The RSPB has released a series of images which show the scale of plans for a huge wind farm planned for the Hebridean island of Lewis.
The charity has superimposed the plans onto a map of the Scottish mainland to highlight the scale of the proposals.
The charity said the 234-turbine development would have an unprecedented impact on hundreds of rare birds.
But the developers, Lewis Wind Power, said revised plans limited the effect on local wildlife.
If it was built on the mainland, the wind farm would stretch north from Edinburgh Zoo to beyond Methil on the other side of the Firth of Forth and west to Dunfermline.
In the west, it would go from Central Station in Glasgow to Falkirk and south to East Kilbride.
Ann McCall, head of planning and development with the bird charity, told BBC Radio Scotland: "We hope these maps will illustrate to the people of Scotland, and particularly MSPs, how this development would look if it were to take place essentially in their back yard.
"By selecting a site protected under EU conservation legislation for this huge wind farm, habitats of vital importance for birds and biodiversity are being seriously threatened.
"We'll be looking at the death of up to 50 golden eagles, 50 merlin, about 250 red throated divers, hundreds of dunlin, hundreds of golden plover too.
"We welcome renewables, but not at the expense of the environment. To locate a wind farm in an area as sensitive as this is very foolish and alternatives must be explored."
Lewis Wind Power director David Hodkinson said concessions included recreating peat habitats elsewhere during construction of the wind farm, phasing construction activity to avoid the bird breeding season and taking bird flight paths into consideration in the layout of the farm.
The scale of the proposed 40km long development would be matched by its economic benefits and electrical output, he added.
He said: "Our environmental work and proposed design have both moved forward considerably since our planning application was submitted in the autumn of 2004.
"We are now confident that we would be able to minimise the effects of the wind farm on birds through a combination of measures.
"These would include the removal of some of the proposed turbines and an operating regime that would allow turbines to be switched off and rotated in response to specific bird behaviours.
"We also now have a much better understanding of how to model the potential effects of the wind farm on the birds, based on the continued survey work we have undertaken."
Mr Hodkinson called on the RSPB to enter into constructive discussions with developers.
He said: "We really would like to talk to the RSPB to see if we can reach some sort of accommodation on this rather than have press releases with words like 'disaster' written in them.
"It would be much better if we could sit down and work this thing through."
Councillors in the Western Isles backed the plans in July.
Their decision came after planning officials recommended that the £400m application - which prompted about 5,000 written objections - should go ahead.
The Scottish Executive is to have the final say on whether or not the wind farm should be built.
Responding to the RSPB's comments, the council's vice-convener Angus Campbell said: "Are they trying to show that the proposed wind farm is big? We know that.
"But Lewis is a large island and superimposing maps on cities is plain silly."
He added: "The Comhairle, the democratically elected represented of the Western Isles, carefully considered all these points in its deliberations of the wind farm proposals and there is nothing new in the information and misinformation being peddled by the RSPB who no-one has elected."
Residents living on Lewis have formed a campaign group against wind farm developments, Moorlands Without Turbines (MWT).