Vol 103, No 2 (2024)

A new species of bristletail, Allopsontus tauricus sp. n., is described from western Crimea. In the external shape of the eyes, the structure of the mandibles, legs, abdominal sternites, ovipositor and male parameres, it seems to be especially similar to A. europeus (Kaplin 1983) from southern Crimea. Their main differences are the relative length of the cerci, the colour of the eyes and the shape of the paired ocelli. The structure of the distal part of the antennal flagellum, the chaetotaxy of the maxillary and lower labial palps in the male also differ significantly, as well as the ratio of the length of the styli to the length of the coxites of abdominal segments VIII and IX in both sexes.

Theoretical predictions usually assume that changes in conditions caused by climate warming would render negative effects on the population dynamics of many bird species, but evidence is only rarely presented. Changes in phenology, nesting timing, and the physical condition of breeders have been published for a wide range of species in most regions of the Northern Hemisphere; however, data are still insufficient for a better understanding of the consequences for changes in productivity, reproductive success and offspring recruitment. Long-term monitoring (1994–2023) the numbers and age structure of premigratory gatherings of Eurasian cranes in the northern Moscow Region, Central Russia, reveals that, despite the climate warming in the region, the proportion of offspring has not changed over the 30-year long period of observation. The number of young birds is positively related to the temperature of the breeding season; in warmer years, the productivity of Eurasian cranes was higher. In seasons with high precipitation rates, the proportion of chicks was decreased. The reproduction efficiency of cranes on Central Russia is controlled by two parameters: the amount of precipitation and the average temperature during the breeding season.More chicks rise in years with a combination of higher temperatures and low precipitation amounts. Increased precipitations and decreased temperatures lead to reduced proportions of chicks in the premigratory gatherings. The most unfavorable situation for common cranes was low temperatures combined with high precipitations, the proportion of chicks being the minimum in such years.

The results of studying the space use and seasonal migrations of the Topozero territorial group of wild forest reindeer females in the Republic of Karelia are presented. Telemetry (GPS-collars) was used to assess the migration of the wild forest reindeer. Individual variations were noted in seasonal migrations: two individuals were relatively sedentary, whereas the third moved long distances during the year, with the distance between the extreme locations amounting to more than 70 km. The timing of the start of seasonal migrations varied between years. The use of the same summer habitats in different years was revealed, but the territories of the rut and winter pastures were different for the same animals. Movements of animals over fairly long distances have been noted, which is probably associated with the disturbance factor on the part of predators and/or humans.

In the conditions of the North-Western Caspian Sea, the state of the midday sand lance population is determined by the dynamics of food resources. An important component of the environment that determines the condition of the midday gerbil is bush thickets, which serve as a good shelter for animals. It has been established that on a sand dune, where a higher density of shrubs is noted, compared to open areas of the deserted steppe, the productivity of vegetation increases and the species composition of plants changes. The relationship between gerbil population density and vegetation productivity was shown (R = 0.74, P < 0.05). In addition, the relationship between the number of gerbils and the productivity of bluegrass bulbs (Poa bulbosa) is shown, which fluctuated during the years of research in the sand dune area from 3.7 to 5.5 c/ha of dry weight, and in the desert steppe area from 2.3 to 3.8 c/ha. In accordance with the nature of the provision of food resources, changes in the number of midday gerbils were noted in different seasons of the year from 4 to 24 individuals/ha on sand dunes and from 2 to 14 individuals/ha in the desert steppe.

Individual and age variations and correlation of the upper cheek teeth were studied in the European beaver, Castor fiber, based on an “elementaristic” description of dental crown elements by means of geometric morphometrics and applying correlation, cluster, and dispersion analyses. The basic algorithm for both within- and between-teeth comparisons was described. The least individual variability is characteristic of the teeth taking middle positions in the cheek tooth row. No clear-cut relation of the levels of individual variation of crown elements is revealed with respect to either their position in the tooth crown or their complexity. The age differences in the shape of crown elements may occasionally be very significant, with the juveniles being the most specific in this respect. The least individually variable dental units (either total teeth or particular elements) appear to generally be the most variable with age, although this result may be purely “statistical” in nature. The correlation between dental crown elements is generally not very high, with within-teeth correlations being slightly stronger than between-teeth ones. The correlations are generally stronger in the adults than in the other age groups. The dental correlations vary with age, with general trends of age differences in correlations being the opposite for within- and between-teeth comparisons. The general levels of correlations and the magnitudes of their age differences are inversely related in the case of between-teeth comparisons. The overall correlation pattern of dental crown elements is more evident in the combined age group of subadults + adults. Further explorations of both the variation and integration patterns of mammalian dentition should be based on an “elementaristic” description of the dental crown.