Talk notes: Hen Harrier Southern Reintroduction Project

(c) Natural England (male hen harrier) 

The talk last week given by Flemming Ulf-Hansen and Sofia Muñoz from Natural England was illustrated with photographs and videos from their project headquarters near Salisbury Plain where their captive hen harriers from France have spent a year acclimatising to their new location, surrounded by species rich grassland. The deliberately low maintenance management of the land on Salisbury Plain makes this location ideal for hen harriers as it is richly populated with voles and farmland birds like corn buntings, linnets, pipits and skylarks, which are the mainstay of their diet.

Hen harriers nest on the ground, preferring deep heather on moors or tucked down amongst high arable crops. It is thought that 50-60% of the young die in any year as they are vulnerable to predators such as foxes, badgers and stoats. Early harvesting in arable fields also brings danger if the nests remain undetected. The captive hen harriers in France and Spain have typically been rescued as fledglings from abandoned nests. 

Male hen harriers are polygynous so they may need to supply several females with food, which adds another precariousness to their young’s chances of reaching adulthood. With 5-10 journeys to each nest per day, bringing food in the first 15 days, a male hen harrier has the sole responsibility for nourishing the chicks before the female begins hunting for supplementary food. With no parental lessons in hunting given, the juveniles have to adapt fast to survive when the time comes to leave the nest. Since hen harriers like to return to their natal area, it is hoped that any juveniles born this year will provide the breeding stock for the future.

For further information about this interesting breeding project and Natural England’s outreach work with gamekeepers and the farming community, please go to their Project blog.