Vol 102, No 8 (2023)

A new oribatid mite genus collected from Cuba – Makaroviella gen. n. (Oribatida, Licnobelbidae), with Makaroviella exigua sp. n. as type species – is proposed and described. It can be distinguished from both known licnobelbid genera (Flabellobelba and Licnobelba) mostly by: the number and the localization of notogastral setae, the localization of rostral setae and adanal setae ad₁, and the absence of lateral enantiophyses. An identification key to the known species of Licnobelbidae is provided.

Numerous individuals of an amphipod previously unreported from the Black Sea were found in 2017 on structures of a mussel and oyster marine farm, near the outer roadstead of the Sevastopol Bay, Crimea. The species discovered was morphologically especially similar to Stenothoe tergestina (Nebeski 1881), provisionally identified as Stenothoe cf. tergestina. The morphology, population structure and ecology of this species were studied. An analysis of the population structure of S. cf. tergestina in 2017–2022 showed that adult females, males and juveniles were present in the samples all over the year. The animals preferred to dwell on surfaces overgrown with periphyton colonies of the hydroid polyp genus Aglaophenia Lamouroux 1812. In the collections of amphipods from the periphyton of the farm structures, S. cf. tergestina turned out to be the most abundant (70–90% of the total number of identified amphipod individuals). The length of adult females was up to 4.5 mm, vs up to 3.6 mm in males.

Key demographic parameters were calculated using the European pied flycatcher (Ficedula hypoleuca) as a model species for the study of bird population ecology. In the Tomsk Region, southeastern part of western Siberia, birds nesting in nest boxes situated in natural forests for 22 years were continuously studied. Where possible, life tables, probability models (CJS), and population matrix models were employed in the calculation of demographics. A comprehensive study of population characteristics made it possible to compare them with the results of other research and to demonstrate the degree of divergence in the estimation of demographic parameters obtained using different methods. On average, nestlings successfully left their nests in 87.6% of breeding attempts. The percentage of immigrants, residents, and autochthons in the static age distribution of females amounted to 41.7, 25.3, and 33.0%, respectively, vs 30.8, 25.3, and 43.9% in males, The maximum age for female autochthons was 7 years, compared to 8 years for male autochthons. Male residents lived to be x + 5 years old, while female residents lived to be x + 7 years old. Autochthonous males and females showed about the same local survival rates. These were the highest in yearlings (0.54) and gradually decreased with the age of individuals. The local survival rate of males of unknown origins is comparable to that of autochthonous males. Females of unknown origins had the lowest local survival rates. Birds could start nesting as young as one year old and as old as six years. Ringing revealed that 68.9% of males started breeding in their first year of life, compared to 59.9% of females that started in their first year. Only 39.2% of females and 46.3% of males among the birds that survived and returned to our control sites started breeding as yearlings, vs 66.9% of two-year-old females and 71.1% of males. The proportion of the birds that returned to their birth place amounted to 11.1%. Females produced 9.1 fledglings on average per lifetime, vs 9.6 fledglings for males. The minimum life expectancy for fledglings was 1.2–1.49 and 1.2–1.62 years, vs the maximum life expectancy for individuals that survived for one year, which was 1.94 and 1.96 years for males and females, respectively. For males and females, the generation time was 3.13–3.32 and 3.18–3.39 years, respectively. The sensitivity and elasticity analysis of the population growth rate based on the constructed projection matrix revealed that it was the survival rate of juvenile and sexually mature individuals between one and two years of age that primarily drove the population growth rate. Using the demographic data obtained for the species’ population in natural habitats in the Southeast of western Siberia and the population matrix model constructed on its basis, we believe it is possible to compare the state of populations inhabiting ecosystems, both unspoiled and disturbed (transformed), in various areas across the distribution range of the European pied flycatcher.

Radiocarbon dating of woolly mammoth remains from the Minusinsk Depression allows for the patterns of its distribution in southern Siberia in the Late Pleistocene to be specified. In the south of Siberia, mammoths are shown to have been most abundant in cold periods, the species having reached its maximum abundance in LGM. So far, there is no single mammoth record that would confidently refer to the warm time interval. During the warm intervals of the Late Pleistocene, the environment in southern Siberia could possibly have not favorable for the permanent habitation of the species Mammuthus primigenius. In general, the mammoths from the Minusinsk Depression retain species-specific features of the content of carbon and nitrogen stable isotopes (δ¹³C and δ¹⁵N) in bone collagen compared to other large herbivores. They show the highest δ¹⁵N values with the lowest δ¹³C, vs reindeer that, on the contrary, demonstrate the lowest δ¹⁵N values and a high δ¹³C. The isotopic signal of other herbivorous mammal species lies between the values of mammoths and reindeer. A comparison of the obtained data on carbon and nitrogen stable isotopes (δ¹³C and δ¹⁵N) of the woolly mammoth remains from the Minusinsk Depression with similar parameters in animals from the north of eastern Siberia reveals significant differences. One of the possible reasons may lie in differences in the diet of animals of the Minusinsk Depression from mammoths of other populations. However, similar trends, i.e. a relatively lower δ¹⁵N and higher δ¹³C content in the Late Pleistocene, are characteristic of both reindeer and woolly rhinoceroses of the Minusinsk Depression. This suggests that the differences in the carbon and nitrogen isotope composition in the Minusinsk Depression mammoths from those from the northern territories are due not only to the type of food, but also to a slightly different isotopic background of the region, associated with the local environment.

For the first time, the allelic diversity of exon 2 of the DRB1 gene (class II of the major histocompatibility complex, MHC) was determined by NGS sequencing in natural populations of two species of the genus Allocricetulus: Eversmann’s hamster (A. eversmanni) and the Mongolian hamster (A. curtatus). These species are genetically close, but allopatric and demonstrate different habitat preferences. Eversmann’s hamster inhabits the steppes and is often associated with agrocenosis, while the Mongolian hamster occures semi-deserts and deserts, where anthropogenic pressure is practically absent. Our analysis revealed a significant effect of positive selection on the diversity of alleles of the DRB1 gene in both study species. However, Eversmann's hamster is characterized by a large average distance between alleles, but a smaller proportion of heterozygous individuals, while the Mongolian hamster is characterized by a larger individual variety of alleles. Thus, despite the extensive range of Eversmann’s hamster, we noted significantly less functional diversity of adaptive genes, which may be due to an increased anthropogenic exposure.