Illegal persecution is the main threat Hen Harriers face today in the UK. During the last 6 years the UK populations has declined by 20%, according to the latest information by the RSPB and illegal killing is the biggest single factor affecting the Hen Harrier, according to the RSPB.
The English population is only 12 pairs although there is potential for more than 300 pairs. At the moment the Hen Harrier is in serious danger of becoming extinct in England.
For more information, see the RSPB Website:
Illegal persecution killing Britain’s hen harrier population
Also see this interview with Brien Etheridge from the RSPB:
Interview with Brian Etheridge about the Hen Harrier in the UK