Denis Cvitković

Colony development of two Carniolan genotypes (Apis mellifera carnica) in relation to environment

Summary The objective of this study was to compare the colony development cycle (unsealed and sealed worker brood, drone brood, pollen and colony strength) of two Apis mellifera carnica subpopulations in two distinct environments (alpine and continental). At each test location were two sub groups of 12 colonies headed by naturally mated sister queens from either the Institute of Apiculture Lunz am See, Austria (AT) or from the Faculty of Agriculture University of Zagreb, Croatia (HR). Colony development was monitored every 14 days. The HR genotype, adapted to a continental climate, had faster spring brood development in both environments. During spring and early summer the AT genotype maintained the number of sealed brood cells at a constant level in the more favourable conditions, although the amount of unsealed brood reached its maximum in early June. The environment influenced colony development, food stores and colony strength. Interaction between genotype and environment did not affect the number of unsealed brood cells, but the difference was statistically significant for the number of sealed brood cells. The study indicated the presence of a number of genotype and environment interactions between the two honey bee genotypes and their colony traits.

Ornithological knowledge for preliminary risk assessment of avian influenza (H5N1): the implementation of the European model in Croatia

The lack of epidemiological knowledge when planning the approach to preventing possible future outbreaks of avian influenza may lead to uncontrolled spreading of HPAI H5N1 virus and, consequently, danger to the poultry industry and human health and threats to the survival of endangered wild birds. The implementation of a model developed for the rapid assessment of ornithological data relevant to the spreading of avian influenza in the EU countries resulted in the identification of 23 Higher Risk Species and 17 Bridge Species for the territory of Croatia. It also identified a number of wetland areas, where Higher Risk Species come together during migration and wintering, as potential AI introduction and outbreak sites. The EU model was adapted to suit the Croatian circumstances. The migratory flyways of Higher Risk Species were analysed using data on birds ringed outside Croatia and found on the territory of Croatia between 1910 and 1992. These results form the ornithological part for the risk assessment of possible future outbreaks both at the national level and internationally, in neighbouring countries. It may also be used for AI research under the global European model. Data on poultry density, type of poultry husbandry, poultry trade and movement are needed. We propose the establishment of a database on the commercial movements of poultry and poultry products under the Early Warning System.