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Katarina Denac

Census of migrating raptors at Breginjski Stol (NW Slovenia) - the first confirmed bottleneck site in Slovenia

From 4 to 31 May 2010, raptor migration was monitored daily between 9.00 and 17.00 hrs CET at Breginjski Stol (NW Slovenia). In all, 2,385 raptor passes were counted, belonging to at least 17 species that were divided into resident and migratory birds. Residents (n = 875 passes) foraged, bred or daily migrated over the area. Among them, Griffon Vulture Gyps fulvus was the most frequent species (n = 575 passes) with the largest observed group of 35 individuals on 26 May. In the morning, Griffon Vultures were flying from west to east in search of food, whereas in the afternoon they were returning in the opposite direction to their colony in Forgaria nel Friuli (Italy). Their numbers increased after 15 May, when Croatian Griffons joined those from Italy. Altogether, 1,510 individuals of migratory raptors were counted, belonging to at least nine species. Among them, Honey Buzzard Pernis apivorus was the most common (1,368 ind., 90.6% of migratory raptors). The migration peak was reached on 14 May, with 552 individuals. Most raptors were seen migrating solitarily or in small flocks (2-4 ind.), whereas on five days (4, 7, 11, 13, 14 May) over 20% of all observed flocks were either medium-sized (5-15 ind.) or large (> 15 ind.). Raptors mostly migrated between 9.00 and 13.00 hrs. Taking into consideration several factors - short observation period and limited number of observation hours per day, overlooked raptors due to human- and topography-related causes, movements of observers between observation points, extremely bad weather and night migration of raptors - we estimate that the actual number of migratory raptors that passed Breginjski Stol in spring 2010 was 3,060-4,660 individuals. Thus, Breginjski Stol is the first confirmed bottleneck site of European importance for migratory raptors in Slovenia, as defined by BirdLife International IBA criterion B1iv, and a natural continuation of migratory pathways from northern Italy.

Open access

Katarina Denac

Abstract

In 2008, the IUCN uplisted the Curlew to near-threatened (NT) on its Red List. The bird’s population in Slovenia is localised and small, thus making it very important to be surveyed every year. Using the point count method, we recorded 9-12 breeding pairs in 2011 and 9-10 pairs in 2012 at Ljubljansko barje. Most of them were distributed in the eastern part of the area between the village of Lipe and the river Iščica, whereas only two occupied territories were discovered in 2011 and one in 2012 in the western part of the area. In a ten-year period, the area underwent agricultural intensification, with lowland non-intensive meadows declining by 50%. As a minimal requirement, meadows within the extent of the Curlew’s current distribution at Ljubljansko barje should be non-intensively managed (late first cut, no fertilizing or sowing of grass mixtures) and all other human activities prohibited from the beginning of March till the end of June (dog walking and training, ballooning, aircraft modelling). Based on the results of 2011 survey, Ljubljansko barje was designated an IBA for breeding Eurasian Curlews under the IBA criteria A1 and C1.

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Katarina Denac and Tomaž Mihelič

Abstract

The paper summarizes current knowledge on the population size, habitat, conservation status and conservation measures for the White-backed Woodpecker Dendrocopos leucotos in Slovenia. The species is an extremely rare forest specialist species. It inhabits mostly Dinaric beech Fagus sylvatica forests from Trnovski gozd, Nanos, Javorniki Mts and Mt Snežnik to the Kočevsko region and Gorjanci Mts. The species is also present in the Zasavje region and Mt Boč. The majority of the population (80%) inhabits the altitudinal belt between 700 and 1400 m a.s.l. The size of the Slovenian breeding population is currently estimated at 100-150 breeding pairs. Using the new survey playback method, we expect to find the species at additional sites. The highest densities were recorded on Mt Snežnik (0.7 breeding pairs/km2 in the Zatrep - Planinc forest reserve, 0.6 breeding pairs/km2 at Gomance) and in the Gorjanci Mts (0.6-0.9 breeding pairs/km2 in the Kobile forest reserve). The species inhabits beech and mixed forests with an important percentage of dead trees. The volume of dead trees was measured only at few sites inhabited by the species and ranged from 42 to 283 m3/ha. Signs of foraging were detected mainly on beech snags and stumps; all nests were found in upright beech snags. In Slovenia, the species is threatened by the low percentage of dead deciduous trees in forests, the construction of new forest roads, the increased annual timber harvest and a weak network of forest reserves. The proposed conservation measures include increasing the amount of dead deciduous trees in managed forests, increasing the area of forest reserves and halting the construction of new forest roads.

