An area 600 metres by 500 metres at the St Brelade beauty spot was left charred this morning just behind the prison.
The service succeeded in containing the fire, but residents fear that a host of animals could have been killed.
Deputy Sean Power, who could see the flames from his home, said: ‘A whole society of pheasants, rabbits and birds have been displaced or destroyed.
At one stage, a nest of hatched one-week-old barn owl chicks looked in real danger, and it remains to be seen if they have survived.’ At the height of the blaze, three fire engines and more than a dozen firefighters were training water on to the blaze as it spread through the tinder-dry vegetation.
This morning a team of six were damping down the undergrowth and a spokesman said that the crew would be at the scene all day.