Conservationists are worried about the future of the rare hen harrier - after it only managed to raise young in one part of the country last year.
Hen Harriers are among England's rarest bird of prey
English Nature, which monitors the endangered birds, say the only
successful breeding ground was in the Forest of Bowland in Lancashire.
Andy Brown, English Nature's chief executive, said the bird's future looked "extremely doubtful."
He said the forest was "one bright spot in an otherwise gloomy picture".
"It is a great pity that the extensive efforts of many people across England have failed to boost numbers of this rare bird," he added.
The harriers are under a protection programme being run by English Nature.
It says that three years of monitoring hen harrier numbers confirm that illegal persecution is the main reason its population is so low in England.
The RSPB claims many hen harriers are shot or poisoned and their eggs destroyed on shooting estates because they prey on grouse chicks.
However, the Game Conservancy Trust told BBC News Online the decline of hen harriers can not be wholly blamed on persecution, as its research shows numbers are also falling in areas where there are no shooting estates.
It said it was opposed to any persecution of the hen harrier, as it was an endangered species, but added proper management of grouse moorland benefits all species of birds that live in those areas.
Mr Brown paid tribute to organisations like the RSPB and the private moorland grouse estates at Bowland, and companies like United Utilities, which had worked to help preserve the hen harrier.
English Nature would like to hear from anyone who has spotted a hen harrier in England.