Damaged cherries at the Perth Hills orchard ( Facebook: Irymple Orchard )
Thousands of rainbow lorikeets have stripped a Perth Hills orchard of its cherries over the past five days, with the owner fearing more losses to come.
Birdlife WA says the pest population, which grew from about just 10 birds in 1968, is now too large to eradicate.
Birdlife WA says authorities need to focus on containment and management, as growers consider netting their orchards to protect the fruit.
A tiny flock of rainbow lorikeets introduced to WA in 1968 has bred into an almighty problem for growers across the south-west of the state — with their latest attack taking out all the cherries at a Perth Hills Orchard.
Over the past five days, Linda Moore watched helplessly as thousands of rainbow lorikeets took off her entire cherry crop.
"We're just letting our poor customers know that our early cherries just won't be there," Ms Moore told Mark Gibson on ABC Radio Perth.
"We're really hoping that we will still have mid cherries and late cherries. But these birds even got into green cherries. They absolutely destroy a cherry."
Not only has she already sustained thousands of dollars in losses, but she also fears this is only the start of the problem.
"This is just the beginning of stone fruit season, so it's only people with very early nectarines, apricots and cherries that have noticed it at this stage," she said.
"But of course, these flocks aren't going to go away."
While rainbow lorikeets are native to the east coast of Australia, they were introduced to Western Australia and are now a declared pest.
"All the birds that we see today [in WA] have stemmed from a population of about 10 escaped or released birds in about 1968," Tegan Douglas, program manager at Birdlife Australia, said.
"Since the late 60s, they've become a really big problem."
Dr Tegan Douglas says the pest lorikeet population is now too large to eradicate. ( ABC Radio Perth: Emma Wynne )
Despite not being native to the landscape, the lorikeets have proven remarkably adaptable and clever at finding food.
"Because they are social, they're smart, they seem to adapt well to our urban lifestyle and that enables them to explore places like Roleystone and places in the Perth hills," she said.
"Once they switch onto something new, they can easily switch from feeding on the lemon-scented gums in the Perth metro on to things like grapes, and in this instance, it seems like cherries and potentially other stone fruit."
Dr Douglas said that the population is now so large that eradication is unfeasible and authorities need to look at containment and management strategies.
"When it comes to impact on primary producers, looking at controlling those birds where they are or deterring them from hanging around in areas where there are tasty, vulnerable crops is going to be the best management approach," she said.
"You can generally scare them out of a single property, but that just makes them your neighbour's issue and nobody wants to be that guy, so what tends to be most effective is where growers and property owners have the capacity to work together."
Rainbow lorikeets may be beautiful to look at but they are a huge pest for agriculture. ( ABC News: Daniel Johnson )
There are a range of options, from lethal control to deterrents like lasers, loud noises or gas guns open to landowners, but Dr Douglas warns the birds are also very adaptable.
"These are birds that have been living in the Perth Metro for decades, so they are used to bright lights, they're used to loud noises, they're used to people being in close proximity to them. It's definitely a marathon. It's not a sprint."
Citrus crops in the Wheatbelt have also been targeted by flocks of up to 100-strong of the declared pests.
Grower Shane Kay said his blood orange orchard in Bindoon, 75 kilometres north-east of Perth, had copped a lot of damage.
Shane Kay, Sue Middleton and Liz Brennan from Moora Citrus. ( Jo Prendergast )
Mr Kay estimates he has lost up to 7 per cent of his blood oranges to lorikeets during picking in July-August this year, which cost him about $5,000 a hectare.
He said there was a missed opportunity to effectively control lorikeet populations when they started to soar around the Perth metro area in recent years.
"There was the opportunity to get rid of them and it wasn't done, so now it's been let go for everyone to try and manage," he said.
Mr Kay said orchard netting was a potential solution but cost-prohibitive for growers at roughly $60,000 a hectare.
"It'll help multiple industries for multiple reasons if access to netting is made easier," he said.
In the meantime, Linda Moore is surveying the wreckage and weighing up her next move.
"Maybe we do have to net a whole orchard, but netting cherries is really tricky because you have to get into that tree about four or five times in a season," she said.
"How do you do that and lift a net each time? As soon as you lift the net, the lorikeets come in."
