Bycatch, the unintended capture of animals other than target fish, is one of the most important anthropogenic threats to seabirds worldwide. This problem has been relatively little studied, however. The southern Baltic Sea is one of the three areas worldwide with the highest gillnet bycatch. Forty-eight publications from the years 1982–2021 addressing the problem of seabird bycatch in the Polish Exclusive Economic Zone (PEEZ) of the Baltic Sea were analysed for the purposes of this paper. Twenty-eight bird species were identified in bycatch, 13 of which have threatened or near-threatened status on the European Red Bird List. The magnitude of the annual bycatch was estimated for three periods: 1970s — 47,000 birds, 1980s and 1990s — 39,800 and 2010s — 21,300 birds. The most frequently bycaught species in the 2010s were Long-tailed Duck Clangula hyemalis (9,000 ind. yearly), Greater Scaup Aythya marila (3,500) and Velvet Scoter Melanitta fusca (2,000). Acceptable mortality thresholds calculated using both the Potential Biological Removal (PBR) and the BirdLife International (BLT) methods were found to have been exceeded: for Long-tailed Duck by 175% (PBR) and by 1,061% (BLT); for Greater Scaup by 542% (PBR) and by 3,400% (BLT); for Velvet Scoter by 35% (PBR) and by 495% (BLT). All three species are listed as Vulnerable in Europe. Six distinct bycatch areas have been identified in the PEEZ. Bycatch mitigation is exceedingly difficult to implement: the only effective method currently employed to protect seabirds from bycatch in gillnets involves the temporary closure of bird hotspots to gillnet fishing.

The assessment of the conservation status of a species is the first step to prevent local extinction and to plan appropriate, effective and scientifically sound conservation actions, hence knowledge of the distribution, population trends and characteristics of preferred habitat is crucial for the conservation of a species. Galliformes are facing increasing threats related to overhunting, habitat loss and fragmentation, and human disturbance. The Sicilian Rock Partridge (hereafter Rock Partridge) Alectoris graeca whitakeri is a significant conservation unit endemic to Sicily (Italy) classified as Near Threatened by the IUCN due to a decreasing population. Few studies have been conducted on the occurrence and population density of this subspecies. Here, we estimated its population density and identified which habitat factors drive the occurrence of this species on Mt. Etna. We used a combination of sampling methods (species-specific play-back calls, distance sampling, camera-trapping) to collect count and presence/absence data, which were then integrated into a single habitat model (presence vs. absence). We obtained 24 responses from play-back calls (plus 8 individuals observed while performing the play-back calls), 8 sightings from distance sampling, 6 detections from camera-trapping. Probability of occurrence of Rock Partridge on Mt. Etna was positively driven by shrub and meadow vegetation, whereas its occurrence decreased with an increase in both woody areas (coniferous and deciduous) and elevation. Population density estimated using play-back call data resulted in 0.80 pairs/km² (95% CI: 0.17–2.22) over an area of 53.7 km². The density of Rock Partridge on Mt. Etna appeared to have slightly declined and its distribution undergone a contraction since the previous survey. Several potential threats to the Rock Partridge in Sicily are currently increasing and should be mitigated to ensure the long-term survival of this unique population on Mt. Etna, as well as in the whole island of Sicily.

Studies on nest-site selection can reveal aspects of habitat requirements of the target species, and can be useful to infer about how habitat changes can affect local populations. The Helmeted Manakin, Antilophia galeata, is a piprid that inhabits mainly the humid gallery forests that occur along watercourses of the savanna-like Cerrado biome from central South America, and like most tropical forest understory passerines, it is poorly known under a nest-site selection perspective. Here we provide nest-site selection assessment based on nine variables for a population of the Helmeted Manakin from southeast Brazil. We found that females strongly selected Miconia nervosa (Melastomataceae) as a nesting plant species. Further, we demonstrated that the presence of nests was positively associated with canopy cover and with the occurrence of the endangered jussara palm trees, Euterpe edulis. These results suggest that the Helmeted Manakin is specialized in reproducing in mature and well-preserved gallery forest tracts. Gallery forests are narrow stripes of riparian vegetation from the endangered Cerrado domain, and here we showed that even in these linear habitats, the Helmeted Manakin can seek for specific portions for nesting. This is one of the few studies reporting nest-site specialization in a Neotropical forest-dwelling passerine.

