Patterns of nest placement in a population of Marsh Tits Poecile palustris

The factors influencing nest placement by territorial birds are not fully understood, including the roles played by habitat, conspecific attraction and female experience of a previous nesting location. We used 7 years of Marsh Tit (Poecile palustris) nest-site and territory data, and high-resolution vegetation models derived from remote sensing, to investigate spatial patterns of nest placement with regard to previous female experience and age, conspecific attraction, and habitat in a woodland environment. We found no evidence for an effect of conspecific attraction or previous nest location on nest placement within the territory. However, first-year (FY) females placed nests in a random spatial pattern within their territories, and after first-year (AFY) females predominantly placed nests within the central parts of their territories, away from conspecifics. The core area of each breeding territory was centred on a region of comparatively taller overstorey and less understorey than other parts of the territory. Nest-sites were situated in localised areas of a similar structure, although absolute differences between selected and non-selected areas of the territory were not substantial. Both female age groups nested in areas of the territory where the overstorey contained relatively more Common Ash (Fraxinus excelsior) and Field Maple (Acer campestre), which may have been related to tree height, but there was no selection for English Oak (Quercus robur). We found no significant habitat differences between the territories of FY and AFY females that explained their differing patterns of nest placement.