Hoeveel bomen heeft een Havik Accipiter gentilis nodig?

In the nature reserve Planken Wambuis, situated on the Veluwe in the central Netherlands, clear-felling of stands of Scots and Corsican pine Pinus sylvestris and P. nigra in the winter of 2009/2010 removed several tens of ha of the nesting habitat of a pair of Goshawks Accipiter gentilis, although both nesting trees were spared. The latter remained as two solitary trees amidst an open wasteland. This nesting territory had become occupied in 2008 (female in her 3rd calender-year), when the pair built a nest (in the Corsican pine) but refrained from egg laying. In 2009, the same pair built another nest, in a Scots pine some 400 m away, produced 3 eggs but failed in the midnestling stage. After forestry operations ceased late February 2010, display activities were again recorded in the nesting territory, and the pair commenced egg laying on 20 April (in 2009: 11 April), using the nest in the solitary Corsican pine as nesting site. In 2010, other Goshawks breeding within 6 km of this pair had started egg laying by 2, 5, 5, 5, 6, 15, 16 and 17 April. The “Corsican” pair produced 3 eggs, all of which hatched and from which two females fledged. It should be noted that this pair bred in a 750 ha large section of the nature reserve where the public is not allowed to enter and where human activities are restricted to monitoring and surveillance. Both nests were destroyed in the course of the summer, following heavy rainfall and strong winds.