Open access

Katarina Denac, Primož Kmecl, Gregor Domanjko and Damijan Denac

Abstract

Due to numerous bird surveys in the past 20 years, the avifauna of Goričko is relatively well known. For some species, the very first national ecological researches were conducted in this area. The article summarizes all bird surveys so far. It presents population trends of farmland species which is one of the most threatened bird groups in Europe. Most of the qualifying species of this habitat that are protected within the Natura 2000 network have suffered a decline at Goričko, specifically Quail Coturnix coturnix, Scops Owl Otus scops, Hoopoe Upupa epops, Woodlark Lullula arborea and White Stork Ciconia ciconia. The number of breeding pairs of the latter has not changed, but its fecundity has decreased. Furthermore, populations of other farmland bird species have decreased, for example Skylark Alauda arvensis, Stonechat Saxicola rubicola, Serin Serinus serinus and Common Linnet Linaria cannabina, as well as butterfly populations and tracts of grassland habitat types. National agricultural and nature conservation policies are evidently inefficient in protecting the biodiversity of Goričko. The most probable cause for bird population decline is agricultural intensification, which manifests itself at Goričko as disappearance and intensification of meadows, land consolidation, degradation of traditional orchards and use of pesticides. As a result of land consolidation hedges, uncultivated strips between fields, individual trees and bushes and minority habitat types are disappearing, whereas the surface of arable fields is increasing. Nature conservation measures performed by the Public Institute Goričko Nature Park with the support of DOPPS – BirdLife Slovenia volunteers seem to be efficient, but are spatially and temporally constrained. For this reason, they cannot serve as a substitute for insufficient systemic financing which could be improved by substantive and financial reform of the agri-environmental scheme. Currently, a negligible percentage (1% in 2016) of Goričko is covered by agrienvironmental scheme measures with positive influence on qualifying species and habitat types. As a consequence, only an insignificant share of subsidies from the Rural Development Plan is used for nature protection at Goričko. If the system of agricultural subsidies remains unaltered, no improvement of the conditions for bird conservation at Goričko can be expected.

Open access

Al Vrezec, Dare Fekonja and Katarina Denac

In 2014, 162 bird species were recorded during the bird ringing activities in Slovenia. Of 155 species, 62,275 birds were ringed, and 107 recoveries of birds ringed in Slovenia and found abroad, 148 foreign recoveries in Slovenia and 1395 local recoveries were recorded. The most frequently ringed species were Blackcap Sylvia atricapilla and Great Tit Parus major. As far as ringed nestlings are concerned, Great Tits and Barn Swalllows Hirundo rustica predominated. Considering the recoveries ringed of found birds abroad, the commonest were Black-headed Gulls Chroicocephalus ridibundus and Mute Swans Cygnus olor. The farthest recovery was a Barn Swallow Hirundo rustica found in the Democratic Republic of Congo (5171 km away). Among the more interesting finds was also the so far southernmost recovery of a Sand Martin Riparia riparia found in Israel. Let us also mention the first recovery of a Corncrake Crex crex, which bred and was ringed in 2013 at Planinsko polje (central Slovenia) and was found in the 2014 breeding season in the Czech Republic. Among rare species, two Little Buntings Emberiza pusilla were caught and ringed. After nine years, the Roller Coracias garrulus bred again in Slovenia in 2014 and its nestlings were ringed. The paper also brings the description of the migration route of the first African migrant, the Black Stork Ciconia nigra, marked with a GPS/GSM telemetric device, which migrated across the Adriatic Sea, Sicily and Sahara to Nigeria.