[EN] 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-Garciá, J.M. (2019). Coccidian prevalence and intensity in free-ranging and rehabilitating wild raptors.

Este informe recopila información de 145 especies que se reparten por toda la geografía nacional. Aunque desde hace algunos años las citas y observaciones se encuentra por diversas plataformas, foros, blogs, etc., se recomienda el envío de observaciones de algunas especies de presencia puntual o escasa y que recientemente ha salido de la lista de aves raras (véanse Rouco et al., 2017; De Juana y García, 2015; Gil-Velasco et al., 2017). La secuencia taxonómica sigue la Lista de Aves de España (Gutiérrez et al., 2012). Por otro lado, para registrar y consultar los datos del Noticiario Ornitológico, así como de aves exóticas o de aves raras se dispone de una aplicación, con la opción de ser utilizada a través de la telefonía móvil: www.gruposdetrabajoseo.org

Diet and breeding performance show variations across species’ range and between different habitats. In the present paper, we report data on the diet and breeding performance of Golden Eagles Aquila chrysaetos monitored during a ten-year period in two semi-natural landscapes located at the eastern and western extremities of the Pyrenees mountain range. In the Mediterranean area of the Corbieres, the diet was dominated by the Rabbit Oryctolagus cuniculus (31.5% of the prey items). In the Atlantic area of the Basque Country, the diet was more diverse, with the highest proportion of intra-guild predation and the highest diet breadth ever recorded for the species (Levins index of diet breadth: 12.14 vs 6.81 in the Corbieres). The proportion of successful breeding attempts was significantly higher in the Corbieres (60%) than in the Basque Country (38.5%). The same was true for mean productivity, with 0.70 and 0.45 fledglings per territory and year, respectively. These differences were partly related to the excess of snow cover in April in the Basque Country. Our results provide an example of intra-population variability in a long-lived apex predator at the extremes of a geographical gradient involving climate and prey availability.

Summary. Morphological methods to distinguish between avian groups of research interest (e.g. different sexes, populations or cryptic species) need to be externally validated to ensure reliable performance across situations. In this study, we used stable hydrogen isotope ratios of feathers (δ2Hf) to test the validity of morphological classification functions (MCFs) previously designed to assess the migratory behaviour of European Robins Erithacus rubecula wintering in southern Iberia. Our results show that a great number of migrants (mostly females and juveniles) were erroneously assigned as sedentary, which could compromise the reliability of previous ecological studies that made use of these MCFs. The development of improved MCFs or the use of alternative differentiation methods (δ2Hf) could help us to gain a more realistic insight into the habitat distribution and ecological interactions of sympatric migratory and sedentary robins overwintering in southern Iberia.

Coastal specialised species have naturally restricted distribution areas and may be drastically affected by fragmentation or loss of their habitats due to ongoing changes, such as artificialisation, shoreline erosion, rising water levels or colonisation by invasive species. In this context we characterise the land occupation strategies of a Western Atlantic French coastal endemic bird: the Bluethroat Cyanecula svecica namnetum. Our study focuses on a key period of the life cycle of this species: the post-breeding moult. Capture and recapture sessions in intertidal habitats have allowed us to retrieve 26% of local breeders during their moulting period. The modeling of moult kinetics revealed that moult of flight feathers takes 37–50 days. A radio-tracking survey of moulting birds revealed exploitation by individuals of both the lowest and tallest vegetal formations of intertidal sites and exploitation of small home ranges (0.42–1.34 ha), typical of locations where trophic resources tend to be abundant and predictable. Analyses of droppings highlighted that Coleoptera, Aranea and marine crustaceans (Amphipoda) contributed most of the prey biomass consumed, amphipods being particularly selected by birds in active moult. Our results underline the importance of intertidal wetlands in terms of trophic opportunities to compensate for the energy costs of moult for the Bluethroat. Given the global changes already dramatically affecting coastal habitats, we emphasise that special attention should be given to the conservation of intertidal wetlands for marshland passerines of conservation concern such as the Bluethroat, and that restoration of adjacent coastal terrain is a promising development.

