V. N. Ryzhanovskii

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It has been shown that the white wagtail at the northern limit of its range forms a population or a group of populations with a high degree of independence from conditions of illumination (photoperiod) in the Subarctic and southern Arctic. The boundary between the tundra and boreal populations in Yamal lies in the forest-tundra: wagtails of the tundra(More)
260 Most passerine birds of high latitudes migrate to the forest–tundra and tundra to spend there a relaa tively short breeding period, which usually lasts 3– 4 months, from late May to late August or September. These birds spend the winter in the zone from 45° N (the limit of snowless winters) to the equator and even in areas south of the equator. In some(More)
In 2003, it will be 100 years since W. Johanssen published his book Über Eblichkeit in Population und in reinen Linien , in which the concept of population was introduced for designating an aggregate of freely crossing individuals of the same species. At present, a population is regarded as a real panmictic evolving unit of the species, which has inhabited(More)
In the nominotypical subspecies of the citrine wagtail, M. c. citreola Pall., the density of nesting pairs in the northern part of its range in the central Yamal Peninsula reaches a peak in the moss-lichen tundra subzone, while similar biotopes (moist herb-moss willow scrub) are also present in the forest-tundra and shrub tundras. It is suggested that one(More)
The arctic warbler, which nests in the Polar Urals and in northwestern Siberia, has one full molt in wintering areas in the first year of life; over the next years, two molts: partial postnuptial in the nest area and complete prenuptial in the wintering part of the area. The molt in the first year of life, according to the photoperiodic response to the(More)
Over 2500 species of invertebrate macrofauna and over 177 species of avifauna live in the forest–tundra of the Lower Ob region and adjacent areas of the northern taiga and shrub tundra. About half of the invertebrate species of the study area are northern—mostly hypo- and hemiarctic—tundra species; the rest are boreal and arctomontane-boreal Holarctic and(More)
On the basis of a long-term study of passerines in the Lower Ob’ region, data were obtained on the beginning and duration of arrival and flying away, reproduction periods, and post-breeding and post-juvenile molting. The triggering factors are discussed in this paper.
297 It is generally accepted that the main natural reservoir of influenza viruses is in Southeast Asia, wherefrom strains A/Singapore/57, A/Hong Kong/68, and recent “A/H5N1” have originated. Waterfowl and waders wintering in this region spread the viruses over the Pacific (L’vov and Il’ichev, 1979). The list of such birds is long enough, but there are no(More)
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