Abstract So far, much effort has been invested in the conservation of vulnerable freshwater habitats, yet their number still displays a decreasing tendency worldwide. Although many species have accepted man-made wetlands, their frequent disturbance may have a negative impact on these species. In this study, we examined the effects of human disturbance on the Great Reed Warbler, Acrocephalus arundinaceus, nesting population in a semi-urban reed habitat (canal) in Sombor, north-western Serbia. We found that Great Reed Warblers avoided nesting in canal sections where humans altered the reed and bank vegetation by cutting and building piers and other objects. The nesting population moved to other, less disturbed canal sections. Despite the disturbance, the breeding parameters, such as brood parasitism, nest predation, nest desertion and nesting success, did not show significant variations. We conclude that human disturbance does not change breeding performance but may cause adult birds to leave the habitat. We suggest that any human disturbance should be limited and carefully undertaken by following governmental rules.

AbstractThe population ecology of the Eurasian BullfinchPyrrhula pyrrhulais almost unknown in Iberia, where the subspeciesiberiaelives. The present study provides a first approach to the population attributes of this subspecies in an area located in northern Spain, characterised by a landscape dominated by hedgerows and meadows. In particular, I analysed the population density, age distribution and sex ratio during a six-year period (2001–2006). By exploring the entire area, I estimated the density in each month, and distinguished males, females and juveniles. In winter, samplings by line transect were also used to obtain abundance indices to compare different days, months and years (1999−2005 period). Density values during the breeding season were similar between years, but winter abundances changed considerably at different temporal scales. A density peak was found in July–August, with the highest percentages of juvenile individuals occurring in August– September. Individuals clearly performing post-juvenile moult were seen during August–November. Sex ratio was markedly biased towards males throughout the year. Several biological and ecological characteristics of the Bullfinch, together with a favourable habitat and small changes of environmental conditions from year to year, seemingly promoted the relatively high stable breeding population densities estimated during the study period. The high variation in winter abundances was likely due to short-medium range movements. The high population density in late summer was a consequence of the addition of juveniles each year. The greater parental effort of females compared to males – since the former are responsible for most of the reproductive tasks and directly suffer considerable predation during incubation – was probably a root cause of the skewed sex ratio.

Abstract The first national Corncrake Crex crex survey in Slovenia was performed in 1992/93, followed by further five in 1999, 2004, 2010, 2015 and 2020. In 2004, annual monitoring of eight most important Corncrake Natura 2000 sites (SPAs) began. Both datasets showed a moderate population decline since 1992. After Slovenia’s accession to the EU in 2004, Corncrake population steeply declined at SPA Breginjski Stol and moderately declined at SPA Dobrava - Jovsi due to scrub encroachment, whereas moderate decline at SPA Ljubljansko barje can be attributed mostly to intensive grassland management and the conversion of grasslands to arable land, resulting in nest and habitat destruction. In 2020, the number of calling males in Slovenia was smaller by 55 % compared to 1999, when the highest number ever was recorded (683). The highest average number of Corncrakes in the 1992–2021 period was counted at SPA Ljubljansko barje (139 calling males/year), whereas the smallest number was recorded at SPA Snežnik - Pivka (8 calling males/year). A comparison of target values for Corncrake population size on individual SPAs from the national Natura 2000 management programme for the 2015–2020 period with counted population sizes showed that, with the exception of SPA Lake Cerknica, all SPAs are falling behind the target values by 32–90%, depending on the site. Likewise, the majority of sites are far from reaching target values for the enrolment of agri-environmental measure VTR (first cut after 1 Aug). The article also discusses the weaknesses of current VTR, its reform in 2021, as well as other potential measures and financial sources for Corncrake conservation.

Abstract The article presents a historical revision of data on the occurrence of the Cream-coloured Courser Cursorius cursor in Slovenia. A review of historical sources revealed that the species occurred in Slovenia at least three times after 1800, for the first time between 27 and 31 December 1847 in Šentvid near Ljubljana (specimen in the collection of the Slovenian Museum of Natural History, Ljubljana, Slovenia), for the second time in November 1892 near St. Janž (present day Starše) on the Drava plain (specimen in the collection of the Joanneum Museum, Graz, Austria) and last on 3 October 1976 at the Sečovlje salt pans (observation was not documented with preserved specimen or photograph). All three data have previously been published in various historical sources, but some were overlooked during the preparation of lists of Slovenian avifauna.

