Dynamics of populations may be synchronized at large spatial scales, indicating driving forces acting beyond local scales, but may also vary locally as a result of site‐specific conditions. Conservation measures for fragmented and declining populations may need to address such local effects to avoid local extinction before measures at large spatial scales become effective. To assess differences in local population dynamics, we aimed to determine the demographic drivers controlling population trends in three remaining populations of the Northern Wheatear Oenanthe oenanthe in the Netherlands, as a basis for conservation actions. An integrated population model (IPM) was fitted to field data collected in each site in 2007–2011 to estimate fecundity, survival and immigration. Sites were 40–120 km apart, yet first‐year recruits were observed to move between some of the sites, albeit rarely. All three populations were equally sensitive to changes in fecundity and first‐year survival. One population was less sensitive to adult survival but more sensitive to immigration. A life table response experiment suggested that differences in immigration were important determinants of differences in population growth between sites. Given the importance of immigration for local dynamics along with high philopatry, resulting in low exchange between sites, creating a metapopulation structure by improving connectivity and the protection of local populations are important for the conservation of these populations. Site‐specific conservation actions will therefore be efficient and, for the short term, we propose different site‐specific conservation actions.

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A better understanding of factors affecting population change is needed to explain declines of longdistance migrants. As juvenile survival is generally an important determinant of population dynamics, assessing whether juvenile survival is primarily affected either during the post-fledging stage on the natal site or during the migration and winter stages (migration-winter) is important for developing conservation strategies. Here, we assess variation in stage-dependent survival of juvenile Northern Wheatears (Oenanthe oenanthe), a threatened passerine in northwestern Europe. We estimate apparent survival in a Dutch coastal breeding population based on frequent resightings during the whole breeding season. We show that post-fledging survival on the natal grounds was not clearly different from survival during migration-winter and that late fledging reduces survival during both post-fledging and migration-winter. It is unknown which factors are causal to lower survival of late-fledged juveniles and this hampers effective conservation. Meanwhile, conservation measures focusing on nest protection should increase average juvenile survival in the remaining small populations in the short term because the number of successfully fledged early juveniles should increase. Flüggewerden die Ü berlebenswahrscheinlichkeit sowohl in der Nachbrutzeit als auch während des Zuges und der Ü berwinterung verringert. Es ist unbekannt, welche Faktoren das geringere Ü berleben der spät ausgeflogenen Jungvögel bewirken, was einen effektiven Schutz erschwert. Mittlerweile führen Schutzmaßnahmen mit Fokus auf den Schutz von Nestern kurzfristig zu einem Anstieg der durchschnittlichen Ü berlebenswahrscheinlich der Jungvögel in den verbliebenen kleinen Populationen, da die Anzahl der erfolgreich ausgeflogenen frühen Jungvögel ansteigt.