Nest hole age decreases nest site attractiveness for the European Starling (Sturnus vulgaris).

I studied whether the European Starling Sturnus vulgaris has a preference for a particularage of their nesting hole in an old deciduous forest in Central Poland. I documented theprobabilitythat Starlings bred in natural holes (excavated byGreat Spotted WoodpeckerDendrocopos major) of a known age in consecutive seasons. Occupation rates decreasedlinearlywith a hole’s age. Holes were occupied significantlymore frequentlyin the firstyear after their excavation then older holes. Experimentallyadding old nest material tonestboxes in order to simulate prior occupancylowered the occupancyrate in a similarmanner as observed in the natural cavities. Whereas avoidance of predation risk is the tra-ditional explanation for avoidance of old sites, myresults suggest that factors like pres-ence of old nest material (with ectoparasites), and physical deterioration in the hole’squalityshould also be considered.

T.D. Mazgajski, Ornis Fennica 84:32-38. 2007