Although 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.
Grassland birds were surveyed in two mountain pastures (Zaprikraj and Zapleč) in the southern part of the Julian Alps, Slovenia. The survey was carried out during the mornings between 26 and 30 June ...2005. Due to the incomplete survey (only one visit, no nocturnal or targeted surveys and late season survey), the surveyed birds’ breeding density is only a rough estimate. 167 pairs belonging to 12 species were counted, with Tree (average density of 1.64 p/10 ha) and Water Pipit (average density of 1.60 p / 10 ha) being the most abundant. Both were observed in all altitudinal belts. The highest density in individual altitudinal belt was calculated for Red-backed Shrike
(3.78 p/10 ha) and Water Pipit (3.61 p/10 ha). In well preserved grasslands in the study area, most species reached high breeding densities compared to other parts of Slovenia and all were recorded higher than during the 1992 survey, although still mostly within limits of the elevations elsewhere in Slovenia. Breeding density of Skylark
decreased with the elevation. Whinchat
, Skylark and Red-backed Shrike used significantly gentler slopes, while Pipits showed no preference for particular slopes.
Abstract Between 1984 and 2017, 1,388 Black Kites were recorded, mostly in lowlands with 70% of observations made at Dravsko polje. They were observed from sea level to around 1,600 m a.s.l. with an ...average elevation of 271 m a.s.l. The species was present in Slovenia from mid-March to early December with indistinct spring and autumn migrations. The highest number of observations was recorded in May. The Black Kite was observed in 71 out of 238 10x10 km grid squares in Slovenia (29.8%), with more observations around known breeding sites and at sites with higher observer effort. Both the number of observations and the number of probable and confirmed breeding pairs increased. In 2011–2018, 10 breeding pairs were found at 7 sites (3–7 per year). Additionally, 11 probable breeding pairs at 9 sites (0–6 pairs per year) were found. The breeding population in 2011–2018 is estimated at 10–21 pairs with an average breeding density of 0.3–0.9 breeding pairs per 100 km 2 . The highest density was recorded at Dravsko polje with 0.6–2.2 breeding pairs per 100 km 2 . If possible breeding (breeding attempts) were also taken into consideration, the estimate would be up to five breeding pairs higher. The species was recorded at known breeding sites in most years after the breeding was confirmed. Black Kites were observed closer to larger water bodies and to rubbish tips than expected by chance. More Black Kites were recorded in areas with a lower percentage of forest and arable land and a higher percentage of meadows, settlements and wetlands.
The 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 like
ducks, use wetlands differently, with Tufted Ducks
observed more on Open water and Ferruginous Ducks
more 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 Coots
were 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.
Abstract
The Red Kite Milvus milvus breeds alomost exclusively in Europe, its population is in decline. In the past, it was regarded as a rare migrant in Slovenia. In the 1990s it was classified as a ...possible breeder, extremely rare winter guest with more observations during migration. Between 1977 and January 2017 117 records of 121 individuals were gathered. Most (113) involved single birds on migration. Exceptionally, birds were present for a longer period - a single record of a summering bird is known. Since 1980 the number of birds per year increased from 1 to 1.1, 3 and 9 after 2009. Possible reasons are increased awareness and population increases to the north and northeast of Slovenia. Red Kites were observed throughout the year with the lowest numbers during summer and winter, which surprising, because the species is increasingly common during winter in central Europe. Migration of Red Kites in Slovenia begins in February with a peak in early April and May and between August and mid-November with a peak in early in October. The migration period coincides with arrivals and departures from breeding grounds. Red Kites have been observed all across the country, with more observations at well-watched sites. Birds were observed between sea level and 1740 m a.s.l. with only a handful of observations above 1000 m a.s.l.
Artificial feeding is a widely used management tool, but it often attracts nontarget species, including birds, to permanent feeding sites. This study used camera traps to monitor the presence of ...birds at selected sites used for bear management in Dinaric forest. A large number of bird species (35) were recorded, representing roughly half of all species breeding in the surrounding area. These species were grouped based on monthly and hourly presence, and corresponded to food groups, with most belonging to granivores or scavengers. Some species, such as Pigeons (Columba sp.), Raven (Corvus corax) and Buzzard (Buteo buteo), adapted their presence to the availability of food at the feeding sites, while others were not affected by this. Both Chaffinches (Fringilla coelebs) and Jays (Garrulus glandarius) frequented the feeding sites, but their temporal presence was influenced by their biology rather than by food availability. The Sparrowhawk (Accipiter nisus) also adapted its presence to food availability, and its presence was closely associated with that of the Jay. This study confirms the temporal differences in the use of feeding sites by birds and mammals, which is likely due to their different biology and past management. This can be used to make wildlife management more efficient and reduce the undesirable effects of artificial feeding.
