Gniježđenje gavrana Corvus corax na stupovima dalekovoda u Baranji

The Common Raven is a habitat generalist breeding throughout forested and open regions of the Northern Hemisphere. The species has undergone a large increase over the last 40 years in Europe. In the same period, it has begun to nest on pylons of the transmission lines; nowadays, it is a common phenomenon in Europe, including the eastern lowland areas of Croatia. In this study, surveys of the Common Raven nests were conducted on eight power lines in the area of Baranya in Eastern Croatia in 2006 and 2016 respectively. In 2006, 23 active Common Raven nests were found along seven power lines, while in 2016, 37 nests were recorded on eight lines, with a population increase of 60.9%. The average breeding density in 2016 was 3.3 pairs per 10 km of line, while the average frequency of occupied pylons was 10.2%. The mean distance between neighbouring nests amounted to 3128 m, and the distribution of nests along the power lines was probably affected by food availability. The majority of pylons supporting a Common Raven nest was placed in open agricultural areas (81.1%). Power lines proved to be important landscape elements in the avian conservation point of view.Gavran nastanjuje raznolika šumska i otvorena staništa širom sjeverne polutke. Tijekom posljednjih 40 godina populacija vrste u Europi je značajno porasla i istovremeno su se počeli gnijezditi na stupovima dalekovoda. Danas je ova pojava opće poznata po Europi, Sjevernoj Americi i Aziji, uključujući i istočne ravničarske krajeve Hrvatske. Prvi slučaj gniježđenja gavrana na stupu dalekovoda zabilježen je krajem 80-tih godina 20. stoljeća u Istočnoj Slavoniji. Ovaj rad prikazuje rezultate istraživanja gavrana koji se gnijezde na osam linija dalekovoda na području Baranje. Tijekom 2006. godine na ukupno sedam dalekovoda zabilježeno je gniježđenje 23 para gavrana, dok je 2016. godine na osam dalekovoda nađeno ukupno 37 aktivnih gnijezda. Velik porast populacije (60,87%) uzrokovan je gradnjom novog dalekovoda čije su stupove gavrani vrlo brzo zauzeli. Na većini ostalih dalekovoda populacija gavrana se stabilizirala. Prosječna gustoća gniježđenja tijekom 2016. godine dosegla je 3,27 parova/10 km dalekovoda što je najveća dosad zabilježena gustoća u Europi i svijetu. Prosječna zauzetost stupova tijekom 2016. godine bila je 10,24%, dok je srednja udaljenost između susjednih gnijezda iznosila 3128 m. Raspored gnijezda na dalekovodima nije ujednačen, već vrlo vjerojatno ovisi o mozaičnosti staništa i sukladno tome, o količini raspoložive hrane. Kao i drugdje u svijetu, u Baranji je većina gnijezda nađena na stupovima smještenim na otvorenim poljoprivrednim staništima (81,08%). Iako dalekovodi često uzrokuju ugibanje ptica putem sudara ili elektrokucije, njihovi stupovi mnogim vrstama također predstavljaju važna alternativna mjesta za gradnju gnijezda, čime doprinose povećanju bioraznolikosti, osobito u intenzivno obrađivanim poljoprivrednim područjima. Gavrani i sive vrane najčešće su gnjezdarice stupova u Hrvatskoj, a njihova prazna gnijezda često zauzimaju vjetruše i sokolovi lastavičari, te ponekad stepski sokolovi. Stoga, dalekovodi svakako imaju važnu ulogu u zaštiti i opstanku strogo zaštićenih grabljivica te je potrebno posvetiti više pažnje njihovom redovitom istraživanju

Observation of the Waxwings Bombycilla garrulus in Osijek and Baranja in the winter of 2005/2006

In Osijek and Baranja, Waxwings were observed 15 times in the period between 12th January and 21st March 2006. Their number fluctuated between 2 and 180 specimens. On 16th and 17th February the flock of 180 individuals was intensively singing on the trees and feeding with Viscum album and Sophora japonica fruits

Observation of the Waxwings Bombycilla garrulus in Osijek and Baranja in the winter of 2005/2006

In Osijek and Baranja, Waxwings were observed 15 times in the period between 12th January and 21st March 2006. Their number fluctuated between 2 and 180 specimens. On 16th and 17th February the flock of 180 individuals was intensively singing on the trees and feeding with Viscum album and Sophora japonica fruits

Spring migration of waterbirds on a temporary pool near Darda village

During the springs of 2015 and 2016 the waterbird fauna of a temporary pool was studied on agricultural field near Darda village in Baranya. In the two years of research, a total of 19 waterbird species was detected, of which 10 species belonged to Charadriiformes, 5 species to Ciconiiformes, and 4 species to Anseriformes. The spring migration of waterbirds on the pool reached its height in the second half of April, but most species were seen in early May. The three most abundant species were: Wood Sandpiper Tringa glareola, Blackwinged Stilt Himantopus himantopus, and Mallard Anas platyrhynchos. The most interesting is the first observation of Common Shelduck Tadorna tadorna in the area of Darda municipality, and the occurrence of Eurasian Spoonbill Platalea leucorodia that very rarely lands in Baranya outside Kopački rit Nature Park. Results of this study indicate the great importance of periodic pools in agricultural habitats as stopover sites for migrating waterbirds, especially for shorebirds

