Migratory birds are declining across North America, and many studies have used long-term datasets to estimate trends in abundance for migratory birds. To prioritize at-risk populations most efficiently, it is critical to know the current trend status of migratory species, which involves accurately assessing the most appropriate timescale for monitoring changes in populations. In this study, we analyzed autumn bird banding data from the Block Island Banding Station on Block Island, Rhode Island, USA, over a 52-year period (1970-2021), focused exclusively on hatch-year birds, to examine long-term abundance trends for 22 species of migratory songbirds and compared our results to trends from Manomet Conservation Sciences and the USGS Breeding Bird Survey. We ran 4 models (no change, linear, quadratic, and breakpoint) for each species and used model selection with AICc to determine the best model. Eighteen of the 22 species were best represented by breakpoint models, indicating that they experienced a sudden change in slope during the study period. All 18 breakpoint species experienced the largest decline in the first 2 decades of the study (between 1976 and 1986), and 17 of 18 species were stable or recovering after the breakpoint. Of the 4 species without a significant breakpoint, 1 had no change over the study period, 2 were best represented by linear models, and 1 was best represented by a quadratic model. Trend classifications varied across time, methods, and the geographic regions of the subpopulations sampled. These results present evidence that despite initial declines, many species are currently stable or in recovery. We also highlight that modern conservation efforts need to account for abrupt changes in trend direction within long-term time series analyses to most accurately assess current abundance trends for the conservation of vulnerable species. center dot Migratory songbirds have declined across North America, although the extent of decline and resulting conservation status depend on the chosen timescale.center dot We assessed long-term changes (1970-2021) in relative abundance of hatch-year migratory songbirds of 22 species at the Block Island Banding Station on Block Island, Rhode Island, USA, and compared these to trends from another long-term coastal banding station and the North American Breeding Bird Survey.center dot We evaluated 4 models (no change, linear, quadratic, and breakpoint) for 22 species and found that trends for 82% of species had breakpoints indicating sudden changes in trajectory over the 52 years.center dot The pattern for these 18 species was a sharp decline in the 1970s and 1980s followed by stabilization, recovery, or slower decline for the remainder of the study. Only 2 species declined throughout the entire study.center dot Conservation prioritization schemes should consider these abrupt changes in long-term trends when determining which species are most vulnerable. Las aves migratorias est & aacute;n disminuyendo en toda Am & eacute;rica del Norte, y muchos estudios han utilizado bases de datos a largo plazo para estimar las tendencias de abundancia de estas aves. Para priorizar de manera eficiente las poblaciones en riesgo, es fundamental conocer el estado actual de las tendencias en las especies migratorias, lo cual implica evaluar con precisi & oacute;n la escala temporal m & aacute;s adecuada para monitorear los cambios poblacionales. En este estudio, analizamos datos de anillado de aves de oto & ntilde;o provenientes de la Estaci & oacute;n de Anillado de Block Island, en Block Island, Rhode Island, EE.UU., durante un per & iacute;odo de 52 a & ntilde;os (1970-2021), centr & aacute;ndonos exclusivamente en aves de hasta un a & ntilde;o, para examinar las tendencias de abundancia a largo plazo de 22 especies de aves canoras migratorias y comparamos nuestros resultados con las tendencias obtenidas por el centro de Ciencias de la Conservaci & oacute;n de Manomet y el Censo de Aves Reproductoras del Servicio Geol & oacute;gico de Estados Unidos. Ejecutamos 4 modelos (sin cambio, lineal, cuadr & aacute;tico y de punto de quiebre) para cada especie y utilizamos la selecci & oacute;n de modelos con el criterio de informaci & oacute;n de Akaike corregido (AICc por sus siglas en ingl & eacute;s) para determinar el modelo m & aacute;s adecuado. Dieciocho de las 22 especies fueron mejor representadas por modelos de punto de quiebre, lo que indica que experimentaron un cambio repentino en la pendiente durante el per & iacute;odo de estudio. Las 18 especies con punto de quiebre experimentaron el mayor descenso en las dos primeras d & eacute;cadas del estudio (entre 1976 y 1986), y 17 de las 18 especies estuvieron estables o en recuperaci & oacute;n despu & eacute;s del punto de quiebre. De las 4 especies sin un punto de quiebre significativo, 1 no present & oacute; cambios durante el per & iacute;odo de estudio, 2 estuvieron mejor representadas por modelos lineales, y 1 estuvo mejor representada por un modelo cuadr & aacute;tico. Las clasificaciones de tendencias variaron seg & uacute;n el tiempo, los m & eacute;todos y las regiones geogr & aacute;ficas de las subpoblaciones muestreadas. Estos resultados ofrecen evidencia de que, a pesar de los descensos iniciales, muchas especies actualmente est & aacute;n estables o en recuperaci & oacute;n. Tambi & eacute;n destacamos que los esfuerzos actuales de conservaci & oacute;n deben considerar los cambios abruptos en la direcci & oacute;n de las tendencias dentro de los an & aacute;lisis de series temporales a largo plazo para evaluar con mayor precisi & oacute;n las tendencias actuales de abundancia para la conservaci & oacute;n de especies vulnerables.
