RARE hen harriers have had their best breeding season in England for years, with 60 chicks fledging from 19 nests, including some in Yorkshire.

Chicks successfully fledged from nests across Northumberland, Yorkshire Dales, Cumbria and Lancashire in the best breeding season on record since a recovery project began in 2002, Government agency Natural England said.

Once found across upland and lowland Britain, including in many English counties, hen harriers became extremely rare as a breeding bird in England after 1830 as a result of persecution.

Despite protection, today they remain England’s most threatened bird of prey, coming into conflict with commercial shooting estates because they catch red grouse chicks to feed their young.

This year’s success, which means that 141 hen harrier chicks have fledged over the past three years, has been put down to factors including high numbers of voles, which are a key food source, and good weather.

Natural England also attributed the record year to strong partnership working with groups including the RSPB, Forestry Commission, Moorland Association, United Utilities and the National Trust.

It is a marked improvement from a low point in 2013 when there were no successful nests or fledged chicks, raising fears that the bird was becoming extinct as a breeding species in England.

Natural England chairman Tony Juniper said there has been “great progress” in boosting numbers but warned that too many birds still go missing in unexplained circumstances and called for persecution of them to stop.

“2020 has seen the best breeding season for England’s hen harriers in years and I thank all those who’ve helped achieve this wonderful result, including landowners and managers, campaigners, conservation groups, police officers and our own Natural England staff and volunteers,” he said.

“Despite the great progress there is, though, no cause for complacency.

“Too many birds still go missing in unexplained circumstances and I urge anyone who is still engaged in the persecution of these magnificent creatures to cease at once.

“Hen harriers remain critically endangered in England and there is a long way to go before the population returns to what it should be.”

A study released by Natural England last year analysing satellite tagging data found that young hen harriers suffer abnormally high death rates, with illegal killing the most likely cause.

An action plan to boost hen harrier numbers since 2016 includes monitoring, diversionary feeding and, more controversially, “brood management” options to remove and rear chicks in captivity to prevent their parents preying on red grouse chicks.

Amanda Anderson, director of the Moorland Association, said it had been a “fantastic” year for hen harriers, with increases in successful nests and chick numbers for three years running.

She added: “Twelve of the nests reported today are on land managed for grouse shooting and this reflects a genuine commitment from moor owners and managers to work with others and help rebuild the harrier population.”

Mark Thomas, the RSPB’s head of investigations, said: “The news that 60 hen harrier chicks have fledged in England this year is encouraging, and testament to the crucial monitoring from raptor workers.”

But he said there is enough habitat and prey to support more than 12 times this year’s total and illegal persecution is still the most serious threat to the species.

Since 2013, 43 hen harriers are known to have been killed or “gone missing” after fledging, he said.

“If this painfully slow recovery is to gather pace, and these beautiful birds are to become as common across our landscapes as they should be, the illegal persecution must stop.”