Abstract: Individual survival are important factors affecting the population dynamics of small passerines. Understanding variation in the population dynamics and survival rates is critical for ecological studies and nature conservation. The aim of this study was to investigate the annual capture-recapture, apparent survival, capture probability and sex ratio of the Eurasian Nuthatch (Sitta europaea Linnaeus, 1758) occurring in western Hungary. Data from 184 juveniles, 66 adults and 239 individuals of unknown age came from a constant-effort ringing scheme, using three ringing periods, spanning 29 years. The annual captures did not show a significant linear trend from 1998 to 2025 and the sex ratio was nearly balanced in the study site for the species, which indicated high habitat quality and a local population that was stable in both abundance and structure. According to the Cormack-Jolly-Seber model, apparent survival and capture probability were age-, sex and year dependent, but the very high mean apparent survival rates and low capture probabilities of the age and gender groups were not significantly different. The apparent survival rate of males showed a significant positive linear trend, while those of females, adults and juveniles showed no significant positive linear trend during 1998-2025. Overall, the Eurasian Nuthatch population tend to remain relatively balanced under stable ecological conditions.

Key words: demography, population dynamics, capture-recapture, Cormack-Jolly-Seber model, Tömörd Bird Ringing Station