A wildfire that has burned for two weeks in the Cairngorms National Park has left an “apocalyptic” scene of devastation, say park bosses.

The fire has destroyed about 10 sq miles (25 sq km) of moorland and forestry near Aviemore since Wednesday 15 July.

Malcolm Smith, farming advisor to the Cairngorms National Park Authority (CNPA), said: “You are passing through just bare forest now and birds flying about looking for their nests.”

RSPB Scotland, whose Loch Garten reserve at Abernethy has been badly burned, said it could takes weeks before the fire was extinguished.

Dozens of firefighters helped by volunteers and water bombing by helicopters are continuing to tackle hotspots.

It is hoped that cooler weather and rain will help prevent a further spread of flames.

Smith said the impact on the landscape was “heartbreaking”.

“It is a really sad sight,” he added.

“You are used to these beautiful mountains all summer and seeing them covered in snow in winter.

“To see the fires getting up to where people ski you really wouldn’t have thought that was possible.”

Smith praised local communities for supporting firefighters, farmers and other volunteers.

RSPB Scotland said its Loch Garten reserve was home to 5,000 species, and insects, reptiles along with trees, lichens and mosses had been killed.

The charity’s James Reynolds said the wildfire had left a 6,177-acre (2,500ha) burn scar and the sight of it was “ugly and upsetting”.

He said: “This is still very much a live situation.

“There are smouldering points – hotspots – in the soil which is quite peaty and when the wind get up that reignites and there are flames again.”

Reynolds said it could be “weeks or more” before the wildfire was finally extinguished. “We are praying for rain,” he added.

RSPB Scotland said affected habitats should recover, but it was not known how long that would take.

The fire broke out near the village of Glenmore, outside Aviemore, on 15 July and led to residents and campsites being evacuated.

At its height, more than 500 firefighters were involved in the response and Police Scotland declared it a “major incident” on Friday.

Some local groups had been critical of the Scottish government for being slow in scaling up the response to the blaze.

The Scottish Fire and Rescue Service (SFRS) is due to provide an update on the firefighting effort later.