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During migration, landbirds normally need to stop-over in order to rest and/or acquire fuel stores that power their flight. Refuelling strategies become particularly evolutionarily relevant when birds must cross broad geographic barriers, where the chance to land and get food is nil, such as when crossing oceans. Our objective was to learn more about the use of the small islands located close to the mainland coast as stopover areas by small migratory birds that cross the Bay of Biscay. Using data collected in a constant-effort mist-netting programme conducted on Izaro Island (northern Spain) during autumn migration (years 2018 to 2021), we aimed to determine (1) which species land on the island and for how long they stay there, and (2) their fuel load and fuel deposition rate. Structurally, the assemblage was dominated by Willow Warblers Phylloscopus trochilus, which on average accounted for 84% of the abundance. Clustering analyses reveal that the assemblage was rather homogeneous across the four study years. Most birds probably stayed on the island for less than 24 hours, with fewer than 5% being recaptured one or more days after their first capture. The first-capture-event body mass of Willow Warblers captured only once (8.0g, 95%CI 7.8-8.4g) did not differ from the initial body mass of those captured two or more times within a season (8.0g, 95% CI 7.0-9.0g), and those stopping over on Izaro had a negative mean fuel deposition rate of –0.2g/day (SE = 0.1g/d). Overall, Izaro was used as an emergency stopover site during the course of this study, where exhausted birds landed after sea-crossings. From a conservation standpoint, and as compared to other stopover sites used as 'emergency' stopover sites, results suggest that Izaro is of little value for replenishing the fuel stores of these small birds during autumn migration.—Betanzos-Lejarraga, L., Guzmán, I., Escandell, R., Unamuno, E. & Arizaga, J. (2023). Stopover ecology of passerine birds on an islet in the Bay of Biscay in autumn reveals a pattern similar to their use of small Mediterranean islands in spring. Ardeola, 70: 241-255. Durante la migración, las aves terrestres normalmente necesitan detenerse para descansar o adquirir las reservas que después consumirán durante el vuelo. Las estrategias para ganar estas reservas se vuelven particularmente relevantes desde el punto de vista evolutivo cuando las aves han de cruzar grandes barreras geográficas en las que la posibilidad de aterrizar y alimentarse es nula, como ocurre al atravesar océanos. El objetivo de este artículo es profundizar en el uso de las pequeñas islas situadas cerca de la costa por las pequeñas aves migratorias que cruzan el golfo de Vizcaya. Utilizando los datos que fueron recolectados mediante un programa de anillamiento científico desarrollado en la isla de Izaro (norte de España) durante el periodo de paso posnupcial (años 2018 a 2021), se pretendió identificar (1) cuáles son las especies que usan la isla y cuánto tiempo permanecen allí, y (2) cuál es su cantidad y tasa de deposición de reservas. Estructuralmente, el ensamblado estuvo dominado por el mosquitero musical Phylloscopus trochilus, que en promedio representó el 84% de la abundancia. Los análisis de clusters revelaron un ensamblado muy homogéneo a lo largo de todo el periodo de estudio. En general el periodo de estancia en la isla fue de un día para la mayoría de los ejemplares capturados para anillamiento, y de ellos menos del 5% fueron recapturados uno o más días después de su primera captura. La masa corporal de la primera captura no varió entre mosquiteros musicales capturados una sola vez en la isla (8,0 g, IC 95 % 7,8-8,4 g) y capturados dos o más veces en la temporada (8,0 g, IC 95 % 7,0-9,0 g). La tasa de ganancia de reservas de los recapturados fue negativa (–0,2 g/d; SE = 0,1 g/d). En general, nuestros resultados sugieren que Izaro es usada como punto de parada migratoria de emergencia por las aves que, tras cruzar el Cantábrico, llegan exhaustas a la costa del norte de España. Desde el punto de vista de la conservación, y en comparación con otros sitios de parada migratoria utilizados, Izaro parece tener poco valor como punto de ganancia de reservas durante el periodo de paso posnupcial. —Betanzos-Lejarraga, L., Guzmán, I., Escandell, R., Unamuno, E. y Arizaga, J. (2023). La ecología de parada de descanso migratorio de las aves paseriformes en un islote del golfo de Vizcaya en otoño revela un patrón similar al uso de las pequeñas islas mediterráneas en primavera. Ardeola, 70: 241-255. [ABSTRACT FROM AUTHOR]

Copyright of Ardeola is the property of Sociedad Espanola de Ornitologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Ardeola is the property of Sociedad Espanola de Ornitologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Ardeola is the property of Sociedad Espanola de Ornitologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Ardeola is the property of Sociedad Espanola de Ornitologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Ardeola is the property of Sociedad Espanola de Ornitologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The article explores the phenological parameters of bluethroats Luscinia svecica azuricollis population breeding in high altitude in central Spain. The small percentage of moulting first-year birds compared to all captured in August and September suggests that birds experience post-juvenile moult just after fledging. First-year birds appeared within the population in June. Population of adults in breeding area fell from August to the rest of the year.

