Siniša Ozimec

Heavy metal concentrations in the liver of two wild duck species: influence of species and gender

Abstract The risk of wild ducks exposure to heavy metals in the environment was assessed by analyzing 20 wild ducks shot in the hunting area at the fish farm in Donji Miholjac, Eastern Croatia. Liver samples obtained from 10 Mallards and 10 Common Pochards were examined for heavy metals (Cd, Pb, As, Hg) by using flame atomic absorption spectrophotometry (AAS). Significant difference in heavy metal content between analyzed species was confirmed only for Cd (P≤0.01), and no differences were found between genders within species. The results obtained suggest the importance of wild ducks as bioindicators of heavy metal pollution, especially Common Pochard for Cd, and Mallard for Pb accumulation.

Preliminary serological and molecular investigation of selected viral pathogens in Croatian cervid species

A total of 131 blood samples and 175 spleen samples were collected from three cervid species: roe deer (Capreolus capreolus), red deer (Cervus elaphus) and fallow deer (Dama dama) inhabiting the continental part of Croatia. Serum samples were tested for antibodies against bovine herpesvirus 1, parainfl uenza-3 virus, bluetongue virus, bovine respiratory syncytial virus, hepatitis E virus, bovine viral diarrhoea virus and enzootic bovine leukosis virus. The tested sera were negative for bovine viral diarrhoea virus, enzootic bovine leukosis virus, bluetongue virus, bovine respiratory syncytial virus and hepatitis E virus antybodies. The antibody prevalence in roe deer and red deer samples was 21.11% for bovine herpesvirus 1 and 75.55% for parainfl uenza-3 virus. Sera from bovine herpesvirus 1 positive animals were subsequenty tested with comparative virus neutralization test and bovine herpesvirus 1 neutralising antibodies were found in 18 (out of 19) sera. In fallow deer, no antibodies against any of the viral pathogens were detected. All spleen samples tested for bovine viral diarrhoea virus and enzootic bovine leukosis virus came back negative, except for one red deer spleen sample found to be weakly diarrhoea virus-positive. Our fi ndings provide the fi rst information on the exposure of Croatia-inhabiting cervid species to viral pathogens, and could serve as valuable baseline data for future investigations regarding deer exposure to various pathogens and the distribution of diseases shared between wildlife and livestock. As of now, the epidemiology of these viruses in the Croatian cervid population has been only poorly understood, so that further research is recommended.

Habitat conditions for wildlife management in the Dinaric regions of Croatia and Montenegro

Hunting is an important socio-economic activity, particularly in rural areas. Characteristics and quality of habitat are important in the sustainable management of game animals and wildlife conservation. Three hunting grounds were analysed and their habitat composition was compared with regard to abundance of main game animal species. Hunting ground VIII/2 “Bjelolasica” is located in Gorski kotar region; XVII/6 “Maglaj-Cista” in the inland of middle Dalmatia; and hunting ground “Dragišnica” is located in northern part of Montenegro.

Early spring flora of the Sub-Pannonic steppic grassland (NATURA 2000 site) in Bilje, northeast Croatia

Abstract The diversity of early spring vascular flora was studied in the Sub-Pannonic steppic grassland in the village of Bilje, north eastern Croatia. In all, 109 plant taxa within 35 families were found. The highest number of taxa belongs to the families Poaceae, Fabaceae, Asteraceae, Caryophyllaceae, Lamiaceae and Rosaceae. Specific habitat conditions, characterized by moderately wet and moderately acidic soil with intermediate fertility and the effects of the continental climate favour the development of different plant life forms. Out of the total recorded plant taxa, hemicryptophytes make up 59.6%, followed by therophytes (22.0%) and geophytes (13.8%). Chorological analysis shows that the most numerous are plants of Eurasian (33.9%), Pontic-Central-Asian (21.1%) and Central European (21.1%) floral elements. According to their status in the Red List, three critically endangered (CR), one vulnerable (VU) and three nearly threatened (NT) plant species were found. Altogether, the steppe-like grassland in Bilje is a unique habitat rich in valuable plants of the Croatian flora, including the critically endangered Doronicum hungaricum, therefore it is of great importance to preserve it. Important management tools include mowing and controlling the spreading of cultivated and invasive plant species.

Influence of biotic and abiotic environmental conditions on sunflower (Helianthus annuus L.) grain yield

Way of pollination in sunflower is allogamy and therefore the presence of insects is essential for successful production. Trial material was consisting of six sunflower hybrids that were grown on majority of sunflower’ s fields in Croatia. Trial was conducted on trial-field situated in Kneževi Vinogradi (Baranja region). Honey bees were transported in Langstroth-Rooth (LR) beehives to the trial field ; three days before sunflower’ s blooming. Impact of honey bee on selection and production traits of sunflower was expressed as a difference between results gained by free pollination and results under the condition of isolation. The most important pollinator of sunflower is a honey bee. Weather conditions (air temperature, relative air humidity and rainfalls) considerably influenced activities of honey bees during sunflower blooming. Honey bees were mostly active during the days without rain, at air temperature from 23 to 26 oC and relative air humidity from 65 to 75 %. The most attractive hybrid for honey bee was hybrid H4. Presence of pollinators resulted in improvement of selection and production traits of sunflower: number of flowers per head, number of full up field grains per head, percentage of pollination, 1000 kernel weight, hectolitre mass, oil content and oil yield.Considerable economic rationale was determined for the introduction of pollination with honey bee in agriculture practice.