Artificial feeding is a widely used management tool, but it often attracts nontarget species, including birds, to permanent feeding sites. This study used camera traps to monitor the presence of ...birds at selected sites used for bear management in Dinaric forest. A large number of bird species (35) were recorded, representing roughly half of all species breeding in the surrounding area. These species were grouped based on monthly and hourly presence, and corresponded to food groups, with most belonging to granivores or scavengers. Some species, such as Pigeons (Columba sp.), Raven (Corvus corax) and Buzzard (Buteo buteo), adapted their presence to the availability of food at the feeding sites, while others were not affected by this. Both Chaffinches (Fringilla coelebs) and Jays (Garrulus glandarius) frequented the feeding sites, but their temporal presence was influenced by their biology rather than by food availability. The Sparrowhawk (Accipiter nisus) also adapted its presence to food availability, and its presence was closely associated with that of the Jay. This study confirms the temporal differences in the use of feeding sites by birds and mammals, which is likely due to their different biology and past management. This can be used to make wildlife management more efficient and reduce the undesirable effects of artificial feeding.
The main aim of this study was to investigate which weather parameter has greater influence on nest abandonment in the Great Tit Parus major, temperature or rain, and to determine during which ...breeding period nests are the most susceptible to abandonment. Breeding parameters of a nest-box population in Slovenia were monitored over a three year period at two locations in three altitude belts. Weather parameters were measured daily. From 160 first nesting attempts, 35 nests were abandoned. The majority of abandoned nests were found during the incubation period, followed by the first half of the nestling period. The amount of rainfall was more important than temperature in explaining variation in nest abandonment.
Abstract Migration poses a high risk to birds. Crossing of large bodies of water is especially demanding for land birds. One of the dangers faced by migrants are opportunistic predators like gulls. ...Most gulls Laridae are generalist predators with omnivorous diets. Attacking on migrating birds was investigated during ground observations of bird migration at Ada Island (S Montenegro) between 17 Mar and 10 Apr 2015. We recorded 20 attacks on 22 individuals of six species and on one unidentified passerine. In four instances gulls attacked birds of prey, in two Hoopoe Upupa epops and in 16 passerines. Except for two cases when small flocks of two birds were attacked, gulls attacked individuals migrating singly. Considering our data around one percent of passerines migrating during the day across the southern Adriatic Sea can expect to be attacked by gulls. This percentage can be as high as 9.5% for passerines migrating singly.
Spring migration of birds, particularly waterbirds and raptors, was monitored from dawn till dusk from an observation point located on the levee on the northern side of the Medvedce reservoir ...(Dravsko polje, NE Slovenia) in three separate years (1-17 Mar 2009; 25 Mar-10 Apr 2011; 28 Feb-12 Apr 2012). In all three years, 42,045 individuals of 89 species (66 waterbirds, 23 raptors) migrated over the site. 38,238 of these were waterbirds. The most numerous species was Lapwing Vanellus vanellus (11,813 individuals), followed by Blackheaded Gull Chroicocephalus ridibundus (10,515 individuals). In total, 3807 migratory storks, raptors and Cranes Grus grus were counted. Harriers (2303 individuals) were by far the most numerous group. The prevailing direction of migration was SW-NE. Half of all migrating birds were observed in the altitudinal belt between 10 and 100 m above ground level. Harriers were mostly observed up to 100 m above ground level, whereas storks, other raptors and Cranes were observed most often in the altitudinal belt between 100 and 500 m above ground level. The highest numbers of waterbirds were observed between 10 and 100 m above ground level. In the first five hours after sunrise, 61.3% of all waterbirds, 44.0% of all storks and raptors and only 20.5% of Cranes were observed. Although other parts of Dravsko polje have never been studied in such detail, it is possible that a significant portion of migrating birds from a larger area gathers at this site. This study confirms the importance of the area for migrating and staging birds, especially for Great Egret Ardea alba, Marsh Circus aeruginosus and Hen Harriers C. cyaneus, Osprey Pandion haliaetus, Crane, Ruff Calidris pugnax and Black-headed Gull that all reached at least 0.1% of their respective biogeographic populations. Internationally significant are particularly the numbers of migrating Marsh (1079 individuals in 2012) and Hen Harriers (408 individuals in 2012), as there are only few sites where these species migrate in such high numbers in spring.
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