Time filter

Source Type

Shurulinkov P.,National Museum of Natural History Sofia | Chakarov N.,Bielefeld University | Daskalova G.,Bulgarian Society for the Protection of Birds
Parasitology Research | Year: 2012

Blood parasites of migrating yellow wagtails of two subspecies - Motacilla flava feldegg and Motacilla flava flava - were studied on a sample of 473 birds caught in spring and autumn periods in Bulgaria. We controlled eight "migration waves" (flocks captured in different evenings) of yellow wagtails for four parameters - average body mass, average fat level, average wing length, and average prevalence of different hematozoan species. Gametocytes or meronts of a total of six species of hematozoa belonging to three genera were identified - Haemoproteus motacillae, Haemoproteus anthi, Plasmodium relictum, Plasmodium subpraecox, Plasmodium cathemerium, and Tryponosoma avium. Mixed infections were detected in 31 cases, of which 14 were of H. anthi/H. motacillae type. Parasite species composition was similar in the two studied subspecies of M. flava. We did not find any significant differences in the overall infection prevalence or number of infecting parasites between M. f. flava and M. f. feldegg. Parasite prevalence and the number of co-infecting parasites in spring were much higher than in fall. Season had a strong influence on the prevalence of H. anthi and H. motacillae, and for both, there was a marginally significant interaction between subspecies and season, but not a seasonindependent influence of subspecies. Males of M. f. feldegg had a significantly higher overall blood parasite prevalence and prevalence of H. anthi than females. Sex-related differences in the prevalence of other parasites were not significant. Migration waves of yellow wagtails differed in overall infection status and in H. motacillae prevalence, but not for H. anthi prevalence. We also found significant differences in fat score, weight, and wing length between the studied migration waves of the yellow wagtails. Fat scores of birds infected with different hematozoa were lower compared with those of the non-infected birds. This only marginally was true for body weight and was not the case for wing length. Overall, infected birds were in worse condition (estimated as the residual weight after regression with wing length) compared with the non-infected birds, but after controlling for seasonal effects, the differences in condition appeared to be due to migration season and did not significantly differ between infected and non-infected birds caught in the same season. © Springer-Verlag 2012.

Mateo R.,Institute Investigacion en Recursos Cinegeticos IREC | Petkov N.,Bulgarian Society for the Protection of Birds | Lopez-Antia A.,Institute Investigacion en Recursos Cinegeticos IREC | Rodriguez-Estival J.,Institute Investigacion en Recursos Cinegeticos IREC | Green A.J.,CSIC - Doñana Biological Station
Environmental Research | Year: 2016

The red-breasted goose Branta ruficollis is a globally threatened species (IUCN Vulnerable) and the only European goose species currently in decline. Working on the wintering grounds on the Black Sea Coast, we address two potential causes of decline of this species for the first time: lead poisoning, and contamination from pesticides. We quantified the densities of spent Pb shot in three wetlands used by the geese in north-east Bulgaria, and analysed the Pb concentration in the faeces of red-breasted geese and the more abundant greater white-fronted geese Anser albifrons, using Al concentration as an indicator of soil ingestion. Pb shot densities in sediments were low, and we found no evidence for Pb shot ingestion in red-breasted geese. On the other hand, we found that the geese were feeding on wheat whose seeds were treated with four fungicides: thiram, tebuconazole, difenoconazole and fludioxonil, and the two first were even detected in geese faecal samples. Using data on the daily food intake, we estimated the exposure levels of the geese to these fungicides, both by measuring the concentrations remaining on seeds and by estimating the amount used to coat the seeds at the time of sowing. We found that the exposure rates estimated during the sowing period for both geese species can exceed the recognized hazardous doses for thiram, and to a lesser extent for tebuconazole, which indicates that some pesticides may be playing a previously overlooked role in the decline of red-breasted geese. © 2016 Elsevier Inc.

