A spokesperson for the RSPB Scotland said colleagues from neighbouring Wildland Ltd and Rothiemurchas Estates are also in attendance using multiple fogging units on ATVs (all-terrain vehicles) and additional water pumps.
He said: “Support is also either present or on the way from other neighbouring estates and their staff, including Dorback, Moray, Seafield and Kinveachy to help fight this significant fire.
“The front of the fire extends for roughly 1km, and is presently travelling south on to neighbouring land owned by Forest and Land Scotland.”
The charity is in the process of getting a private helicopter to assess the incident which will need to be approved by the SFRS.
They added: “We are hopeful that we can secure helicopter support soon, but they are presently unavailable due to attending fires south of the border in England.”
Ross Ewing, from Scottish Land and Estates, said the incident was “clearly serious and fast-moving” and urged members of the public to keep routes clear for emergency vehicles.
He also encouraged landowners and land managers to take precautionary measures including the readying of specialist fire equipment.
Staff at Glenmore Outdoor Centre, which is near the blaze, asked people not to travel to the area.
They said: “Follow official advice from Scottish Fire and Rescue Service, and be patient with staff while the ongoing situation is managed appropriately.”
A spokesperson for the Cairngorms National Park Authority said the fire was “deeply concerning”.
They added: “This incident – alongside wildfires we are seeing across the UK this week – serves as a stark reminder of the risks that periods of drier, hotter weather can pose.”
