Introduced Corella
The Corella species present in large numbers.
Flocking around the Busselton and Dunsborough townsites are the Little Corella (Cacatua sanguine gymnopis) and the Eastern Long Billed Corella (Cacatua tenuirostris).
These species are considered to be introduced to this region because they are made up of birds previously held in captivity that have either escaped, or were released. Little Corellas are native to the Gascoyne, Pilbara and Kimberley regions of Western Australia. Eastern Long-billed Corellas are native to south-central New South Wales, south-western Victoria and south-eastern South Australia.
Flock of Corellas feeding on grass at Port Geographe
These species pose a significant threat to native fauna by out-competing native birds for nesting hollows and interbreeding with West Australian sub-species of Corella. The Corellas also impact on public amenity and vegetation. Left uncontrolled, issues of noise nuisance and public health, such as faecal contamination of public eating areas, are likely to increase.
Advice was sought from Department of Biodiversity, Conservation and Attractions (DBCA) on appropriate control methods. Corellas are attracted to a trapping site by free feeding with bird seed. When a regular feeding pattern is established, the trap (a remotely triggered net) is used to catch the birds and they are then euthanised by shooting. No poisons are used. The City undertakes the control program in accordance with a licence from DBCA.
These species of Corella have now been placed in the category of Managed Fauna for the district of Busselton by DBCA. Landowners impacted by these species of Corella can shoot individual corellas on their property without requiring a licence. For further information about Managed Fauna contact DBCA.
Rabbits
The European rabbit is well adapted to living in all areas of the South West. The numbers of rabbits present ebb and flow with the seasons, viruses and control programs. The City has two rabbit control programs.
Residential areas
In residential areas poisons are not used to control rabbits because of the risks of poisoning of domestic animals. Calicivirus, a virus specific to the European rabbit, is used to control rabbits in Coastal foreshores and other reserves where rabbits are known to be present, in spring and autumn every year.
For rabbit control on residential properties try the following approaches to reduce damage by rabbits:
- Remove harbourage areas such as piles of wood or other materials,
- Prevent access to areas by fencing with rabbit netting,
- Prevent undermining of buildings by laying rabbit netting flat on the ground or trenching and burying netting, around structures you want to protect,
- Seek advice from Department of Agriculture on other approved methods 08 9368 3333, or
- Seek assistance from a qualified pest controller on specific advice for your property.
If you observe rabbits in City reserves you can notify the City by phone on 08 9781 0444. The City will investigate reports of rabbit activity and seek recommendations for control from a licensed pest controller.
Rural areas
The City manages many reserves in rural areas, some of which have a high level of biodiversity with rare or endangered native flora. Protection of native flora from grazing by rabbits is necessary to maintain the biodiversity of our bushland reserves.
In rural areas the City controls rabbits in large reserves where rabbits are active using 1080 poison. The baiting program is undertaken by a licensed pest controller in accordance with all relevant licences and permits. Surrounding residents are notified of forthcoming baiting periods.
Foxes
Residential Areas
The red fox is a skilled hunter of wildlife and domestic poultry. Cage trapping is one way to safely control foxes where it is not safe to bait or shoot. Protocols for more effective use of cage traps for foxes have been developed and summarised in the City’s Fox Trapping brochure.
Three fox cage traps are available for loan free of charge, with payment of a fully refundable bond, when the trap is returned to the City. To enquire about the loan of a fox trap contact the City on 08 9781 0444.
Rural Areas
The City manages many reserves in rural areas, some of which have a high level of biodiversity with rare or endangered native flora and fauna. Fox control is necessary to protect native fauna from predation by foxes in our reserves. In some of our larger reserves in rural areas the City uses 1080 poison egg baits to control foxes during Autumn and Spring every year. The baiting program is undertaken by a licensed pest controller in accordance with all relevant licences and permits. Surrounding residents are notified of forthcoming baiting periods. The program is reasonably successful, taking foxes from each reserve in the program every baiting period. Rural landowners wanting to use 1080 to control foxes should contact Department of Primary Industry and Regional Development on 08 9368 3333.
Polyphagous shot hole borer
Polyphagous shot-hole borer (PSHB, Euwallacea fornicates) is a beetle native to Southeast Asia. The beetles attack a wide range of plants by tunnelling into trunks, stems and branches.
PSHB cultivates a fungus (Fusarium) inside the host tree as a food source. In susceptible trees, the fungus kills vascular tissue causing Fusarium dieback and tree death.
To date, PSHB has only been found in the Perth metropolitan area. The Department of Primary Industries and Regional Development (DPIRD) has installed traps in Harvey, Mt Barker, Manjimup and Bunbury. To date, these traps have not returned any positive PSHB detections.