Demerdzhiev D.,Bulgarian Society for the Protection of Birds | Dobrev V.,Bulgarian Society for the Protection of Birds | Popgeorgiev G.,Bulgarian Society for the Protection of Birds
Acta Zoologica Bulgarica | Year: 2014

The conversion of pastures into arable lands has led to the decrease in the populations of many bird species throughout Europe. We evaluated the effect of land conversion on the distribution and breeding parameters of the Long-legged Buzzard, a medium-sized SE-European bird of prey, which is potentially vulnerable to these landscape changes. We mapped the distribution of this species in Besaparski Ridove Special Protection Area (southern Bulgaria) in 57 study plots in 2007 and 2011. The productivity in 2011 was 24.56% lower than in 2007. The breeding success was 59.31% lower during the second study period than in 2007. The success rate decreased by 29.87%. The density of breeding pairs was 9.6 pairs/100 km2 in 2007 and 4.8 pairs/100 km2 in 2011. Significant changes in the study area were found in arable lands, orchards and vineyards as well as in several types of grasslands. A significant reduction of the areas of all categories of grasslands was observed. High positive correlation was observed between occupied territories and the area of quarries, grasslands, shrubs, grassland with single trees, and grassland with shrubs < 25%. Strong negative correlation existed between occupied territories and urban areas, arable lands and waters. The parameters of the breeding success were in a positive correlation with quarries, shrubs, forests, groups of trees, grasslands, grasslands with single trees, grassland with < 25% shrubs and Habitat diversity index (H'). A negative correlation existed between the breeding success and urban areas, arable lands, orchards and vineyards, waters and grassland with > 25% shrubs.

Tzonev R.T.,Sofia University | Gussev C.V.,Bulgarian Academy of Science | Popgeorgiev G.S.,Bulgarian Society for the Protection of Birds
Acta Zoologica Bulgarica | Year: 2014

Ten types of non-forest habitats according to Directive 92/43/EEC (4060, 5130, 6210, 6230, 62A0, 6410, 6510, 6520, 7140 and 8210) are identified and map in Ponor Special Protection Area (included in Natura 2000 network). The conservation status of the habitats 4060, 62A0, 6230 and 6210 was assessed as "Favorable". On the other hand, the conservation status for the habitats 5130, 6520, 6410 and 7140 was evaluated as "Unfavourable - inadequate". The status of the habitats 6210 and 6510 were assessed as "Unfavourable - bad". The threats to the habitats also are identified. The main reasons leading to the unfavourable assessment are the overgrazing, invasion of shrub and trees after their abandonment, changes in the water regime. Some recommendations for the improvement of the conservation status are made for every habitat type. The habitat "6520 Mountain hay meadows" has the widest distribution (8101.455 ha) and is rich of some orophytic relic plants like Artemisia chamaemelifolia, Hypericum linarioides, etc. Relict steppes which have been widespread in Bulgaria during the ice age, are preserved in Ponor Mt. due to the specific geological and climatic characteristics. The areas are characterized by exceptional biodiversity (flora, fauna, plant communities and habitats) and its protection is essential to the conservation of biodiversity in the Balkans and Europe.

Tzonev R.T.,Sofia University | Gussev C.V.,Bulgarian Academy of Science | Popgeorgiev G.S.,Bulgarian Society for the Protection of Birds
Acta Zoologica Bulgarica | Year: 2014

Within the territory of Besaparski Hills Natura 2000 site, four types of non-forest habitats (5210, 6210, 62A0 and 6220) were identified. The habitats were mapped and their conservation status was assessed. The conservation status of habitats 6210, 62A0 and 6220 were assessed as "Unfavourable inadequate", while habitat 5210 was assessed as "Favourable". The main threats for the habitats are the development of new quarries, overgrazing, ploughing of grasslands. The habitat 62A0 "Eastern sub-Mediterranean dry grasslands" is the most widespread in the site and it also has an important role for the preservation of the populations of rare animals (including birds) as well as of endemic and protected plants. This study highlights the importance of Besaparski Ridove Special Protection Area for the nature conservation in Bulgaria, especially with its richness of petrophytic steppes. Their protection is essential to the conservation of the biodiversity not only at the national level but also as representative habitats for the Balkans and Europe.

