Search

The accumulation of prey remains in the pellets of the great gray owl in the winter and nesting periods was studied over a number of years at the contact of the taiga and northern forested steppe belts in the Trans-Urals. It is shown which of the characteristics of the hunting territory and the population of small mammals have the greatest effect on the composition and ratio of prey species. A comparison with the results of the feeding activity of the eagle owl was also made. Published information concerning four places of long-term nesting on rocks in the river valleys of the western slope of the Middle Urals in similar natural conditions was used as well. Selective accumulation of prey remains of these two owl species was revealed to lie in a small number of the main prey species, those mostly populating open habitats. In both owls, mammal species of closed forest (transitional) habitats served as concomitant (secondary) prey. The eagle owl was characterized by a large size range of prey. Special attention was paid to the indicator roles the concomitant prey play in paleoreconstructions. [ABSTRACT FROM AUTHOR]

The variability of the body shape of minnows in populations from different-size watercourses of the Sylva River basin (Middle Urals) is studied by geometric morphometrics. Twenty-six homologous landmarks were used to describe the body shape variability of the fish. Four geographically adjacent minnow populations isolated by artificial and natural dams were investigated. More than 56% of the variance of intergroup differences in the body shape is determined by the habitation of minnows in the large watercourse of the main flow (the Sylva River) and its small tributaries (the Lomovka, Musorka, and Sarga rivers). The main-flow minnow is characterized by relatively large eyes, low body, and small short jaws. On the contrary, the tributary minnow is characterized by a relatively high body, small eyes, and long jaws. Along with the significant differentiation of the isolated minnow populations from the main flow and its tributaries, a high level of individual morphological differences was discovered, which indicates some directional change in the fish development trajectory in the population from each watercourse. The discrimination level of individuals reached 97.9%. A low intragroup morphological diversity was revealed for the minnow population in the large watercourse of the Sylva River with a multispecies ichthyological community. Minnows from the small watercourses of the Lomovka, Musorka, and Sarga rivers with a low species diversity have a high intragroup morphological diversity in the body shape. This may indirectly show some ontogenetic change in the individuals from the small tributaries due to the formation of a wide range of ontogenetic trajectories and suggests a high phenotypic plasticity of the species. The role of the hydrological regime in the small watercourses and the role of the taxonomic diversity of fish communities in the formation of the morphological diversity of minnows is hypothesized. [ABSTRACT FROM AUTHOR]

Martes mandibles from Late Pleistocene and Holocene sites in the Middle Urals were identified to the species level using discriminant analysis. As has been shown, sable lived there in the Late Pleistocene, with its geographic range covering all this area until the end of the 18th century; however, its range started to reduce towards the north and northeast in the early 19th century. Over 150 years, the southwestern boundary of the sable range shifted by 3° to reach the current position by the mid-20th century. The pine marten appeared in the Middle Urals in the Holocene no later than 8000 years ago and inhabits this territory at present. [ABSTRACT FROM AUTHOR]