The paper presents the results of the 2003 and 2006 environmental virological monitoring surveys on the Malyi Zhemchuzhnyi Island where a large breeding colony of sea gull (Laridae) is located. In the past several years, expansion of cormorants (Phalacrocorax carbo) has enhanced the intensity of populational interactions. The investigators isolated 13 strains of influenza A virus (Orthomyxoviridae, Influenza A virus) subtype H13N1 (from sea gulls (n = 4), cormorants (n = 9) 1 strain of Dhori virus (Orthomyxoviridae, Thogotovirus) from a cormorantwith clinical symptoms of the disease, 3 strains of Newcastle disease virus (Paramyxoviridae, Avulavirus) from cormorants. RT-PCR revealed influenza A virus subtype H5 in 3.1% of the cloacal lavages from cormorants. Neutralization test indicated that sera from cormorants contained specific antibodies against West Nile (Flaviviridae, Flavivirus) (15.0%), Sindbis (Togaviridae, Alphavirus) (5.0%), Dhori (10.0%), and Tahini (Bunyaviridae, Orthobunyavirus) (5.0%); sera from herring gulls had antibodies against Dhori virus (16.7%); there were no specific antibodies to Inco (Bunyaviridae, Orthobunyavirus) and mountain hare (Lepus timidus) (Bunyaviridae, Orthobunyavirus) virus.