ABSTRACT Capsule This first detailed investigation into the diet of Little Terns along the North Atlantic coast of Morocco, focusing on the tidal zone of Mansouria over six years, highlights the species’ dietary composition during chick-feeding at an important nesting site. Aims To assess the diet composition and foraging behaviour of Little Terns in the tidal habitat near its breeding site on the Mansouria coast, in Morocco, with a focus on prey diversity and changes the prey species delivered to chicks over time. Methods Fieldwork was conducted over six breeding seasons (2009–2014) in a 38-ha estuarine area (2 km long, 0.3 km wide) near the Moroccan cities of Mohammedia and Bouznika. Data collection included direct visual observations, photographic documentation of foraging behaviour and analysis of prey remains found near nests. Results From a total of 105 prey items identified, Little Tern chick diet predominantly consisted of fish (n = 93, 88.6%) and arthropods (n = 12, 11.4%). Key fish species identified were European Pilchards (Sardina pilchardus; n = 33, 31.4%), gobies (mainly Gobius niger; n = 20, 19.0%), White Seabreams (Diplodus sargus; n = 16, 15.5%) and sand smelts (Atherina spp; n = 13, 12.4%). Chicks were initially fed small fish, with prey size increasing as the chicks grew. Conclusion This study provides an initial assessment of Little Tern chick diet in Moroccan coastal waters. While limited to low-tide observations, the findings emphasize the significance of the Mansouria tidal zone as a critical feeding habitat, supporting calls for its conservation.

ABSTRACT Bird colonies can provide better protection against predators for other bird species, although negative interspecies interactions are possible. The presence of colonies of small gulls (Laridae) and marsh terns Chlidonias spp. is important for breeding Black-necked Grebes. The clutch size and breeding success of Black-necked Grebes were studied at 18 fishponds in southern Poland, with measurements taken of the distance of a grebe nest to the nearest nests of associated species (Black-headed Gull Chroicocephalus ridibundus or Whiskered Tern Chlidonias hybrida). There was no significant difference in the number of eggs laid between Black-necked Grebe nests located within colonies of gulls or terns. However, grebe nests were significantly farther from tern nests than from gull nests. The breeding success of Black-necked Grebes was significantly higher in Black-headed Gull colonies compared to Whiskered Tern colonies, possibly because the greater aggression of terns was directed at the grebes themselves.

ABSTRACT Capsule Sedge Warblers Acrocephalus schoenobaenus that stopover along the Atlantic flyway refuelled at varying rates, depending on age, initial body condition and latitude; refuelling rates were poorly structured among sites, suggesting a broad capacity of birds to exploit various wetlands during stopover. Aims To test how Sedge Warblers accumulate fuel during stopovers in a major migratory corridor along coastal Atlantic wetlands, from northern France to the Bay of Biscay in Spain, and to identify factors affecting the fuel deposition rate (FDR). Methods We analysed 7,149 records of Sedge Warblers captured at least twice within the same site and year, collected over 32 years across 28 wetlands. We used linear mixed models to test the effect of age, initial body mass, date, latitude and habitat structure on FDR. Additionally, we modelled initial body mass as a response variable to examine large-scale variation in the arrival condition of birds, with age, date, latitude and habitat features as predictors. Results The fuel deposition rate declined with increasing initial body mass. The effect of latitude varied with age: for yearlings, refuelling rates increased from north to south, while adults showed relatively constant rates along the flyway. Initial body mass was higher in birds captured later in the season and in those using landscapes with smaller and more fragmented wetlands, but decreased with latitude. Habitat metrics had limited explanatory power. Conclusion Sedge Warblers appeared to refuel opportunistically throughout the extensive network of wetlands that spans the Atlantic flyway. This finding reinforces the importance of preserving habitat connectivity along migratory routes and supports a landscape-scale conservation approach that integrates ecological functionality and behavioural flexibility.

ABSTRACT Capsule Wetlands and lagoons of the Mediterranean region are important wintering areas for some species of raptors that breed in Europe. Aims We report the abundance, density and habitat choice of raptors wintering in coastal wetlands, lagoons and surrounding habitats of western Greece. Methods Data were collected during roadside surveys. Species abundance was calculated with the kilometric abundance index, while densities were estimated through density surface models. Results Marsh Harriers Circus aeruginosus and Common Buzzards Buteo buteo were the most abundant raptors recorded, with the former mostly detected in wetlands and the latter on arable land. Nearly all wintering Marsh Harriers were adult females and immatures. Few Kestrels Falco tinnunculus were detected. A flock of 28 Greater Spotted Eagles Clanga clanga was observed roosting at the Amvrakikos gulf. Conclusion Marsh Harriers and Common Buzzards were the most abundant wintering raptors recorded in Greek coastal wetlands. Few records of Kestrels are consistent with previous suggestions of interspecific competition with Common Buzzards, combined with the greater ability of Common Buzzards to cross water barriers, which may influence their relative wintering distribution in the Mediterranean basin. The importance of Greek coastal wetlands was confirmed as one of the most important wintering areas for the Greater Spotted Eagles in the Mediterranean Basin.

ABSTRACT In one of the very few investigations of the movements of the Eurasian Hobby, we caught and GPS-tagged two females in north-eastern Poland. Tracked individuals had strikingly different breeding home ranges of 1.5 km2 and 83.2 km² and moved, on average, a respective 23 and 61 km per day. On 1 September 2021, both birds began migrating and flew directly south, covering up to 999 km per day, and averaging 276 km for the first female and 327 km for the second. After the birds moved approximately 10,000 km, their signals were lost in central and southern Africa, respectively.