For many birds breeding success may be related to the availability of nesting sites, particularly in ecologically specialized cavity-nesting birds. For burrow-nesting species, the selection of an appropriate substrate may be fundamental to a successful breeding attempt. The Lesser Crescent-chested Puffbird Malacoptila minor is a bucconid with a restricted distribution, which is found in the states of Maranhão and Piauí, in northeastern Brazil. It is the only bucconid listed as threatened with extinction, and little is known about its natural history. A total of 49 nests were found over three breeding seasons (2017–2020). Nests consist of burrows dug in the ground that are used only once for breeding. Incubation lasted 21.2 ± 1.3 days and the nestlings fledged after 19.5 ± 2.9 days. The nests contained two or three eggs. The mean hatching rate was 0.46 ± 0.47 eggs per nest and the fecundity rate was 1.0 fledgling per female. The production was 0.53 fledglings per nest, apparent reproductive success was 22.4% (N = 49), and was 15.7% (N = 49) when based on Mayfield's protocol. The probability of breeding success per period was greater during the incubation phase than during the nestling phase. Predation was identified as the principal cause of nest failure (77.5%), mainly during the incubation phase. Three predators were identified: the Crab-eating Fox Cerdocyon thous, the fire ant Solenopsis saevissima, and a lizard, the Common Tegu Salvator merianae. Breeding season starts with the onset of rainy season and nest flooding did not appear to be a concern, which contrasts with the available data on other bucconids. The results of the present study are the first data on the breeding biology of the Lesser Crescent-chested Puffbird, and represent an important advance in the understanding of breeding patterns in the Bucconidae.

The seasonal presence of the Oriental Honey Buzzard Pernis ptilorhynchus in Israel has changed during the last two decades. Up until the late 1990s, it occurred in Israel as a rare spring migrant, but has since been more frequently observed. In the last decade, it has established itself as a regular over-winterer in Eilat, as well as a rare summer visitor. The reasons for this change are unclear; however, this process is concurrent with the invasion of the Dwarf Honey Bee Apis florea to the southern part of Arava, the region extending from the Gulf of Aqaba to the southern tip of the Dead Sea. Similar invasions of this social honey bee, native to East Asia, have been reported from East Africa and the Arabian Peninsula. Using standardized line transects to count Oriental Honey Buzzard, and by creating a Honeybee Invasion Index (HII) for Dwarf Honey Bee, based on data collected by the Israel Nature and Parks Authority to estimate its distribution, we show that the abundance of overwintering Oriental Honey Buzzard in Eilat is significantly related to the distribution of DHB in southern Arava. We suggest that the invasion of Dwarf Honey Bee in the area facilitates the presence of Oriental Honey Buzzard outside the migration season.

Cavities provide suitable microhabitats for various organisms. Therefore, cavity excavators are important species in forest environments. We observed large differences in both persistence and occupancy of the cavities of Grey-headed Woodpecker Picus canus monitored during the whole cavity lifespan in a 33-year study in southern Finland. Of a total of 80 cavities studied, the median persistence time was 17 years, but this varied from a median lifespan of 29 years for cavities in living trees to only 9 years for cavities in dead trees. The expected number of life-span nests of forest bird species per old cavity was 4.2 in living, and only 1.6 in dead trees. Ten bird species utilised the old cavities (most frequently Great Tit Parus major, Grey-headed Woodpecker and Pied Flycatcher Ficedula hypoleuca). The results show that both suitable living and dead trees should be available for cavity excavators such as the Grey-headed Woodpecker, and that living and dead trees may have different, but important ecological roles for cavity-nesting birds in boreal forests.

The decrease in chick survival has been one of the most important reasons for the decline in the abundance of Grey Partridges Perdix perdix in Europe in the recent decades. Therefore, it is important to know the habits of these birds during the period of raising chicks. The habitat use, movements and home range sizes of partridges rearing their chicks up to three weeks old were studied in western Poland in the years 1995–2001. Twenty one pairs with chicks were localized daily by radiotracking. The partridge broods mostly used cereals (54.4% of their locations), but permanent wild vegetation (19.6%) turned out to be preferred. Most locations (56.8%) took place up to 10 m from field edges. The average distance of daily movements was 160 m (range 0–890 m) and was shorter in the diversified landscape of small fields than in the simplified landscape of large fields. The area of home ranges (100% MCP) during the first three weeks of chick's life averaged 12.0 ha (range 2.9–34.1 ha) and no significant differences were found between the two field types. The size of home ranges decreased with the proportion of cereals and wild vegetation in the regions where individual broods occurred. It was concluded that large-scale crop fields create worse living conditions for Grey Partridge broods than more diverse small fields.

