The decline of this impressive bird of prey has been attributed to the activities, sometimes illegal, of gamekeepers in Scotland and elsewhere seeking to safeguard populations of red grouse for the shooting fraternity.
But , without specifically naming Avery, rural affairs writer Robin Page has hit out at "certain conservationists" for being "fixated with raptors".
He says this derives from "a reaction" to Victorian times when they were widely persecuted.
|Hen harrier ( Stephen Allen - British Wildlife Wiki)|
His concern is that encouraging species such as the hen harrier is likely to lead to the loss not just of grouse but also of other birds such as grey partridges, golden plovers, skylarks and lapwings - one of his favourite species.
He believes a potential solution (suggested to him by an unnamed RSPB warden) might be to let one pair of harriers nest on every country estate and then allow any additional birds to be "moved on".
The outcome, he believes, would be beneficial to a range of species - not just hen harriers.
The debate has implicatons for Lincolnshire - not because of the hen harrier, which no longer breeds in the county, but for the marsh harrier which is now widespread from the Humber to The Wash and south into East Anglia.
|Marsh harrier (Wikipedia Commons)|
As with the magpie versus songbird debate, it is a tricky subject with no easy answers.