Bodembroedende Buizerd Buteo buteo in de polder Mastenbroek

Polder Mastenbroek is a grassland polder north of the town of Zwolle in the central Netherlands. On 7 May 2006 a local farmer discovered a nest on the ground in the comer of a meadow, next to a water-filled ditch. The nest contained two incubated eggs. One egg had hatched on 17 May, and two chicks were recorded on 22 May. However, a visit on 27 May revealed that the chicks had disappeared without a trace. It is thought that adverse weather conditions had caused the chicks to die; late May was characterized by downpours and low temperatures. A ground nest is easily waterlogged, and remains wet during a much longer period than a tree nest. Within 200 m of the nest two electricity pylons were available, but were ignored as nesting site. In other parts of Polder Mastenbroek, Buzzards have been recorded nesting in electricity pylons. Furthermore, some 500 m away a small woodlot also offered nesting sites without being used. Why this pair built a nest on the ground, remains a mystery. Previous ground nests of Buzzards in The Netherlands were reported in 1999 at Hommerts (province of Friesland), in 2000 at Aldeboam (Friesland), and in 2003 and 2005 near Eemnes (Utrecht). All these sites were – as in the present case – situated in grassland dominated by dairy farming, and were typified by a scarcity (but not absence) of alternative sites. Except once, all nests failed to fledge chicks.