The yellow-legged Gull Larus michahellis atlantis (YLG) is a generalist and opportunistic species that explores different habitats and resources and easily adapts to humanised environments, sometimes posing problems related to aircraft security, public health or predation on other species, for example. we examined the distribution and foraging behaviour of YLGs on the oceanic island of Madeira. GPS-GSM devices were deployed on ten breeding individuals and samples of blood (adults) and feathers (chicks) were collected to examine their stable isotope signatures in relation to those of their prey. Tracked YLGs did not migrate. Birds remained mostly inland during the day (up to 60% of fixes) and barely 5% of the fixes were at sea. Eighty-eight out of 192 gull trips to the sea were in interaction with local fishing vessels, 91% of which involving purse seiners that were active at night. The diet of the adult YLGs consisted of refuse, fish and small petrels, whereas the chick diet included mainly fish. YLGs on this oceanic island are strongly dependent on anthropogenic resources, scarcely relying on natural marine prey. The desired control of this gull population could perhaps be achieved by the reduction of accessibility to organic waste.-Romero, J., Catry, P., Menezes, D., Coelho, N., Silva, J.P. & Granadeiro, J.P. (2019). A gull that scarcely ventures on the ocean: yellow-legged Gulls Larus michahellis atlantis on the oceanic island of Madeira. Ardeola, 66: 101–112.

The Eurasian Griffon Vulture Gyps fulvus population has increased significantly over the last four decades in Spain as well as general knowledge about its biology. However it remains unclear if this species performs a true long distance migration or just dispersal movements between Europe and Africa. This is one of the least monitored species during spring migration at the Strait of Gibraltar, which is the most important migratory bottleneck for Eurasian Griffon Vultures in the world. The aim of this work is to provide information about the number, age composition, and the timing of Eurasian Griffon Vultures crossing from Africa to Europe during the 2017 spring migration—Ramírez, J., Zufiaur González de Langarica, F.M^a and Guerrero Molina, M. (2019). Spring migration of Eurasian Griffon Vultures across the Strait of Gibraltar: number, timing and age composition. Ardeola, 66: 113-118.

we studied autumn migratory patterns of four north-west Russian Ospreys Pandion haliaetus from 2015 to 2017. No previous information has been published on migration of Russian Ospreys. the mean start date was August 26th and the mean journey distance was 6258km. Ospreys reached their final destinations (in eastern, central or south-western Africa) via Suez and Cyprus. we identified several stop-over areas along these routes. Ospreys mostly showed an intensive off-route displacement during their autumn migration, suggesting that they simultaneously explore areas while travelling. we observed high variability within individuals, which suggests that Ospreys continuously adjust their migratory behaviour according to different environmental cues and internal factors. however, the low repeatability may also suggest that each Osprey is consistent but that all of them change their behaviour in the same way. this is important because it means that the environment encountered along the migratory route may trigger the same response by all individuals.–Babushkin, M., kuznetsov, A. & Delgado, M^a.M. (2019). Autumn migratory patterns of north-west Russian ospreys Pandion haliaetus.Ardeola, 66: 119-128.

Bird migration studies have been given added impetus recently thanks to the miniaturisation of tracking devices. However, tracking methodologies have remained impractical for the smallest pelagic species and so important gaps in knowledge still exist. In the case of the European Storm-petrel Hydrobates pelagicus, while Atlantic populations are thought to overwinter along the south-western African coast, the winter quarters of Mediterranean birds remain more enigmatic. We performed stable isotope analysis (SIA) of C and N on P1, S8 and P10 feathers from 33 adult birds captured in three Atlantic colonies and 156 adult birds in seven western Mediterranean colonies to infer their wintering areas. In addition, we collated all observational field data, both from peer-reviewed publications and the wider literature, to complement our inferences from SIA. Within the Atlantic, isotopic profiles of feathers moulted at the breeding grounds (P1) differed between birds captured at northern Atlantic and Canary Islands colonies, but were similar for feathers moulted in winter quarters (S8 and P10), indicating low migratory connectivity. Isotopic values of feathers from western Mediterranean birds differed from those of Atlantic birds and showed Mediterranean values for all feathers, indicating that the former overwinter in Mediterranean waters. Variance in the isotopic values was greater in winter than in breeding season feathers, suggesting that birds disperse over larger areas in winter. Isotopic values of feathers moulted during the non-breeding period could match a post-breeding movement towards the southern and eastern Mediterranean. This inference matches the distribution of the few winter reports, which are mainly concentrated in the south-central Mediterranean, mostly in the Tunisian Platform. Our results suggest that this region is the principal wintering area of Mediterranean Storm-petrels.—Martínez, C., Roscales, J.L., Sanz-Aguilar, A. & González-Solís, J. (2019). Inferring the wintering distribution of the Mediterranean populations of European Storm-petrels Hydrobates pelagicus melitensis from stable isotope analysis and observational field data. Ardeola, 66: 13-32.

