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The Eurasian wigeon (Mareca penelope) is one of the most numerous migrant species of waterfowl in the Palearctic. Annually, significant part of the world’s wigeon population makes seasonal flights over distances from tens to thousands or more kilometers. According to different estimates based on banding data, five geographic populations of the species were described in the Palearctic. However, distinct borders between the populations have not been identified. At the same time, no phylogeographic studies have been carried out for the complete native range of wigeon so far. In addition to the fundamental importance of such a study, knowledge of the genetic structure of populations is necessary for the development of measures to increase the number of and preserve this valuable game species. The aim of our work was a phylogeographic analysis of the wigeon across its vast native range in the Palearctic including ducks wintering in North America. We examined genetic diversity and differentiation of wigeon populations identified with banding data, phylogenetic relationships of mtDNA haplotypes and demographic history of populations and species as a whole by sequencing a 661 base-pair 5’-fragment of the mitochondrial control region from 195 individual ducks collected throughout the Palearctic and Nearctic. Genetic diversity was high in all studied populations. A reconstruction of haplotypes phylogeny revealed the absence of geographic structure in the data. Nonetheless, analysis of molecular variance (AMOVA) identified two groups of populations: EuropeanSiberian and East Asian. The former included wigeons from Europe, Siberia and the Atlantic coast of North America, and the latter comprised ducks from Russian Far East, Kamchatka Peninsula, Chukotka Autonomous District, the Aleutian Islands, Alaska, and the Pacific coast of North America.

The role of birds in the focus of tick-borne infections was studied from 2006 to 2011. The frequency index of ticks carried by ground dwelling birds is about 49.7%. The index of their abundance is 3.8. The larvae of ticks have been found on birds in 43.8% of cases. Nymphs and adult ticks have been found in 39.9 and 16.3%, respectively. It was revealed that Ixodex pavlovskyi was transferred and dominated in the urban microfoci because of its ornithophily. The markers of infectious agents have been recorded in 42 of 60 bird species under study.

We studied two urban and two suburban biotypes of Tomsk City for tick-transmitted diseases prevalence in naturally collected ticks. Tick-borne encephalitis virus (TBEV) was found in 6.5% of tick samples, West Nile virus (WNV) in 2.2%, Borrelia spp. in 8%, Rickettsia spp. in 2.5%, and Ehrlichia spp. in 1.7% of samples. Genetic markers of Powassan virus, Bartonella spp., and Balbesia spp. were not found. Analysis of the genetic diversity of revealed pathogens resulted in the following conclusions: 1. TBEV strains belong to Siberian and Far-Eastern subtypes, and Far-Eastern subtype of TBEV is most frequent in urban biotypes (up to 43 % of urban strains of TBEV); 2. WNV strains belong to genotype la; 3. Borrelia spp. were classified as B. garinii; 4. Rickettsia spp. were classified as R. tarasevichiae and probably as a new Rickettsia raoultii subspecies; 5. Ehrlichia spp. were classified as E. muris. The coexistence of several pathogens was found in 5.7% of tick samples, and the most frequent combination was TBEV + Borrelia spp.