The cyclical nature of hen harrier breeding success

2019 was a record-breaking year for hen harrier breeding success in England, with 15 nests producing 47 chicks, beating the previous high point of 46 chicks in 2006. It was encouraging that those nests were in a wider variety of areas than before, with chicks being fledged in Northumberland, the Yorkshire Dales, Nidderdale, Derbyshire and Lancashire. Eleven of those 15 nests were on a land managed for grouse shooting, and of the three nests that failed, two were lost due to bad weather, with the third to predation.

There is a real need to improve the conservation status of the hen harrier in England, and Defra's Hen Harrier Action Plan provides us with the best opportunity to understand and reverse the decline of the species. All component parts of that plan have a vital role to play, and one of those is the trial brood management scheme, which is a positive development in efforts to improve hen harrier numbers. The scheme was successfully used for one of last year's nests, with the hen harrier chicks being released back into the area from where they were collected, once they were capable of fending for themselves.

Nesting on the ground, the hen harrier is particularly vulnerable to the weather, disturbance, lack of available prey, and predation by avian and mammalian predators. Along with illegal persecution, these can all impact on the hen harrier's breeding success, but they do not explain its cyclical nature, the reason for which is unknown. That cycle can be clearly seen in a chart that the Alliance has produced. Using figures provided by Natural England, the chart shows the number of hen harrier breeding attempts, successful nests, and chicks fledged over the last 34 years. It is too early to know how successful this season will be, but hopefully the upward trend will continue.