The eating habits of Australia’s largest bird of prey are being tracked to try to change farmers’ perceptions of them as a threat to lambs.

Wedge-tailed eagles have been fitted with solar-powered satellite tracking devices to follow their movements and see what they are eating. 

South Australian raptor expert Ian Falkenberg says the data is helping paint a wider picture of the birds’ behaviour.

“[It] helps give us a better understanding of how the eagles survive and, particularly for an eagle that has been probably the most persecuted worldwide, how they’re managing to survive and cope with that sort of treatment,” Mr Falkenberg said.

Ian Falkenberg said one of the tracked eagles covered more than 16,000 kilometres in 12 months, flying between Clare in SA, to the Victorian Grampians, Nowra in NSW, and the Strzelecki Desert.(Supplied: Dan Clarke)

“The second part of the project was really around education and awareness, particularly for the farming community … that wedge-tails aren’t the killers that they’re perhaps perceived to be and that wedge-tailed eagles can provide a fantastic service in getting rid of vermin and cleaning up properties.”

He said some farmers saw wedge-tailed eagles as a major threat to their lambs.

“There have been some long-running studies conducted in Australia to look at the actual predation rate of eagles on lambs and, by and large, it’s been found that less than 1 per cent of lamb deaths have been attributed to eagles,” Mr Falkenberg said.

Eagles eating carrion

Satellite trackers weighing only 30 grams are fitted to fledglings just before they are ready to leave the nest.(Supplied: Mark Lethlean)

“By far the biggest issue is simply the eagles feeding on the dead carcasses of lambs that have already died,” Mr Falkenberg said.

He said this was more common in marginal areas where conditions had dried out and ewes were under stress during lambing season.

“Quite often in those cases … farmers are experiencing some high mortalities of lambs through malnutrition, mismothering and those sort of issues, and the eagles will hone in on that food supply pretty quickly,” he said.

Mr Falkenberg said farmers who wanted to deter eagles should remove the carrion food supply in their paddocks and look at scaring techniques.

He also recommended providing shelter for stock, and keeping fox numbers under control — as they were a far bigger predator of lambs.

Rabbits on the menu

The monitored eagles were seen eating foxes, cats, and other smaller birds — but their top prey was rabbits.

“A wedge-tail eagle could potentially eat one rabbit a day, so a pair of wedge-tailed eagles on a property would be taking in excess of 700 rabbits a year and that’s a pretty good control method by anyone’s standards,” Mr Falkenberg said.

Rabbits were by far the eagles’ favourite meal, but they would also eat other birds such as ravens, along with young foxes and cats.(Supplied: Dan Clarke)

Happy to co-exist

SA farmer Sid Nicholls.(Supplied: Dan Clarke)

Farmer Sid Nicholls has a pair of wedge-tailed eagles nesting on the edge of his property north of Clare, in SA’s mid-north, and regularly sees the birds flying around.

“I have seen them kill foxes and rabbits, so they’re cleaning up pest species as well on our property,” Mr Nicholls said.

“If you shoot a feral deer and leave it, you’ll see [the eagles] on those carcasses.

“There are other things to focus on our property like sheep nutrition, shelter when lambing — all those sorts of things that would be a lot more achievable and make a lot more difference to our bottom line than worrying about a pair of eagles flying around that may or may not be killing lambs.”

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