Breeding biology of the Common Reed Bunting Emberiza schoeniclus: an analysis of Polish nest records

ABSTRACT Citizen-science projects have been remarkably valuable in studying biology of many bird species. Here, I present the analysis of the data on various aspects of breeding biology of the Common Reed Bunting which were collected by volunteer citizen scientists in the Polish Nest Record Scheme. Data from each nest were recorded in form of a card which provided the following parameters: nesting habitat, nesting location, nest structure, nest height, breeding phenology and brood survival. Overall, 420 nest cards collected over the period of 53 years (1969–2022) were analysed. Most nests were found in meadows and pastures. Late April and early May were identified as the peak of the breeding season, with the highest number of initiation dates recorded in nest cards. The most frequent clutch size was five, with a mean of 4.71 eggs. Daily survival rate for nests at the egg stage was 0.95, and at the nestling stage 0.99. The results were consistent with the findings of other authors. In conclusion, nest record schemes provide insight into the breeding biology of many bird species on a scale that would not be achievable in systematic studies.