At least 1,000 people have been evacuated as a forest fire in southern Spain threatened a national park famous for its biodiversity and endangered species.

The flames advancing east have reached the Donana Nature Reserve, one of Spain’s most important wildlife sanctuaries and a Unesco World Heritage site since 1994.

“The fire has entered in the limits of the reserve, and that is where we are focusing our efforts,” said Jose Gregorio Fiscal Lopez from the regional Andalucian authority in charge of the environment.

Susana Diaz, the regional president of Andalucia, said no one has died and “there’s no risk to the population” after about 1,000 were evacuated from campsites and houses near the town of Moguer on Spain’s southern coast, where the fire started on Saturday night.

But Mr Diaz said fighting the fire was difficult due to hot, dry weather, with temperatures reaching 39 degrees Celsius (102 degrees Fahrenheit), and shifting winds.

Over 550 firefighters, soldiers and police supported by 21 air units were combating the blaze on Sunday.

Mr Diaz said the human factor had not yet been ruled out as a possible cause of the fire.

Spain’s interior minister, Juan Ignacio Zoido, said: “We are taking special measures, even though the wind is pushing the fire toward (the reserve) to keep the damage to a minimum.”

The reserve protects over 264,403 acres considered of extreme ecological value for their mix of ecosystems, including wetlands, dunes and woods.

It is a key stop for migratory birds home to a variety of animals, including about a fifth of the 400 remaining Iberian lynxes.

Ecologists who work in the park are concerned that the fire could wipe out some of the area’s prized species and terrain.

“We are worried because the impact could be huge,” said Carlos Molina, an ornithologist who works inside the reserve.

“Donana is probably one of the most important areas for birds in all of Europe, and we just happen to be in a nesting season for several species,” said Mr Molina.

While Mr Molina said the reserve’s endangered Iberian imperial eagle should not be in danger, the area immediately threatened is territory for the extremely endangered lynx.

Juan Sanchez, director of Andalucia’s forest fire prevention unit, said the fight was in its critical phase due to strong winds whipping up the flames.

“Right now, the fire is developing how we expected. The wind is shifting, gaining strength, which is normal as we get to the afternoon,” said Mr Sanchez.

“We are managing it, but a change in the direction of the wind could alter the situation.”

The fire comes a week after wildfires killed 64 people in neighbouring Portugal which, like Spain, is suffering from lack of rain and high temperatures.