been trialled within the City. Using a variety of techniques is necessary to address the adaptability of Corellas to various control mechanisms. 

The combination of techniques outlined in the Little Corella Management Plan are: 

• Trapping events at the City control sites. 

• Shooting when trapping is not possible at the control site. 

• Increased deterrence efforts within urban areas using Department of Biodiversity Conservation and Attractions (DBCA) approved dispersal techniques – the implementation of scare kites and firing of blanks within licensed areas. 

• Investigating the feasibility of flight path and movement tracking to outline roosting locations. 

• Identify opportunities to collaborate with the Port of Bunbury and neighbouring Local Government Authorities. 

• Provide community advice/education on deterrence and dispersal mechanisms that can be undertaken on private property. 

• Continue to identify suitable control sites within the Greater Bunbury region. 

All control and dispersal activities are undertaken under licence and in accordance with relevant legislation. No poison is or can be used.

Control measures undertaken are done so as a last resort and are implemented to reduce the pest Corella population to levels that are ecologically sustainable. 

The damage caused by Little Corellas is seasonal, mainly occurring from late October through to July. This is when management actions are implemented. 

Due to the size and distribution of the introduced Little Corella population in the South West, management of the birds is likely to be an ongoing issue for foreseeable future. 

Eradication of the Corella population is not realistic. Management actions aim to reduce the impacts on community during the season when Corellas are arriving to feed and roost in Bunbury. 

Control techniques fall into three categories, population reduction, deterrence/dispersal and habitat modification. The limitations of these control techniques are outlined in the table below.   

 

Control technique	Challenges /Limitations	Methods
Population reduction	Population reduction is only used in conjunction with other management activities and would not be effective as a solution by itself. Suitable control sites are difficult to find and contractors are reliant on the birds visiting these areas.	Shooting and trapping. Trapping and euthanasia will be undertaken by contractors and/or staff with appropriate training and experience, in accordance with all legislative requirements including the WA Animal Welfare Act 2002 and Department of Biodiversity, Conservation and Attraction guidelines.
Deterrence/  Dispersal	Reactive dispersal used on an as-needs basis provides immediate, although likely temporary, relief from Corella impacts. Birds are likely to realise the scare tactics do not actually harm them and return if these activities aren’t undertaken sporadically.	May include scare kites and firing of blanks within licensed areas. The intention is to unsettle the Corellas from congregating in urban areas and in turn, attract them to decoy sites where their impacts can be tolerated and/or further control techniques can be undertaken.
Habitat modification	Habitat modification is based on manipulating the relationship between the roost and easy access to food and/or water. Does not necessarily reduce roost sizes or changes to roost location.	May include vegetation management, alternative feeding areas and bait stations, lure/sacrificial crops, removal of roost structures, water spray devices, food removal.

 

Between 2016 and 2019 Western Australia Local Government Authority (WALGA), with funding provided by DBCA and Local Governments, undertook a Coordinated Corella Control Program in Perth, Peel and the South West to assist with the cross-boundary management of this species.

Since the program ceased, the City has continued to collaborate with other local governments and relevant stakeholders on a regional approach to Corella control through the development of a formal working group.

Additionally, the City continues to advocate for support from the State Government through research, funding and to drive legislative changes to help remove some of the limitations that currently exist around corella management.  

The State Government is developing a Pest Parrot and Cockatoo Strategy for Western Australia. The aim is to implement a collaborative strategic framework to achieve the effective long-term management of pest parrots and cockatoos in Western Australia.

The strategy will consider funding support, as well as effective monitoring and evaluation of control programs. 

If you/your property is impacted by Corellas or you have knowledge of local flock feeding or roosting sites, please let us know via the interactive map and or chat forum on the Corella Management Program page.

Your input will support the City to gain a better understanding of key feed sites, roost sites, potential control sites, and movement patterns to assist with future control efforts. 

There are a range of measures you can take to reduce the number of Corellas on your property, and decrease potential damage/destruction they may cause: 

• Protect or cover any open water sources that might attract Corellas. 

• Remove bird feeders and refrain from handfeeding all birds. 

• Place netting on any fruit trees or large trees that may be used for roosting. 

• Make noise to move any Corellas away and disrupt roosting (e.g. blowing a whistle, shooing, tapping tree trunks, using clap boards, downloading a bird repellent sound app). Please consider your neighbours if using noise as a deterrent. 

• Shine a bright light or torch into roosting flocks at night as they arrive and are beginning to settle. 

• Plant native species that are not favourable to Corellas.