Publications by authors named "Valchuk O"

Determining the dynamics of where and when individuals occur is necessary to understand population declines and identify critical areas for populations of conservation concern. However, there are few examples where a spatially and temporally explicit model has been used to evaluate the migratory dynamics of a bird population across its entire annual cycle. We used geolocator-derived migration tracks of 84 Dunlin (Calidris alpina) on the East Asian-Australasian Flyway (EAAF) to construct a migratory network describing annual subspecies-specific migration patterns in space and time.

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Sequence polymorphism of the mitochondrial DNA cytochrome b gene fragment was analyzed in 21 specimens of subspecies Luscinia calliope calliope (Pallas, 1776) and two specimens of L. c. anadyrensis (Portenko, 1939).

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First evidence for the presence of copies of mitochondrial cytochrome b gene of the subspecies group Luscinia calliope anadyrensis-L. c. camtschatkensis in the nuclear genome of nominative L.

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Waterfowl (Anseriformes) and shorebirds (Charadriiformes) are the most common wild vectors of influenza A viruses. Due to their migratory behavior, some may transmit disease over long distances. Migratory connectivity studies can link breeding and nonbreeding grounds while illustrating potential interactions among populations that may spread diseases.

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For the first time, genetic diversity and intraspecific subdivision of Luscinia calliope was studied according to the data of the mtDNA cytochrome b gene sequencing. The strong differentiation of haplotypes of the Siberian Rubythroat into western and eastern groups, which include subspecies according to their geographical attachment, was revealed. A high-haplotypic (Hd = 0.

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The ranges of the great tit Parus major and the Japanese tit P. minor overlap in the middle Amur region, where hybridization of these two species occur. These species have contacted for nearly a century on the western slope of the Malyi Khingan Ridge (the central part of the sympatry zone), but the great tit has colonized territories to the east of the ridge only in the last two decades.

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The great tit complex is divided into four groups, each containing several subspecies. Even though the groups are known to differ markedly on morphological, vocal and behavioural characters, some hybridization occurs in the regions where they meet. The great tit has often been referred to as an example of a ring species, although this has later been questioned.

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The specific composition and number of midges in nest biotopes of birds of forest formations of Western Sikhote-Alin are given. 17 species of the genus Culicoides were found to attack 17 species of birds during the nesting period. The number of midges in nests depends both on the biotopical distribution of nests and mode of living of birds and on the total number of midges in nature.

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