Hen Harrier - Forestry and Hen Harriers

Forestry and Hen Harriers

The Hen Harrier is a bird of open habitats such as heather moorland and extensive agriculture. However, much of its range, particularly in Ireland and parts of western Britain, has been (and continues to be) afforested, predominantly with non-native conifers such as Sitka Spruce (Picea sitchensis) from North America (Barton et al. 2006, Fielding et al. 2010). Hen Harriers nest and forage in commercial forestry when it is young, before the canopy closes (typically at between 9–12 and years old), but do not make much use of thicket and subsequent growth stages (Madders 2000, O'Donoghue 2004), which typically comprise between two thirds and three quarters of the commercial growth cycle. Where forests replace habitats that were used by Hen Harriers they will therefore tend to reduce overall habitat availability (O'Flynn, 1983). However, where afforestation takes place in areas that were previously underutilised by Hen Harriers, it may increase the value of such areas to this species in the long-term (Wilson et al. 2009, Haworth & Fielding 2009). Areas dominated by forestry may remain suitable to Hen Harriers provided that a mosaic of age classes is maintained within the forest, such that areas of young, pre-thicket forest are always available.