Demerdzhiev D.A.,Bulgarian Society for the Protection of Birds
Acta Zoologica Bulgarica | Year: 2014

A total of 184 species of birds belonging to 17 orders were recorded in Besaparski Ridove Special Protection Area. Ninety-nine species are of European conservation concern (SPEC); 10 of them fall under the category SPEC 1, 23 as species threatened in Europe (SPEC 2) and and 48 as SPEC 3. Twelve of the recorded species are globally threatened, 6 of are near threatened, 4 are classified as vulnerable and 2 species are endangered. The area is of global significance for the conservation of the globally threatened Eastern Imperial Eagle (Aquila heliaca) and one of the most important territories of European significance in Bulgaria for the breeding Tawny Pipit (Anthus campestris), Long-legged Buzzard (Buteo rufinus) and Calandra Lark (Melanocoryphacalandra). A decline was recorded in species such as Common Buzzard (Buteo buteo), Grey Partridge (Perdix perdix), Black-eared Wheatear (Oenanthe hispanica) and Lesser Grey Shrike (Lanius minor), while an increase was recorded in the populations of Stone Curlew (Burhinus oedicnemus) and European Bee-eater (Merops apiaster).

Popgeorgiev G.,Bulgarian Society for the Protection of Birds | Tzankov N.,Bulgarian Academy of Science | Kornilev Y.,Bulgarian Society for the Protection of Birds | Plachiyski D.,Bulgarian Society for the Protection of Birds | And 2 more authors.
Acta Zoologica Bulgarica | Year: 2014

After 2007, the Bulgarian farmers have started benefiting from the newly available agro-environmental schemes through the European Union, which have promoted significant landscape changes. However, the impact on the local environment and the herpetofauna is yet to be determined. This has prompted us to undertake a comparative study on the changes in the area of habitats in a biodiversity hotspot, Besaparski Ridove Special Protection Area, between 2006 and 2010. We mapped 584 new exact localities of 25 species of herptiles from this site, doubling the previously known localities. Herptiles were detected in 85% of the squares of the 2×2 km UTM grid. Pastures and natural grasslands have decreased by roughly 9%, on account of the increase of non-irrigated and permanently irrigated arable lands; open pastures have decreased by 51%. The most important habitats for the herpetofauna include water bodies, various kinds of pastures and natural grasslands (Chao1 index for expected diversity of species per habitat ≥ 12). Industrial or commercial units and permanently irrigated lands are the least viable habitats (Chao1 ≤ 5). Inevitably, loss of suitable habitats through agriculture negatively impacted species, including those of high conservation value: e.g. Elaphe sauromates, Testudo hermanni and Eryx jaculus. Therefore, the conservation of species and habitats might need re-assessment and more stringent national criteria than those enacted by the reformed Common Agricultural Policy (2014-2020).

Popgeorgiev G.S.,Bulgarian Society for the Protection of Birds | Tzankov N.D.,Bulgarian Academy of Science | Kornilev Y.V.,Bulgarian Society for the Protection of Birds | Naumov B.Y.,Bulgarian Academy of Science | Stoyanov A.Y.,Bulgarian Academy of Science
Acta Zoologica Bulgarica | Year: 2014

We present the first comprehensive review of the diversity of the herpetofauna of the Natura 2000 site Ponor Special Protection Area. We compiled data from 22 publications covering 20 species and carried out multiple field visits between 1998-2012, recording 375 locations confirming all previously reported species and reporting four new species. These are Hyla arborea complex, Bufotes viridis complex, Coronella austriaca and Zamenis longissimus; we exclude Anguis fragilis complex due to recent taxonomic changes in this group. The presence of three additional potential species (Emys orbicularis, Testudo hermanni and Darevskia praticola) remains to be confirmed. All collected localities fall within 60 of 113 2×2 UTM squares, providing > 53% coverage. The elevation ranges for the species generally conform with their expected distributions in Bulgaria. Nine habitat types are of particular importance for the herpetofauna in Ponor Special Protection Area (Shannon diversity index H' = 2.00), containing 77% of the locations for the observed species and 100% of the species. Four are either open habitats with high level of naturalness or small-scale extensive agricultural lands and four are natural broad-leaf forests. The currently obtained herpetological data can be used in the development of future management plans for this protection area and should be included in the update of the Natura 2000 Standard Data Form. Ponor Special Protection Area is demonstrated as a site of substantial local importance for the conservation of amphibian and reptile communities.