Common signs to look for include:
- Beetle entry/exit holes - approximately the size of a ballpoint pen tip.
- Galleries - when pruning branches or inspecting fallen branches, check for evidence of galleries caused by the tunnelling action of PSHB beetles.
- Discoloration/staining - this is caused by the fungus.
- Gumming - thick resin or sap.
- Frass - produced by the beetles tunnelling, frass may be seen on the tree exterior. This can indicate a high level of infestation.
- Sugar volcanoes - crystalline foam is exuded from entry/exit holes.
- Dieback and tree death - the fungus disrupts the tree vascular symptom causing dieback and death.
For more information on symptoms visit the Department of Primary Industries and Regional Development website >>
Favourite host tree species
PSHB particularly favours the Box Elder Maple (Acer negundo). Other popular reproductive hosts (susceptible trees) include Plane (Platanus), Poplars (Populus), Oak (Quercus), Avocado (Persea), Fig (Ficus), Black Locust (Robinia), Willow (Salix), Mulberry (Morus), Poinciana (Delonix regia) and Coral Tree (Erythrina).
A list of host tree species in WA where the beetles have successfully reproduced is accessible here.
DPIRD are requesting the location of all Box Elder Maple trees (Acer negundo) is reported to assist with ongoing monitoring.
What to do
There are no known effective chemical treatments for PSHB; therefore, early diagnosis and immediate removal or pruning of affected trees is critical to limiting PSHB spread and reducing future effects on surrounding trees.
Residents are encouraged to inspect backyard trees for suspected borer damage and should report to DPIRD’s Pest and Disease Information Service on (08) 9368 3080, email padis@dpird.wa.gov.au or via the MyPestGuide Reporter app. For more information on PSHB visit www.agric.wa.gov.au/borer
Quarantine Area
A Quarantine Area Notice (QAN) restricting the movement of wood and plant material has been put in place to help stop the spread of PSHB.
The QA was extended on 6 September 2024 to cover the entire Perth Metropolitan area, extending across 30 local government areas.
The QA encompasses two zones.
- Zone A covers an area with high numbers of infested plants and has intensive control activities, such as plant removal, underway. This zone has more restrictions on the movement of high-risk materials.
- Zone B covers an area with fewer to no infested plants and has heightened surveillance underway to identify and control any new infestations discovered. This zone will help create a buffer between areas of high infestations and the rest of WA to further protect our flora.
The City of Busselton is outside the quarantine area. Residents and visitors should not bring untreated or unseasoned wood and plant materials from inside the quarantine area to the South West.
Polyphagous shot-hole borer - Department of Primary Industries and Regional Development
Rabbit activity has increased across the City over the last 6 months with urban areas being impacted more than usual.
In response the City has expanded its autumn rabbit control program which this year takes place over May and June (later than normal due to late rains).
Reserves and local roads in hotspot areas have been baited using Rabbit Haemorrhagic Disease Virus (RHDV) and will be monitored. RHDV is deadly to rabbits but not to other animals or humans and is the safest form of rabbit control in built up areas.
Treated areas will be checked for any residual rabbit activity and follow up control will be carried out if needed.
There was also 7 local area control programs organised by residents in Rural Residential areas. The City supported these programs by paying for rabbit control on City managed land within the local control areas. The feedback from participants in local control areas has been positive.
The control method uses Rabbit Haemorrhagic Disease Virus (RHDV), which is deadly to rabbits but not other animals or humans. RHDV is the safest form of rabbit control, which is why it can be used in built up areas. Oats are soaked in a solution of the virus and then laid out in rabbit feeding areas. Once a rabbit is infected the virus can be passed on to other rabbits so the area of control can sometimes be larger than areas where the baits are laid. The use of RHDV eliminates the risk to all other species as it can not spread to any other birds or animals including humans.
Baiting using RHDV is most effective in spring and autumn when the temperatures are cooler, the soils are moist and humidity is high. This increases the period of time that the virus is still active on the bait, before being eaten by the rabbits. The control programme started later than usual this year due to long period of dry weather.
Treatment of one or two properties within an area is not effective as rabbits will soon move in from neighbouring properties. For most effective control of rabbits it is recommended all landowners within a local area consider what they can do on their properties to control the rabbits.
The next level of control methods include the use of poisons and/or traps which do come with a higher risk. These methods include;
These methods require expertise and licences/permits to implement safely and effectively so that only the target animals are controlled. Native fauna should be a key consideration in any pest control program to ensure they are not impacted.
Landowners considering these higher risk methods should seek assistance from someone with expertise and the requisite licenses and qualifications to advise on the methods of control that are suited to the conditions of the site and/or undertake the work.
For these twice yearly baiting programs to work most effectively it is recommended all landowners with rabbit issues consider the low risk control methods listed above.