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Observaciones de aves raras en España, 2017. El presente informe publica 247 registros estudiados y aceptados por el Comité de Rarezas, relativos a la presencia de 93 taxones de aves raras en el conjunto de España. El índice de aceptación de las citas obtenidas se ha situado en el 92%. Las citas más destacadas incluidas en el presente informe son las de correlimos grande Calidris tenuirostris –primera para España–, cuervo desertícola Corvus ruficollis –primera para España–, la subespecie centroeuropea de mito Aegithalos caudatus europaeus –primera para España–, pardillo norteño Acanthis flammea flammea –primera para España–, cuclillo piquicualdo Coccyzus americanus –segunda para España–, zarapito trinador americano Numenius hudsonicus –segunda para España–, alcaudón meridional estepario Lanius meridionalis pallidirostris –segunda para España–, gaviota cocinera Larus dominicanus –tercera cita para España– y correlimos zancolín Calidris himantopus –tercera para España. Además, se recogen un buen número de observaciones con interés a nivel regional. Entre ellas destacan las observaciones de petrel gon gon Pterodroma feae –segunda para España peninsular–, barnacla carinegra Branta bernicla –un ejemplar de la subespecie groenlandesa hrota, segunda para Canarias–, piquero pardo Sula leucogaster –segunda y tercera para Canarias–, charrán sombrío Onychoprion fuscatus –segunda y tercera para Canarias– y charrán real Sterna maxima –segunda para Canarias. También se recogieron números sin precedentes de pardillo alpino Acanthis flammea cabaret y alondra ibis Alaemon alaudipes, además del primer caso de nidificación en España de corneja cenicienta Corvus cornix y un nuevo caso de reproducción de corredor sahariano Cursorius cursor. Por último, se ha proseguido con la revisión de citas relevantes homologadas en el pasado, utilizando los nuevos criterios de identificación. En este sentido, se rechazan las dos observaciones de avefría coliblanca Vanellus leucurus homologadas en España (lo que significa la salida de la especie de la Lista Patrón), así como algunas citas de tarabilla siberiana Saxicola maurus, una cita de gaviota cocinera Larus dominicanus, una de halcón sacre Falco cherrug y una de correlimos acuminado Calidris acuminata.

Este informe recopila información de 194 especies que se reparten por toda la geografía nacional. Se hace una revisión de 35 especies escasas o que se presentan de forma puntual para el año 2017 mostrando su distribución en espacio y tiempo, la mayoría incluidas en la lista de aves raras hasta hace poco tiempo (véanse Rouco et al., 2018; Gil-Velasco et al., 2018, Gutiérrez, 2018; Reservoir Birds, 2018). Se presentan algunos mapas y gráficas que recogen el número de citas que proporcionan información sobre su patrón de presencia, sin incluir Canarias. La secuencia taxonómica sigue la Lista de Aves de España (Gutiérrez et al., 2012).