ABSTRACT Capsule Camera and automated image analysis technologies offer one solution to the challenges of seabird monitoring; however, their application is often not straightforward and there is currently unlikely to be a universally applicable method across sites and species. Aims Evaluate a range of time-lapse camera and automated image analysis methods to monitor seabirds in various coastal settings. Provide recommendations and guidelines on the minimum equipment needed to obtain representative information from time-lapse images. Methods To establish an efficient and effective method to generate count and/or presence/absence data from images of seabirds, we assess the application of two image analysis methods: (1) bespoke and site-specific object detection, and (2) open-source and generalised object detection. Using a worked example of time-lapse photography of three coastal seabird roosts, we compare data from each image analysis method, evaluating performance and overall success relative to manually collected data from the same images. Results When detecting seabird presence/absence, we found no consistency in image analysis performance (3.2–94.7% correct detection of true presence; 9.8–98.2% correct detection of true absence). When generating counts, the performance of the different approaches varied (6.3–37.5% of automated counts were correct, relative to manual counts). Notably, whilst the bespoke method was the most successful when generating counts, both object detection methods consistently underestimated seabird abundance. Conclusions Bespoke, site-specific analyses could be required where count data are needed, whereas open-source generalized detection methods may be suitable where presence/absence data are sufficient to meet study aims. Automating image analysis is unlikely to remove the need for manual analysis, whether to produce training data sets, validate output, and/or compliment observations. By offering lessons learnt from a worked example and resultant recommendations, this study informs future projects aiming to use inexpensive and accessible image technologies for ecological research.

ABSTRACT Capsule We describe the movements of colour-ringed White-tailed Eagles, observed in later stages of life, from their hatching sites. Aims To investigate the movement distance of individuals of various ages from their hatching sites in an increasing population, and to study the influence of natal habitat type and possible changes over time. Methods We analysed ring recovery data collected between 1988 and 2023 in Lithuania, from 315 local and 74 foreign-ringed White-tailed Eagles and tested the effects of individual age and natal habitat type (coastal and inland) on recovery distance. We also compared recovery distances between 1988–2012 (the early stages of population establishment) and 2013–2023. Results White-tailed Eagles in Lithuania were recovered, on average, 128 km ± 209 SD (n = 388) from their ringing locations, and we found no significant differences in recovery distance between immatures (mean 137 km from hatching sites) and adults (mean 111 km). However, outside of Lithuania, immatures showed a southward directional preference compared to adults. Eagles hatched in coastal areas were recovered at significantly shorter distances from their nest sites (mean 51 km) than those hatched inland (mean 215 km). Recovery distances decreased significantly over the last decade, particularly for birds originating from inland habitats. Conclusion For White-tailed Eagles in Lithuania, the distance between hatching location and recovery sites during the later stages of life was strongly dependent on natal habitat, but not the age of individuals. The almost three-fold decrease in recovery distance in recent years suggests that the growing population is shifting to more localized movements within the region. Our study highlights the role of natal habitat quality and/or population density in shaping movement behaviour and suggests potential future implications for population dynamics, habitat occupation and inter-species interactions within the region.

ABSTRACT Water availability is crucial for birds, especially during high temperatures when hydration needs increase. While food provisioning has been well studied, less is known about how artificial water sources affect avian behaviour. We examined whether the colour of water containers (white, green, red) influences bird visitation rates and species richness in a rural garden. Over 30 days, we recorded 304 visits by four species. Birds initially avoided red containers, but visit rates increased over time, suggesting habituation. Green containers attracted the highest number of visits, whereas temperature significantly affected species richness and visitation rates. These findings highlight the importance of accessible water sources under warm conditions and provide insights into bird interactions with anthropogenic resources in modified landscapes.

ABSTRACT Capsule Long-term monitoring revealed density-dependent regulation of a recovering population of White Storks in northern Spain. Aim To analyse long-term changes in the population size, productivity and colony dynamics of the White Stork at the northern edge of its breeding range in Spain. Methods We used breeding data from 1948 to 2024 to obtain population trends, reproductive output and spatial nesting patterns (proportion of isolated versus colonial nests, and nest substrate) in Álava, in northern Spain. Results The population showed a three-phase trajectory: a decline until the early 1980s, followed by a rapid growth through the 2010s, followed by a recent stabilization or slight decline. Colony formation increased with population size, indicating a density-related response, although colonial nesting did not improve reproductive success. Productivity declined with increasing population size and over time, and was higher in nests with presumed site fidelity. Conclusion Our findings suggest that density-dependent factors were now regulating this White Stork population, consistent with patterns reported in other parts of Europe. Anticipated reductions in food availability from landfill closures could limit future population growth. Long-term data are essential to understand population dynamics and to guide adaptive conservation in changing landscapes.

ABSTRACT Capsule Red Kite populations in Sardinia are very small but show a strong spatial overlap with current and planned wind energy infrastructure, highlighting a conservation concern. Aims To assess the status of the Red Kite population in Sardinia and evaluate the potential conflict between its distribution and the development of wind energy. Methods Breeding populations were surveyed through road transects, while wintering numbers were assessed with coordinated roost counts. Spatial overlap with operational and planned wind farms was analysed using distribution data from breeding and wintering areas. Results The Sardinian population comprises 10–13 breeding pairs and up to 87 individuals in winter. A total of 188 operational turbines currently occur within the breeding range and 417 within the wintering range. Planned developments include an additional 265 turbines in the breeding area and 440 in the wintering area, indicating substantial overlap with key sites for Red Kite. Conclusions The large degree of overlap between areas utilized by Red Kites and wind farms raises concerns over collision risk and habitat displacement. Integrating updated distribution data into wind energy planning is essential to reconcile renewable energy goals with raptor conservation. Transboundary cooperation is needed to ensure the long-term conservation of Mediterranean island populations.