An aerial examination has established that half of the landmass of Killarney National Park has been severely damaged by weekend fires, far more than had been originally feared.
However, most of the park's precious oak woods have been saved.
2,500 to 3,000 hectares have been damaged out of the national park's total land mass of 5,000 hectares.
The Director of Services at Kerry County Council has said that further reconnaissance helicopter flights will be carried out later this evening and in the morning to make sure there are no further hotspots in the park.
However, John Breen said he is satisfied that the blaze has been extinguished.
There has been huge destruction to wildlife and the flora and fauna but Mr Breen said there is a need to focus on restoration and the future.
Speaking on RTÉ's Six One, he said that ancient oakwoods have been saved due to efforts of the fire service and the air support over the weekend.
Last night the blaze had come perilously close to a school, a church and other properties in the Black Valley.
Mr Breen said at this early stage it was very difficult to ascertain the cause of the fire. He said gardaí will be carrying out an investigation and anyone with information as to how this blaze started should pass this on to gardaí.
The manager of the hen harrier project at Killarney National Park said one hen harrier nest was destroyed in the park fire and the hunting grounds for three other pairs have been lost.
Fergal Monaghan told RTÉ's News at One that the hen harrier is an indicator species, a specialist predator which is dependent on an adequate prey base and adequate habitats for it to nest, so "they're a very good indicator of how that upland eco system is functioning".
He said Killarney National Park is a very important area for hen harriers nationally and "this is a big loss".
Mr Monaghan said the last national survey found only 108 hen harrier pairs in the country, with 13 pairs in the Killarney area of Kerry.
Additional reporting Kate Carolan