Recent changes in farming throughout Europe are threatening steppe birds, such as Montagu's Harrier Circus pygargus, a steppe raptor that nests in cereal crops, and is therefore threatened by the destruction of its nests by harvesters. Here we analyse the reproductive biology of Montagu's Harrier in Granada province of (south-eastern Spain), based on 184 nests monitored from 2003 to 2014. The mean laying date in our study area is one of the earliest recorded for the species, and mean clutch size one of the lowest, as expected considering the latitude at which the population is located. We also found that laying date was progressively earlier over the study period, whereas both clutch size and productivity have increased. The results show high reproductive success (82%), with a productivity of 2.67 fledglings per nest. However, this high productivity was achieved thanks to the nest rescue campaigns. Had the nests saved been lost, productivity would be only 1.47 fledglings per nest. Therefore, nest-rescue campaigns are fundamental for the conservation of the Montagu's Harrier population of south-eastern Spain.—Moreno-Rueda, G., Lopezosa, P. & Rivas, J.M. (2019). Breeding biology of Montagu's Harrier Circus pygargus in south-eastern Spain. Ardeola, 66.1: 3–11.

We monitored the number of pairs and the diet of Black-winged Kite Elanus caeruleus on the Lleida Plains (Catalonia, NE Spain) from 1998 to 2012. We examined the diet by means of pellet analysis. Nesting was irregular with peak numbers in some years (2009-2010). We found a positive relationship between the percentage of rodents in the diet and breeding success, an inverse relationship between dietary breadth and breeding success, a negative relationship between dietary breadth and the percentage of rodents in the diet and no significant variation in diet composition or breeding success between low kite population and high kite population years. All of this was consistent with the response of a specialist predator taking advantage of rodent outbreaks. We conclude that the breeding of the Black-winged Kite on the Lleida Plains is more consistent with the existence of irruptive events than with a real colonization of the area.—Llorente-Llurba, E., Bota, G., Pujol-Buxó, E., Bonfil, J., Gálvez, M., Montés, G., Bas, J., Moncasí, F., Pont, F. & Mañosa, S. (2019). Diet composition and breeding success of the Black-winged Kite on the Lleida Plains in relation to population size. Ardeola, 66: 33-50.

The migration strategies of smaller, south European, Mediterranean birds are less well known than those of northern and central European birds. We used geolocators to map individual spatiotemporal migration schedules of three species breeding in the Iberian Peninsula: the White-rumped Swift Apus caffer, rufous-tailed Scrub-robin Cercotrichas galactotes and Bluethroat Cyanecula svecica. The three species crossed the Sahara desert with a westward detour, to reach West African winter grounds in the Sahel (Bluethroats and Scrub-robins) or the rainforest belt (Swifts). Despite the proximity of the breeding grounds to the desert barrier, all but one individual stopped over before the desert crossing during autumn migration. After spending six months on average in sub-Saharan Africa with variable itinerancy, spring migration was faster overall and more direct than in autumn. Autumn migration was of similar duration to that found in related northern European migrants and therefore slower in southern birds. Spring migration was completed in less time than in the northern migrants (data only for Swifts and Scrub-robins). The shorter migration distance and proximity to the barrier potentially allow south European trans-Saharan migrants to migrate more slowly than northern migrants but only when less time-constrained in autumn.—Lomas vega, M., Willemoes, M., Arizaga, J., Onrubia, A., Cuenca, D., Alonso, D., Torralvo, C., Tøttrup, A.P. & Thorup, K. (2019). Migration strategies of Iberian breeding White-rumped Swifts Apus caffer, rufous-tailed Scrub-robins Cercotrichas galactotes and Bluethroats Cyanecula svecica. Ardeola, 66: 51-64.