Spring migration of waterbirds on a temporary pool near Darda village

During the springs of 2015 and 2016 the waterbird fauna of a temporary pool was studied on agricultural field near Darda village in Baranya. In the two years of research, a total of 19 waterbird species was detected, of which 10 species belonged to Charadriiformes, 5 species to Ciconiiformes, and 4 species to Anseriformes. The spring migration of waterbirds on the pool reached its height in the second half of April, but most species were seen in early May. The three most abundant species were: Wood Sandpiper Tringa glareola, Blackwinged Stilt Himantopus himantopus, and Mallard Anas platyrhynchos. The most interesting is the first observation of Common Shelduck Tadorna tadorna in the area of Darda municipality, and the occurrence of Eurasian Spoonbill Platalea leucorodia that very rarely lands in Baranya outside Kopački rit Nature Park. Results of this study indicate the great importance of periodic pools in agricultural habitats as stopover sites for migrating waterbirds, especially for shorebirds

The first nesting attempt of the Common Redshank, Tringa totanus, in the Kopački rit Nature Park

We have described the first nesting attempt of the Common Redshank Tringa totanus in the Kopački rit Nature Park. Four adults were observed feeding in the Podunavlje fishponds within the Park’s border on 19th April and 7th May. On 10th May, a singing male was observed at the same spot – a small island formed in the middle of a pond, together with two incubating pairs of Black-winged Stilts Himantopus himantopus, and four, presumably breeding, Lapwings Vanellus vanellus pairs. Unfortunately, heavy rains in May caused an increase in the water level, so that the island was flooded and the breeding interrupted

The first nesting attempt of the Common Redshank, Tringa totanus, in the Kopački rit Nature Park

We have described the first nesting attempt of the Common Redshank Tringa totanus in the Kopački rit Nature Park. Four adults were observed feeding in the Podunavlje fishponds within the Park’s border on 19th April and 7th May. On 10th May, a singing male was observed at the same spot – a small island formed in the middle of a pond, together with two incubating pairs of Black-winged Stilts Himantopus himantopus, and four, presumably breeding, Lapwings Vanellus vanellus pairs. Unfortunately, heavy rains in May caused an increase in the water level, so that the island was flooded and the breeding interrupted

Contribution to the knowledge of the autumn migration of shorebirds Charadriiformes in the Vransko Lake Nature Park

The Vransko Lake Nature Park is an internationally important area for waterbirds. Its avifauna has been well studied, with a total of 261 species recorded. In times of low water level, it provides good feeding and resting habitats for a number of shorebirds (36 species recorded up to date). The dry summer of 2017, with an extremely low water level, resulted in extensive muddy and rocky shores appearing in north-western part of the lake, in the area of Special ornithological reserve. In the period between 14 and 19 August 2017, regular counts of shorebirds were carried out on a stretch of about 1 km of muddy lakeshore. This resulted in the observation of 21 species, with daily maximum numbers ranging from 31 to 53 individuals of shorebirds. The most common species were Sandpipers Tringa spp. and Calidris spp., Plovers Charadrius spp. and the Lapwing Vanellus vanellus. Some of the more rare or irregular passage migrants were observed too: 1 Broad-billed Sandpiper Calidris falcinellus, 3 Ruddy Turnstones Arenaria interpres, 2 Kentish Plovers Charadrius alexandrinus and 1 Temminck´s Stint Calidris temminckii. In late August, other observers saw another irregular species – a juvenile Red Knot Calidris canutus. Although the total number of observed individuals of shorebirds is relatively low, the area is undoubtedly an important stopover site for a large number of species during their migration from northern Europe and Siberia towards Africa

The wintering of Bewick’s Swans Cygnus columbianus in Kopački rit

During a regular bird monitoring on Podunavlje fishponds, Kopački rit Nature Park, between 4th December 2004 and 22nd January 2005 authors observed three Bewick’s Swans. Three adult Bewick’s Swans were wintering in the area at least 50 days when they were observed for 8 times. After 22nd January 2005 authors could not find Bewick’s Swans despite regular monitoring suggesting that the birds left the area. The main reason was probably the weather condition, since after that date a long cold period, with snow and low air temperatures (–20 °C) started

The wintering of Bewick’s Swans Cygnus columbianus in Kopački rit

During a regular bird monitoring on Podunavlje fishponds, Kopački rit Nature Park, between 4th December 2004 and 22nd January 2005 authors observed three Bewick’s Swans. Three adult Bewick’s Swans were wintering in the area at least 50 days when they were observed for 8 times. After 22nd January 2005 authors could not find Bewick’s Swans despite regular monitoring suggesting that the birds left the area. The main reason was probably the weather condition, since after that date a long cold period, with snow and low air temperatures (–20 °C) started