Afro-Palearctic migrants move between breeding and wintering grounds along flyways determined by several factors (bird morphology, geography, behavioural adaptations) and raptors often concentrate at straits to avoid long sea crossings. Here we test the hypothesis that raptor passages across different areas of the Turkish straits are similar in species composition as well as flight behaviour. We made simultaneous observations at the Bosphorus and at the Dardanelles in autumn 2010. We tested the influence of weather, time of day and flock size on the intensity and spatial shift of migratory flow as well as the tendency to cross the Dardanelles Strait rather than follow the peninsula. We also collected information of the flight altitude of raptors using an optical range finder. The species composition observed at the two sites was completely different, with eagles predominating at the Bosphorus and small and medium-sized raptors predominating at the Dardanelles Strait. Compensation for wind drift at the Bosphorus was species-specific, with small and medium-sized raptors showing a drift effect by crosswinds, and eagles showing compensation and overcompensation. Mean flight altitude was similar among species, while the response to weather conditions varied, being mainly affected by wind. In the case of Short-toed Snake-eagles, flight ability and response to weather conditions was also age-dependent. These results show that the flight strategies of migrating raptors are species-specific even if some flight parameters may converge as a result of risk minimisation. The differences between species and flyways probably reflect interspecific differences in the ability to fly over water.

Summary. Sexual size dimorphism (SSD) may favour physiological peculiarities in diet, behaviour and home-range size both across species and within species. Sex-specific differences in diet and behaviour have been reported in several bird species but there are fewer studies of foraging area size in sexually dimorphic bird species. Foraging area size should be greater in the bigger sex according to home-range size predictions based on body mass. We tested this prediction in a winter study of foraging area size in the Great Bustard Otis tarda, the most sexually size-dimorphic bird species, which forages in unisexual flocks. In this species the temporal pattern of a flock's feeding intensity; the proportion of birds actively feeding (FI) and the size of the morning foraging area (MFA) of each sex are unknown. We recorded the behaviour and movements of unisexual flocks of Great Bustards during winter mornings and sampled food availability to take into account its effect on FI and MFA. FI increased and then dec...

Summary. Estimating the productivity of colonial waterbirds can have important conservation and management implications. For tree-nesters, investigators must climb nest trees to obtain productivity data. In this study, we employed indirect inspection of nest status by using a pole-mounted camcorder at 77 nests in five colonies of tree-nesting grey herons Ardea cinerea in northern Poland. We found no significant relationship between the time spent recording per nest and the age or height of the inspected trees. We found that nestlings did not react to the presence of the climber manipulating the polemounted camcorder. However, we did record visible reactions from small chicks (< 4 weeks old) to the presence of cameras close to the nest, including threat poses and upright, forward and snap displays. For older nestlings (≥ 4 weeks old) we recorded only threat postures. This novel method allows the collection of ecological and/or behavioural data that cannot be obtained by observation from the ground, for exa...

Suboptimal temperatures may exert negative effects on altricial nestlings, especially during their first days of life, when thermoregulation is not yet fully developed. We experimentally lowered nest temperatures by a mean of 4.5 °C during early development of great tit Parus major nestlings from the Mediterranean region. The thermal treatment only affected nestling size, as cooled nestlings had smaller tarsi by day 15 than controls. Female brooding constancy remained unaltered and female body condition was not negatively affected, so females did not incur additional energetic costs to ameliorate thermal conditions for nestlings. In conclusion, we found that colder nest microclimates may impair nestling growth, which may have negative consequences on future survival.

Summary. Since 2005, Morocco has designated many Ramsar wetlands, yet little is known about factors determining their occupation by waterbird communities. In this study, we assessed the relationship between the occupation of Moroccan Ramsar wetlands during the breeding season by two globally threatened waterbirds, the marbled teal Marmaronetta angustirostris and the ferruginous duck Aythya nyroca, and geographical, topographical and macrohabitat factors. Habitat-based statistical models showed that the presence of these two threatened waterfowl species at Moroccan wetlands was positively correlated with the number of emergent vegetation species, and negatively correlated with altitude and the distance to the nearest coastline. These results highlighted previous findings regarding the significant and positive relationship between the number of plant taxa and the number of threatened waterbird species at Moroccan wetlands. Further investigations should be conducted at regional (Maghreb region) and internati...