Coccidians infect the intestines and other organs in vertebrates, causing pathogenicity ranging from asymptomatic infections to death. However, knowledge about coccidian infections is lacking for most free-living raptor species. Gathering basic information on coccidian infection would allow a better understanding of the basic ecology of raptors and would improve conservation actions. In this study, we assessed the prevalence and parasitic loads of coccidians in several free-ranging and rehabilitating wild raptor species in recovery centres in Spain and Belgium from 2015 to 2017. Faecal samples from 129 individuals of 17 different raptor species were collected. Coccidian oocysts were found in nine species. Significant differences were found in the prevalence of coccidians between the two countries, with higher rates in Belgium (45.0%) than in Spain (20.2%), as well as between age categories, with nestlings and juveniles showing a higher prevalence (30.5%) than adults (11.4%). Three different coccidian genera were identified. Caryospora spp. and Eimeria spp. were found in diurnal raptors and owls with medium/high loads (median ranging from 75-91344 ooc/g), while Isospora spp. was found only in Griffon Gyps fulvus and Egyptian Vultures Neophron percnopterus at low infection intensities (62-170 ooc/g). We present the first case of Isospora spp. in European vultures, although it is unclear if this is a true intestinal parasitisation or a pseudo-parasitisation with oocysts from livestock on which the vultures fed. Despite the limited sample size in our study, our results contribute to filling a gap in the knowledge of coccidian infections in wild birds.—Crespo-Ginés, R., López, D.S, Berriatua, E., Blanco, G., Candela, M.G. & Pérez-García, J.M. (2019). Coccidian prevalence and intensity in free-ranging and rehabilitating wild raptors. Ardeola, 66: 65-76.

Scatter-hoarder birds can play a key role in the dispersal and recruitment of forest tree species through caching seeds, but accurate evaluation of their importance in this respect would require detailed monitoring of post-dispersal seed fate. To quantify seed fate under wild conditions researchers often use visual marks to locate the seed caches. However, the effect that these marks may have on scatter-hoarder birds, and hence on the estimation of post-dispersal seed fate, has so far been neglected. In this study, we experimentally analyse whether different visual marks used to locate caching sites may affect the removal rate of cached seeds by a scatter-hoarder corvid, the Eurasian Magpie Pica pica. We used three different procedures (treatments) to mark the caches: a small wooden stake placed at 50cm from the cache, a large wooden stake placed at the same distance, and no stake (no visual mark). Dispersal of walnuts placed in feeders was monitored with radio-tracking, and assigning the dispersed nuts to each procedure followed a stratified process that allowed us to create similar conditions across treatments. We found that mark type did not affect the recovery rate of cached nuts, which validates the results of the recovery rate in previous studies of this system. Marking cached nuts with wooden stakes up to 20cm above ground as done in this study seems therefore to be an appropriate way to assist researchers to locate sampling points when studying nut dispersal by magpies.—Molina-Morales, M., Albaladejo, G. & Castro, J. (2019). Cache marking under field conditions does not affect nut recovery rate by the Eurasian Magpie Pica pica, a scatter-hoarder corvid. Ardeola, 66: 77-87.

Factors that influence the distribution and abundance of the endemic and threatened owls of the Andaman Islands have not been assessed, in contrast to those affecting diurnal birds. Such studies would assist in prioritising habitats that have high conservation importance for owls. We evaluated the status and species composition of owls along c. 343km of the Andaman Trunk Road, employing one-time point counts between December 2013 and April 2015. We conducted spontaneous listening, broadcasting of conspecific calls and spotlight searches as survey protocols. The pointcentred quarter method was used to evaluate the habitat at each count site. We recorded five owl species whose mean abundance was 2.09 owls/point. Species richness and abundance were greater in unlogged sites and deciduous forests. Habitat differences between owl species were noted according to land use, cover type and intensity of logging activity. However, these factors had no significant effect on the abundance of Oriental Scops-owl and Hume's Boobook, but were significant for Andaman Boobook and Andaman Scops-owl. Mean understory height, tree height and grass cover positively influenced the owl species richness and abundance. The Andaman Boobook and Andaman Scops-owl appeared stenotopic in habitat use and in contrast to the eurytopic Oriental Scops-owl and Hume's Boobook. A review of the conservation status of Andaman Scops-owl and Andaman Boobook is suggested bearing in mind their low abundance, restricted distribution and less preference for altered habitats.–Babu, S., Sureshmarimuthu, S. & Kumara, H.N. (2019). Ecological determinants of species richness and abundance of endemic and threatened owls in the Andaman Islands, India.Ardeola, 66: 89-100.