AbstractThe difference in habitat use by the observed waterbird species at Rački ribniki (Rače Ponds, NE Slovenia) was studied between June and August 2011. It was assessed that different waterbird species, even closely related species likeAythyaducks, use wetlands differently, with Tufted DucksA. fuligulaobserved more on Open water and Ferruginous DucksA. nyrocamore often amongst Floating vegetation. The latter was used more often probably due to the abundance of food in the habitat. Highest species richness was recorded on Floating vegetation as well. This was reflected in species richness of individual ponds, where ponds with more floating vegetation had higher species richness. Although CootsFulica atrawere expected to utilize Floating vegetation more often due to their feeding preferences, they were observed more often on Open water probably feeding on fish fodder available there. The difference in habitat use by the families and nonbreeding individuals of the same species was noted, too, mostly by observing families in habitats that provide more cover from predators (Reeds), or more invertebrate food (Floating vegetation) for the young that often feed on different food than adults. Furthermore, it was suggested that overall management of wetlands should consider providing more suitable wetlands with larger aquatic vegetation cover.

AbstractAlthough the Mallard is one of the most numerous and best-studied waterbirds in the world, it received almost no attention in Slovenia. It is one of the most frequently observed waterbirds in our country, with frequency often reaching 100%. Sites with lower frequency either freeze in winter or have a low number of individuals to start with. The Mallard is also the most dominant species (17.5% and 89.0%) with higher dominance at sites less suitable for waterbirds due to the lack of available shoals. Mallards reach their maximum numbers during fall migration and winter. Spring migration has no discernible peak and has been significant only for Lake Cerknica. On shallow waters, the maximum is reached in August and September, a month before fall migration begins, indicating local movement to food-rich sites. Females make up only 36.7% of the observed Mallards and reach the maximum proportion (41.5%) in winter and the lowest in April and May (14.7%), when they nest. The breeding season in Slovenia lasts from mid-January to early December, with the majority of females rearing broods from April to July. Average brood size is 6.2 ± 2.66 and declines with season, age of young and altitude. It varies between habitat types and is highest on Treatment and Coastal Wetlands (7.3) and lowest on deep waters such as Reservoirs (5.7) and Lakes (5.6). No really high breeding densities were found in Slovenia and were similar to those in other countries. Breeding densities are higher on smaller Ponds (< 8 ha), on sites with isolated islands and breeding colonies of gulls and terns (e.g. Lake Ptuj). Breeding density also decreases with elevation. Slovenian breeding population is estimated at 1,473–3,763 bp and wintering population averages 22,237 (10,376–32,010) individuals. Data suggest a decline in the wintering population most likely due to warmer winters. The majority of Mallards winter in NE Slovenia, where eight of eleven sites have a maximum of more than 1,000 Mallards. Most Mallards winter on the Drava river with Ptuj and Ormož lakes, where the highest numbers of Mallards were also recorded (Lake Ptuj: 8,330 ind., Lake Ormož: 5,400 ind.). The highest number of individuals during spring migration was recorded on Lake Cerknica (4,581) and during autumn migration on Medvedce reservoir (3,379). Apart from standing waters, the highest density of wintering Mallards is found in urban sections of slow-flowing rivers, probably due to higher safety and food availability.72,731 Mallards were hunted between 2001 and 2018, mainly in NE Slovenia (28% in the Pomursko hunting management district). The number of Mallards hunted is declining in all hunting areas and has declined by 64% since 2001 and even more since the 1990s. According to hunt data, hunting is by far the most important cause of the Mallard mortality in Slovenia (97.4%), followed by predation (1.1%). The Mallard mortality in Slovenia is largely unstudied and natural mortality is most likely underestimated, not only because it does not include mortality in the pre-fledging period, a period with the lowest survival, but also because the detectability of natural mortality is considerably lower. In contrast to the hunted numbers, there have been only nine recoveries of ringed individuals from abroad in the last 100 years, suggesting that hunters may not be reporting recoveries to the ringing centre. Apart from the 1972–1975 period, when 87% of Mallards were ringed, the intensity of ringing of Mallards in Slovenia is low, resulting in only seven Mallards recovered abroad. The longest distance of a Mallard ringed in Slovenia comes from Ukraine (1,290 km), while the longest distance between ringing and recovery sites is 2,075 km from an individual ringed in Finland. The only colour morphs documented in Slovenia are Mallards with paler feathers, attributed to one of the colour aberrations resulting from lower melanin productivity. Only few hybrids and mixed pairings with other wild duck species were observed.