Nest Design and Breeding Success: Replicability of Methodologies and Research Findings in Secondary Hole Nesting Passerines

More than 40 hypotheses predict associations between features of nest architecture and at least one measure of reproductive success. However, quantitative studies of reproductive consequences of nest characteristics remain scarce. In addition, most studies were conducted on model species of which nests can be easily monitored with artificial nest-boxes. Here, we review the replicability of research protocols and findings in model species, with many repeat studies focusing mainly on nest-size components, animal-derived nest material, or fresh greenery in model species of secondary hole-nesting birds: Blue Tits (Cyanistes caeruleus), Great Tits (Parus major), Tree Swallows (Tachycineta bicolor), and Starlings (Sturnus spp.). The studies looked for correlations between nest traits and aspects of breeding performance that can be easily quantified in the field, such as clutch size, brood size at hatching or fledging, the percentage of eggs that hatch or fledge, or nestling characteristics assumed to reflect qualities associated with survival probabilities (e.g., morphometry, body condition, blood profiles). We discuss the consequences of poor replicability of research methodologies and provide explanations for why many of these studies reported poor associations between nest design and breeding success at different spatiotemporal scales. We also make suggestions for future research.