Shurulinkov P.,Bulgarian Academy of Science | Daskalova G.,Bulgarian Society for the Protection of Birds | Ralev A.,Balkani Wildlife Society | Elenkova V.,Balkani Wildlife Society
Acta Zoologica Bulgarica | Year: 2010

First separate breeding colony of White-winged Tern (Chlidonias leucoptera TEMMINCK, 1815) in Bulgaria was discovered in Chairya marsh, in the northeastern parts of the country. Until present separate nesting pairs of this species were found on rare occasions in large colonies of Whiskered Tern (Chlidonis hybrida). We estimated that in the colony nested about 55-60 pairs of White-winged Tern. The colony was found in the deepest part of the marsh where the water vegetation was dense, consisting mainly of Rorripa amphibia. The average dimensions of the nests were as follows: average maximal outer diameter: 17.3 cm (15.0-19.0 cm) (n=13); average minimal outer diameter: 16.2 cm (13.5-18.0 cm) (n=13); average inner diameter: 11.2 cm (10.0-12.0 cm); average height of the nest: 4.65 cm (3.0-6.0 cm), (n=10). The average distance between two nests was 31.6 m (n=15), varying between 3 and 93 m. The average clutch size calculated in the third decade of May was 2.65 eggs/per nest (n=23). The average dimensions of White winged Tern eggs were as follows (n=27): length: 34.99 mm (31.5-37.2 mm); width: 25.53 mm (23.8- 27.2 mm). In six out of 16 found nests on 5 June 2010 we encountered hatchlings. Most of the hatchlings already jumped from the nests and swam very well. We determined that the incubation in the colony had started around 12-16 May 2010. Most probably the extremely high water level in Chairya marsh during spring and summer of 2010 was the key factor for the creation of this new White-winged Tern colon.

Radovic A.,University of Zagreb | Nikolov S.C.,Bulgarian Society for the Protection of Birds | Tepic N.,National Center for External Evaluation of Education | Mikulic K.,Association BIOM | And 2 more authors.
Folia Zoologica | Year: 2013

The abandonment of less productive agricultural land and the intensification of agricultural land use are the main features of the Common Agricultural Policy (CAP) that Croatia will enforce now as new member of the EU. Due to demographic changes and the economic transition in Croatia resulting from war in the 1990s, substantial tracts of agricultural land were abandoned. We investigated two habitat types in the protected floodplain landscape of Lonjsko polje in the continental part of the country: arable land and pastures. Both habitats were maintained by agricultural management and suffered from partial abandonment. Land abandonment increased the susceptibility to encroachment by the invasive plant species Amorpha fruticosa. Data on bird communities were obtained during the breeding season in 2010 while there were high water levels in the floodplain. Data were collected from 63 points, and a total of 1447 individuals from 70 species were recorded during the study. We found that the bird community structure was primarily related to the presence/abandonment of agricultural land use and the habitat type. Further, we detected that the bird community structure in the same habitat type differed by management intensity. Open habitat specialists were most influenced by land abandonment. However, the conservation value (according to the Species of European Conservation Concern value, SPEC) of grazed pastures and abandoned pastures did not differ significantly, in part because the overgrown pastures with high water levels were found to be suitable for Acrocephalus species. The shift in bird community structure between abandoned and managed arable lands were smaller than those detected in the pastoral communities. Because land abandonment is a widespread phenomenon in Croatia, we emphasize the urgent need for a nationwide monitoring program for farmland birds to register the resulting changes in farmland bird communities and to develop appropriate agri-environment measures to mitigate the process.

Loading Bulgarian Society for the Protection of Birds collaborators
Loading Bulgarian Society for the Protection of Birds collaborators