Grondnest van Buizerd Buteo buteo op bruggetje

After initial observations of alarming Common Buzzards in mid-March, in early April a ground nest of a Buzzard with a single (cracked) egg was found in an open polder, used for dairy farming, near Eemnes in the central Netherlands. The completed clutch contained 3 eggs (mid-April). The nest was situated near a small bridge close to a fence, and was made of reed stems and other plant material from cleaned ditches. On 21 April 2003, the nest was empty, presumably depredated during the egg stage by a polecat Mustela putorius that frequented the area in search of muskrats Ondatra zibethicus. Within a radius of 1000-1300 m, three other nests of Common Buzzards, two nests of Northern Goshawks Accipiter gentilis and one nest of Eurasian Kestrel Falco tinnunculus (in a nest box) were present; these pairs occupied all available nesting sites in this open polder. The scarcity of nesting trees may have forced this pair to start nesting on the ground. The polder is attractive as a nesting area for raptors because of its abundance of food (dead muskrats, discarded by trappers, and high densities of moles Talpa europaea and – in some years – common voles Microtus arvalis). This observation is consistent with two other Dutch records of ground-nesting Buzzards, all of which occurred in open farmland with a sparsity of nesting trees.