Farmers are calling on the government to help them cope with the toll wedge-tailed eagles are taking on lambs and a researcher believes the answer may lie in discouraging large groups of juveniles that hunt in packs.
Pembroke Poll Dorset stud owner Kathy Simons farms at Telangatuk East bordering the Black Ranges National Park near the Grampians and is one of many sheep graziers battling predation from wedge-tailed eagles.
Eighty artificially-inseminated stud ewes scanned at 160 per cent in-lamb were due over four days but the result made Ms Simons want to "sit down and cry".
She told of the morning she drove to the lambing paddock, ready to tag and weigh newborns.
"There were four ewes all in one spot but all the lambs were still wet, so we decided to let them settle but when we returned four hours later, they had all vanished," she said.
"It was the middle of the day, so it wasn't foxes, and close to 20 pairs of big, dark eagles arrive from the Black Ranges in time for lambing season.
"They live in the forest and hunt on our farm.
"I've seen them sit in a circle around a lamb and sit over ewes and take the first lamb while she's having the second and we're losing 10 to 20pc each season."
Predatory attacks are not limited to newborns.
The Harris family of Dumbalk North in South Gippsland was gathered for a party overlooking a paddock in January, when a coordinated eagle attack unfolded.
"Two eagles singled out one hogget that would have weighed 40 kilograms and herded it down to the creek, the other two joined in," Adrian Harris said.
"Every time the lamb tried to jump out of the creek, they would push it back in.
"My son got the motorbike but, by the time he got there, the eagles had opened up that lamb under the front shoulder."
In August, the Harris family videoed around a dozen wedge-tailed eagles circling a lambing paddock.
"We scanned 115 ewes at 200pc but when they started lambing and dropping twins, the eagles would be sitting behind them and taking the first lamb as they dropped the second one," he said.
"We reckon they got 45 lambs out of that paddock alone."
Help needed
Both Kathy Simons and Adrian Harris denounced recent poisonings but called on the government to act.
"If the government wants us farmers to protect the eagles, well then they've got to pay compensation when they're killing these lambs, that's our income," Mr Harris said.
"I love the eagles but we've got to get through to the government departments that eagles kill and, this year, they've been a much bigger problem than the foxes."
Ms Simons was desperate for answers.
"What can I do?" she asked.
"We're early lambers, so we get hit hard.
"Alpacas are really good for foxes but our neighbours have alpacas and still have eagle problems.
"I'd really like to hear about some solutions because simply saying predation is 'not common' is burying your head in the sand.
"A pair of nesting eagles is not a problem but huge groups of them are."
Referring to the mass poisonings that killed hundreds of wedge-tailed eagles in Gippsland, Ms Simons said, "As much as it frustrates me, I'm certainly not backing what that guy did."
"The last thing we want is for what happened in Gippsland to happen again."
"Youth gangs"
Simon Cherriman has been researching wedge-tailed eagles for a decade.
"Eagles are predatory, they can kill lambs," Mr Cherriman said.
"The key emphasis is that there's no evidence of them being documented to destroy anyone's business.
"What needs to happen for eagles that are potentially eating people's livestock is a long-term solution, which involves bringing biodiversity back into the landscape to reduce the probability that eagles will kill animals that we place economic value on.
"The areas where people say, 'Yes, we have we have eagles nest on our farm, we've never had a problem' are those with bush remnants throughout their property or adjacent to parks where there are alternative food sources for eagles.
"When it's just sheep and stubble, eagles are predatory."
Mr Cherriman said the social behaviour of eagles may be the secret to reducing losses.
"Biodiversity attracts territorial breeding adults, which will occupy an area they will defend the food source that is going to sustain them in the long term," he said.
"Those birds expel the younger, juvenile nomadic birds that tend to accumulate in places where there are high densities of lambs.
"Work has shown that constant baiting of dingoes actually increases the number of dingoes in the landscape because you're getting new animals moving into baited areas that don't have any social hierarchy.
"They team up into youth gangs and run amok and kill loads of sheep and cows together but, once the social hierarchy is established within the dingo population, the actual overall predation on livestock is reduced.
"It's similar with eagles. Where you don't have any breeding birds, you have lots of nomadic young ones and they all team up together.
"They're the ones that do work in packs to bring down larger mammals."
Mr Cherriman said farmers could also trial 'sacrificial' carcases.
"I have friends who leave out big sheep that died of natural causes or shoot a kangaroo so there's a sacrificial food source," he said.
"For some people, it works to lessen predation because it's obviously easier for eagles to forage on a on a dead kangaroo than it is to go and actually hunt."
Mr Cherriman said while eagles were predatory, there was no research to support a serious impact on Australian farming businesses.
"There has never been evidence of people's business collapsing," he said.
"Where there has been evidence of that in other countries like in Scotland ... they build it into their economic model so that they can be compensated.
"But all the Australian research has shown the number of losses to eagles is still insignificant when compared with the losses to foxes, bad weather and mis-mothering."
VFF says farmers should not foot the bill alone
It is time for government and farmers to discuss who should bear the costs of protected wildlife often shouldered by farmers, according to the Victorian Farmers Federation.
VFF Land Management Committee chair Gerald Leach raised the question after farmers shared their experiences of costly lamb losses to wedge-tailed eagles.
"Firstly, from a VFF perspective, our view is that there's no doubt that there are times when wildlife - and it's not just wedge-tailed eagles - do harm to commercial farming," Mr Leach said.
"Kangaroos, emus and wedge-tailed eagles are all protected wildlife - it's important to emphasise they are protected - but there are times when they do damage.
"We're happy to talk to government agencies about it about what might be the best ways to mitigate or ameliorate the the impact of wildlife on farming."
There was a lack of research regarding the extent of farming losses caused by wedge-tailed eagles but Mr Leach said it was clear that it varied enormously.
"I don't know what the percentage of lambs lost to wedgies would be - that might depend on where you are, how many wedgies there are, what sorts of foods there are, all sorts of issues," he said.
There was a need for greater collaboration to address the issue.
"I'd like to see government sit down and talk to us about the problems and and see if we can where we can find common ground," Mr Leach said.
He said that common ground was currently lacking in some cases.
"I think that interaction can be greatly improved by sitting down and seeing if we can find solutions rather than just identifying the problems," Mr Leach said.
"Some sort of non-lethal deterrent is potentially a way of overcoming the problem.
"It also has to be recognised that farming, by providing food and water, sometime creates large numbers of wildlife than would actually otherwise exist.
"We need to look at what type of technology is available to act as deterrents and look at the potential cost-sharing arrangement because, at the moment, what you have is the farming community bearing the cost for an outcome for the broader community.
"We'd be very keen to have that philosophical discussion with government.
"There are precedents where it's been done and worked quite successfully."
The Department of Environment, Land, Water and Planning (DELWP) said there had been no increases in applications for Authorities to Control Wildlife for wedge-tailed eagles in the last five years, with an authority was issued in 2015 to scare-only for two of the birds.
"Wherever possible, DELWP advocates non-lethal management of wildlife," a spokesperson said.
"Where non-lethal techniques are ineffective or impractical, lethal control may be necessary.
"It is DELWP policy that a land manager exhausts all practical non-lethal options before applying for an ATCW for lethal control, which is a last resort."