The typically resident Coal Tit Periparus ater, which is widespread in Eurasia, may migrate from breeding sites in large numbers in certain environmental conditions. I used observations from 2005–2023 in a lowland area of south-eastern Hungary to detect irruptive movements of the species. In total, I observed Coal Tits on 258 different days. In some years, they were absent, while in others they occurred in higher numbers. Comparing my data with literature suggests that the birds occurring in south-eastern Hungary are not of the same origin as the birds migrating more regularly through western Hungary. The birds in the study area instead likely originate from the mountainous areas of Romania or the northern Great Hungarian Plain. I found no correlation between the annual numbers of occurrences in south-eastern Hungary and northern Europe, so northern birds likely do not normally enter the Carpathian Basin. However, in 2018, Coal Tits were present in higher numbers in the Great Hungarian Plain as well as in northern Europe, so it is possible that some northern individuals may appear in eastern Hungary during large northern invasions.

The blowfly Trypocalliphora braueri is a subcutaneous parasite infesting nestlings. We investigated the occurrence of blowfly larvae in Willow Warbler Phylloscopus trochilus nestlings on the Kola Peninsula, Russia, in 2023–2024. The infestation rate was 46.9% of nests and 37.9% of chicks. The highest infestation rates were observed during a season with a late beginning of bird breeding and an unusually warm summer. In the infested nests, 86.2% (28.6–100%) of nestlings contained 1–11 larvae. Chicks with many larvae or with vital organ damage died. Nestling survival in the infested nests decreased by 15.4% compared to that in uninfected nests, but these differences were not statistically significant. We also found no significant differences in infestation rates between areas with varying levels of anthropogenic pressure.

The breeding success of a nest-box breeding population of Pied Flycatcher Ficedula hypoleuca in subalpine birch forest in Swedish Lapland was studied over 55 years, with emphasis on the impact of small mustelids and ambient temperature during egg laying, incubation, and brood care. The proportion of nests predated was used as an index for mustelid abundance. Breeding failures were either total, due to breeding interruptions, or partial due to partial hatching failure or nestling death. Overall, mustelid abundance explained the rate of breeding interruptions at any breeding phase, but not when seasons with exceptional (>10%) predation rates were excluded. Variation in the rate of partial failure was unrelated to mustelid abundance. Climatic conditions affected clutch size, rate of breeding interruption, and partial loss of clutches or broods, with particularly pronounced effects during the incubation period. The mustelid abundance and weather conditions also influenced rates of nest-box occupation in subsequent breeding seasons, and the next-box population dynamics covaried with surrounding populations.

Knowledge of migration patterns plays an essential role for understanding spatiotemporal distribution of birds. Here we used >15,000 sightings of 1,473 colour-ringed Common Cranes Grus grus to study migration patterns of birds breeding in five regions along a longitudinal gradient of Fennoscandia. Our results confirm that Fennoscandian cranes mainly use either a Western European flyway (W-flyway), to winter mainly in France or Spain, or a Central European flyway (C-flyway), to winter in Hungary or Israel. Finnish cranes showed the greatest variation in migration patterns in terms of distance and direction and only Finnish cranes were recovered in Africa. Many of the Finnish cranes, starting along C-flyway change to the W-flyway and winter in SW Europe or NW Africa. On the other hand, the Scandinavian cranes are rarely observed along the C-flyway. However, substantial numbers of cranes from NE Sweden cross the Baltic Sea and migrate via Finland but then follow the W-flyway from Germany and southwards, especially during autumn. These results can be used for conservation and management, e.g. to coordinate monitoring. They are also relevant for land use planning, e.g. to avoid windfarms at sites important for migrating soaring birds while crossing seas, so-called ‘thermal bottleneck sites’.

We tested for airborne epimeletic (care-giving) behaviour in Common Swift Apus apus towards young swifts during their first flight. Tests were performed where colonies of Common Swift and Western House Martin Delichon urbicum co-occur. Three variants of a flying dummy were used; two with pointed wings of which one entirely black (1) and one with partly white body (2). The third was black with broad wings (3). Reactions were documented on film. Swifts and martins had opposite reactions to dummies 1 and 2. As we anticipated, martins seemed supportive in a test with dummy 2 and seemed to “guide” the dummy epimeletically. However, a swift approached dummy 2 in a support-like attempt, but deviated after a close look. In a test with dummy 3, swifts acted highly hostilely. We discuss reasons for these outcomes and the importance of dummy appearance. We illustrate the flight paths of the dummy, swifts and martins with trajectories, and the behaviour of the Western House Martin is shown in stepwise larger magnification stills of a video.

In recent decades, interest has grown in how increasing populations of herbivorous geese and swans (Anseriformes: Anatidae: Anserinae) affect macrophyte communities in wetlands, especially because many waterbodies are simultaneously subjected to stressors like eutrophication and biodiversity declines. Here, we review the literature on methods applied in grazing experiments that have been conducted in aquatic ecosystems. We also investigate and how different macrophyte characteristics may respond to waterfowl herbivory. Results indicate that both research methodology and responses of macrophytes differ widely among studies. While most experimental studies on grazing pressure employ a ‘paired plot design’ with exclosures and open control plots, the structure, size, and placement of plots vary among studies. Commonly sampled macrophyte variables are biomass (of either above- or below-ground plant parts), density, height, plant cover, and community composition. The literature provides support that geese and swans significantly affect several of these variables, but the outcome depends on additional factors, e.g., waterfowl density, water depth, and timing (within or between seasons/years). Because of the persisting conservation threats to aquatic ecosystems, more knowledge is needed about potential direct and indirect consequences of waterfowl herbivory in these environments.

Breeding European Shag Gulosus aristotelis in in the Russian part of the Barents Sea was first noted in 1932, but the population has remained small. Currently, breeding sites are known from the Seven Islands, the Gavrilovsky Islands, the Ainovy Islands, the Bazarnaya Guba, and the Pechenga Guba. Here we report the breeding of this species near Ura-Guba and in parts of the Barents Sea coast where it has not been found before.