LeeJ.-H., KimS.-Y., ChoD.-H. and SungH.-C. 2023. Nest entry shape change may cause nest abandonment in urban cavity-nesting species: a case study of the Tree Sparrow Passer montanus. Acta Zoologica Academiae Scientiarum Hungaricae. 69, 1 (Feb. 2023), 63-72. DOI:https://doi.org/10.17109/AZH.69.1.63.2023.