The article discusses research which investigated the impact of meteorological conditions and bird's age on the landing decisions of migrating sedge warblers, Acrocephalus schoenobaenus, in northern Iberia. Topics explored include the breeding and migratory behavior of sedge warblers, the sampling and analysis of capture-mark-recapture (CMR) data gathered, and the recording of other factors which tend to influence bird migration.

The article presents a study which examined the characteristics of Riparia riparia colonies in artificial river walls. 16 variables from artificial walls with pipes in channelled rivers between walls holding or not holding a colony of the species were compared. The presence of colonies was found to be negatively associated with the distance of the breeding wall from the water and positively with flooding risk.

The article discusses a study which assessed the apparent survival rate and its variation between age classes and years for a breeding population of bluethroat Luscinia svecica azuricollis in Spain. Topics discussed include the importance of survival estimation to understanding population dynamics, the use of Cormack-Jolly-Seber models on capture-recapture data obtained during the 1998-2005 breeding season and the higher apparent survival exhibited by bluethroats.

The article discusses research on the dynamics and structure of the wintering population of reed bunting Emberiza schoeniclus in northern Iberia. The reed bunting is described as a common Palearctic songbird that tends to select Iberia as one of its main wintering grounds. It is noted that male reed buntings are expected to be more abundant during mid-winter because they prefer to remain close to breeding areas during the winter season. Details concerning sampling site selection, bird subject collection, and wing length recording are reported. It is also mentioned that flight-associated morphology tend to vary seasonally and between bird age classes and sexes.

The article discusses research on the stopover behaviour of two bluethroat subspecies, Luscinia svecica namnetum and Luscinia svecica cyanecula, in northern Iberian region during the autumn season. The bird is described as a polytypic Holarctic passerine that tends to breed from Iberia. Details concerning selection of sampling area and bird subject collection are reported. The study reportedly used a Cochran-Mantel-Haenzel chi-square test for examining bird age class proportion and General Linear Models for analysing timing of passage.

The article discusses a research study which analyzed whether blackcaps Sylvia atricapilla stopping over in southern Iberia gain sufficient fuel in this region to be able to cross the Sahara in tropical Africa. Results revealed the lower fuel loads of blackcaps at Doñana in southern Iberia and their slower fuel disposition rate than at Loza in northern Iberia with similar stopover duration at both localities. The researchers observed longer estimated flight ranges in Loza than in Doñana, as well as the proportionally more abundance of recaptures at Loza. Observation showed the insufficiency of both sites for the blackcaps to refuel in order to reach tropical Africa.

The article focuses on a study which examined the migration strategy, specifically stopover duration and fuel load, of bluethroats Luscina svecica cyanecula in northern Iberia during the autumn migration period. Data were obtained in the reed bed Phragmites australis that surrounds the Badina de Escudera lagoon near Villafranca, Spain. Stopover duration was calculated by means of minimum stopover duration and Cormack-Jolly-Seber models. Findings reveal that the stopover duration was nearly 30 days and that adults were more fuel loaded than juveniles. The article notes that the results suggest that birds with long stopovers were not true fuelling migrants but wintering birds with balanced energy budgets.

The article focuses on the study which examines the migration strategies of goldfinches Carduelis carduelis as they pass through the western edge of Pyrenees. The study considered the species' time-associated variations in age and sex ratios and morphology. It was carried out through systematic sampling sessions during a specific period. After data analysis, it was revealed that spring migrants showed a shorter wing and tail and were more fuel loaded than birds from autumn and winter. Adults also tended to pass later than juveniles during the autumn season.

The article focuses on one study which examines the effect of haemosporidians on fuel deposition rate and fuel load in a population of population of migratory blackcaps Sylvia atricapilla in Loza lagoon, northern Iberia. Fuel deposition rate is defined as method that determines bird migration strategies. Blood samples were taken from recaptured birds and were analyzed to determine haemospiridian content. The results revealed that these birds' mass deposition rate, fat score and body mass remain the same if compared with non-infected birds. They suggested that infected birds are unable to migrate south from their breeding areas in central and northern Europe.