Published online by Cambridge University Press: 06 June 2009
In 2003–2005 we investigated current contamination of small birds in Chornobyl zone, as vertebrates with the largest diversity and biomass, and inherent season migrations. A whole-body live counting method was used to analyze 90Sr and 137Cs in the birds. Total number and biomass of small birds was estimated using 1) data of birds population density in different kinds of biogeocenosis, 2) ratio of biogeocenosises area at the zone, 3) data of biomass of species. We used GIS application, an electronic map of the Chernobyl zone contamination and 90Sr and 137Cs transfer factor “soil–bird” to calculate average contamination of birds at any location regardless they had been caught there or hadn't. According to our assessment total number of small birds by the end of breeding season in 2004 amount to at least 5.14 million individuals, total biomass – 134 tons, total stock of radionuclides – 74.7 MBq 90Sr and 55 MBq 137Cs. All these birds can export no more 80% of their initial contamination outside the zone. Together with total avian flow yearly passed through the region (2600 km2) they export up to 2.47 GBq 137Cs and 3.70 GBq 90Sr.