Coastal ecosystems provide important feeding opportunities for shorebirds, depending on their prey availability, hydrodynamic conditions and human pressure. We aimed to evaluate short-term responses (occurrence and minimum approach distance) of shorebirds to urbanization and natural drivers on an extensive beach arc adjacent to the largest hypersaline coastal lagoon of South America. The presence of the migrant Sanderling Calidris alba and resident Collared Plover Charadrius collaris was geo-coordinated and for each record and an equivalent number of random points we measured the distance from urban settlements, swash width and invertebrate abundance (food availability) in a snapshot sampling. The distance at which each shorebird flock escaped from humans was determined (minimum approach distance). The occurrence of shorebirds was predicted by food availability, and higher crustacean density was found in areas of shorebird occurrence (37 ± 19 individuals/m²) compared to random points (10 ± 10 individuals/m²). This result highlights the importance of the beach as a feeding area and the need for conservation of shorebirds' prey. The resident Collared Plover delayed their escape from humans in areas closer to urban areas, suggesting a higher tolerance to humans on disturbed beaches, where they can prioritize the food intake rather than vigilance. The larger flocks let the researcher get closer, corroborating the risk-dilution theory stating that flocking behaviour during foraging provides protection of birds from predators. In conclusion, our results showed that monitoring of sandy beaches based on shorebirds' presence and behaviour can be a reliable tool, especially close to coastal lagoons that constitute foraging sites for these charismatic species.

Understanding the year-round movement behaviour is fundamental for the effective conservation management of an ecologically important species. In the heavily human-modified landscape of Central Europe, Saker Falcons Falco cherrug have adapted to intensively managed agricultural habitats, often nesting and roosting on electrical pylons. We studied the ranging behaviour and habitat selection of one juvenile and three adult Saker Falcons equipped with GPS/GSM loggers in the Czech Republic and Austria between 2015–2017. Upon release from a rescue centre, the juvenile Saker Falcon used temporary settlement areas (TSAs) with a median size of 231 km² (minimum convex polygons, MCP 95%). Median of breeding season home ranges for the three adults was 15 km² over six breeding events. After breeding period, the adults remained close to the nest site, occupying an area with median of 10 km² until they departed for their autumn migration. Departure dates ranged from 21 September to 9 November. Winter TSA sizes had median of 99 km². Adults returned to the breeding area between 12 February and 4 March. Annual breeding home ranges overlapped by approximately 84–99% indicating high site fidelity. The most utilised land cover types within winter TSAs included arable land and heterogeneous agricultural areas. Analysis of night-time roosting sites showed a substantial preference for high voltage pylons compared to trees. Our results could benefit conservation planning and species management practices, focusing on both improving the safety of anthropogenic elements and increasing habitat diversity.

Measuring the productivity of gulls Laridae and terns Sternidae is often difficult, due to natural obstacles of site access and the need to avoid disturbing nesting birds. Drones are increasingly being used for conservational and ecological applications and their use seems to overcome these problems, but data are still scarce on their use to assess breeding success. Our objective was to compare the effectiveness, time consumption, and safety for birds of drone-conducted monitoring of nest-specific hatching success with usual ground surveys of two species of gulls, including Slender-billed Gulls Chroicocephalus genei and Mediterranean Gulls Larus melanocephalus, and two species of terns, including Gull-billed Terns Gelochelidon nilotica and Sandwich Terns Thalasseus sandvicensis, breeding in the Adriatic wetlands of northeast Italy. We studied 400 nests (100 per species distributed in eight plots, each with 50 nests) and found no significant difference between the two methods in determining the number of eggs either laid or hatched per nest for all four focal species. The average coefficient of agreement between methods was high (kappa > 0.80 for all comparisons). The mean time spent determining the hatching success of 50 clutches with a drone (263 sec per plot) was significantly less than with ground surveys (760 sec per plot). There were no apparent negative effects of drone flights on nesting pairs, clutches, or young. Our results suggest that drones allow effective, rapid, and safe measurement of seabird breeding success in coastal areas.

Studies of long-term trends in avian populations require large-scale data not available for most bird species. The White Stork Ciconia ciconia is unique being monitored for over a century and well-reflecting modern environmental changes. Its worldwide and national populations are estimated every 10 years thanks to the International White Stork Censuses (IWSC). We present the yet unpublished data of the last IWSC 2014 from the main species stronghold, Poland. We assessed the population size and compared its changes with the previous IWSC 2004 in 23% of the country area, including mountains. We looked for potential drivers of trends among land use transformations, checked population changes along altitudinal gradient, and compared the long-term trends in the global, national and regional populations. In 2014, 2560 pairs (3.61 pairs/100 km²) bred in south-western Poland, a decline by 35.5% compared to 2004. Decreases were strongly inversely related to the altitude, i.e. declines in lowlands were twice as high as in the mountains. Changes in area of grasslands, croplands, forests, and built-up areas were all weak predictors of the decline. Stork decrease in south-western Poland contradicts a stable country-wide trend in 2004–2014 (although the latest countrywide data also suggest a decline), which is inconsistent with the increase of the global population. Heterogeneity in trends indicates that Poland could be currently viewed as a transitional area, lying between large breeding areas inhabited by increasing stork populations. Notably, the western border between areas of increases and decreases coincides with the division into two migratory populations suggesting that the heterogeneity of trends may be related to migration paths and wintering grounds. Overall, our data confirm recent range shift of the species, and show difficulties in drawing general conclusions on stork demography based on regional data.