Smoke from the heath fire could be seen across Poole Harbour
A cigarette thrown from a car has been identified as the likely cause of a heathland fire in Dorset which killed hundreds of rare lizards and birds.
The National Trust said it was probably thrown from a car in Ferry Road and destroyed 2.5 hectares (6.2 acres) on the Studland peninsula.
More than 120 firefighters battled the blaze on Tuesday afternoon at the Site of Special Scientific Interest.
National Trust experts believe at least 500 reptiles are likely to have died.
It is one of the few places in Britain where six native reptile species can be found.
Alongside the adder, the grass snake, the common lizard and slow worm are vulnerable populations of the country's two rarest species, the sand lizard and the smooth snake.
Nests and broods of several species of birds associated with lowland heath, such as the linnet and the Dartford warbler, were thought to have been caught up in it.
Nick Moulton, a reptile expert from the Herpetological Conservation Trust, said: "The snakes usually move out before the flames reach them, and their drab colouring makes them extremely hard for predators to see.
"But the lizards are sitting ducks - they tend to stay put and suffer the consequences.
"If they do survive they are easy for birds of prey and other predators to pick out, particularly the males with their bright green colouring."
A spokeswoman for Dorset Fire and Rescue said the blaze was not suspicious and that a cigarette was the most likley cause.
At its height police said the fire was "spreading unpredictably in the wind" and the Sandbanks chain ferry had to be stopped.
Reptiles that are found unharmed will be relocated to areas unaffected by the fire.
It is expected to take up to 20 years for the area to be fully recolonised.
David Hodd, the National Trust head warden for Purbeck, said: "Almost everything in the area has been killed by the flames and smoke.
"It could not have come at a worse time for the wildlife on the heath because it is the breeding season."
The area has been the victim of arson attacks in the past including a large fire in March 2006, which destroyed 200 hectares (494 acres) of sensitive heath.