Honolulu firefighters are making progress in fighting a brush fire that has charred more than 1,000 acres on the windward side of the Waianae mountains.

Capt. David Jenkins, a Fire Department spokesman, said an aerial assessment was to be conducted Monday morning and firefighters and Department of Land and Natural Resources personnel are concentrating firefighting efforts on the upper slope of the Waianae mountains, to keep it from reaching a nature preserve.

Winds in the area have died down, helping firefighters begin to contain the blaze in the upper slopes, Jenkins said.

The massive brush fire is threatening 90 rare and endangered plant and animal species in the Honouliuli Forest Reserve, according to the state Department of Land and Natural Resources. The endangered Oahu elepaio bird and endangered “singing” kahuli tree snail also live there.

The fire, which began Friday, prompted the evacuation of about 20 houses on and near Umena Street in Makakilo and 20 cabins and other structures at Camp Timberline. One home sustained minor structural damage.

The homeowners were allowed back to their residence at noon Sunday.

Jenkins said the fire on the lower slopes of the ridge near Umena street is contained.

Eleven fire companies, involving 35 firefighters and 15 state workers, and four helicopters were called out to battle the blaze.

The Fire Department helicopter was joined by three private helicopters hired by the DNLR to drop water on the brushfire.

Children playing with a lighter started the fire, officials said.