An Australian bird expert has labelled the country's biggest wind farm a "black hole" for endangered wedge-tailed eagles.

The Woolnorth farm in north-west Tasmania has 62 wind turbines and is one of the largest wind farms in the Southern Hemisphere, but the group Birds Tasmania says the farm could already have killed 18 endangered eagles.

The company that runs the wind farm says it is doing everything it can to minimise the danger to the birds.

The Woolnorth farm was fully commissioned last May.

Birds Tasmania chairman Dr Eric Woehler says the estimates for eagle deaths since then vary.

"The proponents [of the wind farm] say 11 birds have been killed by wind farms [but] we believe the number might be slightly higher, possibly as high as 18 birds," he said.

He says he describes the area as a "black hole" area for these birds because the wind farm area overlaps several territories of eagles.

"With every death it allows an opening - if you like - for a bird from an adjacent area looking for a territory to move in," he said.

"These birds then are essentially naive to the area - they don't recognise the turbines and they then in turn get killed.

"So essentially what's happening is that you're killing birds, drawing birds in from surrounding areas, those birds get killed, and so for the foreseeable future we would expect to see - as I've used the phrase elsewhere - 'a black hole' for the eagles.

"It's a one-way trip into Woolnorth - they don't come out."

Too fast

Dr Woehler says although eagles can see the turbine blades, they have evolved over time in a landscape without wind farms.

"The tips of some of the very large blades are 45 metres long, and some of these are travelling at approximately 300 kilometres an hour - it's just too fast for the birds to avoid," he said.

There are less than 1,500 Tasmanian wedge-tailed eagles left.

In hindsight, Dr Woehler says maybe the wind farm should not have been placed in such an ecologically sensitive area of Tasmania.

But he acknowledges the company running the farm, the Roaring 40s, is trying to do the right thing.

Roaring 40s managing director Mark Kelleher says it has introduced measures that turn off the machines at identified high-risk times.

"There's certain directions and speeds of winds that seem to attract the eagles closer to the turbines," he said.

"So we have shut down times during those periods of time."

However, the Roaring 40s disputes Dr Woehler's figures, with Mr Kelleher saying the turbines have only killed 11 of the eagles.

But he says the company is investigating other options to protect the endangered birds.

"We've had people looking overseas and looking for devices, say radar-type things that will detect when an eagle's coming along, and either shut the wind farm down or be able to scare the bird off with a loud noise or something," he said.

"We're hopeful those sort of activities will have a further benefit."